Item 1A. Risk Factors

In conducting our business, we face many risks that may interfere with our business objectives. Some of these risks could materially and adversely affect our business, financial condition and results of operations. In particular, we are subject to various risks resulting from inherent unknowns and uncertainties in the drug development process, as well as changing economic, political, industry, regulatory, business and financial conditions. The risks and uncertainties described below are not the only ones we face.

You should carefully consider the following factors and other information in this Annual Report before you decide to invest in our common stock. If any of the negative events referred to below occur, our business, financial condition and results of operations could suffer. In any such case, the trading price of our common stock could decline, and you may lose all or part of your investment.

Risk Factor Summary

The following is a summary of certain important factors that may make an investment in our company speculative or risky. You should carefully consider the fuller risk factor disclosure set forth in this Annual Report, in addition to the other information herein, including the section of this report titled “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and our financial statements and related notes.

We have a limited operating history, have incurred significant losses since our inception and anticipate that we will continue to incur significant losses for the foreseeable future.

We have never generated any revenue from product sales, have generated only limited revenue since inception, and may never be profitable.

The coronavirus pandemic has caused interruptions and delays of our business plan for the past two years and may continue to have a significant adverse effect on our business.

We expect that we will need to raise additional capital, which may not be available on acceptable terms, or at all.

The clinical studies involving our initial COVID-19 vaccine candidate, ARCT-021, have concluded dosing and we might not proceed with further development of ARCT-021. If we cannot quickly develop and achieve approval of a COVID-19 vaccine candidate, we may be unable to effectively market and sell a COVID-19 vaccine.

Even if we successfully develop a COVID-19 vaccine, we may not be able to sell it profitably, or it may not be accepted in the market.

Our next generation COVID-19 vaccine candidate, ARCT-154, does not have marketing approval and may never achieve marketing approval. Regulators may refuse to approve ARCT-154 as a booster shot because we have not yet received approval for ARCT-154 as a primary vaccination series for COVID-19.

There is significant competition in the development of a vaccine against COVID-19, some competitors’ vaccines are already widely accepted in the market, and many of our competitors have substantially greater financial, scientific and other resources than we have.

If we are unable to generate successful results from preclinical and clinical studies of our product candidates, or experience significant delays in doing so, our business may be materially harmed..

Our platform focuses on nucleic acid technology, and mRNA drug products in particular, which are relatively new and any adverse results from nucleic acid or mRNA technologies in the industry could significantly impact our ability to develop and commercialize marketable products..

We may not be successful in our efforts to identify or discover potential product candidates.

If clinical trials of our product candidates fail to demonstrate safety and efficacy to the satisfaction of regulatory authorities or do not otherwise produce positive results, we may incur additional costs or experience delays in completing, or ultimately be unable to complete, the development and commercialization of our product candidates.

We may find it difficult to identify and enroll patients in our clinical studies, and the limited number of patients who have the diseases for which certain of our product candidates are being studied could delay or prevent clinical studies of certain of our product candidates.

If any of our product candidates cause undesirable side effects or have other properties impacting safety, their regulatory approval could be prevented, delayed or limited.

Even if we complete the necessary preclinical studies and clinical trials, we cannot predict whether or when we will obtain regulatory approval to commercialize a product candidateand we cannot, therefore, predict the timing of any revenue from a future product.

Even if we obtain regulatory approval for a product candidate, we will still face extensive regulatory requirements and our products may face future development and regulatory difficulties.

We may use our financial and human resources to pursue a particular research program or product candidate and fail to capitalize on programs or product candidates that may be more profitable or for which there is a greater likelihood of success.

If we fail to comply with environmental, health and safety laws and regulations, we could become subject to fines or penalties or incur costs that could have a material adverse effect on the success of our business.

Manufacturing issues may arise that could increase product and regulatory approval costs or delay or hinder commercialization.

If our alliance partners do not perform in accordance with the terms of our agreements, our potential to generate future revenue from these programs would be significantly reduced and our business would be materially and adversely harmed.

We face significant competition from other biotechnology and pharmaceutical companies and our operating results will suffer if we fail to compete effectively.

The commercial success of our product candidates will depend upon the acceptance of these product candidates by the medical community, including physicians, patients and healthcare payors.

If we are unable to establish cost-effective sales and marketing capabilities or enter into agreements with third parties to market and sell our product candidates, we may be unable to generate any revenues.

If we obtain approval to commercialize any approved products outside of the United States, a variety of risks associated with international operations could materially adversely affect our business.

If our strategic alliances are unsuccessful or are terminated, we may be unable to commercialize certain product candidates and generate revenues.

If the outside contractors we rely on to conduct some aspects of our compound formulation, research and studies do not perform satisfactorily and meet deadlines, development of our product candidates could be delayed or precluded.

If the contract manufacturers we rely on to produce the supply of our preclinical and clinical product candidates, including materials for the manufacture of our product candidates, do not timely deliver adequate quantities of quality materials, development and commercialization of our product candidates would be hindered.

Any disruption in the supply chain of raw materials for, or in the manufacturing capacity and timing for the manufacture of drug substance or drug product for, our product candidates may cause a delay in developing and commercializing these product candidates and limit the revenues that we could generate.

If the contract research organizations and clinical trial sites we rely on to conduct, supervise and monitor our clinical trials perform in an unsatisfactory manner, it may harm our business.

If we are unable to obtain or protect intellectual property rights related to our future products and product candidates, we may not be able to compete effectively in our markets.

Claims that we infringe the intellectual property rights of others, especially in the crowded and competitive field of mRNA patents, may prevent or delay our development and commercialization efforts.

If we fail to obtain licenses to necessary intellectual property or do not comply with our obligations in license agreements, we could lose important rights.

We may be involved in lawsuits to protect or enforce our patents or the patents of our licensees, which could be expensive, time consuming and unsuccessful.

RISKS RELATED TO OUR FINANCIAL CONDITION AND NEED FOR ADDITIONAL CAPITAL

We have a limited operating history, have incurred significant losses since our inception and anticipate that we will continue to incur significant losses for the foreseeable future.

We are a global clinical-stage messenger RNA medicines company with a limited operating history. Since inception, our operations have been primarily limited to acquiring and licensing intellectual property rights, developing our product platform, undertaking basic research and conducting studies for our initial product development programs. We have not yet obtained regulatory approval for any product candidates. Consequently, any predictions about our future success or viability, or any evaluation of our business and prospects, is difficult and may not be accurate.

We have incurred losses in each year since our inception. Our net losses were $203.7 million and $72.1 million for the years ended December 31, 2021 and 2020, respectively. As of December 31, 2021, we had an accumulated deficit of $347.5 million.

We have devoted most of our financial resources to research and development, including our preclinical and clinical development activities. To date, we have funded our operations primarily through upfront payments, research funding and milestone payments from strategic alliances and collaborations, and through the sale of equity and convertible securities. We expect to continue to incur substantial and increased expenses, losses and negative cash flows as we expand our development activities and advance our programs. If our product candidates are not successfully developed or commercialized, including because of a lack of capital, or if we do not generate enough revenue following marketing approval, we will not achieve profitability and our business may fail. Even if we or our strategic alliance partners successfully obtain regulatory approval to market a product candidate, our revenues will also depend upon the size of any markets in which our product candidates have received market approval and our ability to achieve sufficient market acceptance and adequate market share for our products.

We expect to continue to incur significant expenses and increasing operating losses for the foreseeable future. The net losses we incur may fluctuate significantly from quarter to quarter. We anticipate that our expenses will increase substantially if and as we:

• seek to identify additional targets and product candidates;

• acquire or in-license other products and technologies;

• advance product candidates into and through clinical trials;

• maintain, expand and protect our intellectual property portfolio;

We have never generated any revenue from product sales, have generated only limited revenue since inception, and may never be profitable.

Our ability to generate revenue and achieve profitability depends on our ability, alone or with strategic alliance partners, to successfully complete the development of, obtain the necessary regulatory approvals for and commercialize our product candidates. Our ability to generate revenues from product sales depends heavily on our success in:

• completing our research and development of product candidates;

• maintaining, protecting and expanding our intellectual property portfolio; and

• attracting, hiring and retaining qualified personnel.

Because of the numerous risks and uncertainties associated with pharmaceutical product development, we are unable to predict reliably the timing or amount of increased expenses and when we will be able to achieve or maintain profitability, if ever. In addition, our expenses could increase beyond expectations if we are required by the FDA, or other foreign regulatory agencies to perform studies and trials in addition to those that we currently anticipate.

Even if one or more of the product candidates that we independently develop is approved for commercial sale, we anticipate incurring significant costs associated with commercializing any approved product. Even if we are able to generate revenues from the sale of any approved products, we may not become profitable and may need to obtain additional funding to continue operations.

The coronavirus pandemic has caused interruptions and delays of our business plan for the past two years and may continue to have a significant adverse effect on our business.

In December 2019, a strain of coronavirus, COVID-19, was reported to have surfaced in Wuhan, China, and on March 12, 2020, the World Health Organization declared COVID-19 to be a pandemic. In an effort to contain and mitigate the spread of COVID-19, many countries, including the United States, Canada and China, have imposed unprecedented restrictions on travel, quarantines, and other public health safety measures. This pandemic has adversely affected our operations in many ways, including:

• delayed enrollment and difficulty retaining patients in clinical trials;

• suspensions and delays in completion of clinical trials;

• slower expected development timelines for our product candidates.

The extent to which the pandemic will continue to adversely affect our business and the global economy and its full impact will depend on future developments, which are highly uncertain and cannot be reliably predicted.

We expect that we will need to raise additional capital, which may not be available on acceptable terms, or at all.

Developing pharmaceutical products, including conducting studies and clinical trials, is extremely expensive. We expect our research and development expenses to substantially increase in connection with our ongoing activities, particularly as we advance our product candidates towards and through clinical trials. We may need to raise additional capital to support our operations and such funding may not be available to us on acceptable terms, or at all. As of December 31, 2021, we had unrestricted cash and cash equivalents of $370.5 million, which we expect should be sufficient to fund currently planned operations for at least one year. But if our plans change or we face unexpected circumstances, our capital resources may be depleted more rapidly than we currently anticipate. For example, our clinical trials may encounter technical, regulatory or other difficulties. Additionally, our strategic alliance collaborators may elect not to pursue the development and commercialization of any of our product

candidates that are subject to their respective strategic alliance agreements with us. Any of these events would increase our development costs more than we expect. In order to support our long-term plans, we will need to raise additional capital or otherwise obtain funding through additional strategic alliances if we choose to initiate preclinical or clinical trials for product candidates that are not currently subject to a collaboration. In any event, we will require additional capital to obtain regulatory approval for, and to commercialize, future product candidates.

A significant portion of our current cash balance is expected to be utilized during 2022 to fund our continued preclinical and clinical development activities for our pipeline, including manufacturing activities to support such development activities and corresponding manufacturing activities and resources to preparing filings with regulatory authorities.

Any additional Phase 3 trial of our LUNAR-COV19 vaccine candidate, if any, may need to be primarily or exclusively funded through our cash reserves. If we achieve EUA approval to market our LUNAR-COV19 vaccine candidate, we will need to raise additional funds through equity transactions, additional debt or prepayments from potential customers, among other options, to fund commercialization of LUNAR-COV19.

Any additional fundraising efforts may divert our management from our day-to-day activities, which may delay and hinder our ability to develop and commercialize future product candidates. We may be unable to raise sufficient amounts of additional capital when needed and on acceptable terms, which could require us to:

We are exposed to interest rate risk, including under our loan agreements.

We are exposed to market risk from changes in interest rates. Exposure to interest rate risk results from our debt obligations, including the loan agreement entered into on October 12, 2018 by our wholly-owned subsidiary, Arcturus Therapeutics, Inc., with Western Alliance Bank (the “Western Loan Agreement”). The Western Loan Agreement bears a variable interest rate of 1.25% above the prime rate published by the western edition of the Wall Street Journal. As of December 31, 2021, we had $15.2 million outstanding under the Western Loan Agreement. If we were to experience a 10% adverse change in the prime rate referenced above, the annual effect such change would have on our statement of operations, based on the amount we had outstanding as of December 31, 2021, under the Western Loan Agreement, would be negligible.

Additionally, on November 7, 2020, we entered into a Manufacturing Support Agreement with the EDB. Pursuant to the Manufacturing Support Agreement, the Economic Development Board of the Republic of Singapore (the “EDB”) agreed to make a term loan (the “Singapore Loan”) of up to S$62.1 million, subject to the satisfaction of customary deliveries, to support the manufacture of the LUNAR-COV19 vaccine candidate (ARCT-021). The Singapore Loan accrues interest at a rate of 4.5% per annum calculated on a daily basis. We elected to borrow the full amount available under the Support Agreement of S$62.1 million, or US$46.6 million, as a result of applicable exchange rates, on January 29, 2021.

Our indebtedness could materially and adversely affect our business, financial condition and results of operations.

Agreements with our lenders, including with Western Alliance Bank, create several limitations on us, including but not limited to:

Our ability to comply with these covenants in future periods will depend on our financial and operating performance, which in turn will be subject to economic conditions and to financial, market and competitive factors, many of which are beyond our control. Any of these factors or others described in the Western Loan Agreement could materially and adversely affect our business, financial condition and results of operations.

Our debt contains customary default clauses, a breach of which may result in acceleration of the repayment of some or all of this debt.

The Western Loan Agreement contains customary default clauses. In the event we were to default on our obligations under our debt and were unable to cure or obtain a waiver of such default, the repayment of our debt may be accelerated. If such acceleration were to occur, we would be required to promptly secure alternative sources of equity or debt financing to be able to repay the debt. Alternative financing may not be available on terms satisfactory to us, or at all. New debt financing may require the cooperation and agreement of our existing lenders. If acceptable alternative financing were unavailable, we would have to consider alternatives to fund the repayment of the debt, which could materially and adversely affect our business, financial condition and results of operations.

RISKS RELATED TO THE DEVELOPMENT AND COMMERCIALIZATION OF PRODUCT CANDIDATES

The planned multinational Phase 3 vaccine trial against COVID-19 with a global entity, for which our initial COVID-19 vaccine candidate, ARCT-021, was selected, has taken longer than anticipated to proceed with ARCT-021 and might not ever proceed with ARCT-021. We have completed dosing in the studies involving ARCT-021 and do not have current plans to sponsor additional development studies of ARCT-021 unless and until the global entity determines to proceed with ARCT-021 in the multinational Phase 3 vaccine trial. We have developed next generation COVID-19 candidates, namely ARCT-154, that we have progressed further in clinical development, but advancing these next generation candidates has taken significant time and resources. Further, the existence of several other COVID-19 vaccines that have achieved approval and widespread global adoption makes it significantly more challenging for us to run clinical trials on, and to achieve marketing approvals (including emergency use authorizations) for, any of our COVID-19 vaccine candidates. Data from our ongoing Phase 1/2/3 clinical trials of ARCT-154 in Vietnam may not provide sufficient evidence to the Vietnamese regulatory authorities, the US FDA or regulatory authorities in other jurisdictions that it is sufficiently safe and effective to achieve any marketing approval (including any emergency use authorization) or to have a plausible clinical path to an approval.

Clinical trial results are inherently uncertain, and a significant portion of our potential success and business prospects currently depend on our COVID-19 vaccine program. If we cannot demonstrate sufficient safety and efficacy and complete these clinical trials on a timely basis, we likely will have missed a substantial market opportunity for COVID-19 vaccines, after dedicating significant efforts and financial resources to this program.

Even if we successfully develop a COVID-19 vaccine, we may not be able to sell it profitably.

If the prevalence of COVID-19 continues to decline and more people get vaccinated, the potential market opportunity is likely shrinking for any vaccine, including any booster we may be able to develop. As further COVID-19 vaccines are approved, production of existing COVID-19 vaccines improves and the COVID-19 impact transitions from pandemic to endemic stage, there may be downward pressure on prices. Although many developing countries have large populations for whom COVID-19 vaccines have not been available, it may not be easy or profitable to get vaccines to those populations. The price at which COVID-19 vaccines could be sold to developing countries is not likely to be as high as prices paid by wealthier countries eager to get vaccines when first available. Therefore, even if we can get through the extremely costly, long and risky process of developing and obtaining

regulatory approval to market a vaccine, it may not be commercially successful. This failure could be due to reduced demand for COVID-19 vaccines, lower prices, distribution problems, competitors’ products or many other reasons. Our manufacturing process for our current COVID-19 vaccine candidates include a step for lyophilization to enhance the stability of the vaccine product. The additional step of lyophilization adds time and costs to the overall production output, which could adversely impact the production volumes and profitability of our COVID-19 vaccines if approval to market a vaccine is achieved.

In the coming months, we expect to receive important clinical data on ARCT-154, and the data may not support a regulatory approval (including emergency use authorization). Regulatory authorities, including the FDA, may deem the data we expect to collect from studies outside of the United States to be inadequate or unacceptable. Regulatory authorities, including the FDA, may also determine to foreclose or make more difficult a path to emergency use authorization. If key regulatory authorities, such as the FDA, determine that our data is inadequate or unacceptable, or make the path to regulatory approval more difficult, we may not be able to achieve regulatory approval (including EUA) and any additional study may prove too costly for us to conduct without a strategic partner

Though we have exciting preliminary clinical data on ARCT-154 as a booster series, we do not have approval for ARCT-154 (or any vaccine candidate) as a primary vaccination series anywhere in the world. We have completed EUA submission in Vietnam for ARCT-154 on the primary vaccination series. But we cannot provide any assurance that the Vietnam Ministry of Health will approve the EUA, or that any other country will provide an EUA or other approval on the primary vaccination series. We are not aware of the FDA authorizing use of any COVID-19 vaccine or any other vaccine as a booster shot unless the FDA has previously authorized that vaccine to be used as a primary vaccine series. We cannot provide any assurance that the FDA would be willing in the future to approve a COVID-19 vaccine as a booster shot without prior approval as a primary vaccine series. The FDA and regulators in other jurisdictions may still refuse to approve ARCT-154 or any other vaccine as a booster even if our COVID-19 vaccine candidate demonstrates safety and efficacy. In such event, we will not be able to sell a COVID-19 vaccine and our financial condition could be substantially harmed.

Even if one of our vaccine candidates is approved for sale, it may not be accepted in the market, despite limitations on the effectiveness of some approved vaccines.

Notwithstanding the ongoing rollout of vaccines, it will still take a substantial amount of time to produce, distribute and administer the vaccines worldwide and, as a result, to achieve broad protection of the global population. It is also still unclear if the vaccines will enable adequate long-term protection, as (i) many vaccinated individuals have become ill due to “breakthrough infections” and have transmitted the virus to many others, (ii) there are millions of individuals who refuse to be vaccinated or who cannot be vaccinated due to pre-existing conditions, (iii) it is unclear how long the vaccine protection will last, and (iv) genetic mutations or variants of the virus already have had, and are expected to continue to have, an adverse impact on the efficacy of available vaccines. If we cannot develop and commercialize a vaccine that adequately addresses some of these shortcomings of vaccines currently on the market, we cannot expect to have commercial success.

A large number of biopharmaceutical companies, academic institutions and other organizations currently have programs to develop COVID-19 vaccine candidates and many are further along in development of their vaccine candidates. Pfizer, Moderna and Johnson & Johnson have received full approvals or emergency use authorization from the FDA and many other health regulatory authorities throughout the world, and other biopharmaceutical companies have received approvals or authorizations from many health regulatory authorities other than the FDA, for their COVID-19 vaccines and have already commercialized them on a large scale and have vaccinated billions of people around the world.

Despite funding provided to us to date, we are already at a significant competitive disadvantage to those companies with vaccines on the market, as well as many other competitors pursuing vaccine candidates. Many other

competitors have significantly greater product candidate development, manufacturing and marketing resources than we do. Larger pharmaceutical and biotechnology companies have extensive experience in clinical testing and obtaining regulatory approval for their products, and may have the resources to heavily invest to accelerate discovery and development of their vaccine candidates. Our business could be further materially and adversely affected by our competitors commercialization of their vaccines before we complete development and seek approval for our vaccine candidate; if they develop and commercialize one or more COVID-19 vaccines that are safer, more effective against multiple variants, have fewer or less severe side effects, have broader market acceptance, are more convenient or are less expensive than any vaccine candidate that we may develop. Furthermore, if any competitors are successful in producing a more efficacious vaccine or other treatment for COVID-19, or if any competitors are able to manufacture and distribute any such vaccines or treatments with greater efficiency, there may be a diversion of potential governmental and other funding away from us and toward such other parties.

If we are unable to generate successful results from preclinical and clinical studies of our product candidates, or experience significant delays in doing so, our business may be materially harmed.

We have no products approved for commercial marketing and all of our product candidates are in preclinical or clinical development. Before obtaining regulatory approval for the commercial distribution of our product candidates, we or an existing or future collaborator must conduct extensive preclinical studies and clinical trials to demonstrate the safety and efficacy of our product candidates.

The success of our product candidates will depend on several factors, including the following:

• receipt of marketing approvals from applicable regulatory authorities;

If we do not achieve one or more of these factors in a timely manner or at all, we could experience significant delays or an inability to successfully complete the development or commercialization of our product candidates, which would materially harm our business.

We have concentrated our therapeutic product research and development efforts on nucleic acid technology, and mRNA in particular, and our future success depends on the successful development and acceptance of this technology for drug products. The development and commercialization of drug products based on nucleic acid technologies, including mRNA, are relatively new. The scientific evidence to support the feasibility of developing product candidates based on these discoveries is both preliminary and limited. If nucleic acid or mRNA approaches to drug products encounter setbacks based on the safety, efficacy, distribution, costs or other factors, it will significantly hurt our prospects and the value of our common stock.

Our focus on nucleic acid technology for developing drugs as opposed to more proven technologies for drug development increases the risks associated with the ownership of our common stock. If we are not successful in developing any product candidates using nucleic acid technology, we may be required to change the scope and direction of our product development activities. In that case, we may not be able to identify and implement successfully an alternative product development strategy.

We may not be successful in our efforts to identify or discover potential product candidates.

The success of our business depends primarily upon our ability to identify, develop and commercialize messenger RNA medicines. Our research programs may initially show promise in identifying potential product candidates, yet fail to yield product candidates for clinical development for a number of reasons, including:

If any of these events occur, we may be forced to abandon our development efforts for a program or programs, which would have a material adverse effect on our business and could potentially cause us to cease operations. Research programs to identify new product candidates require substantial technical, financial and human resources. We may focus our efforts and resources on potential programs or product candidates that ultimately prove to be unsuccessful.

Before obtaining marketing approval from regulatory authorities for the sale of product candidates, we or our strategic alliance partners must conduct extensive clinical trials to demonstrate the safety and efficacy of the product candidates in humans. Clinical trials are expensive, difficult to design and implement, can take many years to complete and are uncertain as to the outcome. A failure of one or more clinical trials can occur at any stage of testing. The outcome of preclinical studies and early clinical trials may not be predictive of the success of later clinical trials, and interim results of a clinical trial do not necessarily predict final results. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval for their products. Furthermore, even if prior animal studies have demonstrated the potential safety and efficacy of our product candidates, there can be no guarantee that such results will be reproducible in preclinical studies and clinical trials involving human subjects.

Events which may result in a delay or unsuccessful completion of clinical development include:

• delays in recruiting suitable patients to participate in a trial;

• clinical sites dropping out of a trial to the detriment of enrollment;

• time required to add new clinical sites; or

If we or our strategic alliance partners are required to conduct additional clinical trials or other testing of any product candidates beyond those that are currently contemplated, are unable to successfully complete clinical trials of any such product candidates or other testing, or if the results of these trials or tests are not positive, are only modestly positive or if there are safety concerns, we or our strategic alliance partners may:

• be delayed in obtaining marketing approval for our future product candidates;

• not obtain marketing approval at all;

• be subject to additional post-marketing testing requirements; or

• have the product removed from the market after obtaining marketing approval.

Our product development costs will also increase if we experience delays in testing or marketing approvals. We face risks that clinical trials may not begin as planned, may need to be restructured or may not be completed on schedule, or at all. Significant clinical trial delays also could shorten any periods during which we may have the exclusive right to commercialize our product candidates or could allow our competitors to bring products to market before we do, which would impair our ability to successfully commercialize our product candidates. Any inability to timely and successfully complete preclinical and clinical development, whether independently or with our strategic alliance partners, could result in additional costs to us or impair our ability to generate revenues from product sales, regulatory and commercialization milestones and royalties.

Identifying and qualifying patients to participate in clinical studies of our product candidates is critical to our success. The timing of our clinical studies depends in part on the speed at which we can recruit patients to participate in testing our product candidates, and we may experience delays in our clinical studies if we encounter difficulties in enrollment.

Because of the aggressive roll-out of COVID-19 vaccines, we have found it challenging to enroll sufficient subjects in our LUNAR-COV19 trials who have not otherwise received a vaccine. Additionally, competing COVID-19 vaccine clinical trials make it more difficult to enroll subjects in our LUNAR-COV19 trials. We may also find it more difficult to identify subjects willing to participate in our studies. The regulatory authorities of certain countries have restricted placebo-controlled trials in studies for COVID-19 vaccine candidates. Such restrictions may make it more difficult to seek approval to proceed with certain clinical trial designs, and for the ultimate likelihood of approval of such candidates.

In addition, certain conditions for which we plan to evaluate our current product candidates are rare genetic diseases, and have limited patient pools from which to draw for clinical studies. For example, we estimate that approximately 8,000 patients in the developed world suffer from late-onset OTC deficiency, for which LUNAR-OTC is being studied. In addition to the rarity of these diseases, the eligibility criteria of our clinical studies will further limit the pool of available study participants as we will require patients to have specific characteristics that we can measure or to assure their disease is either severe enough or not too advanced to include them in a study. The process of finding and diagnosing patients may prove costly, especially since the rare diseases we are studying are commonly underdiagnosed. We also may not be able to identify, recruit, and enroll a sufficient number of appropriate patients to complete our clinical studies because of demographic criteria for prospective patients, the perceived risks and benefits of the product candidate under study, the proximity and availability of clinical study sites for prospective patients, and the patient referral practices of physicians. The availability and efficacy of competing therapies and clinical studies can also adversely impact enrollment.

If we are unable to promptly enroll an adequate number of patients in our studies for the foregoing or other reasons, the timeline for conducting studies and obtaining regulatory approval of potential products may be delayed,

the commercial prospects of our product candidates will be harmed, and our ability to generate product revenue from any of these product candidates could be delayed or prevented. Furthermore, many of the factors that cause, or lead to, a delay in the commencement or completion of clinical studies may also ultimately lead to the denial of regulatory approval of our product candidates. Delays in achieving approval to conduct and in completing our clinical studies will increase our costs, slow down our product candidate development and approval process, and jeopardize our ability to commence product sales and generate revenue. Any of these occurrences may harm our business, financial condition, and prospects significantly.

If any of our product candidates cause undesirable side effects or have other properties impacting safety, their regulatory approval could be prevented, delayed or limited.

Undesirable side effects caused by our product candidates could cause us or regulatory authorities to interrupt, delay or halt clinical trials and could result in a more restrictive label or the delay or denial of regulatory approval by the FDA or other regulatory authorities. It is likely that there will be side effects associated with use of our product candidates. If results of our trials reveal a high and unacceptable severity and prevalence of side effects, our trials could be suspended or terminated and the FDA or comparable foreign regulatory authorities could order us to cease further development of, or deny approval of, our product candidates for any or all targeted indications. Such side effects could also affect patient recruitment, the ability of enrolled patients to complete the trial or result in potential product liability claims. Any of these occurrences may materially and adversely affect our reputation and financial condition.

Further, clinical trials by their nature test product candidates in only samples of the potential patient populations. With a limited number of patients and limited duration of exposure in such trials, rare and severe side effects of our product candidates may not be uncovered until a significantly larger number of patients are exposed to the product candidate.

If any of our product candidates receives marketing approval, and causes serious, unexpected, or undesired side effects, a number of potentially significant negative consequences could result after we begin commercialization, including:

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

• our reputation may suffer.

Any of these events could prevent us or our partners from achieving or maintaining market acceptance of the affected product and could substantially increase the costs of commercializing our future products and impair our ability to generate revenues from the commercialization of these products either by us or by our strategic alliance partners.

Even if we complete the necessary preclinical studies and clinical trials, we cannot predict whether or when we will obtain regulatory approval to commercialize a product candidate and we cannot, therefore, predict the timing of any revenue from a future product.

The extent and timing of any product revenue is highly unpredictable because regulatory authorities may not complete their review processes in a timely manner, or we may not be able to obtain regulatory approval for many reasons including:

Additional delays may result if an FDA advisory committee recommends restrictions on approval or recommends non-approval. In addition, we or our strategic alliance partners may experience delays or rejections based upon additional government regulation from future legislation or administrative action, or changes in regulatory agency policy during the period of product development, clinical trials and the review process.

Even if we obtain regulatory approval for a product candidate, we will still face extensive regulatory requirements and our products may face future development and regulatory difficulties.

Even if we obtain regulatory approval in the United States, the FDA may still impose significant restrictions on the indicated uses or marketing of our product candidates, or impose ongoing requirements for potentially costly post-approval studies or post-market surveillance. The FDA may also require a risk evaluation and mitigation strategy as a condition of approval of our product candidates, which could include requirements for a medication guide, physician communication plans or additional elements to ensure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. Additionally, the manufacturing processes, packaging, distribution, adverse event reporting, labeling, advertising, promotion, and recordkeeping for the product will be subject to extensive and ongoing FDA regulatory requirements, in addition to other potentially applicable federal and state laws. These requirements include monitoring and reporting of adverse events and other post-marketing information and reports, registration, as well as continued compliance with current good manufacturing practice, or cGMP, regulations. The holder of an approved NDA must also submit new or supplemental applications and obtain FDA approval for certain changes to the approved product, product labeling or manufacturing process. If we or a regulatory agency discovers previously unknown problems with a product such as adverse events of unanticipated severity or frequency, or problems with the facility where the product is manufactured, a regulatory agency may impose restrictions relative to that product or the manufacturing facility, including requiring recall or withdrawal of the product from the market or suspension of manufacturing.

If we or our strategic partners fail to comply with applicable regulatory requirements following approval of any of our product candidates, a regulatory agency may:

• issue a warning letter asserting that we are in violation of the law;

• seek an injunction or impose civil or criminal penalties or monetary fines;

• suspend or withdraw regulatory approval;

• suspend any ongoing clinical trials;

• refuse to approve a pending NDA or supplements to an NDA submitted by us;

• seize product or require a product recall; or

Any government investigation of alleged violations of law could require us to expend significant time and resources in response and could generate negative publicity. The occurrence of any event or penalty described above may inhibit our ability to commercialize our future products, if approved, and generate revenues.

As a result of our limited financial and human resources, we will have to make strategic decisions as to which targets and product candidates to pursue and may forego or delay pursuit of opportunities with other product candidates or for other indications that later prove to have greater commercial potential. Our resource allocation decisions may cause us to fail to capitalize on viable commercial products or profitable market opportunities. For example, we have allocated significant resources to the testing and development of our LUNAR-COV19 and LUNAR-OTC vaccine candidates, but competitors Pfizer, Moderna and Johnson & Johnson have already received full approvals or emergency use authorization from the FDA for their COVID-19 vaccines, which have achieved regulatory approval and widespread global adoption. Although we are seeking to develop a next-generation COVID-19 vaccine candidate, our spending on research and development programs and product candidates for COVID-19 may prove to have been unwise. If we do not accurately evaluate the commercial potential or target market for a particular product candidate, we may relinquish valuable rights to that product candidate through strategic alliance, licensing or other royalty arrangements in cases in which it would have been more advantageous for us to retain sole development and commercialization rights to such product candidate, or we may allocate internal resources to a product candidate in a therapeutic area in which it would have been more advantageous to enter into a partnering arrangement.

We are subject to numerous environmental, health and safety laws and regulations, including those governing laboratory procedures and the handling, use, storage, treatment and disposal of hazardous materials and wastes. Our operations involve the use of hazardous and flammable materials, including chemicals and biological materials. Our operations also produce hazardous waste products. We generally contract with third parties for the disposal of these materials and wastes. We cannot eliminate the risk of contamination or injury from these materials. In the event of contamination or injury resulting from our use of hazardous materials, we could be held liable for any resulting damages, and any liability could exceed applicable insurance coverage we may have as well as our financial resources. We also could incur significant costs associated with civil or criminal fines and penalties.

Although we maintain workers’ compensation insurance to cover us for costs and expenses we may incur due to injuries to our employees resulting from the use of hazardous materials or other work-related injuries, this insurance may not provide adequate coverage against potential liabilities. In addition, we may incur substantial costs in order to comply with current or future environmental, health and safety laws and regulations. These current or future laws and regulations may impair our research, development or production efforts. Failure to comply with these laws and regulations also may result in substantial fines, penalties or other sanctions.

Manufacturing issues may arise that could increase product and regulatory approval costs or delay or hinder commercialization.

As we scale-up manufacturing of product candidates and conduct required stability testing, product, packaging, equipment and process-related issues may require refinement or resolution in order to proceed with any clinical trials and obtain regulatory approval for commercial marketing. We may identify significant impurities, which could result in increased scrutiny by the regulatory agencies, delays in clinical programs and regulatory approval, increases in our operating expenses, or failure to obtain or maintain approval for product candidates or any approved products. We have limited stability data on ARCT-154, and though we have more extensive stability data for ARCT-021 and believe that our LUNAR platform should persuade regulatory authorities to consider ARCT-021 stability data for ARCT-154, regulatory authorities may disagree and require additional data. We are performing long term stability studies on ARCT-154 and are continuing storage shipping validation studies and continuous process and quality verification programs, but we cannot be sure of the outcomes of such studies and programs. Poor results could impact the prospects, timing and cost of our programs. Furthermore, we are required by our contract manufacturers to make financial commitments in advance of the receipt of clinical data or feedback from regulatory authorities, which could result in significant financial obligations.

If our strategic alliance partners elect to further pursue the development and commercialization of any of the product candidates that are subject to our strategic alliance agreement, we will have limited influence and/or control over their approaches to development and commercialization. If strategic alliance partners do not perform in the manner that we expect or fail to fulfill their responsibilities in a timely manner, or at all, the clinical development, regulatory approval and commercialization efforts related to product candidates we have licensed to such strategic alliance partners could be delayed or terminated. If we terminate any of our strategic alliances or any program thereunder, we may have the right to assume the responsibility at our own expense for the development of the applicable product candidates. Assuming sole responsibility for further development will increase our expenditures, and may mean we will need to limit the size and scope of one or more of our programs, seek additional funding and/or choose to stop work altogether on one or more of the affected product candidates. This could result in a limited potential to generate future revenue from such product candidates and our business could be materially and adversely affected.

We face significant competition from other biotechnology and pharmaceutical companies and our operating results will suffer if we fail to compete effectively.

The biotechnology and pharmaceutical industries are intensely competitive. We have competitors both in the United States and internationally, including major multinational pharmaceutical companies, biotechnology companies and universities and other research institutions. Many of our competitors have substantially greater financial, technical and other resources, such as larger research and development staff and experienced marketing, regulatory and manufacturing organizations. Additional mergers and acquisitions in the biotechnology and pharmaceutical industries may result in even more resources being concentrated in our competitors. Competition may increase further as a result of advances in the commercial applicability of technologies and greater availability of capital for investment in these industries. Our competitors may succeed in developing, acquiring or licensing on an exclusive basis, drug products that are more effective or less costly than any product candidate that we may develop.

The commercial success of our product candidates will depend upon the acceptance of these product candidates by the medical community, including physicians, patients and healthcare payors.

The degree of market acceptance of any product candidates will depend on a number of factors, including:

• demonstration of clinical safety and efficacy compared to other products;

• the prevalence and severity of any adverse events;

• limitations or warnings contained in the FDA-approved label for such products;

• availability of alternative treatments;

• pricing and cost-effectiveness;

• our ability to obtain hospital or payor formulary approval;

Unless other formulations are developed in the future, we expect our compounds to be formulated in an injectable form. Injectable medications may be disfavored by patients or their physicians in the event drugs which are easy to administer, such as oral medications, are available. If any of our products is approved, but does not achieve an adequate level of acceptance by physicians, patients and healthcare payors, we may not generate sufficient revenues from such product and we may not become or remain profitable. Such increased competition may decrease any future potential revenue for future product candidates due to increasing pressure for lower pricing and higher discounts in the commercialization of our product.

In order to market any products that may be approved, we must build our sales, marketing, managerial and other non-technical capabilities or make arrangements with outside parties to perform these services. With respect to certain of our current programs as well as future programs, we may rely completely on a strategic alliance partner for sales and marketing. In addition, we intend to enter into strategic alliances with other parties to commercialize other product candidates, if approved, including in markets outside of the United States or for other large markets that are beyond our resources. Although we intend to establish a sales organization if we are able to obtain approval to market any product candidates for niche markets in the United States, we will also consider the option to enter into strategic alliances for future product candidates in the United States if commercialization requirements exceed our available resources. This will reduce the potential profit generated from the sales of these products.

Our current and any future strategic alliance partners may not dedicate sufficient resources to the commercialization of our product candidates, if approved, or may otherwise fail in their commercialization due to factors beyond our control. If we are unable to establish effective alliances to enable the sale of our product candidates, if approved, to healthcare professionals and in geographical regions, including the United States, that will not be covered by our own marketing and sales force, or if our potential future strategic alliance partners do not successfully commercialize the product candidates that may be approved, our ability to generate revenues from product sales will be adversely affected.

If we are unable to establish adequate sales, marketing and distribution capabilities, whether independently or with third parties, we may not be able to generate sufficient product revenue and may not become profitable. We will be competing with many companies that currently have extensive and well-funded marketing and sales operations. Without an internal team or the support of a third party to perform marketing and sales functions, we may be unable to compete successfully against these more established companies.

If we obtain approval to commercialize any approved products outside of the United States, a variety of risks associated with international operations could materially adversely affect our business.

If we obtain approval to commercialize any approved products outside of the United States, we expect that we will be subject to additional risks related to entering into international business relationships, including:

• different regulatory requirements for drug approvals in foreign countries;

• reduced protection for intellectual property rights;

• unexpected changes in tariffs, trade barriers and regulatory requirements;

• foreign taxes, including withholding of payroll taxes;

If coverage and adequate reimbursement is not available for any of our future products, it would be difficult for us to sell that product profitably.

Market acceptance and sales of any product candidates that we develop will depend on coverage and reimbursement policies and may be affected by future healthcare reform measures. Government authorities and third-party payors, such as private health insurers, government payors and health maintenance organizations, decide which drugs they will pay for and establish reimbursement levels. We cannot be sure that coverage and adequate reimbursement will be available for any future product candidates. In the United States, the Centers for Medicare &

Medicaid Services (“CMS”), an agency within the U.S. Department of Health and Human Services, decides whether and to what extent a new drug will be covered and reimbursed under Medicare. Private payors tend to follow the coverage reimbursement policies established by CMS to a substantial degree. It is difficult to predict what CMS will decide with respect to reimbursement for novel product candidates. Inadequate reimbursement amounts could substantially reduce the demand for, or the price of, our future products. Further, one payor’s determination to provide coverage for a product does not assure that other payors will also provide coverage for the product. If reimbursement is not available, or is available only at limited levels, we may not be able to successfully commercialize product candidates that we develop and that may be approved. Thus, even if we succeed in bringing a product to market, it may not be considered medically necessary or cost-effective, and the amount reimbursed for any products may be insufficient to allow us to sell our products on a competitive basis.

In addition, we cannot be certain if and when we will obtain formulary approval to allow us to sell any products into our target markets. Obtaining formulary approval from hospitals and from pharmacy benefits payors can be an expensive and time-consuming process. Failure to obtain timely formulary approval will limit our commercial success.

There have been a number of legislative and regulatory proposals to change the healthcare system in the United States and in some foreign jurisdictions that could affect our ability to sell products profitably. These legislative and/or regulatory changes may negatively impact the reimbursement for drug products, following approval. The availability of numerous generic treatments may also substantially reduce the likelihood of reimbursement for our future products. We expect to experience pricing pressures in connection with the sale of any products that we develop, due to the trend toward managed healthcare, the increasing influence of health maintenance organizations and additional legislative changes. The downward pressure on healthcare costs in general, and prescription drugs in particular, has and is expected to continue to increase in the future. For instance, government and private payors who reimburse patients or healthcare providers are increasingly seeking greater upfront discounts, additional rebates and other concessions to reduce prices for pharmaceutical products. If we fail to successfully secure and maintain sufficient reimbursement coverage for our future products or are significantly delayed in doing so, we will have difficulty achieving market acceptance of our future products and our business will be harmed.

In addition, in some non-U.S. jurisdictions, the proposed pricing for a drug must be approved before it may be lawfully marketed. The requirements governing drug pricing vary widely from country to country. For example, the EU provides options for its member states to restrict the range of medicinal products for which their national health insurance systems provide reimbursement and to control the prices of medicinal products for human use. A member state may approve a specific price for the medicinal product or it may instead adopt a system of direct or indirect controls on the profitability of the company placing the medicinal product on the market. If any country that has price controls or reimbursement limitations for pharmaceutical products does not allow favorable reimbursement and pricing arrangements for any of our products, our sales and profits from that product could be severely limited. Historically, products launched in the EU do not follow price structures of the U.S. and generally tend to be priced significantly lower

RISKS RELATED TO OUR RELIANCE ON OUTSIDE PARTIES

If our strategic alliances are unsuccessful or are terminated, we may be unable to commercialize certain product candidates and generate revenues.

We depend on alliance partners for financial and scientific resources for the clinical development, manufacture and commercialization of certain of our nucleic acid product candidates. These alliances will likely provide us with limited control over the course of development of a nucleic acid product candidate, especially once a candidate has reached the stage of clinical development. Our ability to ultimately recognize revenue from our strategic relationships will depend upon the ability and willingness of our alliance partners to successfully meet their respective responsibilities under our agreements with them.

Our ability to recognize revenues from strategic alliances may be impaired by several factors, including:

If any of our alliance partners do not elect to pursue the development and commercialization of our nucleic acid development candidates or if they terminate the strategic alliance, then, depending on the event:

Any of these events would have a material adverse effect on our results of operations and financial condition.

We do not independently conduct all aspects of our drug discovery activities, compound formulation research or preclinical and clinical studies of product candidates. We currently rely and expect to continue to rely on outside contractors to conduct some aspects of our preclinical and clinical studies and formulation development, but we remain responsible for ensuring that each of our IND-enabling studies and clinical trials are conducted in accordance with the study plan and protocols for the trial.

If these outside parties terminate their engagements with us or do not successfully carry out their contractual duties, meet expected deadlines or conduct our studies in accordance with regulatory requirements or our stated

study plans and protocols, we will not be able to complete, or may be delayed in completing, the necessary preclinical studies to enable us or our strategic alliance partners to select viable product candidates for IND submissions and will not be able to, or may be delayed in our efforts to, successfully develop and commercialize such product candidates.

If the contract manufacturers we rely on to produce the supply of our preclinical and clinical product candidates, including materials for the manufacture of our product candidates do not timely deliver adequate quantities of quality materials, development and commercialization of our product candidates would be hindered.

We rely on outside contractors to produce the supply of our preclinical and clinical product candidates, and we intend to rely on outside contractors to produce future clinical supplies of product candidates and commercial supplies of any approved product candidates. Reliance on outside suppliers and manufacturers entails risks, some of which we would not be subject to if we manufactured the product candidates ourselves, including:

• a delay or inability to procure or expand sufficient manufacturing capacity;

• manufacturing and product quality issues related to scale-up of manufacturing;

• costs and validation of new equipment and facilities required for scale-up;

• a failure to comply with cGMP and similar foreign standards;

• carrier disruptions or increased costs that are beyond our control; and

Any of these events could lead to clinical study delays or failure to obtain regulatory approval, or impact our ability to successfully commercialize future products, if approved. Some of these events could be the basis for detrimental FDA action, including injunction, product recall or seizure, or total or partial suspension of production.

We have established manufacturing relationships with a limited number of suppliers to supply raw materials used to create our product candidates and with a limited number of contract manufacturers to manufacture drug substance and drug product. The availability of continued supply and manufacturing capacity from our current vendors, and the availability of additional suppliers and manufacturers, is limited. We have experienced some supplier shortages and delivery delays since the COVID-19 pandemic began in early 2020. If our vendors fail to supply materials or to manufacture substances or products in the required quantities on a timely basis and at commercially reasonable prices, and we are unable to secure one or more replacement vendors in a timely manner at a substantially equivalent cost, our clinical trials may be delayed and our commercialization prospects could be materially diminished.

Prior to marketing approval for any of our product candidates, a manufacturer and its processes are required to be qualified by the FDA. If supply from the approved manufacturer is interrupted, there could be a significant disruption in our sales of any product. An alternative vendor would need to be qualified through an NDA supplement which could result in further delay. The FDA or other regulatory agencies outside of the United States may also require additional studies if a new supplier is relied upon for commercial production. Switching vendors may involve substantial costs and is likely to result in a delay in our desired clinical and commercial timelines.

In addition, if our alliance partners elect to pursue the development and commercialization of certain programs, we will lose control over the manufacturing of the product candidate subject to the agreement. Also, we will not be able to ensure that the product candidates will be manufactured under the correct conditions to permit the product candidates to be used in such clinical trials.

If the contract research organizations and clinical trial sites we rely on to conduct, supervise and monitor our clinical trials perform in an unsatisfactory manner, it may harm our business.

We and our strategic alliance partners rely on CROs and clinical trial sites to ensure the proper and timely conduct of our clinical trials. We and our strategic alliance partners have limited control or influence over their actual performance, but remain responsible for ensuring that clinical trials are conducted in accordance with the applicable protocol, legal, regulatory and scientific standards.

If we or our CROs fail to comply with applicable good clinical practices , the clinical data generated in our clinical trials may be deemed unreliable and the FDA or applicable non-U.S. regulatory agency may require us to perform additional clinical trials before approving any marketing applications. In addition, our future clinical trials will require a sufficiently large number of test subjects to adequately evaluate the safety and effectiveness of a potential drug product. Accordingly, if our CROs fail to comply with these regulations or fail to recruit a sufficient number of patients, we may be required to repeat such clinical trials, which would delay the regulatory approval process and increase our costs.

Our CROs are not our employees, and we are not be able to control whether or not they devote sufficient time and resources to our clinical and nonclinical programs. These CROs may also have relationships with other commercial entities, including our competitors, for whom they may also be conducting clinical trials or other drug development activities, which could possibly harm our competitive position. If our future CROs do not successfully carry out their contractual duties or obligations, fail to meet expected deadlines, or if the quality or accuracy of the clinical data they obtain is compromised due to the failure to adhere to our clinical protocols or regulatory requirements, or for any other reasons, our clinical trials may be extended, delayed or terminated, and we may not be able to obtain regulatory approval for, or successfully commercialize our product candidates. As a result, the commercial prospects for such products and any product candidates that we develop would be harmed, our costs could increase, and our ability to generate revenues could be delayed.

We rely on other outside parties to store and distribute drug products for clinical trials. Any performance failure or delays by our distributors could delay clinical development, marketing approval or commercialization of our product candidates, resulting in additional losses and depriving us of potential product revenue.

RISKS RELATED TO OUR INTELLECTUAL PROPERTY

If we are unable to obtain or protect intellectual property rights related to our future products and product candidates, we may not be able to compete effectively in our markets.

Our success depends in part on our ability to obtain and maintain patents and other forms of intellectual property rights, including in-licenses of intellectual property rights of others, for our product candidates, methods used to develop and manufacture our product candidates and methods for treating patients using our product candidates, as well as our ability to preserve our trade secrets, to prevent third parties from infringing upon our proprietary rights and to operate without infringing upon the proprietary rights of others. As of February 28, 2022, we own over 253 patents and pending patent applications including 38 U.S. patents, 33 pending U.S. patent applications, 12 pending international applications under Patent Cooperation Treaty (“PCT”), 82 foreign patents and 88 pending foreign patent applications. The strength of patents in the biotechnology and pharmaceutical field involves complex legal and scientific questions and can be highly uncertain. The patent applications that we own or in-license may fail to result in patents with claims that cover our products or methods in the United States or in other countries.

Our patents could be prevented from issuing or be invalidated after issuance for many reasons, including:

• relevant prior art relating to our patents and patent applications; or

If the patent applications we hold or have in-licensed with respect to our programs or product candidates fail to issue or are invalidated or if their breadth or strength of protection is threatened, it could dissuade companies from collaborating with us to develop product candidates, and threaten our ability to commercialize, future products. For example, we have been subjected to re-examination of, or oppositions to, patents owned by or licensed to us. Although we believe these concluded proceedings did not result in a commercially relevant impact on the individual patents, future challenges could deprive us of rights necessary for the successful commercialization of any product candidates that we or our strategic alliance partners may develop.

If we do not prevail in any challenge to our intellectual property rights, we could be required to cease using the related technology or to license rights to it from the prevailing party. Our business could be harmed if the prevailing party does not offer us a license at all, or on commercially reasonable terms. Our defense of a patent or patent application in such a proceeding may not be successful and, even if successful, may result in substantial costs and distract our management and other employees. Even if our patent are issued and are not challenged or invalidated, our patents and patent applications may not adequately protect our intellectual property or prevent others from designing around our claims. In addition, patents have a limited lifespan. In the United States, the natural expiration of a patent is generally 20 years after it is filed. Various extensions may be available however the life of a patent, and the protection it affords is limited. Once the patent life has expired for a product, we may be open to competition from generic medications. Further, if we encounter delays in regulatory approvals, the period of time during which we could market a product candidate under patent protection could be reduced.

In addition to the protection afforded by patents, we rely on trade secret protection and confidentiality agreements to protect proprietary know-how that is not patentable, including processes for which patents are difficult to enforce and any other elements of our drug discovery and development processes that involve proprietary know-how, information or technology that is not covered by patents. Although each of our employees agrees to assign their inventions to us through an employee inventions agreement, and all of our employees, consultants, advisors and any third parties who have access to our proprietary know-how, information or technology are required to enter into confidentiality agreements, such agreements may not be effective in preventing our trade secrets and other confidential proprietary information from being disclosed or accessed by competitors. In addition, competitors and others may independently discover our trade secrets and proprietary information or independently develop substantially equivalent information and techniques. For example, the FDA, as part of its Transparency Initiative, is currently considering whether to make additional information publicly available on a routine basis, including information that we may consider to be trade secrets or other proprietary information, and it is not clear at the present time how the FDA’s disclosure policies may change in the future, if at all.

Further, the laws of some foreign countries do not protect proprietary rights to the same extent or in the same manner as the laws of the United States. As a result, we may encounter significant problems in protecting and defending our intellectual property both in the United States and abroad. If we are unable to prevent material disclosure of the non-patented intellectual property related to our technologies to third parties, and there is no guarantee that we will have any such enforceable trade secret protection, we may not be able to establish or maintain a competitive advantage in our market, which could materially adversely affect our business.

Claims that we infringe the intellectual property rights of others, especially in the crowded and competitive field of mRNA and delivery technology patents, may prevent or delay our development and commercialization efforts.

As the biotechnology and pharmaceutical industries expand and more patents are issued and as our activities expand, the risk increases that our product candidates and activities may be subject to claims of infringement of the patent rights of others. This risk is significantly heightened because of the many patents and other intellectual property rights in messenger RNA and delivery technology, which is being relied on by many companies, including us, developing mRNA-based vaccines.

Since the outbreak of the COVID-19 pandemic, many companies have devoted substantial effort to developing vaccines and therapeutics that use mRNA technology and have developed their own intellectual property

rights, applied for patents, and licensed rights to patents held by other companies or research institutions. Some of these patents may have broad claims that cover our current or expected activities.

We are aware of patent challenging and enforcement activities in connection with technologies used in mRNA-based COVID-19 vaccines. The outcomes of such activities and the advancement of our programs could give rise to third party claims of infringement against us and our partners.

Parties making claims against us may obtain injunctive or other equitable relief, which could effectively block our ability to further develop and commercialize a COVID-19 vaccine or one or more of our other product candidates. Defense of these claims, regardless of their merit, would involve substantial litigation expense and would be a substantial diversion of employee and financial resources from our business. In the event of a successful claim of infringement against us, we may have to pay substantial damages, including treble damages and attorneys’ fees for willful infringement, pay significant royalties, or try to redesign our infringing products, which may be impossible or require substantial time and monetary expenditure, further delaying and commercialization and substantially reducing potential market revenue. Or, in order to continue development, manufacture or sale of a product, we may need to obtain a license from the owner of intellectual property, which may not be available on commercially reasonable terms or at all.

If we fail to obtain licenses to necessary intellectual property or do not comply with our obligations in license agreements, we could lose important rights.

We may need to obtain licenses from owners of intellectual property to advance our research or allow commercialization of our product candidates, and we have done so from time to time. If may fail to obtain any of these licenses at a reasonable cost and on reasonable terms, we would be unable to further develop and commercialize one or more of our product candidates, which could harm our business significantly.

We may be involved in lawsuits to protect or enforce our patents or the patents of our licensees, which could be expensive, time consuming and unsuccessful.

Competitors may infringe our patents or the patents of our licensees. To counter infringement or unauthorized use, we may be required to file infringement claims, which can be expensive and time-consuming. In addition, in an infringement proceeding, a court may decide that a patent of ours or of our licensees is not valid or is unenforceable, or may refuse to stop the other party from using the technology at issue on the grounds that our patents do not cover the technology in question. An adverse result in any litigation or defense proceedings could put one or more of our patents at risk of being invalidated or interpreted narrowly and could put our patent applications at risk of not issuing.

Our defense in a lawsuit may fail and, even if successful, may result in substantial costs and distract our management and other employees. We may not be able to prevent, alone or with our licensees, misappropriation of our intellectual property rights, particularly in countries where the laws may not protect those rights as fully as in the United States.

Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation, there is a risk that some of our confidential information could be compromised by disclosure during the course of litigation. There could also be public announcements of the results of hearings, motions or other interim proceedings or developments. If securities analysts or investors perceive these results to be negative, it could have a material adverse effect on the price of our common stock.

If we are subject to claims that our employees, consultants or independent contractors have wrongfully used or disclosed confidential information of third parties, we could incur substantial expenses.

We employ individuals who were previously employed at other biotechnology or pharmaceutical companies. We may be subject to claims that we or our employees, consultants or independent contractors have inadvertently or otherwise used or disclosed confidential information of our employees’ former employers or other third parties. We may also be subject to claims that former employers or other parties have an ownership interest in our patents. Litigation may be necessary to defend against these claims. We may not be successful in defending these claims, and if we are successful, litigation could result in substantial cost and be a distraction to our management and other employees.

RISKS RELATED TO OUR BUSINESS OPERATIONS AND INDUSTRY

We may need to expand our organization and may experience difficulties in managing this growth, which could disrupt our operations.

As of December 31, 2021, we had 177 employees. In the future we may expand our employee base to increase our managerial, scientific, operational, commercial, financial and other resources and we may hire more consultants and contractors. Future growth would impose significant additional responsibilities on our management, including the need to identify, recruit, maintain, motivate and integrate additional employees, consultants and contractors. Also, our management may need to divert a disproportionate amount of its attention away from our day-to-day activities and devote a substantial amount of time to managing these growth activities. We may not be able to effectively manage the expansion of our operations, which may result in weaknesses in our infrastructure or give rise to operational mistakes, loss of business opportunities, loss of employees or reduced productivity among remaining employees. Our expected growth could require significant capital expenditures and may divert financial resources from other projects, such as the development of additional product candidates. Moreover, if our management is unable to effectively manage our growth, our expenses may increase more than expected, our ability to generate and/or grow revenues could be reduced, and we may not be able to implement our business strategy. Our future financial performance and our ability to commercialize product candidates and compete effectively will depend, in part, on our ability to effectively manage any future growth.

We have recently experienced high turnover and if we cannot continue to attract, retain and motivate key executives and qualified scientists and other personnel, we will not be able to effectively operate our business.

We are highly dependent on principal members of our executive team, and any reduction or loss of their services may adversely impact the achievement of our objectives. While we have entered into employment agreements with each of our executive officers, any of them could leave our employment at any time, as all of our employees are “at will” employees. Recruiting and retaining other qualified employees for our business, including scientific and technical personnel, will also be critical to our success. During the COVID-19 pandemic over the past two years, we have experienced a high number of resignations, as well as our Chief Medical Officer stepping down recently to a part-time role. There was already a shortage of skilled executives as well as scientific and technical personnel in our industry prior to COVID-19, which was exacerbated by the pandemic and is likely to continue. As a result, competition for skilled personnel is intense and the turnover rate can be high, as we have recently seen. We may not be able to attract and retain personnel on acceptable terms given the competition among numerous pharmaceutical companies for individuals with similar skill sets. In addition, failure to succeed in preclinical studies and clinical trials may make it more challenging to recruit and retain qualified personnel. The inability to recruit any executive or key employee or the loss of the services of any executive or key employee might impede the progress of our research, development and commercialization objectives.

Our employees may engage in misconduct or other improper activities, including noncompliance with regulatory standards and requirements and insider trading.

We are exposed to the risk of employee fraud or other misconduct. Employee misconduct could have significant negative impacts on our business. Misconduct by employees could include intentional or nonintentional failures to comply with the regulations of the FDA and other regulators, to provide accurate information to the FDA and other regulators, to comply with healthcare fraud and abuse laws and regulations in the United States and abroad, to report financial information or data accurately or to disclose unauthorized activities to us. In particular, 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.

Employee misconduct could also involve the improper use of information obtained in the course of clinical trials, which could result in regulatory sanctions and cause serious harm to our reputation. Although we have adopted a code of conduct and procedures, we may not always be effective in identifying and deterring employee misconduct, 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 these laws or regulations. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could result in the imposition of civil, criminal and administrative penalties, damages, fines, possible exclusion from Medicare, Medicaid and other government healthcare programs, additional reporting requirements

and/or oversight, particularly if we become subject to a corporate integrity agreement or similar agreement to resolve allegations of non-compliance, disgorgement, imprisonment, and contractual damages. Even if we are ultimately successful in defending any such action, we could be required to divert financial and managerial resources in doing so and adverse publicity could result, all of which could harm our business.

If we do not fully comply with applicable healthcare fraud and abuse laws, false claims laws and health information privacy and security laws, we could face criminal sanctions, civil penalties, contractual damages, reputational harm and diminished profits and future earnings.

If we obtain FDA approval for any of our product candidates and begin commercializing those products in the United States, our operations may be directly, or indirectly through our customers, further subject to various federal and state fraud and abuse laws, including, without limitation, the federal Anti-Kickback Statute and the federal False Claims Act. These laws may impact, among other things, our proposed sales, marketing and education programs. In addition, we may be subject to patient privacy regulation by the federal government and by the U.S. states and foreign jurisdictions in which we conduct our business. The healthcare laws and regulations that may affect our ability to operate include:

In addition, the European Union (“EU”) has established its own data security and privacy legal framework, including but not limited to Directive 95/46/EC (the “Data Protection Directive”). The European General Data Protection Regulation (“GDPR”) took effect on May 25, 2018, which contains new provisions specifically directed at the processing of health information, higher sanctions and extra-territoriality measures intended to bring non-EU companies under the regulation. We anticipate that over time we may expand our business operations to include additional operations in the EU, including potentially conducting preclinical and clinical trials. With such expansion, we would be subject to increased governmental regulation in the EU countries in which we might operate, including regulation due to the GDPR.

If our operations are found to be in violation of any of the laws described above or any other governmental regulations or laws that apply to us, we may be subject to substantial penalties, including, without limitation, civil, criminal and administrative penalties, damages, fines, possible exclusion from Medicare, Medicaid and other government healthcare programs, additional reporting requirements and/or oversight, particularly if we become subject to a corporate integrity agreement or similar agreement to resolve allegations of non-compliance, disgorgement, imprisonment, contractual damages, reputational harm, diminished profits and future earnings, and curtailment or restructuring of our operations, any of which could adversely affect our ability to operate our business and our results of operations.

Recent and future healthcare legislation may further impact our business operations.

The United States and some foreign jurisdictions are considering or have enacted a number of legislative and regulatory proposals to change the healthcare system in ways that could affect our ability to sell our products profitably. Among policymakers and payors in the United States and elsewhere, there is significant interest in promoting changes in healthcare systems with the stated goals of containing healthcare costs, improving quality or expanding access. In the United States, the pharmaceutical industry has been a particular focus of these efforts and has been significantly affected by major legislative initiatives. For example, in March 2010, the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010 (the “ACA”) was enacted, which made a number of substantial changes in the way healthcare is financed by both governmental

and private insurers. The ACA included a number of provisions that may reduce the profitability of drug products, including revising the rebate methodology for covered outpatient drugs under the Medicaid Drug Rebate Program, extending Medicaid rebates to individuals enrolled in Medicaid managed care plans, and requiring drug manufacturers to pay an annual fee based on their market share of prior year total sales of branded programs to certain federal health care programs.

There remain executive, legal and political challenges to certain aspects of the ACA. For example, in December 2017, Congress repealed the tax penalty for an individual’s failure to maintain ACA-mandated health insurance as part of the Tax Cuts and Jobs Act of 2017 (the “Tax Act”), effective January 1, 2019. On December 14, 2018, a Texas U.S. District Court Judge ruled that the ACA is unconstitutional in its entirety because the “individual mandate” was repealed by Congress as part of the Tax Act. On December 18, 2019, the U.S. Court of Appeals for the Fifth Circuit upheld the District Court ruling that the individual mandate was unconstitutional and remanded the case back to the District Court to determine whether the remaining provisions of the ACA are invalid as well. On March 2, 2020, the U.S. Supreme Court granted the petitions for writs of certiorari to review the case and held oral arguments on November 10, 2020. Although the U.S. Supreme Court has not yet ruled on the constitutionality of the ACA, on January 28, 2021, President Biden issued an executive order to initiate a special enrollment period from February 15, 2021 through May 15, 2021 for purposes of obtaining health insurance coverage through the ACA marketplace. The executive order also instructs certain governmental agencies to review and reconsider their existing policies and rules that limit access to healthcare. It is unclear how the U.S. Supreme Court ruling, other such litigation, and the healthcare reform measures of the Biden administration will impact the ACA and our operations.

In addition, other legislative changes have been proposed and adopted in the United States since the Affordable Care Act was enacted. On August 2, 2011, the Budget Control Act of 2011 among other things, created measures for spending reductions by Congress. A Joint Select Committee on Deficit Reduction, tasked with recommending a targeted deficit reduction of at least $1.2 trillion for the years 2013 through 2021, was unable to reach required goals, thereby triggering the legislation’s automatic reduction to several government programs. This includes aggregate reductions to Medicare payments to providers of 2% per fiscal year, which started in April 2013, and, due to subsequent legislative amendments, will remain in effect through 2030 unless additional Congressional action is taken, except for a temporary suspension from May 1, 2020 through March 31, 2021 due to the COVID-19 pandemic. On January 2, 2013, the American Taxpayer Relief Act of 2012 was signed into law, which, among other things, also reduced Medicare payments to several categories of healthcare providers. Additionally, the Bipartisan Budget Act of 2018, among other things, amended the ACA to increase from 50% to 70% the point-of-sale discount that is owed by pharmaceutical manufacturers who participate in Medicare Part D and to close the coverage gap in most Medicare drug plans, commonly referred to as the “donut hole.”

Further, there has been heightened governmental scrutiny in the United States of pharmaceutical pricing practices in light of the rising cost of prescription drugs and biologics. Such scrutiny has resulted in several recent Congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to product pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for products. At the federal level, Congress and the Biden administration may seek new legislative and/or administrative measures to control drug costs. At the state level, legislatures have increasingly passed legislation and implemented regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, to encourage importation from other countries and bulk purchasing.

We expect that healthcare reform measures that may be adopted in the future may result in more rigorous coverage criteria and lower reimbursement, and in additional downward pressure on the price that we receive for any approved product. Any reduction in reimbursement from Medicare or other government-funded programs may result in a similar reduction in payments from private payors.

We cannot predict what healthcare reform initiatives may be adopted in the future. Further federal, state and foreign legislative and regulatory developments are likely, and we expect ongoing initiatives to increase pressure on drug pricing. Such reforms could have an adverse effect on anticipated revenues from product candidates that we may successfully develop and for which we may obtain regulatory approval and may affect our overall financial condition and ability to develop product candidates.

We face potential product liability, and, if successful claims are brought against us, we may incur substantial liability and costs.

The use of our product candidates in clinical trials and the sale of any products for which we obtain marketing approval exposes us to the risk of product liability claims. Product liability claims might be brought against us by consumers, healthcare providers, pharmaceutical companies or others selling or otherwise coming into contact with our product candidates or products. For example, unanticipated adverse effects could result from the use of our future products or product candidates which may result in a potential product liability claim. If we cannot successfully defend against product liability claims, we could incur substantial liability and costs. In addition, regardless of merit or eventual outcome, product liability claims may result in:

• impairment of our business reputation;

• withdrawal of clinical trial participants;

• costs due to related litigation;

• distraction of management’s attention from our primary business;

• substantial monetary awards to patients or other claimants;

• the inability to commercialize our product candidates; and

• decreased demand for our products approved for commercial sale.

We have a limited amount of product liability insurance relating to the use of our therapeutics in clinical trials. However, such insurance coverage may not be sufficient to reimburse us for any expenses or losses we may suffer. Moreover, insurance coverage is becoming increasingly expensive and in the future we may not be able to obtain or maintain insurance coverage at a reasonable cost or in sufficient amounts to protect us against losses due to liability. If and when we obtain marketing approval for product candidates, we intend to expand our insurance coverage to include the sale of commercial products; however, we may be unable to obtain product liability insurance on commercially reasonable terms or in adequate amounts. On occasion, large judgments have been awarded in class action lawsuits based on drugs that had unanticipated adverse effects. A successful product liability claim or series of claims brought against us could cause our share price to decline and, if judgments exceed our insurance coverage, could adversely affect our results of operations and business.

Cyber security risks and the failure to maintain the confidentiality, integrity, and availability of our computer hardware, software, and Internet applications and related tools and functions could result in damage to our reputation and/or subject us to costs, fines or lawsuits.

Our business requires manipulating, analyzing and storing large amounts of data. In addition, we rely on a global enterprise software system to operate and manage our business. We also maintain personally identifiable information about our employees and participants in our clinical trials. Our business therefore depends on the continuous, effective, reliable, and secure operation of our computer hardware, software, networks, Internet servers, and related infrastructure. To the extent that our hardware or software malfunctions or access to our data by internal research personnel is interrupted, our business could suffer. The integrity and protection of our employee and company data is critical to our business and our employees and participants in our clinical trials have a high expectation that we will adequately protect their personal information. The regulatory environment governing information, security and privacy laws is increasingly demanding and continues to evolve. Maintaining compliance with applicable security and privacy regulations may increase our operating costs. Although our computer and communications hardware is protected through physical and software safeguards, it is still vulnerable to fire, storm, flood, power loss, earthquakes, telecommunications failures, physical or software break-ins, software viruses, and similar events. These events could lead to the unauthorized access, disclosure and use of non-public information. The techniques used by criminal elements to attack computer systems are sophisticated, change frequently and may originate from less regulated and remote areas of the world. As a result, we may not be able to address these techniques proactively or implement adequate preventative measures. If our computer systems are compromised, we could be subject to fines, damages, litigation and enforcement actions, and we could lose trade secrets, the occurrence of which could harm our business. In addition, any sustained disruption in internet access provided by other companies could harm our business.

Business interruptions could delay us in the process of developing our future products.

Our headquarters are located in San Diego, California. We are vulnerable to natural disasters such as earthquakes, mudslides, floods and wildfires, as well as other events that could disrupt our operations. We do not carry insurance for earthquakes or other natural disasters and we may not carry sufficient business interruption insurance to compensate us for losses that may occur. Any losses or damages we incur could have a material adverse effect on our business operations.

RISKS RELATED TO OUR COMMON STOCK

Our ability to use our net operating loss carryforwards and certain other tax attributes may be limited.

Under the Tax Cuts and Jobs Act, as modified by the Coronavirus Aid, Relief, and Economic Security Act, or CARES Act, U.S. federal net operating losses (“NOLs”) incurred in 2018 and in future years may be carried forward indefinitely, but the deductibility of such federal NOLs is limited. It is uncertain if and to what extent various states will conform to the Tax Cuts and Jobs Act. To the extent that we continue to generate taxable losses for United States federal income tax purposes, unused NOLs will carry forward to offset future taxable income (subject to any applicable limitations), if any. Under Sections 382 and 383 of the Internal Revenue Code, as amended, if a corporation undergoes an “ownership change,” generally defined as a greater than 50% change (by value) in its equity ownership over a three-year period, the corporation’s ability to use its pre-change NOLs and other pre-change tax attributes (such as research tax credits) to offset its post-change income may be significantly limited. We believe we may have triggered an “ownership change” limitation; however, we have not completed a study in accordance with Sections 382 and 383 of the Code to determine whether this ownership change has occurred or what the possible effects of an ownership change would be on our ability to use NOLs. We may also experience ownership changes in the future as a result of subsequent shifts in our share ownership. As a result, if we earn net taxable income, our ability to use our pre-change NOL carryforwards to offset U.S. federal taxable income may be subject to limitations, which could potentially result in increased future tax liability to us. Similar provisions of U.S. state tax law may also apply to limit our use of accumulated state tax attributes, including our state NOLs. In addition, at the state level, there may be periods during which the use of NOLs is suspended or otherwise limited, which could accelerate or permanently increase state taxes owed. As a result, even if we attain profitability, we may be unable to use a material portion of our NOLs and other tax attributes, which could negatively impact our future cash flows.

We do not intend to pay dividends on our common stock so any returns to investors will be limited to the value of our shares.

We have never declared or paid any cash dividends on our common stock. We currently anticipate that we will retain future earnings for the development, operation and expansion of our business and do not anticipate declaring or paying any cash dividends for the foreseeable future.

GENERAL RISK FACTORS

The market price of our common stock has been, and is expected to continue to be, highly volatile and investors may not be able to resell shares at or above the price at which they purchased the shares.

The trading price of our common stock is likely to continue to be volatile. Our share price could be subject to wide fluctuations in response to a variety of factors, including but not limited to the following factors:

• adverse results or delays in preclinical studies or clinical trials;

• inability to obtain additional funding;

• adverse regulatory decisions;

• introduction of new products, services or technologies by our competitors;

• failure to meet or exceed financial projections we may provide to the public;

• additions or departures of key scientific or management personnel;

• significant lawsuits, including patent or licensing matters;

• changes in the market valuations of similar companies;

• sales of our common stock by us or our shareholders in the future; and

• trading volume of our common stock.

In addition, companies trading in the stock market in general, and Nasdaq in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of these companies. Broad market and industry factors may negatively affect the market price of our common stock, regardless of our actual operating performance.

The requirements of being a publicly traded company may strain our resources and divert management’s attention.

As a publicly traded company, we have incurred, and will continue to incur, significant legal, accounting and other expenses that we did not incur as a private company. In addition, the Sarbanes-Oxley Act, as well as rules subsequently implemented by the SEC and Nasdaq have imposed various requirements on public companies. In July 2010, the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) was enacted. There are significant corporate governance and executive compensation related provisions in the Dodd-Frank Act that require the SEC to adopt additional rules and regulations in these areas such as “say on pay” and proxy access. Shareholder activism, the current political environment and the current high level of government intervention and regulatory reform may lead to substantial new regulations and disclosure obligations, which may lead to additional compliance costs and impact the manner in which we operate our business in ways we cannot currently anticipate. Our management and other personnel will need to devote a substantial amount of time to these compliance initiatives. Moreover, these rules and regulations will increase our legal and financial compliance costs and will make some activities more time-consuming and costly. For example, we expect these rules and regulations to make it more difficult and more expensive for us to obtain director and officer liability insurance and we may be required to incur substantial costs to maintain our current levels of such coverage.

Failure to comply with these requirements could subject us to enforcement actions by the SEC, divert management’s attention, damage our reputation, and adversely affect our business, results of operations, or financial condition. In particular, if our independent registered public accounting firm is not able to render the required unqualified attestation, it could result in a loss of investor confidence in the accuracy, reliability, and completeness of our financial reports. Our loss of “emerging growth company” status and our current status as a “large accelerated filer,” and compliance with these additional requirements will require management to expend additional time while also condensing the time frame available to comply with certain requirements, which can be expected to further increase our legal and financial compliance costs.

If we are subject to securities class action litigation, we would incur substantial costs and diversion of management’s attention.

We may be at risk of securities class action litigation. This risk is especially relevant for us due to our dependence on positive clinical trial outcomes and regulatory approvals of each of our product candidates. In the past, medicines, biotechnology and pharmaceutical companies have experienced significant stock price volatility,

particularly when associated with binary events such as clinical trials results and product approvals. If we face such litigation, it could result in substantial costs, divert management’s attention and resources, and have a very material adverse effect on our business, operating results and prospects.

Sales of a substantial number of shares of our common stock in the public market by our existing shareholders could cause our share price to fall.

If our existing shareholders sell, or indicate an intention to sell, substantial amounts of our common stock in the public market, the trading price of our common stock could decline significantly. In particular, the former shareholders, warrant holders and noteholders of Arcturus Therapeutics, Inc. received an aggregate of 6,631,712 of our common stock pursuant to the merger with Alcobra Ltd. in an unregistered transaction, which shares may be sold pursuant to Rule 144 under the Securities Act of 1933, as amended (the “Securities Act”). Those shareholders are eligible to sell those shares in the public market without restriction, except for shareholders who are deemed our “affiliates” under Rule 144 under the Securities Act. In addition, common stock that is either subject to outstanding options or reserved for future issuance under our employee benefit plans, may become eligible for sale in the public market to the extent permitted by vesting schedules and Rule 144 under the Securities Act. If common stock is sold, or if it is perceived that it will be sold, in the public market, that could cause the trading price to decline.

Future sales and issuances of our common stock or rights to purchase common stock, including pursuant to our equity incentive plans, could result in additional dilution of the percentage ownership of our shareholders and could cause our share price to fall.

We expect that significant additional capital will be needed in the future to continue our planned operations. To the extent we raise additional capital by issuing equity securities, our shareholders may experience substantial dilution. Pursuant to our 2019 Omnibus Equity Incentive Plan, our management is authorized to grant options and other equity-based awards to our employees, directors and consultants. We may issue and sell additional shares of common stock, convertible securities or other equity securities in one or more capital-raising or other transactions at prices and in a manner we determine from time to time, any of which may result in material dilution to investors and/or our existing shareholders. New investors could also be issued securities with rights superior to those of our existing shareholders.

We may be unable to comply with the applicable continued listing requirements of Nasdaq.

Our common stock is currently listed on Nasdaq. In order to maintain this listing, we must satisfy minimum financial and other continued listing requirements and standards, including a minimum closing bid price requirement for our common stock of $1.00 per share. There can be no assurance that we will be able to comply with the applicable listing standards. For example, if we were to fail to meet the minimum bid price requirement for 30 consecutive business days, we could become subject to delisting. Although Nasdaq may provide us with a compliance period in which to regain compliance with the minimum bid price requirement, we may not be able to regain compliance within the period provided by Nasdaq. In order to regain compliance with such requirement, the closing bid price of our common stock would need to meet or exceed $1.00 per share for at least 10 consecutive business days during the compliance period. If we were not able to regain compliance within the allotted compliance period for this requirement or any other applicable listing standard, including any extensions that may be granted by Nasdaq, our common stock would be subject to delisting. In the event that our common stock is delisted from Nasdaq, liquidity will be reduced and the trading price of our common stock can be expected to decline immediately. If our common stock is not eligible for quotation or listing on another market or exchange, trading of our common stock could be conducted only in the over-the-counter market or on an electronic bulletin board established for unlisted securities such as the Pink Sheets or the OTC Bulletin Board. In such event, it could become more difficult to dispose of, or obtain accurate price quotations for our common stock and there would likely also be a reduction in our coverage by securities analysts and the news media, which could cause the price of our common stock to decline further.

Item 1B. Unresolved Staff Comments

None.

Item 2. Properties

We have three properties located in San Diego, California. Our principal place of business is located at 10628 Science Center Drive, Suite 250, and consists of approximately 24,700 square feet of office space and laboratory space leased through March 2025. We have the right to extend this lease for an additional five-year term.

On February 16, 2020, we entered into a short-term lease for additional office and laboratory space located in close proximity to our main office at 10578 Science Center Drive, Suite 150. The additional space of approximately 11,750 square feet is leased through March 2025.

On February 26, 2021, we entered into a short-term lease for additional office and laboratory space located in close proximity to our main office at 10240 Science Center Drive, Suite 100. The additional space of approximately 4,312 square feet is leased for a term of twelve months. We have the right to extend this lease for an additional twelve months.

On September 29, 2021, we entered into a lease agreement for office, research and development, engineering and laboratory space located at 10285 Science Center Drive, San Diego, California. The additional space of approximately 43,234 square feet is leased for a term of 10 years and 8 months. The leased premises will serve as an addition to Arcturus’ existing properties.

We believe that our properties are suitable for the conduct of our business.

Item 3. Legal Proceedings

From time to time, we may be involved in various legal proceedings and subject to claims that arise in the ordinary course of business. Although the results of litigation and claims are inherently unpredictable and uncertain, we are not currently a party to any legal proceedings.

On December 13, 2019, a former employee of the Company filed a complaint in San Diego County Superior Court, captioned Adonary Munoz v. Arcturus Therapeutics, Inc., et al, Case No. 37-2019-00066358-CU-PO-CTL. The lawsuit alleged sexual assault by an acquaintance of one of our employees and sought to hold the Company liable on a number of causes of action. On May 5, 2021, the parties settled the dispute, and the parties agreed to dismiss the legal proceedings. The settlement did not result in any material liability to the Company as the settlement payment was covered by the Company’s insurance.

Item 4. Mine Safety Disclosures

Not applicable.

PART II

Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities

Holders of Common Stock

As of February 23, 2022, there were 14 holders of record of our common stock. As of such date, there were 26,375,002 shares of our common stock outstanding.

Dividends

We have never declared or paid any cash dividends on our common stock. We currently intend to retain all available funds and any future earnings to support our operations and finance the growth and development of our business. Any future determination related to our dividend policy will be made at the discretion of our board of directors and will depend upon, among other factors, our results of operations, financial condition, capital requirements, contractual restrictions, business prospects and other factors our board of directors may deem relevant.

Recent Sales of Unregistered Securities

None.

Issuer and Affiliated Purchaser – Purchases of Equity Securities

During the fiscal year 2018, we completed the sale of our intangible assets related to the ADAIR technology. Pursuant to the asset purchase agreement for ADAIR, we received a 30% ownership interest in the common stock of Vallon Pharmaceuticals, Inc. (“Vallon”) in consideration for the sale of the ADAIR technology. Vallon completed an initial public offering and began trading on The Nasdaq Capital Market under the ticker “VLON” in February 2021. After this offering and other previous stock issuances of Vallon, Arcturus owns 843,750 shares of Vallon’s total post-IPO 6,812,836 outstanding shares, or approximately 12%.

Item 6. Selected Financial Data

In accordance with Item 301 of Regulation S-K as amended effective February 10, 2021, we are omitting this disclosure.

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

You should read the following discussion and analysis together with the consolidated financial statements and related notes included elsewhere herein.

This report includes forward-looking statements which, although based on assumptions that we consider reasonable, are subject to risks and uncertainties which could cause actual events or conditions to differ materially from those currently anticipated and expressed or implied by such forward-looking statements.

Overview

Arcturus is a late-stage global clinical messenger RNA medicines company focused on the development of infectious disease vaccines and significant opportunities within liver and respiratory rare diseases. In addition to our messenger RNA platform, our proprietary lipid nanoparticle delivery system, LUNAR®, has the potential to enable multiple nucleic acid medicines, and our proprietary self-amplifying mRNA technology (Self-Transcribing and Replicating RNA, or STARRTM, technology) has the potential to provide longer-lasting RNA and sustained protein expression.

We are leveraging our proprietary LUNAR platform and our nucleic acid technologies to develop and advance a pipeline of mRNA-based vaccines and therapeutics for infectious diseases and rare genetic disorders with significant unmet medical needs. Our key proprietary technology has the potential to address the major hurdles in RNA development, namely the effective and safe delivery of RNA therapeutics to disease-relevant target tissues. We believe the versatility of our platform to target multiple tissues, its compatibility with various nucleic acid therapeutics, and our expertise in developing scalable manufacturing processes puts us in a leading position to deliver on the next generation of nucleic acid medicines.

During 2021, together with Vinbiocare, we advanced ARCT-154, our investigational next generation, self-amplifying mRNA-based vaccine for COVID-19, into a Phase 1/2/3 study in Vietnam, which is being funded by Vinbiocare. With Vinbiocare, we completed submission of regulatory documents to the Ministry of Health in Vietnam with respect to application for an Emergency Use Authorization for ARCT-154 (LUNAR-COV19).

Our activities since inception have consisted principally of performing research and development activities, clinical research activities, general and administrative activities and raising capital to fund those efforts. Our activities are subject to significant risks and uncertainties, including failing to secure additional funding before we achieve sustainable revenues and profit from operations. As of December 31, 2021, we had an accumulated deficit of $347.5 million.

Liquidity and Capital Resources

Overview

Since our inception, we have funded our operations principally with proceeds from the sale of capital stock and revenues earned through collaborative agreements. At December 31, 2021, we had$370.5 million in unrestricted cash and cash equivalents.

Pursuant to the Third Amendment to the Loan and Security Agreement with Western Alliance Bank (the “Loan”), the Bank agreed to make a term loan to us on October 30, 2019, in the amount of $15.0 million (the “Term Loan”). The Term Loan bears interest at a floating rate ranging from 1.25% to 2.75% above the prime rate. The amendment further provides that the Term Loan has a maturity date of October 30, 2023. In October of 2021, we entered into a Fifth Amendment to Loan Agreement which provided for a six month extension to the interest only period which moves the first principal payment to May 1, 2022.

Grants from the Economic Development Board of the Republic of Singapore

On March 4, 2020, we were awarded a grant (“Grant 1”) from the Economic Development Board of the Republic of Singapore (the “EDB”) to support the co-development of a potential COVID-19 vaccine program with the Duke-NUS Medical School. The Grant provides for up to S$14.0 million (approximately US$10.0 million using the exchange rate at the time the grant contract was entered into) in grants to support the development of the vaccine. The Grant has been paid in full by the EDB as a result of the achievement of certain milestones related to the progress of the development of the vaccine, as set forth in the award agreement. The funds received have been recognized as contra research and development expense. The parties are in continued negotiations with respect to amendments of Grant 1. Currently, we are liable for certain expenses during the program and are also subject to certain conditions including the requirement to pay an agreed upon royalty rate to Duke-NUS on future net sales of the LUNAR-COV19 vaccine candidate developed with Duke-NUS in markets or jurisdictions outside of Singapore.

On October 2, 2020, we were awarded another grant (“Grant 2”) from the Singapore EDB to support the clinical development of a potential COVID-19 vaccine (ARCT-021). The grant provides for up to S$9.3 million (approximately US$6.7 million) to support the clinical development of the vaccine candidate for costs incurred in Singapore subject to certain conditions. The grant is paid in two installments upon the achievement of certain milestones related to the progress of the development of the vaccine candidate. We received the first installment of $3.6 million in the fourth quarter of 2020. A portion of the funds received were recognized as contra research and development expense as costs were incurred during the fourth quarter of 2020. As costs were incurred during fiscal year 2021, we recognized the remaining amount of the first installment as contra expense for Grant 2.The parties are in continued negotiations with respect to amendments of Grant 2 that could include initiation of a clinical trial for a variant COVID-19 vaccine.

Manufacturing Support Agreement

On November 7, 2020, we entered into a Manufacturing Support Agreement (the “Support Agreement”) with the EDB. Pursuant to the Support Agreement, the EDB agreed to make a term loan (the “Singapore Loan”) of S$62.1 million, subject to the satisfaction of customary deliveries, to support the manufacture of the LUNAR-COV19 vaccine candidate (ARCT-021). The EDB has agreed to an extension of the reconciliation period to March 31, 2022 with unused funds as of such date to be subsequently returned within thirty days, subject to any further agreed upon extension of the reconciliation date. The parties are in continued negotiations with respect to amendments of the Singapore Loan terms. Under current terms, (i) we are to provide a quarterly reconciliation report within forty-five days of each financial quarter end, (ii) we will provide a projection of expenditures through March 31, 2022 followed by an audited statement of actual expenditures through March 31, 2022 by June 30, 2022, (iii) we are to provide EDB with a right of first refusal on GMP manufacturing slots of the LUNAR-COV19 vaccine candidate up to an agreed-upon maximum amount, (iv) and the obligation to repay the Singapore Loan will be secured by an interest in the raw materials and manufacturing equipment purchased by us with the funds from the Singapore Loan in form and substance satisfactory to the EDB in its sole discretion. We elected to borrow the full amount available under the Support Agreement of S$62.1 million ($46.6 million) on January 29, 2021. As of December 31, 2021, we have reported a portion of the Singapore Loan as current to reflect a potential payment in fiscal year 2022. As of December 31, 2021, we reported a portion of the Singapore Loan as current to reflect a potential principal repayment of approximately 20.9 million Singapore dollars (US $15.2 million) in fiscal year 2022 based on amounts not used toward the manufacture of ARCT-021.

The Singapore Loan accrues interest at a rate of 4.5% per annum calculated on a daily basis. Subject to certain exceptions, the Singapore Loan is intended to be a limited recourse loan that will be repaid solely through a royalty payment of 10% of net sales proceeds of the LUNAR-COV19 vaccine candidate, up to the amount of the outstanding principal and interest under the Singapore Loan. However, all unpaid principal and interest under the Singapore Loan will be due and payable five years after draw date, if net sales of the LUNAR-COV19 vaccine exceed a certain minimum threshold during this five year period or we obtain clearance to sell the vaccine in specified jurisdictions. Unpaid principal and interest under the Singapore Loan will also become due and payable upon an event of default under the Support Agreement. The first vaccine sales, including the amount of net sales, shall be reported to EDB within 10 days of delivery and quarterly reports of aggregate vaccine sales, including net sales proceeds shall be provided within 30 days after quarter end.

The Singapore Loan is forgivable if we have not obtained regulatory approval by the final repayment date and net sales of LUNAR-COV19 are less than $100 million. If, any portion of the Singapore Loan is required to be forgiven pursuant to the terms of the Support Agreement, the EDB has the right to take ownership of certain raw

materials and equipment that were purchased by us with proceeds of the Singapore Loan (the “Specified Assets”). We entered into a security agreement (the “Security Agreement”) for the benefit of the EDB to provide that repayment of the Singapore Loan and related obligations are secured by a lien on the Specified Assets.

In connection with the entry into the Support Agreement, we entered into a consent agreement with Western Alliance Bank (the “Bank”) and an amendment to the Loan and Security Agreement, dated as of October 12, 2018, to exclude the Specified Assets from Western Alliance Bank’s lien on certain assets.

Vinbiocare Agreement

On August 2, 2021, we announced an agreement with Vinbiocare, a member of Vingroup Joint Stock Company, to establish a manufacturing facility in Vietnam for the manufacture of our investigational COVID-19 vaccine program, for sale and use within Vietnam. In addition, Vinbiocare agreed to execute a phase 1/2/3 study in Vietnam.

Under the terms of the arrangement, Vinbiocare is building out a manufacturing facility in Vietnam, and we have provided to Vinbiocare access to proprietary technologies and processes for the manufacture of our investigational COVID-19 vaccine candidate. We also provided Vinbiocare with an exclusive license to manufacture the vaccines in Vietnam at the facility solely for distribution in Vietnam. The license and technology transfer applies toward drug product manufacturing but not toward mRNA drug substance manufacturing. Vinbiocare made an upfront payment of $40 million and is responsible for costs associated with the technology transfer. Vinbiocare will also pay for mRNA drug substance supplied by us and royalties on vaccines produced at the manufacturing facility.

General Financial Resources

A significant portion of our current cash balance of $370.5 million is expected to be utilized during fiscal year 2022 to fund (i) further progress of our COVID and FLU vaccine programs, (ii) the continued Phase 2 trial of ARCT-810, our LUNAR-OTC candidate, (iii) advances to our LUNAR-CF program toward submission of a CTA during the second half of 2022 and (iv) continued expansion of our platform and other general administrative activities.

We expect to receive in the near term significant data from studies of our COVID 19 vaccine and regulatory guidance which will determine our course of action with respect to the development and commercialization of our vaccine candidate. Commercialization of ARCT-154 will require significant additional funds. We are considering additional partnering opportunities to assist in these efforts. We cannot be certain that we will identify a partner or enter into an acceptable arrangement. We will continue to evaluate our business opportunities in a surgical manner to maximize our ability to develop approved products while making most efficient use of our available resources.

We entered into binding agreements with third party contract manufacturing organizations with upfront financial commitments of not less than $13 million.

Our future capital requirements are difficult to forecast and will depend on many factors that are out of our control. If we are unable to maintain sufficient financial resources, our business, financial condition and results of operations will be materially and adversely affected. There can be no assurance that we will be able to obtain additional needed financing on acceptable terms or at all. Additionally, equity or debt financings may have a dilutive effect on the holdings of our existing shareholders.

We expect to continue to incur additional losses for the foreseeable future, and we will need to raise additional debt or equity financing or enter into additional partnerships to fund development. Our ability to transition to profitability is dependent on identifying and developing successful mRNA drug and vaccine candidates. If we are not able to achieve planned milestones, incur costs in excess of our forecasts, or do not meet covenant requirements of our debt, we will need to reduce discretionary spending, discontinue the development of some or all of our programs, which will delay part of our development programs, all of which will have a material adverse effect on our ability to achieve our intended business objectives.

The following table shows a summary of our cash flows for the year ended December 31, 2021, 2020 and 2019 (in thousands):

Year Ended December 31,

Cash provided by (used in):

Operating Activities

Our primary use of cash is to fund operating expenses, which consist mainly of research and development and general and administrative expenditures. We have incurred significant expenses which have been partially offset by cash collected through our collaboration agreements. Cash collections under the collaboration agreements can vary from year to year depending on the terms of the agreement and work performed. These changes on cash flows primarily relate to the timing of cash receipts for upfront payments, reimbursable expenses and achievement of milestones under these collaborative agreements.

Net cash used in operating activities was $135.0 million on a net loss of $203.7 million for 2021, $42.9 million on a net loss of $72.1 million for 2020 and $6.4million on a net loss of $26.0 million for 2019. Adjustments for non-cash charges which includes share-based compensation expense and depreciation and amortization were $37.4 million for 2021, $8.1 million for 2020 and $3.6 million for 2019. Changes in working capital resulted in adjustments to operating net cash inflows of $31.2 million for 2021, $21.2 million for 2020 and $16.0 million for 2019. The significant adjustments to operating net cash inflows for 2021 were primarily due to the agreement with Vinbiocare signed in the third quarter of 2021 along with increased accrued liabilities from LUNAR-COV19 and LUNAR-OTC (ARCT-810) clinical trial activities, which expenses were incurred as discussed below. Adjustments to operating net cash inflows for 2020 were primarily due to the supply agreement with Israeli MOH signed in the third quarter of 2020 along with increased accounts payable and accrued liabilities from LUNAR-COV19 and LUNAR-OTC (ARCT-810) clinical trial activities. Lastly, adjustments to operating net cash inflows for 2019 were primarily due to the third amendment to the collaboration agreement with Ultragenyx during the second quarter of 2019 along with increased accounts payable and accrued liabilities from LUNAR-OTC (ARCT-810).

Investing Activities

Net cash used in investing activities of $3.4 million for 2021, $1.7 million for 2020 and $0.8 million for 2019 reflected the acquisition of property and equipment.

Financing Activities

Net cash provided by financing activities of $48.0 million for 2021 consisted of net proceeds from the Singapore Loan of $46.6 million, proceeds from the exercise of stock options of $0.9 million and proceeds from the issuance of common stock related to our employee stock purchase plan of $0.5 million. Net cash provided by financing activities of $436.1 million for 2020 consisted of net proceeds from the issuance of common stock in three underwritten public offerings totaling $423.8 million, net proceeds of $9.6 million from the issuance of common stock to Ultragenyx upon the exercise of its option and proceeds from the exercise of stock options of $2.7 million. Net cash provided by financing activities of $41.9 million for 2019 consisted of net proceeds from the issuance of common stock of $15.5 million to Ultragenyx, net proceeds from the issuance of common stock of $21.3 million related to public offerings, net proceeds from long-term debt of $4.9 million, and proceeds from the exercise of stock options of $0.1 million.

Funding Requirements

We anticipate that we will continue to generate annual net losses for the foreseeable future, and we expect the losses to increase as we continue the development of, and seek regulatory approvals for, our product candidates, and begin commercialization of our products. As a result, we will require additional capital to fund our operations in order to support our long-term plans. We believe that our current cash position will be sufficient to meet our anticipated cash requirements through at least the next twelve months, assuming, among other things, no significant unforeseen

expenses, continued funding from partners at anticipated levels and our payment obligations continuing to followthe current maturity schedule under our long-term credit facility referenced in Note 7 to our consolidated financial statements in this Annual Report. We intend to seek additional capital through equity and/or debt financings, collaborative or other funding arrangements with partners or through other sources of financing. Should we seek additional financing from outside sources, we may not be able to raise such financing on terms acceptable to us or at all. If we are unable to raise additional capital when required or on acceptable terms, we may be required to scale back or discontinue the advancement of product candidates, reduce headcount, liquidate our assets, file for bankruptcy, reorganize, merge with another entity, or cease operations.

Our future funding requirements are difficult to forecast and will depend on many factors, including the following:

• the development of our LUNAR-COV19 and LUNAR-FLU vaccine candidates;

• the achievement of milestones under our strategic alliance agreements;

• maintaining and/or expanding our manufacturing network and capabilities;

• the number and characteristics of product candidates that we pursue;

• the outcome, timing and cost of regulatory approvals;

• delays that may be caused by changing regulatory requirements;

• the cost and timing of hiring new employees to support our continued growth;

• the costs associated with legal proceedings;

Results of Operations

The following discussion and analysis of our financial condition and results of operations should be read in conjunction with the consolidated financial statements included in this Annual Report. Our historical results of operations and the year-to-year comparisons of our results of operations that follow are not necessarily indicative of future results.

Revenues

We enter into arrangements with pharmaceutical and biotechnology partners and government agencies that may contain upfront payments, license fees for research and development arrangements, research and development funding, milestone payments, option exercise and exclusivity fees and royalties on future sales. The following table summarizes our total revenues for the periods indicated (in thousands):

Year Ended December 31,

Revenue increased by $2.8 million during the year ended December 31, 2021 as compared to the year ended December 31, 2020. The increase in revenue primarily relates to $4.4 million of increased revenue related to the agreement with Vinbiocare executed in the third quarter of 2021. The overall increase in revenue was primarily offset by a decrease in revenue of $1.6 million from our existing collaboration partners.

Revenue decreased by $11.3 million during the year ended December 31, 2020 as compared to the year ended December 31, 2019. The decrease in revenue primarily relates to (i) $5.6 million of decreased revenue from reduced reimbursements associated with the CureVac co-development agreement that terminated in the second quarter of 2019, (ii) a decrease in one-time sublicense revenue from Synthetic Genomics as we recognized sublicense revenue of $3.3 million during the second quarter of 2019, (iii) a reduction of $1.9 million in revenue recognized related to the Ultragenyx Agreement, as we recorded a large amount of upfront payment amortization upon the execution of the Ultragenyx Third Amendment during the second quarter of 2019 and also recognized fewer research and development expense reimbursements related to the Ultragenyx Agreement during 2020, and (iv) lower research and development expense reimbursements recognized in 2020 related to other collaboration agreements, including with Providence Therapeutics and Takeda. The decrease in revenue was partially offset by increased revenue recognition related to the Janssen agreement and other collaboration agreements.

Operating Expenses

Our operating expenses consist of research and development and general and administrative expenses.

Year Ended December 31,

Operating expenses:

The following table presents our total research and development expenses by category:

Year Ended December 31,

External pipeline development expenses:

External platform development expenses:

Research and Development Expenses, net

Our research and development expenses consist primarily of external manufacturing costs, in-vivo research studies and clinical trials performed by contract research organizations, clinical and regulatory consultants, personnel related expenses and laboratory supplies related to conducting research and development activities. Costs to acquire and manufacture pre-launch inventory, mRNA supply for preclinical studies and clinical trials are recognized and included in external pipeline development expenses for the specific program.

LUNAR-COV19 expenses increased by $79.7 million during the year ended December 31, 2021 as compared to the year ended December 31, 2020.Expenses incurred were partially offset with funds awarded by the Singapore

EDB. The LUNAR-COV19 program did not commence until late in the first quarter of 2020 and is now in late-stage clinical trials.

LUNAR-CF expenses were $4.8 million in the year ended December 31, 2021, $4.4 million in the year ended December 31, 2020 and $0.8 million in the year ended December 31, 2019. Expenses incurred were partially offset with funds awarded by the CFF. The increase in LUNAR-CF expenses was due primarily to increased research and development cost incurred in association with the amendment to the CFF Agreement executed in July 2019, and we expect that our development efforts and associated costs will increase over the next several years as the LUNAR-CF program moves toward expected CTA submission in the second half of 2022.

LUNAR-OTC expenses were $7.3 million for the year ended December 31, 2021, $13.0 million for the year ended December 31, 2020 and $15.6 million for the year ended December 31, 2019. The decreases for each year are related to slower than expected recruiting for the ARCT-810 clinical trial caused in part by the ongoing Covid environment.

Discovery technologies represents our efforts to expand our product pipeline and are expected to increase in the near future. Discovery technology expenses were $20.3 million in the year ended December 31, 2021, $1.7 million in the year ended December 31, 2020 and $3.9 million in the year ended December 31, 2019. The increase in 2021 when compared to 2020 is primarily due to increased investment in new capabilities. Further, in the first quarter of 2021, we acquired an exclusive license from Alexion Pharmaceuticals to certain intellectual property for approximately $5.0 million of our common stock, which we expensed in 2021. The decrease in discovery technology expenses from 2019 to 2020 was due to focusing our efforts on the advancement of our LUNAR-OTC and LUNAR-COV19 programs.

Partnered discovery technologies expenses were $0.8 million in the year ended December 31, 2021, $1.5 million in the year ended December 31, 2020 and $1.9 million in the year ended December 31, 2019. The decreases in partnered discovery technologies expenses from 2020 to 2021 and 2019 to 2020 were primarily caused by decreased activity in rare disease targets and a greater focus on vaccine technology. We expect partnered discovery technologies expenses to fluctuate based on the needs of our collaboration partners.

Personnel related expenses, net of funds received from CFF and the Singapore EDB, were $34.9 million in the year ended December 31, 2021, $12.8 million in the year ended December 31, 2020 and $9.0 million in the year ended December 31, 2019. The increases were associated with increased headcount costs necessary to advance our external pipeline, platform and clinical trial efforts as well as increased share-based compensation expense.

Facilities and equipment expenses were $5.1 million in the year ended December 31, 2021, $3.5 million in the year ended December 31, 2020 and $2.4 million in the year ended December 31, 2019. The increases resulted primarily from higher rent and related costs associated with an additional lease that we entered into in February 2020. We expect that the facility and equipment expenses will increase in 2022 as we have added an additional facility in the second quarter of 2022 in order to support our research and development activities.

General and Administrative Expenses

General and administrative expenses consist primarily of salaries and related benefits for our executive, administrative and accounting functions and professional service fees for legal and accounting services as well as other general and administrative expenses.

General and administrative expenses were $41.5 million in the year ended December 31, 2021, $23.2 million in the year ended December 31, 2020 and $12.7 million in the year ended December 31, 2019. The increases resulted primarily from personnel expense due to increased headcount and increased share-based compensation expense. We expect general and administrative expenses to increase in 2022 as we expand our headcount, facilities and professional services to execute our business plan.

Finance income (expense), net

Year Ended December 31,

Finance income (expense), net:

Interest income is generated on cash and cash equivalents. The increases in interest income from 2020 to 2021 and from 2019 to 2020 resulted from increased interest on bank deposits due to higher cash balances, partially offset by lower interest rates earned.

Interest expense during the year ended December 31, 2021 was incurred in conjunction with our Loan and Security Agreement with Western Alliance Bank and the Singapore Loan. The increase in interest expense during 2021 as compared to the prior year period was primarily a result of additional accrued interest expense related to the Singapore Loan that was funded in January 2021. Interest expense was relatively flat for the year ended 2020 as compared to 2019 and was related to the Loan and Security Agreement with Western Alliance Bank.

Critical Accounting Policies and Estimates

We prepare our consolidated financial statements in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”). As such, we make certain estimates, judgments and assumptions that we believe are reasonable, based upon information available to us. These judgments involve making estimates about the effect of matters that are inherently uncertain and may significantly impact our results of operations and financial condition. We describe our significant accounting policies more fully in Note 2 to our consolidated financial statements for the year ended December 31, 2021. In the following paragraphs, we describe the specific risks associated with these critical accounting policies and we caution that future events may not reflect exactly as one may expect, and that best estimates may require adjustment.

The following are our significant accounting policies which we believe are the most critical to aid in fully understanding and evaluating our reported financial results.

Revenue Recognition

Research and development revenue under collaborative agreements

We recognize research and development revenue from several collaboration agreements. Our collaboration agreements typically contain promised goods and services, including technology licenses or options to obtain technology licenses, research and development services, and manufacturing services. Upon entering into a collaboration agreement, we are required to make the following judgments:

Identifying the performance obligations contained in the agreement

Our assessment of what constitutes a separate performance obligation requires us to apply judgment. Specifically, we are required to identify which goods and services we are required to provide under the contract are distinct, if any.

Determining the transaction price, including any variable consideration

To determine the transaction price, we review the amount of consideration we are eligible to earn under the agreement. We do not typically include any payments we may receive in the future in our initial transaction price since the payments are typically not probable because they are contingent upon certain future events.

We are required to reassess the total transaction price at each reporting period to determine if we should include additional payments that have become probable in the transaction price.

Allocating the transaction price to each of our performance obligations

If we were to allocate the transaction price to more than one performance obligation, we would make estimates of the relative stand-alone selling price of each performance obligation, as it is not typical for us to sell our goods or services on a stand-alone basis. The estimate of the relative stand-alone selling price would require us to make significant judgments. To date, we have not entered into a collaboration agreement with more than one performance obligation.

The research and development revenue we recognize each period is comprised of several types of revenue, including amortization from upfront payments, milestone payments, option exclusivity fees and other services. Each of these types of revenue require us to make various judgments and estimates.

Amortization from Upfront Payments

ARCT US Equity

ARCT · 10-K · period ended 2021-12-31

Item 1A. Risk Factors

Item 1B. Unresolved Staff Comments

Item 2. Properties

Item 3. Legal Proceedings

Item 4. Mine Safety Disclosures

Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities

Item 6. Selected Financial Data

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

ARCT US Equity☆

ARCT · 10-K · period ended 2021-12-31

Item 1A. Risk Factors

Item 1B. Unresolved Staff Comments

Item 2. Properties

Item 3. Legal Proceedings

Item 4. Mine Safety Disclosures

Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities

Item 6. Selected Financial Data

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

ARCT US Equity