Item 1A. Risk Factors.

You should carefully consider the risks and uncertainties described below together with all of the other information contained in this Annual Report on Form 10-K, including our financial statements and related notes appearing in this Annual Report on Form 10-K and the section of this Annual Report on Form 10-K titled “Management’s Discussion and Analysis of Financial Condition and Results of Operations.” Negative consequences from these risks could harm our business, prospects, operating results and financial condition or cause the trading price of our common stock to decline. The risks and uncertainties described below are not the only risks we face. Additional risks and uncertainties not presently known to us or that we currently believe to be immaterial may also adversely affect our business. See “Cautionary Note Regarding Forward-Looking Statements.”

Risks Related to the Merger

Failure to complete, or delays in completing, the proposed Merger with Candid could materially and adversely affect our results of operations, business, financial results and/or stock price.

Any failure to satisfy a required condition to closing may prevent, delay or otherwise materially and adversely affect the completion of the Merger, which could materially and adversely affect our results of operations, business, financial results and/or stock price. We cannot predict with certainty whether or when any of the required closing conditions will be satisfied or if another uncertainty may arise and cannot assure you that the proposed Merger will be successfully consummated or that we will be able to successfully consummate the proposed Merger as currently contemplated under the Merger Agreement or at all.

Even if certain of the proposals in the Merger Agreement are approved by our stockholders, specified conditions must be satisfied or, to the extent permitted by applicable law, waived to complete the Merger. We cannot assure you that all of the conditions will be satisfied or waived.

Risks related to the failure to consummate, or delay in consummating, the proposed Merger with Candid include, but are not limited to, the following:

•we would not realize any or all of the potential benefits of the Merger, which could have a negative effect on our results of operations, business or stock price;

•under some circumstances, we may be required to pay a termination fee to Candid of $1.425 million, with expense reimbursement of up to $500,000 credited against the payment of any such termination fee;

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•we would remain liable for significant transaction costs, including legal, accounting, financial advisory and other costs relating to the Merger regardless of whether the Merger is consummated;

•the trading price of our common stock may decline to the extent that the current market price for our common stock reflects a market assumption that the Merger will be completed;

•the attention of our management and employees may have been diverted to the Merger rather than to our historical operations and the pursuit of other opportunities that could have been beneficial to us;

•we could be subject to litigation related to any failure to complete the Merger;

•we could potentially lose key personnel during the pendency of the Merger; and

•under the Merger Agreement, we are subject to certain customary restrictions on the conduct of our business prior to completing the Merger, which restrictions could adversely affect our ability to conduct our business as we otherwise would have done if we were not subject to these restrictions.

The occurrence of any of these events individually or in combination could materially and adversely affect our results of operations, business, and our common stock price, and we may lose some or all the intended benefits of the Merger.

We are substantially dependent on our remaining employees to facilitate the consummation of the Merger.

Our ability to consummate a strategic transaction depends upon our ability to retain our remaining employees required to consummate such a transaction, the loss of whose services may adversely impact the ability to consummate such transaction. As of December 31, 2025, we had only 14 full-time employees. Our ability to successfully complete the Merger depends in large part on our ability to retain key personnel that are necessary to maintain our operations between now and the Effective Time. Despite our efforts to retain these employees, one or more may terminate their employment with us on short notice. Our cash conservation activities may yield other unintended consequences, such as reduced employee morale, which may cause remaining employees to seek alternative employment. The loss of the services of certain employees could potentially harm our ability to consummate the Merger, to run our day-to-day business operations, as well as to fulfill our reporting obligations as a public company.

The Exchange Ratio will not be adjusted based on the market price of our common stock, so the consideration at the closing of the Merger may have a greater or lesser value than at the time the Merger Agreement was signed.

The Exchange Ratio will not change based on changes in the trading price of our common stock. Therefore, if before the completion of the Merger, the market price of our common stock increases from the market price on the date of the Merger Agreement, Candid stockholders could then receive merger consideration with substantially higher value for their shares of Candid common stock than the parties had negotiated when they established the Exchange Ratio. The Merger Agreement does not include a price-based termination right. Immediately after the Merger, our securityholders as of immediately prior to the Merger are expected to own approximately 3.65% of the outstanding shares of the combined company and former Candid securityholders, including purchasers in the Concurrent Financing, are expected to own approximately 96.35% of the outstanding shares of the combined company, subject to certain assumptions, including, but not limited to, (a) a valuation of us equal to $47.5 million, based on certain assumptions, including our net cash as of the closing date of the Merger being equal to $37.5 million, (b) a valuation for Candid equal to $750.0 million and (c) Candid issuing approximately $505.5 million of Candid Common Stock in the Concurrent Financing described in the related proxy statement/prospectus.

The Merger may be completed even though a material adverse effect may result from the announcement of the Merger, industry-wide changes and/or other causes.

In general, either we or Candid can refuse to complete the Merger if there is a Rallybio Material Adverse Effect (as defined in the Merger Agreement) or a Company Material Adverse Effect (as defined in the Merger Agreement), as applicable, between March 1, 2026, the date of the Merger Agreement, and the closing of the Merger. However, certain types of changes do not permit either party to refuse to complete the Merger, even if such change could be said to have a material adverse effect on us or Candid, including:

•general business, political or economic conditions generally affecting the industry in which we or Candid operate, including with respect to the imposition of, or adjustments to, tariffs or other trade restrictions;

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•acts of war, the outbreak or escalation of armed hostilities, acts of terrorism, earthquakes, wildfires, hurricanes or other natural disasters, health emergencies, including pandemics and related or associated epidemics, disease outbreaks or quarantine restrictions;

•changes in financial, banking or securities markets;

•any change in the stock price or trading volume of our common stock (it being understood, however, that any effect causing or contributing to any change in stock price or trading volume of our common stock may be taken into account in determining whether a material adverse effect with respect to us has occurred, unless such effects are otherwise excepted from the definition of Rallybio Material Adverse Effect);

•any failure by us to meet internal or analysts’ expectations or projections or the results of our operations (it being understood, however, that any effect causing or contributing to the failure of us to meet internal or analysts’ expectations or projections or the results of our operations may be taken into account in determining whether a material adverse effect with respect to us has occurred, unless such effects are otherwise excepted from the definition of Rallybio Material Adverse Effect);

•any change in, or any compliance with or action taken for the purpose of complying with, any applicable law or GAAP (or interpretations of any applicable law or GAAP);

•the announcement of the Merger Agreement or the pendency of the Contemplated Transactions; or

•the taking of any action required to be taken by the Merger Agreement.

If a material adverse change occurs with respect to either party or both parties and we and Candid still complete the Merger, the stock price of the combined company following the closing of the Merger may suffer and may reduce the value of the Merger to our stockholders.

Some of our executive officers and directors have interests in the Merger that are different from our stockholders and that may influence them to support or approve the Merger without regard to the interests of our stockholders.

Certain of our executive officers and directors are parties to arrangements that provide them with interests in the Merger that are different from our stockholders, including severance benefits, the acceleration of equity award vesting and continued indemnification.

In addition, Robert Hopfner, a current member of our board, is affiliated with an investment fund participating in the Concurrent Financing.

Our board of directors was aware of and considered these interests, among other matters, in reaching its determination (i) that the terms of the Merger Agreement and the Merger and the other Contemplated Transactions are fair to, advisable and in the best interest of us and our stockholders and (ii) to approve and declare advisable the Merger Agreement and the Contemplated Transactions, including the Merger and the issuance of shares of our common stock to the stockholders of Candid pursuant to the Merger Agreement. These interests, among other factors, may have influenced the directors and executive officers to support or approve the Merger.

Our stockholders may not realize a benefit from the Merger commensurate with the ownership dilution they will experience in connection with the Merger.

If the combined company is unable to realize the full strategic and financial benefits currently anticipated from the Merger, our stockholders will have experienced substantial dilution of their ownership interests without receiving any commensurate benefit, or only receiving part of the commensurate benefit to the extent the combined company is able to realize only part of the strategic and financial benefits currently anticipated from the Merger.

Our equityholders will have a reduced ownership and voting interest in, and will exercise less influence over the management of, the combined company following the completion of the Merger as compared to their current ownership and voting interests in the respective companies.

After the completion of the Merger, our current stockholders will own a smaller percentage of the combined company than their ownership of their respective companies prior to the Merger. Immediately after the Merger, our securityholders as of immediately prior to the Merger are expected to own approximately 3.65% of the

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outstanding shares of the combined company and former Candid securityholders, including purchasers in the Concurrent Financing, are expected to own approximately 96.35% of the outstanding shares of the combined company, subject to certain assumptions, including, but not limited to, (a) our valuation equal to $47.5 million, based on certain assumptions, including our net cash as of the closing date of the Merger being equal to $37.5 million, (b) a valuation for Candid equal to $750.0 million and (c) Candid issuing approximately $505.5 million of Candid Common Stock in the Concurrent Financing.

Lawsuits may be filed against us and the members of our board of directors arising out of the proposed Merger, which may delay or prevent the proposed Merger.

Putative stockholder complaints, including stockholder class action complaints, and other complaints may be filed against us, our board of directors, Candid, the Candid Board of directors and others in connection with the transactions contemplated by the Merger Agreement. The outcome of litigation is uncertain, and we may not be successful in defending against any such future claims. Lawsuits that may be filed against us, our board of directors, Candid, or the Candid board of directors could delay or prevent the Merger, divert the attention of our management and employees from our day-to-day business and otherwise adversely affect our financial condition.

During the pendency of the Merger Agreement, we may not be able to enter into a business combination with another party at a favorable price because of restrictions in the Merger Agreement, which could adversely affect their respective businesses.

Covenants in the Merger Agreement impede our ability to make acquisitions or complete other mergers, sales of assets or other business combinations pending completion of the Merger. As a result, if the Merger is not completed, the parties may be at a disadvantage to their competitors during that period. In addition, while the Merger Agreement is in effect, each party is generally prohibited from soliciting, initiating, knowingly encouraging or entering into specified extraordinary transactions, such as a merger, sale of assets or other business combination, with any third party, subject to specified exceptions, even if any such transaction could be favorable to such party’s stockholders or stockholders, as applicable.

Certain provisions of the Merger Agreement may discourage third parties from submitting competing proposals, including proposals that may be superior to the arrangements contemplated by the Merger Agreement.

The terms of the Merger Agreement prohibit each of us and Candid from soliciting competing proposals or cooperating with persons making unsolicited takeover proposals, except in certain limited circumstances. With respect to us, the board of directors may respond to an unsolicited competing proposal if it determines in good faith, after consultation with its outside financial advisor and outside legal counsel, that the unsolicited competing proposal constitutes, or is reasonably likely to result in, a superior competing proposal and, after consultation with its outside legal counsel, that failure to take such action would be inconsistent with the fiduciary duties of our board of directors. With respect to Candid, following receipt of a bona fide acquisition proposal by any person that the Candid Board has determined is reasonably likely to result in a superior competing proposal, Candid may solicit acquisition proposals and furnish information to, and enter into discussions with, any person (including persons not making such proposal) if the Candid Board concludes in good faith, after consultation with its outside legal counsel and financial advisor, that failure to take such action would be inconsistent with the fiduciary duties of the Candid Board.

In certain circumstances, and subject to compliance with the Merger Agreement, our board of directors or the Candid Board may change its recommendation to its respective stockholders if it determines such recommendation change is required to avoid a breach of its fiduciary duties. Additionally, subject to compliance with the procedures set forth in the Merger Agreement, including paying the applicable termination fee, Candid may terminate the Merger Agreement in order to enter into an agreement with respect to a Superior Offer (as defined in the Merger Agreement).

Upon termination of the Merger Agreement in certain circumstances, a termination fee of $1.425 million may be payable by us to Candid if (i)(a) the Merger Agreement is terminated because the Merger has not been consummated by the End Date or we (1) fail to obtain the requisite stockholder approval of the Rallybio Stockholder Matters or (2) breach the Merger Agreement, (b) an alternative acquisition proposal was announced or disclosed prior to such termination, and (c) within 12 months of the termination of the Merger Agreement, we enter into a definitive agreement with respect to an alternative transaction, (ii) we fail to include our board recommendation in the related proxy statement/prospectus, or (iii) our board of directors changes or withdraws its recommendation in favor of the Merger or approves an alternative transaction, or willfully and intentionally breaches its non-solicitation or certain other obligations under the Merger Agreement.

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Both we and Candid have also each agreed to reimburse the other party for up to $500,000 for third-party expenses, as applicable, if the Merger Agreement is terminated in certain circumstances.

These termination fees and expense reimbursement provisions may discourage third parties from submitting competing proposals to us or Candid or their respective stockholders and may cause our board of directors or the Candid board, as the case may be, to be less inclined to recommend a competing proposal.

If the Merger does not qualify as a reorganization under the Code, U.S. holders of our Common Stock may be taxed on the full amount of the consideration received in the Merger.

Each of we and Candid intend that the Merger qualifies as a “reorganization” within the meaning of Section 368(a) of the Code. Assuming the Merger so qualifies, no gain will be recognized by U.S. holders of Candid shares will not recognize gain or loss for U.S. federal income tax purposes upon the receipt of shares of our common stock in exchange for Candid shares in the Merger. It is not, however, a condition to the parties’ obligation to complete the transactions that the Merger so qualifies. None of the parties to the Merger Agreement have sought or intend to seek any ruling from the Internal Revenue Service (“IRS”) regarding the qualification of the Merger as a reorganization within the meaning of Section 368(a) of the Code. If the Merger does not qualify for the U.S. federal income tax treatment described herein, U.S. holders of Candid shares may be taxed on any gain realized up to the full fair market value of any our Common Stock received in the Merger.

We or Candid may waive one or more of the conditions to the Merger without recirculation of the related proxy statement/prospectus or resoliciting stockholder approval.

Conditions to our or Candid’s obligations to complete the Merger may be waived, in whole or in part, to the extent permitted by law, in certain circumstances unilaterally or by agreement of us and Candid. In the event of a waiver of a condition, our board of directors will evaluate the materiality of any such waiver to determine whether amendment of the related proxy statement/prospectus and re-solicitation of stockholder approval is necessary.

In the event that our board of directors, in its own reasonable discretion, determines any such waiver is not significant enough to require recirculation of the related proxy statement/prospectus and re-solicitation of its stockholders, it will have the discretion to complete the Merger without seeking further stockholder approval, which decision may have a material adverse effect on our stockholders. For example, if we and Candid agree to waive the requirement that the shares of our Common Stock to be issued in the Merger have been approved for listing (subject to official notice of issuance) on Nasdaq as of the closing of the Merger, and their respective boards of directors elect to proceed with the closing of the Merger, Nasdaq may notify the combined company of its determination to delist the combined company’s securities based upon the failure to satisfy the initial inclusion criteria in the Nasdaq application. The combined company may appeal the determination to a hearings panel but such appeal will not stay the suspension and delisting action and Nasdaq may notify the combined company that its common stock will be immediately suspended from trading and delisted.

In addition, in order to meet the initial listing requirements of Nasdaq or as otherwise determined in the discretion of the combined company board pursuant to the terms of the Lock-Up Agreements, our board of directors or combined company board may release stockholders from their Lock-Up Agreements and waive the requirement that such Lock-Up Agreements be in full force and effect immediately following the Effective Time. Such release would increase the number of shares that may be sold in the public market immediately after the Merger and any such sales could cause the combined company’s stock price to decline.

Our winddown of our historical operations, the sale of assets, the suspension of development activities and the proposed Merger, resulting in the conversion of Candid into a public company, will make us subject to the SEC requirements applicable to reporting shell company business combinations. As a result, the combined company will be subject to more stringent reporting requirements, offering limitations and resale restrictions.

According to SEC guidance, the requirements applicable to reporting shell company business combinations apply to any company that sells or otherwise disposes of its historical assets or operations in connection with or as part of a plan to combine with a non-shell private company in order to convert the private company into a public one. As such, our plan to merge with Candid, resulting in the conversion of Candid into a public company, will be subject to the SEC requirements applicable to reporting shell company business combinations, which are as follows:

•the combined company will need to file a Current Report on Form 8-K to report the Form 10 type information (“Super 8-K”) after closing of the Merger reflecting its status as an entity that is not a shell company;

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•the combined company will not be eligible to use a Form S-3 until 12 full calendar months after closing of the Merger;

•the combined company will need to wait at least 60 calendar days after the filing of the Super 8-K to file a Form S-8 for any equity plans or awards, such as the 2026 Plan and the 2026 ESPP;

•the combined company will be an “ineligible issuer” for three years following the closing of the Merger, which will prevent the combined company from (i) incorporating by reference in its Form S-1 filings, (ii) using a free writing prospectus or (iii) taking advantage of the well-known seasoned issuer (“WKSI”) status, even if otherwise eligible based on its public float;

•investors who (i) were affiliates of Candid at the time the Merger was submitted for the vote or consent of Candid’s stockholders, (ii) receive securities of the combined company in the Merger and (iii) publicly offer or sell such securities will be deemed to be engaged in a distribution of such securities, and therefore would be underwriters with respect to resales of those securities; and

•Rule 144(i)(2) will limit the ability of holders of restricted securities, the investors in the Concurrent Financing, and any affiliates of the public company to publicly resell Rule 145(c) securities per Rule 145(d), as well as any other “restricted” or “control” securities of the combined company per Rule 144, until one year after the Form 10 information is filed with the SEC. Our non-affiliate stockholders prior to the Merger will not be subject to such restrictions on public resales of their shares.

The foregoing SEC requirements will increase the combined company’s time and cost of raising capital, offering stock under equity plans, and complying with securities laws. Furthermore, such requirements will add burdensome restrictions on the resale of the combined company common stock by affiliates of Candid and any holders of “restricted” or “control” securities of the combined company.

Our stockholders may not receive any payment on the CVRs and the CVRs may otherwise expire valueless.

The right of our stockholders to receive any future payment for or derive any value from the CVRs will be contingent solely upon (i) our and Candid’s (or the combined company’s) ability to monetize all or any part of the Legacy Assets (as defined below) pursuant to one or more disposition agreements entered into within the time period specified in the CVR Agreement, and the timing and amount of the consideration received thereunder and (ii) the receipt of cash proceeds from Recursion Pharmaceuticals, Inc. (“Recursion”) under the Membership Interest Purchase Agreement, dated July 8, 2025, by and among Recursion Pharmaceuticals, Inc., Exscientia Ventures I, Inc., Rallybio and Rallybio IPB, LLC (the “Membership Interest Purchase Agreement”). If we and/or Candid or the combined company (x) are not successful in entering into disposition agreements related to the Legacy Assets (as defined below) or receiving payments thereunder, or if such payments are not sufficient to result in the payment of any our CVR Payments as a result of permitted deductions thereto and (y) do not receive cash proceeds from Recursion pursuant to the Membership Interest Purchase Agreement, in each case within the time period specified in the CVR Agreement, no payments will be made in respect of the CVRs, and the CVRs will expire valueless.

Following the effective time, the combined company will have sole authority over whether and how to monetize the Legacy Assets (if at all), and the combined company’s only obligations will be to carry out the obligations set forth in the CVR Agreement.

Furthermore, the CVRs will be unsecured obligations of the combined company and all payments under the CVRs and all other obligations under the CVR Agreement and the CVRs and any rights or claims relating thereto will be subordinated in right of payment to the prior payment in full of all current or future senior obligations of the combined company.

The tax treatment of the CVRs is uncertain.

We intend to treat a holder’s receipt of the CVRs as a distribution of property with respect to the holder’s existing shares of our common stock for U.S. federal income tax purposes, which could be taxable to our stockholders without the corresponding receipt of cash. However, the U.S. federal income tax treatment of the CVRs is uncertain. There is no legal authority directly addressing the U.S. federal income tax treatment of the receipt of, and payments under, the CVRs, and there can be no assurance that the IRS would not assert, or that a court would not sustain, a position that could result in adverse U.S. federal income tax consequences to holders of the CVRs.

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If the Merger is not completed, our stock price may decline significantly.

The market price of our Common Stock is subject to significant fluctuations. During the 12-month period ended March 1, 2026, the closing per share sales price of our Common Stock on Nasdaq ranged from a high of $7.54 on February 27, 2026 to a low of $2.00 (after giving effect to our 1-for-8 reverse stock split approved by our stockholders on January 26, 2026 at a Special Meeting of Stockholders and effective as of 12:01 Eastern Time on February 6, 2026) on April 8, 2025. Market prices for securities of pharmaceutical, biotechnology and other life science companies have historically been particularly volatile. In addition, the market price of our Common Stock will likely be volatile based on whether stockholders and other investors believe that we can complete the Merger or otherwise raise additional capital to support our operations if the Merger is not consummated and another strategic transaction cannot be identified, negotiated and consummated in a timely manner, if at all. The volatility of the market price of our Common Stock is exacerbated by low trading volume.

Additional factors that may cause the market price of our Common Stock to fluctuate include:

•the entry into, or termination of, key agreements, including commercial partner agreements;

•announcements by commercial partners or competitors of new commercial products, clinical progress or lack thereof, significant contracts, commercial relationships or capital commitments;

•the loss of key employees;

•future sales of our common stock;

•general and industry-specific economic conditions that may affect our research and development expenditures;

•the failure to meet industry analyst expectations; and

•period-to-period fluctuations in financial results.

Moreover, the stock markets in general have experienced substantial volatility that has often been unrelated to the operating performance of individual companies. These broad market fluctuations may also adversely affect the trading price of our Common Stock. In the past, following periods of volatility in the market price of a company’s securities, stockholders have often instituted class action securities litigation against such companies.

If we do not complete the Merger, we may face substantial competition for attractive counterparties for any proposed strategic transactions.

There can be no assurance that the Merger will be completed. If the Merger is not completed, our board of directors may decide to pursue an alternative strategic transaction. We may face substantial competition for attractive counterparties for any proposed strategic transactions. For example, there may be many other biotechnology and pharmaceutical companies that halt development of their programs and instead choose to pursue strategic transactions like the ones we have been exploring in connection with our strategic review process. These companies may possess greater financial and managerial resources than we do, and they may have more attractive product candidates, intellectual property or other assets. As a result, these other companies may prove to be more attractive than us to counterparties pursuing strategic transactions. There can be no assurance that any future strategic review process will result in us pursuing a transaction, or that any transaction, if pursued, will be completed on terms favorable to us and our stockholders.

If we do not successfully consummate the Merger or another strategic transaction, our board of directors may decide to pursue a dissolution and liquidation of our company. In such an event, the amount of cash available for distribution to our stockholders will depend heavily on the timing of such liquidation as well as the amount of cash that will need to be reserved for commitments and contingent liabilities, as to which we can give you no assurance.

There can be no assurance that the Merger will be completed. If the Merger is not completed, our board of directors may decide to pursue a dissolution and liquidation of our company. In such an event, the amount of cash available for distribution to our stockholders will depend heavily on the timing of such decision and, ultimately, such liquidation, since the amount of cash available for distribution continues to decrease as we fund our operations while pursuing the Merger. In addition, if our board of directors were to approve and recommend, and our stockholders were to approve, a dissolution and liquidation of the company, we would be required under Delaware corporate law to pay our outstanding obligations, as well as to make reasonable provision for contingent and unknown obligations, prior to making any distributions in liquidation to stockholders. Our

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commitments and contingent liabilities may include obligations under our employment and related agreements or policies with certain employees that provide for severance and other payments following a termination of employment occurring for various reasons, including a change in control of the company, litigation against us, and other various claims and legal actions arising in the ordinary course of business, and other unexpected and/or contingent liabilities. As a result of this requirement, a portion of our assets would need to be reserved pending the resolution of such obligations.

In addition, we may be subject to litigation or other claims related to a dissolution and liquidation of our company. If a dissolution and liquidation were to be pursued, our board of directors, in consultation with our advisors, would need to evaluate these matters and make a determination about a reasonable amount to reserve. Accordingly, holders of our common stock could lose all or a significant portion of their investment in the event of a liquidation, dissolution or winding up of the company. A liquidation would be a lengthy and uncertain process with no assurance of any value ever being returned to our stockholders.

Risks Related to Our Financial Position and Need for Additional Capital

We have incurred significant losses since our inception and anticipate that, if we continue to progress the development of our product candidates, we will continue to incur losses in the foreseeable future. We have not commercialized any products and have never generated revenue from the commercialization of any product. We are not currently profitable, and we may never achieve or sustain profitability.

We are a clinical-stage biotechnology company with a limited operating history. As a result, we are not profitable and we have incurred significant operating losses since inception, including net losses of $9.0 million and $57.8 million for the years ended December 31, 2025 and 2024, respectively. Our loss for the year ended December 31, 2025 included a $23.0 million gain in connection with the JV Sale in 2025. As of December 31, 2025, we had an accumulated deficit of $302.0 million. Investment in biopharmaceutical product development is highly speculative because it entails substantial upfront capital expenditures and significant risk that any potential product candidate will fail to gain regulatory approval and become commercially viable. Since inception, we have devoted substantially all of our resources to raising capital, conducting discovery and research activities, acquiring product candidates, establishing and protecting our intellectual property, preparing for and conducting clinical trials, and establishing arrangements with third parties for the manufacture of our product candidates. We do not have any product candidates approved for sale and have not generated any revenue from product sales.

If we continue to progress the development of our product candidates, we expect to incur significant additional operating losses in the foreseeable future as we advance our programs and operate our business. The costs of advancing product candidates through each clinical phase tend to increase substantially over the duration of the clinical development process. The total costs to advance a single product candidate to marketing approval in even a single jurisdiction are substantial. Because of the numerous risks and uncertainties associated with pharmaceutical product development, we are unable to accurately predict the timing or amount of increased expenses or when, or if, we will be able to generate revenue from the commercialization of any product candidates or achieve or maintain profitability. Our expenses will increase substantially if and as we:

▪plan for and conduct any future clinical trials for any of our product candidates, including the ongoing RLYB116 confirmatory clinical PK/PD trial;

▪seek regulatory approvals for RLYB116 and any other product candidates;

▪advance our discovery and preclinical development activities for our product candidates;

▪discover and develop additional product candidates;

▪hire additional clinical, scientific, and commercial personnel;

▪acquire or in-license other product candidates or technologies;

▪maintain, expand, and protect our intellectual property portfolio;

▪secure manufacturing sources and supply chain capacity sufficient to produce adequate clinical and commercial quantities of our product candidates; and

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▪establish a sales, marketing, and distribution infrastructure to commercialize our products, if approved.

We do not know when or whether we will become profitable. Our ability to generate revenue and become profitable depends upon our ability to successfully complete the development of our product candidates and to obtain the necessary regulatory approvals for their commercialization, which is subject to substantial additional risks and uncertainties, as described under “— Risks Related to Discovery, Development, Clinical Testing, Manufacturing, and Regulatory Approval.”

Each of our product candidates will require additional preclinical and/or clinical development, regulatory approval in multiple jurisdictions, the securing of clinical and commercial manufacturing supply, the building of a commercial organization, and substantial investment before we generate any revenue from product sales. As a result, if we continue to progress the development of our product candidates, we expect to continue to incur net losses and negative cash flows in the foreseeable future. These net losses and negative cash flows have had, and will continue to have, an adverse effect on our stockholders’ equity and working capital. The amount of our future net losses will depend, in part, on the rate of future growth of our expenses and our ability to generate revenues. If we are unable to develop and commercialize one or more product candidates, either alone or through current or future collaborations, or if revenues from any product that receives marketing approval are insufficient, we will not achieve profitability. Even if we successfully commercialize RLYB116 or any of our other product candidates, we may continue to incur substantial research and development and other expenses to develop other current or future product candidates. Even if we do achieve profitability, we may not be able to sustain or increase profitability on a quarterly or annual basis or meet outside expectations for our profitability. Our failure to become and remain profitable would decrease the value of the Company and could impair our ability to raise capital, maintain our research and development efforts, expand our business, execute our business plan or continue our operations.

If we continue to progress the development of our product candidates, we will require significant additional capital to fund our operations. If we continue to progress the development of our product candidates and fail to obtain necessary financing, we may not be able to complete the development or commercialization of RLYB116 or any other product candidate. Given our limited resources and access to capital, we may decide to prioritize development of certain product candidates, the choice of which may prove to be wrong and adversely affect our business.

If we continue to progress the development of our product candidates, we expect to spend significant amounts of capital to complete the development of, and if approved, commercialize, one or more product candidates, including RLYB116. We are obligated to make certain payments under our agreements with Affibody, Sobi, and Kymab Limited ("Sanofi"), including milestone and royalty payments in connection with achievement of certain development and commercial milestones as well as the sale of resulting products under such agreements. We may also spend significant capital to develop laboratory tests to identify patients for inclusion in our clinical trials or who are likely to respond to our product candidates.

If we continue to progress the development of our product candidates, we believe that our existing cash, cash equivalents and marketable securities as of December 31, 2025, will be sufficient to fund our operating expenses and capital expenditure requirements for at least 12 months beyond the date of the filing of this Annual Report on Form 10-K. This estimate and our expectation to advance the preclinical and clinical development of RLYB116 and any other product candidates are based on assumptions that may prove to be wrong, or we may be subject to changing circumstances. We could exhaust our available capital resources sooner than we expect. Our business is subject to numerous risks and uncertainties, and we may be unable to accurately estimate the actual amount of funds we will require for development and commercialization of our product candidates. Our future capital requirements, both near and long-term, will depend on many factors, including, but not limited to:

▪the initiation, progress, timing, costs and results of our clinical trials through all phases of development;

▪the outcome, timing and cost of meeting regulatory requirements established by the FDA, EMA, and other comparable foreign regulatory authorities, including any regulatory designations allowing for priority review and any additional clinical trials required by the FDA, EMA or other comparable foreign regulatory authorities;

▪the willingness of the FDA, EMA and other comparable foreign regulatory authorities to accept our clinical trial designs, as well as data from our completed and planned preclinical studies and clinical trials, as the basis for review and approval of RLYB116 and any other product candidates;

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▪the cost and timing of the manufacture and supply of non-clinical, clinical and commercial quantities of RLYB116 and our other product candidates;

▪the identification, assessment, acquisition and/or development of additional research programs and additional product candidates;

▪the cost of filing, prosecuting, and enforcing our patent claims and other intellectual property rights;

▪the cost of defending potential intellectual property disputes, including patent infringement actions brought by third parties against us;

▪the costs associated with potential clinical trial liability or product liability claims, including the costs associated with obtaining insurance against such claims and with defending against such claims;

▪the effect of competing technological and market developments;

▪the cost of making royalty, milestone or other payments under our current or any future in-license agreements;

▪our ability to maintain our collaboration with AbCellera on favorable terms and establish new collaborations;

▪the extent to which we in-license or acquire additional product candidates or technologies; and

▪the costs of operating as a public company.

If we continue to progress the development of our product candidates, we will require significant additional capital, which we may raise through equity offerings, debt financings, marketing and distribution arrangements, strategic alliances and licensing arrangements or other sources. Depending on our business performance, the economic climate and market conditions, we may be unable to raise additional funds when needed on favorable terms, or at all. Furthermore, pursuant to Instruction I.B.6, a company with a public float of less than $75 million measured at certain time periods may not issue securities under Registration Statements on Form S-3 in excess of one-third of its public float in a 12-month period. For purposes of the prior sentence, “public float” means the aggregate market value of a company’s shares held by non-affiliates. We are subject to the limitations of Instruction I.B.6 which may limit the amount of funds we can raise using Registration Statements on Form S-3. Moreover, uncertain geopolitical events, such as the war in Ukraine and conflict in Israel, and uncertain global economic conditions, including as a result of changes in tariffs and other trade restrictions, have impacted the global economy, and a severe or prolonged economic downturn could result in a variety of challenges for our business, including disruptions in the financial markets, which could adversely impact our ability to raise additional capital when needed or on favorable terms, if at all. If we do not succeed in raising additional funds on acceptable terms, we may need to significantly delay, scale back or discontinue the development of one or more of our product candidates or the commercialization of any product that may be approved for marketing, or we could be forced to discontinue operations. In addition, attempting to secure additional financing may divert the time and attention of our management from day-to-day activities and harm our product candidate development efforts.

Because we have limited financial resources, we have focused and may continue to focus on a limited set of research programs and product candidates and for a limited set of indications. We may forego or delay pursuit of opportunities with certain other product candidates or for other indications that could have greater commercial potential or a greater likelihood of success. Our capital allocation decisions may cause us to fail to realize value from, or advance, viable commercial products or profitable market opportunities.

Raising additional capital may cause dilution to our stockholders, restrict our operations or require us to relinquish rights to our intellectual property or product candidates.

If we continue to progress the development of our product candidates, until such time, if ever, as we generate significant revenue from product sales, we expect to finance our operations through the sale of equity, debt financings, collaborations, strategic alliances and licensing arrangements or other sources. We do not currently have any committed external source of funds. In addition, we may seek additional capital due to favorable

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market conditions or strategic considerations, even if we believe that we have sufficient funds for our current or future operating plans.

To the extent that we raise additional capital through the future sale of equity or convertible debt securities, including sales of our common stock pursuant to the Sales Agreement with TD Securities (USA) LLC, each shareholder's ownership interest will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect their rights as a common stockholder. In addition, debt financing and preferred equity financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. If we raise additional funds through debt financing, we may be subject to covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends, and we may need to dedicate a substantial additional portion of any operating cash flows to the payment of principal and interest on such indebtedness. Any future indebtedness, combined with our other financial obligations, could increase our vulnerability to adverse changes in general economic, industry and market conditions, limit our flexibility in planning for, or reacting to, changes in our business and the industry and impose a competitive disadvantage compared to our competitors that have less debt or better debt servicing options. If we raise additional funds through collaborations, strategic alliances or licensing arrangements with third parties, we may be required to relinquish valuable rights to our intellectual property, future revenue streams or product candidates or grant licenses on terms that may not be favorable to us. If we are unable to raise additional funds when needed, we may be required to delay, limit, reduce or terminate development or future commercialization efforts for one or more of our product candidates.

We have a limited operating history and no history of commercializing pharmaceutical products, which may make it difficult to evaluate the prospects for our future viability.

Rallybio was founded in January 2018 and our operations to date have been limited primarily to research and development activities, and raising capital. We have not yet demonstrated the ability to successfully complete a large-scale, pivotal clinical trial, obtain marketing approval, manufacture a commercial-scale product, or arrange for a third-party to do so on our behalf, or conduct sales and marketing activities necessary for successful commercialization. Consequently, predictions about our future success or viability may not be as accurate as they could be if we had a longer operating history or a history of successfully developing and commercializing pharmaceutical products.

As a business with a limited operating history, we may encounter unforeseen expenses, difficulties, complications, delays and other known and unknown challenges. If we continue to progress the development of our product candidates, we will eventually need to transition from a company with a research and development focus to a company capable of supporting commercial activities. We may not be successful in such a transition and, as a result, our business may be adversely affected.

Our quarterly and annual financial results may fluctuate, which makes our results difficult to predict and may cause our results to fall short of expectations.

Our financial condition and operating results have varied in the past and will continue to fluctuate from quarter-to-quarter and year-to-year in the future due to a variety of factors, many of which are beyond our control. Factors relating to our business that may contribute to these fluctuations include the following, as well as other factors described elsewhere in this Annual Report on Form 10-K:

▪variations in the level of expense related to any ongoing development of our product candidates or research pipeline;

▪delays or failures in advancement of any existing or future product candidates into the clinic or in clinical trials;

▪the feasibility of developing, manufacturing and commercializing our product candidates;

▪our relationships, and any associated exclusivity terms, with strategic collaborators;

▪our execution of any additional collaboration, licensing or similar arrangements, and the timing of payments we may make or receive under existing or future arrangements, or the termination or modification of any such existing or future arrangements;

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▪our operation in a net loss position in the foreseeable future;

▪if we continue to progress the development of our product candidates, our ability to consistently manufacture our product candidates, including in sufficient quantities for clinical or commercial purposes;

▪our dependence on, and the need to attract and retain, key management and other personnel;

▪strategic decisions by us or our competitors, such as acquisitions, divestitures, spin-offs, joint ventures, strategic investments or changes in business strategy;

▪potential advantages that our competitors and potential competitors may have in developing and commercializing competing products, securing funding for or obtaining the rights to critical intellectual property;

▪regulatory developments affecting our product candidates or those of our competitors;

▪if any of our product candidates receives regulatory approval, the terms of such approval and market acceptance and demand for such product candidates;

▪developments or disputes concerning patents or other proprietary rights, litigation matters and our ability to obtain and maintain patent protection for our product candidates;

▪business interruptions such as power outages, strikes, civil unrest, wars, acts of terrorism or natural disasters; and

▪our ability to use our net operating loss ("NOL") and income tax credit carryforwards to offset income tax.

Due to these and other factors, the results of any of our prior quarterly or annual periods should not be relied upon as indications of our future operating performance, and a period-to-period comparison of our results of operations may not be a meaningful indication of our future performance. In any particular quarter or quarters, our operating results could be below the expectations of securities analysts or investors, which could cause our stock price to decline.

Our ability to use our net operating loss and income tax credit carryforwards to offset future income tax liabilities may be subject to certain limitations.

We have incurred substantial NOLs during our history. To the extent that we continue to generate taxable losses, unused losses will carry forward and can be used to offset future taxable income, if any, until such unused losses expire. NOLs generated in taxable years beginning after December 31, 2017 are not subject to expiration. Federal NOLs generated in taxable years beginning after December 31, 2017 generally may not be carried back to prior taxable years. The deduction for NOLs arising in taxable years beginning after December 31, 2017 is generally limited to 80% of current year taxable income. We also have substantial federal and state research and development and other tax credit carryforwards. These tax credit carryforwards could expire unused and be unavailable to offset future income tax liabilities. In addition, in general, under Sections 382 and 383 of the U.S. Internal Revenue Code of 1986, as amended, (the “Code”), a corporation that undergoes an “ownership change” is subject to limitations on its ability to use its pre-change NOLs and tax credit carryforwards to offset future taxable income. Some of our historical NOLs may be subject to annual limitations on our ability to use them due to prior ownership changes. Additionally, we may experience such ownership changes in the future as a result of future transactions in our stock, some of which may be outside our control. If we undergo an ownership change, our ability to use our NOLs and income tax credit carryforwards could be further limited. For these reasons, we may not be able to use a material portion of our NOLs or tax credit carryforwards, even if we attain profitability.

Risks Related to Discovery, Development, Clinical Testing, Manufacturing, Marketing Approval and Commercialization

We are heavily dependent on the success of RLYB116, which is in early-stage clinical development. If we continue to progress the development of our product candidates, and we are not able to develop,

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obtain marketing approval for, or successfully commercialize our product candidates, or if we experience significant delays in doing so, our business will be materially harmed.

Our lead program, RLYB116, is in early-stage clinical development and we do not currently have any products that generate revenues or any other sources of revenue. To date, we have invested a significant portion of our efforts and financial resources in the development of RLYB212 and RLYB116. If we continue to progress the development of our product candidates, our future success is substantially dependent on our ability to successfully complete preclinical and clinical development for, obtain marketing approval for, and successfully commercialize, RLYB116 and our other product candidates, which may never occur. None of our product candidates are approved for commercial sale and we may never be able to develop a marketable product.

Before obtaining marketing approvals for the commercial sale of our product candidates, we must demonstrate the safety and efficacy of our product candidates for use in each target indication through lengthy, complex and expensive preclinical studies and clinical trials. Failure can occur at any time during the preclinical study and clinical trial processes. Because our product candidates are in an early stage of development, there is a high risk of failure, and we may never succeed in developing marketable products. If we continue to progress the development of our product candidates, our ability to generate product revenue will depend heavily on the successful development and eventual commercialization of our product candidates, which may never occur. Ongoing and future preclinical studies and clinical trials of our product candidates may not show sufficient safety or efficacy or be of sufficient quality to obtain or maintain marketing approvals. For example, PK data from the Phase 2 clinical trial for RLYB212 demonstrated an inability of the RLYB212 dose regimen to achieve predicted target concentrations, as well as the minimum target concentration required for efficacy. There can be no assurance that any of our product candidates, even if approved, will prove to be commercially viable therapeutics.

RLYB116 is designed for SC self-administration. The formulation or physical properties of RLYB116 may ultimately be determined to be inadequate to support this route of administration. If SC administration is not feasible, then we may need to identify additional formulations or routes of administration, which could delay initiation of our future clinical trials or commercialization and result in significant additional costs. Further, alternative formulations and routes of administration may be required to differentiate our product candidates from competitors and/or secure access to support successful commercialization.

If we continue to progress the development of our product candidates, the success of our product candidates will depend on several factors, including the following:

▪successful and timely initiation of preclinical studies, and successful and timely initiation of, enrollment in, and completion of our clinical trials with results that support a finding of safety and effectiveness and an acceptable risk-benefit profile of our product candidates in the intended populations within the timeframes we have projected;

▪regulatory grants of authorization to proceed under investigational new drug applications or CTAs such that we can commence planned or future clinical trials of our product candidates;

▪sufficiency of our financial and other resources to complete the necessary preclinical studies and clinical trials;

▪our ability to successfully utilize certain delivery systems, such as pre-filled syringes ("PFSs"), pen-injectors and/or autoinjectors, for certain of our product candidates and to obtain marketing approval of any such drug/device combination product;

▪the outcome, timing, and cost of meeting regulatory requirements, including any post-marketing commitments, established by the FDA, EMA and other comparable foreign regulatory authorities;

▪establishing commercially viable arrangements with third-party manufacturers for clinical and commercial supply;

▪obtaining and maintaining patent and trade secret protection and regulatory exclusivity for our product candidates;

▪establishing sales, marketing and distribution capabilities, whether alone or through a collaboration, to support commercialization of our product candidates, if and when approved;

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▪acceptance of the product candidates, if and when approved, by patients, the medical community and third-party payors;

▪effectively differentiating and competing with other therapies approved and/or used for the same indications as our product candidates, particularly RLYB116;

▪obtaining and maintaining third-party coverage and reimbursement;

▪enforcing and defending intellectual property rights and claims; and

▪maintaining an acceptable safety profile of the product candidates following approval.

If we do not successfully address one or more of these factors in a timely manner or at all, we could experience significant delays or an inability to commercialize our product candidates, which would materially harm our business. Due to the uncertain and time-consuming clinical development and marketing approval process, we may not successfully develop any of our product candidates and may choose to discontinue the development of any of our product candidates prior to receiving marketing approval. If we discontinue development of a product candidate, we will not receive anticipated revenues from that product candidate and we may not receive any return on our investment in that product candidate. We may discontinue a product candidate for clinical reasons if it does not prove to be safe and effective for its targeted indications, or if such product candidates do not achieve the necessary efficacy at tolerated doses required for patient benefit. For example, we discontinued RLYB212 development based on PK data from the Phase 2 clinical trial that demonstrated an inability of the RLYB212 dose regimen to achieve predicted target concentrations, as well as the minimum target concentration required for efficacy. In addition, there may be important facts about the safety, efficacy and risk versus benefit of our product candidates that are not known to us at this time. Any unexpected safety events or our failure to generate sufficient data in our clinical trials to demonstrate efficacy may cause a product candidate to fail clinical development. Furthermore, even if that product candidate meets its safety and efficacy endpoints, we may discontinue its development for various reasons, such as changes in the competitive environment or the standard of care and the prioritization of our resources.

The U.S. Supreme Court’s June 2024 decision in Loper Bright Enterprises v. Raimondo overturned the longstanding Chevron doctrine, under which courts were required to give deference to regulatory agencies’ reasonable interpretations of ambiguous federal statutes. The Loper decision could result in additional legal challenges to regulations and guidance issued by federal agencies, including the FDA, on which we rely. Any such legal challenges, if successful, could have a material impact on our business. Additionally, the Loper decision may result in increased regulatory uncertainty, inconsistent judicial interpretations, and other impacts to the agency rulemaking process, any of which could adversely impact our business and operations. We cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative action or as a result of legal challenges, either in the United States or abroad. If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, our business could be materially harmed.

Preclinical studies and clinical trials are expensive, time consuming and difficult to design and implement, and involve uncertain outcomes. If we continue to progress the development of our product candidates, we may incur additional costs or experience delays in completing, or ultimately be unable to complete, the development of our product candidates.

Before obtaining marketing approval from the FDA, EMA or other comparable regulatory authorities for the sale of our product candidates, we must complete preclinical studies and extensive clinical trials to demonstrate the safety and efficacy of our product candidates. To initiate clinical trials for any future product candidates, we must submit the results of preclinical studies to the FDA, EMA or other comparable foreign regulatory authorities, along with other information, including information about CMC and our proposed clinical trial protocol, as part of an IND or similar regulatory filing that must be accepted by the FDA, EMA or other applicable regulatory authorities before we may proceed with clinical development. In the event that regulators require us to complete additional preclinical studies or we are required to satisfy other regulator requests, such as obtaining alignment on the device regulatory pathway for our FNAIT prevention program, the start of our clinical trials may be delayed or prevented. Even after we receive and incorporate guidance from these regulatory authorities, the FDA, EMA or other regulatory authorities could (i) disagree that we have satisfied their requirements to commence our clinical trial, (ii) change their position on the acceptability of our data, trial design or the clinical

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endpoints selected, which may require us to complete additional preclinical studies or clinical trials or (iii) impose stricter requirements for approval than we currently expect.

If we continue to progress the development of our product candidates, we may experience events that could delay or prevent our ability to complete current clinical trials or initiate and complete new trials, any of which may impact our product development timelines, result in increased costs, affect our ability to obtain marketing approval according to our plans, and delay commercialization of our product candidates. These events include, but are not limited to:

▪the FDA, EMA or other comparable foreign regulatory authorities requiring us to submit additional data or imposing other requirements before permitting us to commence a trial;

▪delays in receiving or denial by regulatory agencies of permission to proceed with our planned clinical trials or any other clinical trials we may initiate, or placement of a clinical trial on hold;

▪negative results from our non-clinical trials or clinical trials;

▪challenges, delays and cost involved in identifying, recruiting and retaining suitable participants and clinical trial sites in sufficient numbers to participate in clinical trials;

▪delays in reaching an agreement on acceptable terms with prospective CROs and clinical trial sites, the terms of which can be subject to extensive negotiation and may vary significantly among different CROs and trial sites;

▪delays in obtaining an independent IRB approval at each site within the United States, or Independent Ethics Committee ("IEC") approval at sites outside the United States;

▪delays or problems in analyzing data, or the need for additional analysis or data or the need to enroll additional patients;

▪failure by us, our CROs, trial sites or investigators to adhere to clinical trial, regulatory, legal or contractual requirements and perform trials in accordance with the FDA’s GCP requirements and trial protocol;

▪inadequate quantity or quality of product candidate or other materials necessary to conduct clinical trials, for example as a result of delays in defining and implementing the manufacturing process for materials used in clinical trials or for the manufacture of larger quantities or other delays or issues arising in the manufacturing of sufficient supply of finished drug product;

▪lack of adequate funding to continue a clinical trial, including as a result of unanticipated costs or increases in costs of clinical trials;

▪occurrence of serious adverse events including unexpected serious adverse events, associated with the product candidate or reports from non-clinical or clinical testing of our own or competing therapies that raise safety or efficacy concerns, or delays or failures in addressing patient safety concerns that arise during the course of a trial;

▪changes in regulatory requirements and guidance that require changes to planned or ongoing preclinical and clinical studies, or the conduct of additional studies; and

▪difficulties recruiting and retaining employees, consultants or contractors with the required level of expertise.

In addition, we could encounter delays if a clinical trial is suspended or terminated by us, the IRBs or IECs of the institutions in which such trials are being conducted, the FDA, EMA or other regulatory authorities, or recommended for termination by a Data and Safety Monitoring Board ("DSMB") for such trial. Such authorities may impose a suspension or termination or recommend an alteration to clinical trials due to several factors, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical protocols,

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the identification of safety issues or adverse side effects, failure to demonstrate a benefit from using a drug, changes in governmental regulations or administrative actions.

Furthermore, we rely and will rely on CROs and clinical trial sites to ensure the proper and timely conduct of our clinical trials and, while we have agreements governing their committed activities, we have limited influence over their actual performance, as described in the section titled “— Risks Related to Our Dependence on Third Parties.”

Principal investigators for our clinical trials could serve as scientific advisors or consultants to us from time to time and receive compensation in connection with such services. Under certain circumstances, we may be required to report some of these relationships to the FDA. The FDA may conclude that a financial relationship between us and a principal investigator has created a conflict of interest or otherwise affected interpretation of a clinical trial. The FDA may therefore question the integrity of the data generated at the applicable clinical trial site, and the utility of the clinical trial itself may be jeopardized. This could result in a delay in approval, or rejection, of our marketing applications by the FDA and may ultimately lead to the denial of marketing approval of our product candidates.

Any delays in completing our clinical trials will increase our costs, slow down our product candidate development and approval process and jeopardize our ability to commence product sales and generate revenues. In addition, many of the factors that cause, or lead to, termination or suspension of, or a delay in the commencement or completion of, clinical trials may also ultimately lead to the denial of regulatory approval of our product candidates. Any delays to our clinical trials could shorten any period during which we may have the exclusive right to commercialize our product candidates and our competitors may be able to bring products to market before we do, and the commercial viability of our product candidates could be significantly reduced. Any of these occurrences may harm our business, financial condition and prospects significantly.

If we continue to progress the development of our product candidates, results of preclinical studies, clinical trials or analyses that we may announce or publish from time to time, may not be indicative of results obtained in later trials, and any interim results we may publish could be different than final results.

The results of preclinical studies, clinical trials or analyses of the results from such trials, may not be predictive of the results of later clinical trials. Product candidates in later clinical trials may fail to show the desired safety and efficacy traits despite having progressed through preclinical studies and prior clinical trials or having shown promising results based on analyses of data from earlier trials. Late-stage clinical trials may include a larger number of patients and could differ in other significant ways from early-stage clinical trials, including changes to inclusion and exclusion criteria, patient population, efficacy endpoints, dosing regimen and statistical design. A number of companies in the biopharmaceutical industry have suffered significant setbacks in later-stage clinical trials due to lack of efficacy or adverse safety profiles, notwithstanding earlier promising results. In addition, conclusions based on promising data from analyses of clinical results, such as the prospective and post hoc analysis of results may be shown to be incorrect in subsequent clinical trials that have pre-specified end points or may not be considered adequate by regulatory authorities. We have completed Phase 1 clinical studies for RLYB116, however, even if we complete later clinical trials as planned, we cannot be certain that their results will support the safety and efficacy requirements sufficient to obtain regulatory approval, and, as a result, our clinical development plans may be materially harmed.

Similarly, interim, “top-line” and preliminary data from our clinical trials that we announce or publish may change as more patient data become available or as additional analyses are conducted. The data obtained in such clinical trials are subject to additional audit and verification procedures and following such procedures, such interim data could be materially different from the final data.

Enrollment and retention of patients in rare disease clinical trials is an expensive and time-consuming process and could be made more difficult or rendered impossible by multiple factors outside our control.

If we continue to progress the development of our product candidates, identifying and qualifying patients to participate in clinical trials of our product candidates is critical to our success. We currently are conducting, clinical trials with our product candidates in rare disease indications, which can make completion of such trial more difficult. The timely completion of clinical trials in accordance with their protocols depends, among other things, on the speed at which we can recruit eligible patients to participate in testing our product candidates and our ability to enroll a sufficient number of patients who remain in the study until its conclusion. Clinical trial

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recruitment delays often result in increased costs, delays in advancing product development, delays in testing the effectiveness of technologies, delays in obtaining marketing approval or termination of clinical trials.

Patient enrollment and retention in clinical trials depends on many factors, including:

▪the design of the clinical trial, including the patient eligibility criteria defined in the protocol;

▪the size and nature of the patient population required for analysis of the trial’s primary endpoints;

▪the existing body of safety and efficacy data with respect to the product candidate;

▪the proximity of patients to clinical sites;

▪our ability to recruit clinical trial investigators with the appropriate competencies and experience;

▪clinicians’ and patients’ perceptions as to the potential advantages of the product candidate being studied in relation to other available therapies, including any new drugs or medical devices that may be approved for the indications we are investigating;

▪competing clinical trials being conducted by other companies or institutions, particularly for RLYB116;

▪our ability to obtain and maintain patient consents;

▪the risk that patients enrolled in clinical trials will drop out of the trials before completion; and

▪other factors we may not be able to control that may limit patients, principal investigators or staff, or clinical site availability.

Additionally, we may have difficulty identifying and enrolling patients for any planned clinical trials because the conditions for which we plan to evaluate our current product candidates are rare diseases and we anticipate that there will be limited patient pools from which to draw for clinical trials. Further, because screening for many of these diseases is not widely adopted, and because it can be difficult to diagnose these diseases in the absence of screening, we may have difficulty finding patients who are eligible to participate in our studies or trials. Our clinical trials for RLYB116 may compete with other clinical trials for product candidates that are being tested for the same indications. This competition will reduce the number and types of patients available to us because some patients who might have opted to enroll in our trials may instead opt to enroll in a trial being conducted by one of our competitors. Furthermore, any negative results we may report in clinical trials of any of our product candidates may make it difficult or impossible to recruit and retain patients in other clinical trials of that same or a similar product candidate.

Outside of the United States, our ability to initiate, enroll and complete a clinical trial successfully is subject to numerous additional risks, including:

▪difficulty in establishing or managing relationships with CROs and physicians;

▪different standards for the conduct of clinical trials;

▪our inability to locate qualified local consultants, physicians and partners; and

▪the potential burden of complying with a variety of foreign laws, medical standards and regulatory requirements, including the regulation of pharmaceutical and biotechnology products and treatment.

We may not be able to initiate or continue clinical trials required by the FDA, EMA or other regulatory authorities if we cannot enroll a sufficient number of eligible patients to participate in the clinical trials. If we have difficulty enrolling a sufficient number of patients to conduct our clinical trials as planned, we may need to delay, limit or terminate ongoing or planned clinical trials. Delays or failures in planned patient enrollment or retention may result in increased costs or program delays, which could have a harmful effect on our ability to develop our product candidates or could render further development impossible.

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If we continue to progress the development of our product candidates, any product candidates that we develop or the administration thereof, may cause serious adverse events or undesirable side effects, which may halt their clinical development, delay or prevent marketing approval, or, if approved, require them to be taken off the market, include safety warnings, or otherwise limit their sales.

Adverse events or undesirable side effects caused by any product candidates we develop could cause us or regulatory authorities or IRBs, IECs or DSMBs, where applicable, to interrupt, delay, or halt clinical trials and, if we seek approval of any such product candidate, could result in a more restrictive label, imposition of a REMS program by the FDA or the delay or denial of regulatory approval by the FDA, EMA or other comparable foreign regulatory authorities. Additionally, the administration process or related procedures associated with our product candidates also may cause adverse side effects. Even if we determine that serious adverse events are unrelated to study treatment, such occurrences could affect patient recruitment or the ability of enrolled patients to complete the trial. Results of any clinical trial we conduct could reveal a high and unacceptable severity and prevalence of side effects. For example, complement inhibitors have, by design, immunosuppressive effects and, in some cases, may be administered to patients with significantly compromised health. As a result, administration of RLYB116 could make patients more susceptible to infection. The chronic dosing of patients with RLYB116 could lead to an immune response that causes adverse reactions or impairs the activity and/or efficacy of RLYB116. Patients may develop an allergic reaction to the drug and/or develop antibodies directed at RLYB116, or may require immunization with a meningococcal vaccine and prophylactic antibiotics. An immune response that causes adverse reactions or impairs the activity of RLYB116 could cause a delay in or termination of our development plans.

Some potential therapeutics that initially showed therapeutic promise in early-stage trials have later been found to cause side effects that prevented their further development. In addition, side effects could affect patient recruitment or the ability of enrolled patients to complete a trial or result in potential clinical trial or product liability claims. Inadequate training or failures by clinical trial personnel in recognizing or managing the potential side effects of our product candidates could result in patient injury or death. Furthermore, clinical trials by their nature utilize a sample of the potential patient population. With a limited number of subjects and limited duration of exposure, rare and severe side effects of our product candidates or those of our competitors may only be uncovered when a significantly larger number of patients have been exposed to the drug.

If we or others later identify undesirable side effects caused by any product candidate that we develop after the product is approved, several negative consequences could result, which could materially harm our business, including:

▪regulatory authorities may suspend or withdraw approvals of such product candidate;

▪regulatory authorities may require additional warnings on the label, limit the approved use of such product candidate, or otherwise restrict distribution or marketing such as through requiring adoption of a REMS program;

▪we may be required to conduct additional clinical trials;

▪we could be sued and held liable for harm caused to patients; and

▪our reputation may suffer.

We cannot predict whether our product candidates will cause toxicities in humans that would preclude or lead to the revocation of marketing approval based on preclinical studies or early-stage clinical trials. Even if the side effects do not preclude the drug from obtaining or maintaining marketing approval, undesirable side effects may inhibit market acceptance of the approved product due to its tolerability versus other therapies. Any of these events could prevent us from achieving or maintaining market acceptance of a product candidate, if approved, and could significantly harm our business, results of operations, and prospects.

The marketing approval processes of the FDA, EMA and comparable foreign regulatory authorities, including the MHRA, are lengthy, time- consuming and inherently unpredictable, and if we continue to progress the development of our product candidates, and are ultimately unable to obtain marketing approval for RLYB116 or any of our other product candidates, our business will be substantially harmed.

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In the United States, we are not permitted to market a product candidate until we receive approval of a Biologics License Application ("BLA") or a New Drug Application ("NDA") from the FDA. The process of obtaining BLA and NDA approval is expensive, often takes many years and can vary substantially based upon the type, complexity and novelty of the products involved. Approval policies or regulations may change, and the FDA and other regulatory authorities have substantial discretion in the approval process, including the ability to delay, limit or deny approval of a product candidate for many reasons. In addition, the FDA may require post-approval clinical trials or studies as a condition of approval, which also may be costly. The FDA approval for a limited indication or approval with required warning language, such as a boxed warning, could significantly impact our ability to successfully market our product candidates. The FDA also may require adoption of a REMS requiring prescriber training, post-market registries, or otherwise restricting the marketing and dissemination of these products. Certain of our product candidates will rely on delivery systems, such as PFSs, pen-injectors and/or autoinjectors, and may ultimately be regulated as a drug/device combination product. Although the FDA and similar foreign regulatory agencies have systems in place for the review and approval of combination products, we may experience delays in the development and commercialization of our product candidates due to regulatory timing constraints and uncertainties in the product development and approval process. Despite the time and expense invested in the clinical development of product candidates, regulatory approval is never guaranteed for our product candidates. Assuming successful clinical development, we intend to seek product approvals in countries outside the United States, including in Europe. As a result, we would be subject to regulation by the EMA, as well as the other regulatory agencies in these countries.

Of the large number of drugs in development, only a small percentage successfully complete the marketing approval processes and are commercialized. This lengthy approval process, as well as the unpredictability of future clinical trial results, may result in our failing to obtain marketing approval to market our product candidates and we may be forced to abandon our development efforts for our product candidate, which would significantly harm our business, results of operations, and prospects.

The time required to obtain approval by the FDA, EMA and other comparable foreign regulatory authorities is unpredictable but typically takes many years following the commencement of clinical trials and depends upon numerous factors. In addition, approval policies, regulations, or the type and amount of clinical data necessary to gain approval may change during a product candidate’s clinical development and may vary among jurisdictions. We have not obtained marketing approval for any product candidate and it is possible that we will never obtain marketing approval for any product candidate.

Prior to obtaining approval to commercialize a product candidate in the United States or abroad, we must demonstrate to the satisfaction of the FDA, EMA or other comparable foreign regulatory authority, that such product candidates are safe and effective for their intended uses. Data obtained from preclinical studies and clinical trials are susceptible to varying interpretations, and regulatory authorities may not interpret our data as favorably as we do, which may further delay, limit, or prevent development efforts, clinical trials, or marketing approval. Even if we believe the preclinical or clinical data for our product candidates are sufficient to support approval, such data may not be considered sufficient to support approval by the FDA, EMA and other comparable regulatory authorities.

If we continue to progress the development of our product candidates, the FDA, EMA or other comparable foreign regulatory authority can delay, limit, or deny approval of RLYB116 or any of our other product candidates that we develop or require us to conduct additional preclinical or clinical testing or abandon a program for many reasons, including, but not limited to:

▪the FDA, EMA or other comparable foreign regulatory authorities may disagree with the design or implementation of our clinical trials;

▪we may be unable to demonstrate to the satisfaction of the FDA, EMA or other comparable foreign regulatory authorities that our product candidate is safe and effective for its proposed indication;

▪serious and unexpected drug-related side effects experienced by participants in our clinical trials or by individuals using drugs similar to our product candidates, or other products containing an active ingredient in our product candidates;

▪negative or ambiguous results from our clinical trials or results that may not meet the level of statistical significance required by the FDA, EMA or other comparable foreign regulatory authorities for approval;

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▪the population studied in the clinical trial may not be sufficiently broad or representative to assure safety and efficacy in the full population for which we seek approval;

▪the FDA, EMA or other comparable foreign regulatory authorities may not accept clinical data from trials which are conducted at clinical facilities or in countries where the standard of care is potentially different from that of the United States or the applicable foreign jurisdiction;

▪we may be unable to demonstrate that our product candidate’s clinical and other benefits outweigh its safety risks;

▪the FDA, EMA or other comparable foreign regulatory authorities may disagree with our interpretation of data from preclinical studies or clinical trials;

▪the data collected from clinical trials of our product candidates may not be acceptable or sufficient to support the submission of a BLA or NDA or to obtain regulatory approval in the United States or elsewhere, and we may be required to conduct additional clinical trials;

▪the FDA’s or the applicable foreign regulatory authority’s disagreement regarding the formulation, the labeling, and/or the specifications of our product candidates;

▪additional time may be required to obtain regulatory approval for our product candidates because they are combination products;

▪the FDA, EMA or other comparable foreign regulatory authorities may fail to approve or find deficiencies with the manufacturing processes or facilities of third-party manufacturers with which we contract for clinical and commercial supplies; and

▪the policies, regulations, and guidelines of the FDA, EMA or other comparable foreign regulatory authorities regarding the development, approval, and marketing of drugs and biologics may significantly change, including but not limited to, in the U.S., as a result of the 2025 change in presidential administration, which may render our clinical data insufficient for approval or restrict us from marketing our product candidates in the manner in which we anticipate.

We have never obtained marketing approval for a product candidate. If we continue to progress the development of our product candidates, any delay in obtaining, or an inability to obtain, marketing approvals would prevent us from commercializing our product candidates, generating revenues, and achieving and sustaining profitability.

Our product candidates target rare diseases and conditions, and if we continue to progress the development of our product candidates, the market opportunities for RLYB116 or any of our other product candidates, if approved, may be smaller than we anticipate. We must be able to successfully identify patients and capture a significant market share to achieve profitability and growth.

Our product candidates target rare diseases and conditions. With respect to RLYB116, we estimate that there are approximately 8,000 patients with immune PTR and up to 10,000 patients with refractory APS in the United States. Our projections of the number of eligible patients are based on our beliefs and estimates. These estimates have been derived from a variety of sources, including scientific literature, population statistics and market research, and may prove to be incorrect. Further, new sources may reveal a change in the estimated number of eligible patients, and the number of patients may turn out to be lower than expected. Additionally, the potentially addressable patient population for our current programs or future product candidates may be limited or may not be amenable to treatment with our product candidates, and new patients may become increasingly difficult to identify or gain access to. For example, even if we obtain FDA approval for RLYB116, the drug may be approved for a target population that is more limited than what we currently anticipate. Furthermore, even if we obtain significant market share for any product candidate, if approved, the potential target populations for our product candidates are for rare diseases, and we may never achieve profitability.

Further, in many cases there are either limited screening or diagnostic tests for the indications our product candidates are being developed to potentially treat. The lack of screening and diagnostic tests, coupled with the fact that there is frequently limited awareness among certain health care providers concerning the rare diseases

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we may seek to treat, often means that a proper diagnosis can, and frequently does, take years to identify (or an appropriate diagnosis may never be made for certain patients). As a result, even if one of our product candidates is approved for commercial sale, we may not be able to grow our revenues due to difficulty in identifying eligible patients. There can be no guarantee that any of our programs will be effective at identifying patients that will benefit from our product candidates, and even if we can identify patients that our product candidates can help, the number of patients that our product candidates may ultimately treat may turn out to be lower than we expect, they may not be otherwise amenable to treatment with our product candidates, or new patients may become increasingly difficult to identify, all of which may adversely affect our ability to grow and generate revenue and adversely affect our results of operations and our business. In addition, even in instances where we are able to expand the number of patients being treated, the number may be offset by the number of patients that discontinue use of the applicable product in a given period resulting in a net loss of patients and potentially decreased revenue.

We face significant competition from biotechnology and pharmaceutical companies, and if we continue to progress the development of our product candidates, our operating results will suffer if we fail to compete effectively.

The biotechnology and pharmaceutical industries are highly competitive and subject to significant and rapid technological change. Our success is highly dependent on our ability to acquire, develop, and obtain marketing approval for new products on a cost-effective basis and to market them successfully. If a product candidate we develop is approved, we will face intense competition. There are many public and private biopharmaceutical companies, universities, government agencies and other research organizations actively engaged in the research and development of products that may be like our product candidates or address similar markets. Mergers and acquisitions in the pharmaceutical, biotechnology and diagnostic industries may result in even more resources being concentrated among a smaller number of our competitors. These competitors also compete with us in establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. In addition, the number of companies seeking to develop and commercialize products and therapies competing with our product candidates is likely to increase. However, we seek to build our portfolio with key differentiating attributes to provide a competitive advantage in the markets we target. If we successfully develop and, if approved, commercialize RLYB116, this therapy may compete with anticoagulants such as Warfarin, or potentially be used in conjunction, with currently marketed treatments and any new therapies that may become available in the future.

If we continue to progress the development of our product candidates, competition could render any product candidate we develop obsolete, less competitive, or uneconomical. In addition, product candidates developed by our competitors may prove to be more safe or more effective than our product candidates. Our competitors may, among other things:

▪have significantly greater name recognition and financial, manufacturing, marketing, product development, technical, commercial infrastructure, and human resources than we do;

▪more effectively recruit and retain qualified scientific and management personnel;

▪more effectively establish clinical trial sites and patient registration;

▪develop and commercialize products that are safer, more effective, less expensive, more convenient, or easier to administer, or have fewer or less severe side effects;

▪obtain quicker regulatory approval;

▪better protect their patents and intellectual property or acquire technologies that are complementary to, or necessary for, our programs;

▪implement more effective approaches to sales, marketing, pricing, coverage, market access, and reimbursement; or

▪form more advantageous strategic alliances or collaborations.

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If we are not able to effectively compete for any of the foregoing reasons, our business will be materially harmed.

Disruptions in the FDA and other government agencies caused by funding shortages or global health concerns could hinder their ability to hire and retain key leadership and other personnel, or otherwise prevent new products and services from being developed or commercialized in a timely manner, which, if we continue to progress the development of our product candidates, could negatively impact our business.

The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, ability to hire and retain key personnel and accept the payment of user fees, and statutory, regulatory, and policy changes and other events that may otherwise affect the FDA’s ability to perform routine functions. Average review times at the agency have fluctuated in recent years as a result. In addition, government funding of other government agencies that fund research and development activities is subject to the political process, which is inherently fluid and unpredictable.

Disruptions at the FDA and other agencies may also slow the time necessary for new drugs to be reviewed or approved by necessary government agencies, which would adversely affect our business. For example, in recent years, including for 43 days beginning on October 1, 2025 and for 35 days beginning on December 22, 2018, the U.S. government has shut down several times and certain regulatory agencies, such as the FDA, have had to furlough critical employees and stop critical activities. The Trump Administration has reduced the number of employees serving in government agencies, including the FDA. If a prolonged government shutdown occurs, or if the U.S. government takes other personnel actions, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions, which could have a material adverse effect on our business.

Even if we obtain marketing approval for a product candidate in the United States, we or our current or future collaborators may never obtain approval for or commercialize the product candidate in any other jurisdiction, which would limit our ability to realize its full market potential.

In order to market any product in a particular jurisdiction, we or our current or future collaborators must establish and comply with numerous and varying regulatory requirements regarding safety and efficacy on a country-by-country basis. Approval by the FDA in the United States does not ensure approval by comparable regulatory authorities in other countries or jurisdictions. However, the failure to obtain approval in one jurisdiction may negatively impact our or our collaborators’ ability to obtain approval elsewhere. In addition, clinical trials conducted in one country may not be accepted by regulatory authorities in other countries, and regulatory approval in one country does not guarantee regulatory approval in any other country.

Approval processes vary among countries and can involve additional product testing and validation and additional administrative review periods. Seeking foreign regulatory approval could result in difficulties and increased costs for us and require additional preclinical studies or clinical trials which could be costly and time- consuming. Regulatory requirements can vary widely from country to country and could delay or prevent the introduction of our products in those countries. We do not have any product candidates approved for sale in any jurisdiction, including in international markets, and we do not have experience in obtaining regulatory approval in international markets. If we or our collaborators fail to comply with regulatory requirements in international markets or to obtain and maintain required approvals, or if regulatory approvals in international markets are delayed, our target market will be reduced and we will be unable to realize the full market potential of any product we develop.

Even if we obtain marketing approval for any of our product candidates, we will still face extensive and ongoing regulatory requirements and obligations and continued regulatory review, which may result in significant additional expense. We may be subject to penalties if we fail to comply with regulatory requirements or experience unanticipated problems with any product candidates.

Any product candidate for which we obtain marketing approval will be subject to extensive and ongoing requirements of the FDA and other regulatory authorities. These requirements include submissions of safety and other post- marketing information and reports, establishment registration and drug listing requirements, continued compliance with the FDA's current cGMP requirements regarding the distribution of samples to physicians and recordkeeping and Good Laboratory Practice ("GLP") and GCP requirements for non-clinical studies and any clinical trials that we conduct post-approval.

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The FDA may also require costly post-marketing studies or clinical trials and surveillance to monitor the safety or efficacy of a product. Additionally, the FDA closely regulates the post-approval marketing and promotion of drugs to ensure drugs are marketed only for the approved indications and in a manner that is consistent with the provisions of the approved labeling. If we market our products for uses beyond their approved indications or otherwise inconsistent with the FDA-approved labeling, we may be subject to enforcement action for off-label marketing by the FDA and other federal and state enforcement agencies, including the Department of Justice. Violation of the FDCA and other statutes, including the False Claims Act, and equivalent legislation in other countries relating to the promotion and advertising of prescription products may also lead to investigations or allegations of violations of federal and state and other countries’ health care fraud and abuse laws and state consumer protection laws. Even if it is later determined we were not in violation of these laws, we may be faced with negative publicity, incur significant expenses defending our actions and have to divert significant management resources from other matters.

In addition, later discovery of previously unknown adverse events or other problems with our products, manufacturers, or manufacturing processes or failure to comply with regulatory requirements, may yield various results, including, but not limited to:

▪restrictions on manufacturing such products;

▪restrictions in the labeling or on the marketing of products;

▪restrictions on product distribution or use;

▪requirements to conduct post-marketing studies or additional post-marketing clinical trials;

▪issuance of warning letters or untitled letters;

▪refusal to approve pending applications or supplements to approved applications that we submit, or delays in such approvals;

▪recalls or market withdrawals of products;

▪fines, restitution, or disgorgement of profits or revenues;

▪suspension or termination of ongoing clinical trials;

▪suspension or withdrawal of marketing approvals;

▪refusal to permit the import or export of our products;

▪product seizure; and

▪injunctions, consent decrees, or the imposition of civil or criminal penalties.

If we obtain FDA approval for RLYB116, safety risks not identified in our prior clinical trials may first appear after we obtain approval and commercialize RLYB116. Any new post-marketing adverse events may significantly impact our ability to market the drugs and may require that we recall and discontinue commercialization of RLYB116. Furthermore, if any confirmatory post-marketing trial fails to confirm the clinical profile or clinical benefits of RLYB116, the FDA may withdraw its approval, which would materially harm our business.

We also cannot predict the likelihood, nature, or extent of government regulation that may arise from future legislation or administrative or executive action, either in the United States or abroad. Further, the FDA’s, EMA’s and other comparable regulatory authorities’ policies may change, and additional government regulations may be enacted that could prevent, limit, or delay regulatory approval of a product candidate or increase the costs and regulatory burden of commercialization. If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we may lose any marketing approval that we may have obtained, and we may not achieve or sustain profitability, which would adversely affect our business, prospects, financial condition, and results of operations. Furthermore, non-compliance by us or any collaborator with regulatory requirements, including

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safety monitoring or pharmacovigilance, may also result in significant financial penalties, which would adversely affect our business.

If we continue to progress the development of our product candidates, we may seek Fast Track designation, Breakthrough Therapy designation, or PRIME designation for our product candidates, but we might not receive any such designation, and even if we do, such designation may not actually lead to a faster development or regulatory review or approval process.

If a drug is intended for the treatment of a serious or life-threatening condition, and non-clinical or clinical data demonstrate the potential to address an unmet medical need for this condition, the product candidate may qualify for FDA Fast Track designation, for which sponsors must apply. Sponsors of fast-track products may have more frequent interactions with the FDA, and, in some circumstances, the FDA may initiate review of sections of a fast track product’s application before the application is complete. We may submit an application for Fast Track designation for RLYB116. The FDA has broad discretion whether to grant this designation, and we may not receive it. Moreover, even if we receive Fast Track designation, Fast Track designation does not ensure that we will receive marketing approval and we may not experience a faster development or regulatory review or approval process with Fast Track designation compared to conventional FDA procedures. In addition, the FDA may withdraw Fast Track designation if it believes that the designation is no longer supported by data from our clinical development program. Fast Track designation alone does not guarantee qualification for the FDA’s priority review procedures.

If we continue to progress the development of our product candidates, we also may seek a Breakthrough Therapy designation for some of our product candidates if future results support such designation. A Breakthrough Therapy is defined as a drug (including biologic) that is intended, alone or in combination with one or more other drugs, to treat a serious condition, and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. Sponsors of products that have been designated as breakthrough therapies are eligible to receive more intensive FDA guidance on establishing an efficient drug development program, an organization commitment involving senior managers, and may be eligible for rolling review. Drugs designated as breakthrough therapies by the FDA may also be eligible for other expedited review programs, including accelerated approval and priority review, if supported by clinical data at the time the BLA or NDA is submitted to the FDA.

Designation as a Breakthrough Therapy is within the discretion of the FDA. Accordingly, even if we believe that a product candidate meets the criteria for designation as a Breakthrough Therapy, the FDA may disagree and instead determine not to make such designation. Even if we receive Breakthrough Therapy designation, the receipt of such designation may not result in a faster development or regulatory review or approval process compared to drugs considered for approval under conventional FDA procedures and does not assure ultimate approval by the FDA. In addition, even if a product candidate qualifies as a Breakthrough Therapy, the FDA may later decide that such product candidate no longer meets the conditions for qualification or decide that the time period for FDA review or approval will not be shortened.

In the EU we may seek PRIME designation for some of our product candidates in the future. PRIME is a voluntary program aimed at enhancing the EMA’s role to reinforce scientific and regulatory support in order to optimize development and enable accelerated assessment of new medicines that are of major public health interest with the potential to address unmet medical needs. The program focuses on medicines that target conditions for which there exists no satisfactory method of treatment in the EU or even if such a method exists, it may offer a major therapeutic advantage over existing treatments. PRIME is limited to medicines under development and not authorized in the EU and the applicant intends to apply for an initial MA application through the centralized procedure. To be accepted for PRIME, a product candidate must meet the eligibility criteria in respect of its major public health interest and therapeutic innovation based on information that can substantiate the claims. The benefits of a PRIME designation include the appointment of a CHMP rapporteur to provide continued support and help to build knowledge ahead of a MA application, early dialogue and scientific advice at key development milestones, and the potential to qualify products for accelerated review, meaning reduction in the review time for an opinion on approvability to be issued earlier in the application process. PRIME enables an applicant to request parallel EMA scientific advice and HTA advice to facilitate timely market access. Even if we receive PRIME designation for any of our product candidates, the designation may not result in a materially faster development process, review or approval compared to conventional EMA procedures. Further, obtaining PRIME designation does not assure or increase the likelihood of EMA’s grant of a marketing authorization.

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If we continue to progress the development of our product candidates, we may be unsuccessful in obtaining or may be unable to maintain the benefits associated with orphan drug designation, including the potential for market exclusivity. If our competitors are able to obtain orphan drug exclusivity for products that constitute the same drug and treat the same indications as RLYB116 or any of our other product candidates, we may not be able to have competing products approved by the applicable regulatory authority for a significant period of time.

Regulatory authorities in some jurisdictions, including the United States and the EU may designate drugs for relatively small patient populations as orphan drugs. Under the U.S. Orphan Drug Act, the FDA may designate a drug as an orphan drug if it is a drug intended to treat a rare disease or condition, which is generally defined as a patient population of fewer than 200,000 individuals annually in the United States, or a patient population of more than 200,000 in the United States where there is no reasonable expectation that the cost of developing the drug will be recovered from sales in the United States. In the EU, the EMA’s Committee for Orphan Medicinal Products evaluates, and the EC grants, an orphan drug designation principally to promote the development of products that are intended for the diagnosis, prevention or treatment of a life-threatening or chronically debilitating condition affecting not more than five in 10,000 persons in the EU. In addition, the product under consideration is indicated for a condition where there exists no satisfactory method of diagnosis, prevention or treatment authorized in the EU or, if such method exists, that the medicinal product will be of significant benefit to those affected by that condition. We may seek orphan drug designation in the United States and the EU for certain of our product candidates but may be unsuccessful in doing so. There can be no assurance that the FDA or the EMA’s Committee for Orphan Medicinal Products will consider orphan designation for any indication for which we apply or re-apply, or that we will be able to maintain such designation. In the United States, orphan drug designation entitles a party to financial incentives such as opportunities for grant funding towards clinical trial costs, tax advantages and user-fee waivers. Orphan drug designation neither shortens the development time or regulatory review time of a drug nor gives the drug any advantage in the regulatory review or approval process.

If a product candidate with an orphan drug designation subsequently receives the first marketing approval for the indication for which it has such designation, the product is entitled to a period of marketing exclusivity, which precludes the EMA or the FDA from approving another marketing application for the same drug or biologic for the same orphan designation for that time period, except in limited circumstances, such as a showing of clinical superiority to the product with orphan drug exclusivity or where the manufacturer is unable to assure sufficient product quantity. In the United States, the exclusivity period is seven years. The applicable exclusivity period is ten years in Europe, but such exclusivity period can be reduced to six years in Europe if a product no longer meets the criteria for orphan designation or if the product is sufficiently profitable so that market exclusivity is no longer justified. Moreover, orphan drug exclusive marketing rights in the United States may be lost if the FDA later determines that the request for designation was materially defective or if the manufacturer is unable to assure sufficient quantity of the drug to meet the needs of patients with the rare disease or condition. Similarly, in the EU, the market exclusivity can be broken if the holder of the MA for the original orphan medicinal product is unable to supply sufficient quantities of the medicinal product. In addition, in both the United States and EU, if a different drug is subsequently approved for marketing for the same or a similar indication as any of our product candidates that receive marketing approval, we may face increased competition and lose market share regardless of orphan drug exclusivity, which only protects against approval of the “same” drug for the same indication.

If we continue to progress the development of our product candidates, we may seek accelerated approval by the FDA for one or more of our product candidates. Accelerated approval by the FDA, even if granted for any of our product candidates, may not lead to a faster development or regulatory review or approval process and it does not increase the likelihood that our product candidates will receive marketing approval.

We may in the future seek an accelerated approval for our one or more of our product candidates. Under the accelerated approval program, the FDA may grant accelerated approval to a product candidate designed to treat a serious or life-threatening condition that provides meaningful therapeutic benefit over available therapies upon a determination that the product candidate has an effect on a surrogate endpoint or intermediate clinical endpoint that is reasonably likely to predict clinical benefit. As a condition of approval, the FDA requires that a sponsor of a product receiving accelerated approval perform a post-marketing confirmatory clinical trial or trials. In addition, the FDA currently requires as a condition for accelerated approval the pre-submission of promotional materials to FDA for review.

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Prior to seeking accelerated approval for any of our product candidates, we intend to seek feedback from the FDA and will otherwise evaluate our ability to seek and receive accelerated approval. There can be no assurance that after our evaluation of the feedback and other factors we will decide to pursue or submit a BLA for accelerated approval or any other form of expedited development, review or approval. Furthermore, if we decide to submit an application for accelerated approval there can be no assurance that such submission or application will be accepted or that the FDA will determine that the product candidate is eligible for or grant accelerated approval. A failure to obtain any planned accelerated approval for our product candidates would result in a longer time period to commercialization of our product candidates, if approved, could increase the cost of development of our product candidates and could harm our competitive position in the marketplace. If we receive accelerated approval for any of our product candidates, the FDA may withdraw accelerated approval if, among other things, a confirmatory trial required to verify the predicted clinical benefit of the product fails to verify such benefit or if such trial is not conducted with due diligence. Withdrawal of any accelerated approval could substantially harm our business.

If we continue to progress the development of our product candidates, the successful commercialization of any product candidate we develop will depend in part on the extent to which regulatory authorities and private health insurers establish coverage and reimbursement. Failure to obtain or maintain coverage and reimbursement for our product candidates, if approved, could limit our ability to market those products and decrease our or our ability to generate revenue.

If any product candidate is approved for marketing, coverage and reimbursement for such product by governmental healthcare programs, such as Medicare and Medicaid, private health insurers, and other third-party payors would be essential for most patients to be able to afford the prescription medication. Our ability to achieve acceptable levels of coverage and reimbursement for products or procedures using our products will therefore have an effect on our ability to successfully commercialize any product candidates we develop. We cannot be sure that coverage and reimbursement will be available for our product candidates, if and when such candidates obtain marketing approval, and any reimbursement that may become available may not be adequate and may be decreased or eliminated in the future.

Moreover, increasing efforts by governmental and third-party payors in the United States to cap or reduce healthcare costs may cause third-party payors to limit both coverage and the level of reimbursement for newly approved products and, as a result, such payors may not cover or provide adequate payment for any product we commercialize. We expect to experience pricing pressures in connection with the sale of our product candidates due to the trend toward managed health care and additional legislative, administrative, or regulatory changes. The downward pressure on healthcare costs in general, particularly prescription drugs and biologics and related administration procedures, has become intense and new products face increasing challenges in entering the market successfully. Third-party payors are increasingly challenging the price and examining the cost-effectiveness of new products in addition to their safety and efficacy. To obtain or maintain coverage and reimbursement for any product, we may need to conduct expensive pharmacoeconomic studies to demonstrate the medical necessity and cost-effectiveness of our product.

We may also need to provide discounts to purchasers to encourage purchasing of any approved product and rebates to third party payors to increase the possibility of favorable coverage and adequate cost sharing thresholds for patients. We may be required to provide discounts or rebates on any approved product under government healthcare programs or to certain government and private purchasers in order to obtain coverage under federal health care programs such as Medicaid. Participation in such programs would require us to track and report certain drug prices. We may be subject to fines and other penalties if we fail to report such prices accurately.

No uniform policy for coverage and reimbursement for products exists among third-party payors in the United States. Therefore, coverage and reimbursement for products can differ significantly from payor to payor, and one third-party payor’s decision to cover a particular product does not ensure that other payors will also provide similar coverage. Additionally, the process for determining whether a third-party payor will provide coverage for a product is typically separate from the process for setting the price of such product or establishing the reimbursement rate that the payor will pay for the product once coverage is approved. As a result, the coverage determination process is often a time-consuming and costly process that will require us to provide scientific and clinical support for the use of our product candidates to each payor separately, with no assurance that coverage and reimbursement will be obtained or will be consistent across payors. And, even if products are covered, third party payors may implement various mechanisms to control utilization (e.g., requiring prior approval for coverage for each patient). Additionally, coverage and reimbursement for screening and diagnostic tests

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associated with any products would be assessed and determined separately. Furthermore, rules and regulations regarding reimbursement change frequently, in some cases at short notice, and we believe that changes in these rules and regulations are likely. If coverage or reimbursement is not available or is available only at limited levels, we may not be able to successfully commercialize our product candidates and may not be able to obtain a satisfactory financial return on our product candidates.

We may also be subject to extensive governmental price controls and other market regulations outside of the United States, and we believe the increasing emphasis on cost-containment initiatives in other countries have and will continue to put pressure on the pricing and usage of medical products. In many countries, the prices of medical products are subject to varying price control mechanisms as part of national health systems. Other countries allow companies to fix their own prices for medical products but monitor and control company profits. Additional foreign price controls or other changes in pricing regulation could restrict the amount that we are able to charge for our products. Accordingly, in markets outside of the United States, the reimbursement for products we commercialize may be reduced compared with the United States and may be insufficient to generate commercially reasonable revenue and profits.

If we continue to progress the development of our product candidates, even if a product candidate we develop receives marketing approval, it may fail to achieve market acceptance by physicians, patients, third-party payors or others in the medical community necessary for commercial success.

Even if our product candidates receive regulatory approval, they may not gain market acceptance among physicians, patients, healthcare payors and the medical community. Various factors will influence whether our product candidates are accepted in the market if approved for commercial sale, including, but not limited to:

▪the efficacy, safety and tolerability of our products, and potential advantages compared to alternative treatments;

▪the clinical indications for which the product is approved, and product labeling or product insert requirements of the FDA, EMA or other comparable foreign regulatory authorities, including any limitations or warnings contained in a product’s approved labeling;

▪the effectiveness of sales and marketing efforts;

▪the prevalence and severity of any side effects;

▪the cost of treatment in relation to alternative treatments, including any similar treatments;

▪our ability to offer our products for sale at competitive prices;

▪the availability and access to screening and/or diagnostic tests;

▪the convenience and ease of administration compared to alternative treatments;

▪the willingness of the target patient population to try new therapies and of physicians to prescribe these therapies;

▪the strength of marketing and distribution support;

▪the availability of third-party coverage and reimbursement for any of our products that are approved and any screening and/or diagnostic testing, as appropriate; and

▪any restrictions on the use of our product together with other medications.

Market acceptance of our product candidates is heavily dependent on patients’ and physicians’ perceptions that our product candidates are safe and effective treatments for their targeted indications and willingness to use screening and/or diagnostic tests to identify at-risk target populations for our therapeutics. The perceptions of any product are also influenced by perceptions of competitors’ products that are in the same class or that have a similar mechanism of action. Because we expect sales of our product candidates, if approved, to generate substantially all our revenues in the foreseeable future, the failure of our product candidates to find market acceptance would harm our business and could require us to seek additional financing.

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If approved, our product candidates that are regulated as biologics may face competition from biosimilars approved through an abbreviated regulatory pathway.

The BPCIA was enacted as part of the ACA to establish an abbreviated pathway for the approval of biosimilar and interchangeable biological products. The regulatory pathway establishes legal authority for the FDA to review and approve biosimilar biologics, including the possible designation of a biosimilar as “interchangeable” based on its similarity to an approved biologic. Under the BPCIA, a reference biological product is granted 12 years of data exclusivity from the time of first licensure of the product, and the FDA will not accept an application for a biosimilar or interchangeable product based on the reference biological product until four years after the date of first licensure of the reference product. In addition, the approval of a biosimilar product may not be made effective by the FDA until 12 years from the date on which the reference product was first licensed. During this 12-year period of exclusivity, another company may still develop and receive approval of a competing biologic, so long as their BLA does not rely on the reference product, sponsor’s data or submit the application as a biosimilar application. Any new policies or processes adopted by the FDA could have a material adverse effect on the future commercial prospects for our biological products.

We believe that any of the product candidates we develop that is approved in the United States as a biological product under a BLA should qualify for the 12-year period of exclusivity. However, there is a risk that this exclusivity could be shortened due to congressional action or otherwise, or that the FDA will not consider the subject product candidates to be reference products for competing products, potentially creating the opportunity for biosimilar competition sooner than anticipated. Moreover, the extent to which a biosimilar, once approved, will be substituted for any one of the reference products in a way that is similar to traditional generic substitution for non-biological products is not yet clear, and will depend on a number of marketplace and regulatory factors that are still developing. The approval of a biosimilar of our product candidates could have a material adverse impact on our business due to increased competition and pricing pressure.

If we continue to progress the development of our product candidates, and are unable to establish sales, marketing and distribution capabilities either on our own or in collaboration with third parties, we may not be successful in commercializing any product candidates we develop, if approved.

In order to market and successfully commercialize any product candidates we develop, if approved, we must build our sales and marketing capabilities or enter into collaborations with third parties for these services. We currently have no sales, marketing or distribution capabilities and as a company have no experience in marketing products. If we commercialize any of our product candidates that may be approved ourselves, we will need to develop an in-house marketing organization and sales force across rare disease therapeutic areas, which will require significant expenditures, management resources, and time. There are significant expenses and risks involved with establishing our own sales and marketing capabilities, including our ability to hire, train, retain, and appropriately incentivize a sufficient number of qualified individuals, generate sufficient sales leads and provide our sales and marketing team with adequate access to physicians who may prescribe our products, effectively manage a geographically dispersed sales and marketing team, and other unforeseen costs and expenses. We will have to compete with other pharmaceutical and biotechnology companies to recruit, hire, train, and retrain marketing and sales personnel. Any failure or delay in the development of a product candidate that affects the expected timing of commercialization of the product candidate or results in the failure of the product candidate to be commercialized could result in us having prematurely or unnecessarily incurred costly commercialization expenses. Our investment would be lost if we are unable to retain or reposition our sales and marketing personnel.

We may also enter into collaborations for the sales and marketing of our product candidates, if approved. To the extent that we depend on collaborators for sales and marketing activities, any revenues we receive will depend upon the success of those collaborators’ sales and marketing teams and the collaborators’ prioritization of our products and compliance with applicable regulatory requirements, and there can be no assurance that the collaborators’ efforts will be successful. If we are unable to build our own sales and marketing team or enter into a collaboration for the commercialization of product candidates we develop, if approved, we may be forced to delay the commercialization of our product candidates or reduce the scope of our sales or marketing activities, which would have an adverse effect on our business, operating results and prospects.

Under the current presidential administration, we face uncertainty regarding potential regulatory developments that may adversely affect our business if we continue to progress the development of our product candidates.

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There have been significant and wide-ranging changes in law, regulation and policy under the current Trump administration.Current and future adopt legislation, regulation, or policy could adversely affect our business or creates a more challenging and costly environment to pursue the development and commercialization of our current or future product candidates. For example, the federal government, including theFDA, may implement legislative, regulatory, or policy changes regarding the standards for approving biologic products that we may be unable to satisfy or regarding the marketing of approved biologics that may limit or prohibit the advertising and promotion of our current or future product candidates, if approved. Additionally, the Trump administration has undertaken significant efforts to reduce the size and spending of the federal government, including at the FDA. A significant reduction in the FDA's workforce or the FDA's budget or other disruptions at the FDA could impact the FDA’s ability to engage in routine regulatory and oversight activities and result in delays or limitations on our ability to proceed with clinical development programs and obtain regulatory approvals. It is difficult to predict how executive actions that may be taken under the current Trump administration may affect the FDA’s ability to exercise its regulatory authority. If such executive actions impose constraints on the FDA’s ability to engage in routine oversight and product review activities in the normal course, our business may be negatively impacted.

Risks Related to Our Dependence on Third Parties

If we continue to progress the development of our product candidates, we may pursue business development transactions and collaborate with third parties for the development and commercialization of our product candidates. We may not succeed in identifying and acquiring businesses or assets, in-licensing or out-licensing intellectual property rights or establishing and maintaining collaborations, which may significantly limit our ability to successfully develop and commercialize our product candidates, if at all, and these transactions could disrupt our business, cause dilution to our stockholders or reduce our financial resources.

We acquired all rights to RLYB116 and RLYB114 from Sobi in 2019. We also obtained worldwide exclusive rights to RLYB332 from Sanofi in 2022. If we continue to progress the development of our product candidates, we may acquire or in-license rights to product candidates, products or technologies, acquire other businesses or enter into collaborations with third parties. We may not be able to enter into such transactions on favorable terms, or at all. Any such acquisitions, in-licenses or collaborations may not strengthen our competitive position, and these transactions may be viewed negatively by analysts, investors, customers, or other third parties with whom we have relationships. We may decide to incur debt in connection with an acquisition, or in-license or issue our common stock or other equity securities as consideration for the acquisition, which would reduce the percentage ownership of our existing stockholders.

We could incur losses resulting from undiscovered liabilities of the acquired business that are not covered by the indemnification we may obtain from the sellers of the acquired business. In addition, we may not be able to successfully integrate the acquired personnel, technologies, and operations into our existing business in an effective, timely, and non-disruptive manner. Such transactions may also divert management attention from day-to-day responsibilities, increase our expenses, and reduce our cash available for operations and other uses. We cannot predict the number, timing or size of future acquisitions or in-licenses or the effect that any such transactions might have on our operating results.

We may not realize the anticipated benefits of any current or future collaboration, each of which involves or will involve numerous risks, including:

▪a collaborator may shift its priorities and resources away from our product candidates due to a change in business strategies, or a merger, acquisition, sale, or downsizing;

▪a collaborator may seek to renegotiate or terminate its relationship with us due to unsatisfactory clinical results, manufacturing issues, a change in business strategy, a change of control or other reasons;

▪a collaborator may cease development in therapeutic areas that are the subject of our collaboration;

▪a collaborator may not devote sufficient capital or resources towards our product candidates, or may fail to comply with applicable regulatory requirements;

▪a collaborator may change the success criteria for a product candidate, thereby delaying or ceasing development of such candidate;

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▪a significant delay in initiation of certain development activities by a collaborator will also delay payment of milestones tied to such activities, thereby impacting our ability to fund our own activities;

▪a collaborator could develop a product that competes, either directly or indirectly, with our product candidates;

▪a collaborator with commercialization obligations may not commit sufficient financial resources or personnel to the marketing, distribution, or sale of a product;

▪a collaborator with manufacturing responsibilities may encounter regulatory, resource, or quality issues and be unable to meet demand requirements;

▪a collaborator may terminate a strategic alliance;

▪a dispute may arise between us and a collaborator concerning the research, development, or commercialization of a product candidate resulting in a delay in milestones or royalty payments or termination of the relationship and possibly resulting in costly litigation or arbitration, which may divert management’s attention and resources; and

▪a collaborator may use our products or technology in such a way as to invite litigation from a third-party.

If any collaborator fails to fulfill its responsibilities in a timely manner, or at all, our research, clinical development, manufacturing, or commercialization efforts related to that collaboration could be delayed or terminated, or it may be necessary for us to assume responsibility for expenses or activities that would otherwise have been the responsibility of our collaborator. If we are unable to establish and maintain collaborations on acceptable terms or to successfully transition away from terminated collaborations, we may have to delay or discontinue further development of one or more of our product candidates, undertake development and commercialization activities at our own expense, or find alternative sources of capital, which would have a material adverse impact on our clinical development plans and business. If we fail to establish and maintain collaborations related to our product candidates, we could bear all of the risk and costs related to the development of any such product candidate, and we may need to seek additional financing, hire additional employees and otherwise develop expertise for which we have not budgeted. This could negatively affect the development and commercialization of our product candidates.

We may face significant competition in identifying and acquiring businesses or assets, in-licensing intellectual property rights and seeking appropriate collaboration partners for our product candidates, and the negotiation process may be time-consuming and complex. In order for us to successfully partner our product candidates, potential collaborators must view these product candidates as economically valuable in markets they determine to be attractive in light of the terms that we are seeking and other products or product candidates available for licensing from or in connection with collaborations with other companies. Our success in acquiring business or assets or in partnering with collaborators may depend on our history or perceived capability of successful product development. Even if we are successful in our efforts to acquire businesses or assets, in-license intellectual property rights or establish collaborations, we may not be successful in developing such product candidates or technologies or able to maintain such collaborations if, for example, development or approval of a product candidate is delayed or sales of an approved product are disappointing.

Our reliance on a central team consisting of a limited number of employees and third parties who provide various administrative, research and development, and other services across our organization presents operational challenges that may adversely affect our business.

As of December 31, 2025, we had 14 full-time employees, upon whom we rely for various administrative, research and development, business development and other support services shared among our subsidiaries. The size of our centralized team may limit our ability to devote adequate personnel, time, and resources to support the operations of all of our subsidiaries, including their research and development activities, the management of financial, accounting, and reporting matters, and the oversight of our third-party vendors and partners. If our centralized team or our third-party vendors and partners performing such functions fail to provide adequate administrative, research and development, or other services across our entire organization, our business, financial condition, and results of operations could be harmed.

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Our employees and independent contractors, including principal investigators, CROs, consultants and vendors, may engage in misconduct or other improper activities, including noncompliance with regulatory standards and requirements, which could have a material adverse effect on our business.

Misconduct by our employees and independent contractors, including principal investigators, CROs, consultants, vendors and any third parties we may engage in connection with research, development, regulatory, manufacturing, quality assurance and other pharmaceutical functions and commercialization, could include intentional, reckless or negligent conduct or unauthorized activities that violate various laws, including: (i) the laws and regulations of the FDA, and other similar regulatory authorities, including those laws that require the reporting of true, complete and accurate information to such authorities; (ii) manufacturing standards; (iii) data privacy, security, fraud and abuse and other healthcare laws and regulations; or (iv) laws that require the reporting of true, complete and accurate financial information and data. Sales, marketing and business arrangements in the healthcare industry are subject to extensive laws and regulations intended to prevent fraud, misconduct, kickbacks, self-dealing and other abusive practices. These laws and regulations may restrict or prohibit a wide range of pricing, discounting, marketing and promotion, sales commission, customer incentive programs, and other business arrangements. Activities such as the improper use or misrepresentation of information obtained in the course of clinical trials, creation of fraudulent data in preclinical studies or clinical trials, or illegal misappropriation of drug product, could also result in regulatory sanctions and cause serious harm to our reputation. It is not always possible to identify and deter misconduct by employees and other third parties, and the precautions we take to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to comply with such laws or regulations. Additionally, we are subject to the risk that a person or government agency could allege such fraud or other misconduct, even if none occurred. If any such actions are instituted against us or them and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business and results of operations, including the imposition of significant civil, criminal, and administrative penalties, damages, monetary fines, possible exclusion from participation in Medicare, Medicaid, other U.S. federal healthcare programs or healthcare programs in other jurisdictions, individual imprisonment, other sanctions, contractual damages, reputational harm, diminished profits and future earnings, and curtailment of our operations.

We currently rely and will rely on third parties for the manufacture of drug substance and drug product for our preclinical studies and clinical trials and, if we continue to progress the development of our product candidates, expect to continue to do so for commercialization of any product candidates that we may develop that are approved for marketing. Our reliance on third parties may increase the risk that we will not have sufficient quantities of such drug substance, product candidates, or any products that we may develop and commercialize, or that such supply will not be available to us at an acceptable cost, which could delay, prevent, or impair our development or commercialization efforts.

We have limited personnel with experience in manufacturing, and we do not own facilities for manufacturing RLYB116 or any other product candidate. Instead, we rely on and expect to continue to rely on contract manufacturers for the supply of cGMP-drug substance and drug product of RLYB116 and any other product candidates we develop and, in the future, for commercial supply. Reliance on third parties may expose us to more risk than if we were to manufacture our product candidates ourselves.

We may be unable to establish necessary supply agreements with third-party manufacturers or to do so on acceptable terms. Even if we are able to establish agreements with third-party manufacturers, reliance on third-party manufacturers entails additional risks, including:

▪the possible breach of the manufacturing agreement by the third-party;

▪the possible termination or nonrenewal of the agreement by the third-party at a time that is costly or inconvenient for us;

▪reliance on the third-party for regulatory compliance, quality assurance, safety, and pharmacovigilance and related reporting; and

▪the possible inability of third-party suppliers to supply and/or transport materials, components and products to us in a timely manner as a result of disruptions to the global supply chain.

Third-party manufacturers may fail to comply with cGMP regulations or similar regulatory requirements outside the United States. Any failure to follow cGMP or other regulatory requirements or delay, interruption or other

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issues that arise in the manufacture, fill-finish, packaging, or storage of our product candidates as a result of a failure of our facilities or the facilities or operations of third parties to comply with regulatory requirements or pass any regulatory authority inspection could significantly impair our ability to develop and commercialize our product candidates, including leading to significant delays in the availability of our product candidates for our clinical trials or the termination of or suspension of a clinical trial, or the delay or prevention of a filing or approval of marketing applications for our product candidates. Moreover, our failure, or the failure of our third-party manufacturers, to comply with applicable regulations could result in sanctions being imposed on us, including fines, injunctions, civil penalties, delays, suspension or withdrawal of approvals, license revocations, seizures or recalls of product candidates or medicines, operating restrictions, and criminal prosecutions, any of which could significantly and adversely affect supplies of our medicines and harm our business, financial condition, results of operations, and prospects.

While we provide oversight of manufacturing activities, we have limited ability to control the execution of manufacturing activities by, and are or will be dependent on, our CMOs for compliance with cGMP requirements for the manufacture of our product candidates by our CMOs. As a result, we are subject to the risk that our product candidates may have manufacturing defects or fail to comply with regulatory requirements, which we have limited ability to prevent. CMOs may also have competing obligations that prevent them from manufacturing our product candidates in a timely manner. If a CMO cannot successfully manufacture drug substance that conforms to our specifications and the regulatory requirements, we will not be able to secure or maintain regulatory approval for the use of our product candidates in clinical trials, or for commercial distribution of our product candidates, if approved. In addition, we have limited control over the ability of our CMOs to maintain adequate quality control, quality assurance, and qualified personnel, and we were not involved in developing our CMOs’ policies and procedures.

The facilities and processes used to manufacture our product candidates are subject to inspection by the FDA, EMA and other comparable foreign authorities. If the FDA, EMA or other comparable foreign regulatory authority finds deficiencies with or does not approve these facilities for the manufacture of our product candidates or if it withdraws any such approval or finds deficiencies in the future, we may need to find alternative manufacturing facilities or conduct additional studies, which would delay our development program and significantly impact our ability to develop, obtain regulatory approval for, or commercialize our product candidates, if approved. Furthermore, CMOs may breach existing agreements they have with us because of factors beyond our control. They may also terminate or refuse to renew their agreement at a time that is costly or otherwise inconvenient for us. Finding new CMOs or third-party suppliers involves additional cost and requires our management’s time and focus. In addition, there is typically a transition period when a new CMO commences work.

Any significant delay in the supply of our product candidates or the raw materials needed to produce our product candidates, could considerably delay conducting our clinical trials and potential regulatory approval of our product candidates. If we were unable to find an adequate CMO or another acceptable solution in time, our clinical trials could be delayed, or our commercial activities could be harmed.

RLYB US Equity

RLYB · 10-K · period ended 2025-12-31

Item 1A. Risk Factors.

RLYB US Equity☆

RLYB · 10-K · period ended 2025-12-31

Item 1A. Risk Factors.

RLYB US Equity