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

The following discussion and analysis of our financial condition and results of operations should be read in conjunction with our consolidated financial statements and related notes appearing at the end of this Annual Report on Form 10-K. Some of the information contained in this discussion and analysis or set forth elsewhere in this Annual Report on Form 10-K, including information with respect to our plans and strategy for our business, includes forward-looking statements that involve risks and uncertainties. As a result of many factors, including those factors set forth in the “Risk Factors” section of this Annual Report on Form 10-K, our actual results could differ materially from the results described in, or implied by, the forward-looking statements contained in the following discussion and analysis.

Overview

We are building a leading muscle disease company focused on advancing innovative life-transforming therapeutics for patients with genetically driven diseases. We are utilizing our proprietary FORCE platform to overcome the current limitations of muscle tissue delivery and advance modern oligonucleotide therapeutics for muscle diseases. Our proprietary FORCE platform therapeutics consist of an oligonucleotide payload that we rationally design to target the genetic basis of the disease we are seeking to treat, a clinically validated linker and an antigen-binding fragment, or Fab, that we attach to the payload using the linker. With our FORCE platform, we have the flexibility to deploy different types of oligonucleotide payloads with specific mechanisms of action that modify target functions. We leverage this modularity to focus on muscle diseases with high unmet need, with etiologic targets and with clear translational potential from preclinical disease models to well-defined clinical development and regulatory pathways. Using our FORCE platform, we are assembling a broad portfolio of muscle disease therapeutics, including our lead programs in myotonic dystrophy type 1, or DM1, Duchenne muscular dystrophy, or DMD, and facioscapulohumeral dystrophy, or FSHD. In addition, we plan to expand our portfolio through development efforts focused on rare skeletal muscle diseases, as well as cardiac and metabolic muscle diseases, including some with larger patient populations. Our programs are currently all in the preclinical stage. We expect to submit investigational new drug, or IND, applications to the U.S. Food and Drug Administration, or FDA, for product candidates in each of our DM1, DMD and FSHD programs between the fourth quarter of 2021 and the fourth quarter of 2022.

We were incorporated and commenced operations in 2017. Since our incorporation, we have devoted substantially all of our financial resources and efforts to organizing and staffing our company, business planning, raising capital, conducting research activities and filing and prosecuting patent applications. We do not have any products for sale and have not generated any revenue from product sales or otherwise. To date, we have principally raised capital through sales of equity securities and borrowings under a loan and security agreement, or our loan agreement, with a commercial bank. On September 21, 2020, we completed our initial public offering, or IPO, pursuant to which we issued and sold 14,089,314 shares of our common stock, including 1,837,736 shares pursuant to the full exercise of the underwriters’ option to purchase additional shares. We received net proceeds of $246.4 million, after deducting underwriting discounts and commissions and offering expenses payable by us. On January 25, 2021, we completed a follow-on public offering, which we refer to as the January 2021 offering, pursuant to which we issued and sold 6,000,000 shares of our common stock. We received net proceeds of $157.3 million, after deducting underwriting discounts and commissions and offering expenses payable by us.

Since our inception, we have incurred significant operating losses. Our ability to generate any product revenue or product revenue sufficient to achieve profitability will depend on the successful development and eventual commercialization of one or more product candidates we may develop. For the years ended

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December 31, 2019 and 2020, we reported net losses of $14.9 million and $59.4 million, respectively. As of December 31, 2020, we had an accumulated deficit of $79.2 million.

We expect to continue to incur significant expenses and increasing operating losses for the foreseeable future. We expect that our expenses and capital expenditures will increase substantially in connection with our ongoing activities, particularly if and as we:

• expand the capabilities of our proprietary FORCE platform;

• hire additional clinical, regulatory and scientific personnel;

We will not generate revenue from product sales unless and until we successfully complete clinical development and obtain regulatory approval for any product candidates we may develop. If we obtain regulatory approval for or otherwise commercialize any product candidates we may develop, we expect to incur significant expenses related to developing our commercialization capabilities to support product sales, marketing and distribution. Further, we expect to continue to incur additional costs associated with operating as a public company.

As a result, we will need substantial additional funding to support our continuing operations and pursue our growth strategy. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through a combination of equity offerings, debt financings, collaborations, strategic alliances and licensing arrangements. We may be unable to raise additional funds or enter into such other agreements or arrangements when needed, on favorable terms, or at all. If we fail to raise capital or enter into such agreements or arrangements as and when needed, we may have to significantly delay, reduce or eliminate the development or future commercialization of one or more product candidates we may develop.

Because of the numerous risks and uncertainties associated with product development, we are unable to accurately predict the timing or amount of increased expenses or when, or if, we will be able to achieve profitability. Even if we do achieve profitability, we may not be able to sustain or increase profitability on a quarterly or annual basis. If we fail to become profitable or are unable to sustain profitability on a continuing basis, then we may be unable to raise capital, maintain our research and development efforts, expand our business or continue our operations at planned levels, and as a result we may be forced to substantially reduce or terminate our operations.

We believe that our existing cash, cash equivalents and marketable securities, including the net proceeds from the January 2021 offering, will enable us to fund our operating expenses and capital expenditures into the second half of 2024. We have based our estimates as to how long we expect we will be able to fund our operations on assumptions that may prove to be wrong. We could use our available capital resources sooner than we currently expect, in which case we would be required to obtain additional

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financing, which may not be available to us on acceptable terms, or at all. Our failure to raise capital as and when needed would have a negative impact on our financial condition and our ability to pursue our business strategy. See “—Liquidity and capital resources” below.

Impact of COVID-19 on our business

The worldwide COVID-19 pandemic may affect our ability to initiate and complete preclinical studies, delay the initiation of our future clinical trials, disrupt regulatory activities or have other adverse effects on our business, results of operations, financial condition and prospects. In addition, the pandemic has caused substantial disruption in the financial markets and may adversely impact economies worldwide, both of which could adversely affect our business and operations.

To date, we have not experienced material business disruptions, including with our vendors, or impairments of any of our assets as a result of the pandemic. We are following, and plan to continue to follow, recommendations from federal, state and local governments regarding workplace policies, practices and procedures. In March 2020, we implemented a remote working policy for many of our employees and began restricting non-essential travel, and on May 18, 2020, when Massachusetts began its staged reopening plan, we began implementing a return-to-work plan, in accordance with the guidance and requirements of federal and state authorities. We expect to continue to take actions as may be required or recommended by government authorities or as we determine are in the best interests of our employees and other business partners. We are continuing to monitor the potential impact of the pandemic, but we cannot be certain what the overall impact will be on our business, financial condition, results of operations and prospects.

Components of our results of operations

Revenue

We have not generated any revenue since our inception and do not expect to generate any revenue from the sale of products in the near future, if at all. If our development efforts are successful and we commercialize products, or if we enter into collaboration or license agreements with third parties, we may generate revenue in the future from product sales, as well as upfront, milestone and royalty payments from such collaboration or license agreements, or a combination thereof.

Research and development expenses

Research and development expenses consist primarily of costs incurred for our research activities and development of our programs. These expenses include:

• development and operation of our proprietary FORCE platform;

• costs related to compliance with regulatory requirements.

We expense research and development costs as incurred. Advance payments that we make for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. The prepaid amounts are expensed as the related goods are delivered or the services are performed.

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Our direct external research and development expenses consist of costs that include fees, reimbursed materials and other costs paid to consultants, contractors, CMOs and CROs in connection with our development and manufacturing activities. We do not allocate our research and development costs to specific programs because costs are deployed across multiple programs and our platform and, as such, are not separately classified.

Product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development, primarily due to the increased size and duration of later-stage clinical trials. Accordingly, we expect that our research and development expenses will increase substantially in connection with our preclinical and clinical development activities in the future as we advance our program candidates into IND-enabling studies and clinical trials. At this time, we cannot accurately estimate or know the nature, timing and costs of the efforts that will be necessary to complete the preclinical and clinical development of any product candidates we may develop. The successful development of any product candidate is highly uncertain. This is due to the numerous risks and uncertainties associated with product development, including the following:

• the timing and progress of preclinical and clinical development activities;

A change in the outcome of any of these variables with respect to the development of any product candidate we may develop could significantly change the costs and timing associated with the development of that product candidate. We may never succeed in obtaining regulatory approval for any product candidate we may develop.

General and administrative expenses

General and administrative expenses consist primarily of employee-related expenses, including salaries, related benefits and stock-based compensation, for employees in executive, finance, corporate and business development and administrative functions. General and administrative expenses also include legal fees relating to patent and corporate matters; professional fees for accounting, auditing, tax and

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administrative consulting services; insurance costs; administrative travel expenses; and facility-related expenses, which include direct depreciation costs and allocated expenses for rent and maintenance of facilities and other operating costs.

We anticipate that our general and administrative expenses will increase in the future as we increase our headcount to support our growth strategy and move into our new facility in the second half of 2021. We also anticipate that we will incur increased accounting, audit, legal, regulatory, compliance and director and officer insurance costs as well as investor and public relations expenses associated with our operations as a public company. In addition, if we obtain regulatory approval for a product candidate and do not enter into a third-party commercialization collaboration, we expect to incur significant expenses related to building a sales and marketing team to support product sales, marketing and distribution activities.

Interest income

Interest income consists of interest earned on our cash, cash equivalents and marketable securities. We expect our interest income to increase as we invest the net proceeds received from our sale of Series A preferred stock and Series B preferred stock during 2020, the net proceeds from our IPO in September 2020 and the net proceeds from the January 2021 offering.

Interest expense

Interest expense consisted of interest on borrowings under our loan agreement as well as amortization of debt discount and debt issuance costs. In October 2020, all outstanding borrowings under our loan agreement were repaid.

Change in fair value of preferred stock tranche obligations

Under the terms of the stock purchase agreement that we entered into with purchasers of our Series A preferred stock in November 2018, we were contingently obligated to sell, and the purchasers were contingently obligated to purchase, additional shares of Series A preferred stock upon the achievement of specified milestones.

These contingent rights and obligations, which we refer to as the Tranche Rights, were legally detachable and separately exercisable from the Series A preferred stock. Therefore, we allocated the proceeds from the initial closing of the Series A preferred stock financing in November 2018 between the Tranche Rights (as a liability on the balance sheet) and the Series A preferred stock sold at the initial closing (within equity on the balance sheet). The Tranche Rights were subsequently remeasured at their fair value at the end of each reporting period, with changes in fair value recorded within other income (expense) on the statement of operations.

In September 2019, the Tranche Rights ceased to be remeasured at fair value at the end of each reporting period.

Change in success fee obligation

Our loan agreement required us to pay a success fee upon the occurrence of a specified liquidity event, as defined in the agreement, which included our recently completed IPO. At inception of the loan agreement, this contingent obligation was considered immaterial. The fair value of this liability was remeasured at each reporting date, with changes in fair value recorded as a component of other income (expense) on the statement of operations. Upon the closing of our IPO, the success fee was paid and the remaining liability was eliminated.

Income taxes

Since our inception, we have not recorded any U.S. federal or state income tax benefits for the net losses we have incurred in any year or for our earned research and development tax credits, due to our uncertainty of realizing a benefit from those items. As of December 31, 2020, we had federal and state

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net operating loss carryforwards of $69.1 million and $68.9 million, respectively. The federal net operating loss carryforwards are indefinite lived and the state net operating loss carryforwards begin to expire in 2038. As of December 31, 2020, we also had federal and state research and development tax credit carryforwards $0.8 million and $0.4 million which begin to expire in 2039 and 2033, respectively.

Utilization of the net operating loss carryforwards and research and development tax credit carryforwards may be subject to a substantial annual limitation under Section 382 of the Internal Revenue Code of 1986 due to ownership changes that have occurred previously or that could occur in the future. These ownership changes may limit the amount of carryforwards that can be utilized annually to offset future taxable income. In general, an ownership change, as defined by Section 382, results from transactions increasing the ownership of certain stockholders or public groups in the stock of a corporation by more than 50% over a three-year period. We have not conducted a study to assess whether a change of control has occurred or whether there have been multiple changes of control since inception due to the significant complexity and cost associated with such a study. If we have experienced a change of control, as defined by Section 382, at any time since inception, utilization of the net operating loss carryforwards or research and development tax credit carryforwards would be subject to an annual limitation under Section 382, which is determined by first multiplying the value of our common stock at the time of the ownership change by the applicable long-term tax-exempt rate, and then could be subject to additional adjustments, as required. Any limitation may result in expiration of a portion of the net operating loss carryforwards or research and development tax credit carryforwards before utilization. Further, until a study is completed and any limitation is known, no amounts are being presented as an uncertain tax position.

Results of operations

Comparison of the years ended December 31, 2020 and 2019

The following table summarizes our results of operations for the years ended December 31, 2020 and 2019:

Year Ended December 31,

Operating expenses:

Other income (expense):

Interest expense (396 ) — (396 )

Change in fair value of preferred stock tranche obligations — (1,323 ) 1,323

Change in success fee obligation (450 ) — (450 )

Research and development expenses

The following table summarizes our research and development expenses for the years ended December 31, 2020 and 2019:

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Year Ended December 31,

Laboratory supplies and research materials 2,718 3,464 (746 )

The increase in personnel-related costs and stock-based compensation expense was primarily due to increased headcount in our research and development function. The increases in facility-related and other expenses and in costs for laboratory supplies and research materials were primarily due to the increased costs of supporting a larger group of research and development personnel and their research efforts. The increase in external manufacturing and research costs was primarily due to the development of our manufacturing process, increased research activity and the advancement of our programs.

General and administrative expenses

The following table summarizes our general and administrative expenses for the years ended December 31, 2020 and 2019:

Year Ended December 31,

The increase in personnel-related costs and stock-based compensation expense was primarily the result of an increase in headcount in our general and administrative function. Professional and consulting fees increased primarily due to accounting, audit and legal services as well as costs associated with ongoing business activities and our preparations to operate as a public company.

Interest income

Interest income for the years ended December 31, 2020 and 2019 was $0.1 million and $0.3 million, respectively, due to interest earned on invested cash balances.

Interest expense

Interest expense for the year ended December 31, 2020 was $0.4 million due to interest incurred on outstanding borrowings under our loan agreement. We did not incur any interest expense in the prior year period.

Change in fair value of preferred stock tranche obligations

During the year ended December 31, 2019, we recorded other income of $1.3 million from a decrease in the fair value of our preferred stock tranche obligations resulting from the decrease in the fair value of the underlying Series A preferred stock. The remaining liability was reclassified to permanent equity in September 2019, and the obligations were no longer required to be remeasured.

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Change in success fee obligation

The fair value of the success fee obligation included in our loan agreement increased during the year ended December 31, 2020 by $0.5 million. The obligation was settled in September 2020 and no longer requires recognition.

Liquidity and capital resources

Sources of liquidity

Since our inception, we have incurred significant operating losses. We expect to incur significant expenses and operating losses for the foreseeable future as we support our continued research activities and development of our programs and platform. We have not yet commercialized any product candidates, and we do not expect to generate revenue from sales of any product candidates for several years, if at all. To date, we have funded our operations primarily with proceeds from sales of equity securities, borrowings under our loan agreement and, most recently, with proceeds from the sale of common stock in our IPO and the January 2021 offering. As of December 31, 2020 we had cash, cash equivalents and marketable securities of $345.3 million. On January 25, 2021, we completed a follow-on offering pursuant to which we issued and sold 6,000,000 shares of our common stock at a public offering price of $28.00 per share, resulting in net proceeds of $157.3 million, after deducting underwriting discounts and commissions and offering expenses payable by us.

Cash flows

The following table summarizes our sources and uses of cash for each of the periods presented:

Year Ended December 31,

Net cash used in operating activities $ (46,507 ) $ (11,834 )

Net cash used in investing activities (45,661 ) (1,647 )

Net cash provided by financing activities 380,689 19,989

Net increase (decrease) in cash and cash equivalents $ 288,521 $ 6,508

Operating activities

During the year ended December 31, 2020, operating activities used $46.5 million of cash, due to our net loss of $59.4 million, partially offset by non-cash charges of $7.8 million and net cash provided by changes in our operating assets and liabilities of $5.1 million. Net cash provided by changes in our operating assets and liabilities primarily consisted of a $8.6 million increase in accounts payable and other liabilities, partially offset by a $3.5 million increase in prepaid expenses and other current assets.

During the year ended December 31, 2019, operating activities used $11.8 million of cash, due to our net loss of $14.9 million, partially offset by non-cash charges of $7.8 million and net cash provided by changes in our operating assets and liabilities of $1.6 million. Net cash provided by changes in our operating assets and liabilities primarily consisted of a $1.7 million increase in accounts payable and other liabilities, partially offset by a $0.3 million increase in prepaid expenses and other current assets.

Changes in our operating assets and liabilities during these periods were generally due to growth in our business, the advancement of our research programs and the timing of vendor invoices and payments.

Investing activities

During the year ended December 31, 2020, net cash used in investing activities was $45.7 million due primarily to the purchases of marketable securities.

During the year ended December 31, 2019, net cash used in investing activities was $1.6 million due to purchases of property and equipment during the period.

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Financing activities

During the year ended December 31, 2020, net cash provided by financing activities was $380.7 million, consisting of $246.4 million in aggregate net proceeds from our IPO in March 2019, $134.8 million in net proceeds from issuance of Preferred Stock, and an offset of $0.5 million in the settlement of our success fee obligation.

During the year ended December 31, 2019, net cash provided by financing activities was $20.0 million, consisting solely of the proceeds from our issuance of Series A preferred stock.

Funding requirements

We expect our expenses to increase substantially in connection with our ongoing activities, particularly as we advance our research programs into preclinical and clinical development and incur additional costs associated with operating as a public company. The timing and amount of our operating expenditures will depend largely on:

• the identification of additional research programs and product candidates;

• additions or departures of key scientific or management personnel;

• the costs of operating as a public company.

We believe that our existing cash, cash equivalents and marketable securities, including the net proceeds from the January 2021 offering, will enable us to fund our operating expenses and capital expenditure requirements into the second half of 2024. We expect that our liquidity will be sufficient to enable us to submit INDs in each of our DM1, DMD and FSHD programs and achieve proof-of-concept data readouts in our DM1, DMD and FSHD programs. We have based these estimates on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect.

Until such time, if ever, as we can generate substantial product revenue, we expect to finance our cash needs through a combination of equity offerings, debt financings, collaborations, strategic alliances, and marketing, distribution or licensing arrangements with third parties. To the extent that we raise additional capital through the sale of equity or convertible debt securities, the ownership interest of our stockholders may be materially diluted, and the terms of such securities could include liquidation or other preferences that adversely affect the rights of holders of our common stock. Debt financing and preferred equity financing, if available, may involve agreements that include restrictive covenants that limit our ability to take specified actions, such as incurring additional debt, making capital expenditures or

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declaring dividends. If we raise funds through collaborations, strategic alliances or marketing, distribution or licensing arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to us. We may be unable to raise additional funds or enter into such other agreements or arrangements when needed, on favorable terms, or at all. If we fail to raise capital or enter into such agreements other arrangements as and when needed, we may have to significantly delay, reduce or eliminate the development or future commercialization of one or more of our product candidates we may develop. See Item 1A. “Risk factors” in this Annual Report on Form 10-K for additional risks associated with our substantial capital requirements.

Contractual obligations

We enter into contracts in the normal course of business with CROs, CMOs and other third parties for preclinical research studies, clinical trials and testing and manufacturing services. These contracts typically do not contain minimum purchase commitments and are generally cancelable by us upon written notice. Payments due upon cancellation consist of payments for services provided or expenses incurred, including noncancelable obligations of our service providers, up to the date of cancellation and in the case of certain arrangements with CROs and CMOs may include non-cancelable fees.

We have also entered into a license agreement with the University of Mons under which we are obligated to make specified milestone and royalty payments. The payment obligations under this agreement are contingent upon future events, such as our achievement of specified development, regulatory and commercial milestones, or generating product sales. We are unable to estimate the timing or likelihood of achieving these milestones or generating future product sales. For additional information about our license agreement with the University of Mons and amounts that could become payable in the future under that agreement, see Item 1. “Business—Intellectual Property—License Agreement with the University of Mons” in this Annual Report on Form 10-K.

In May 2019, we entered into a sublease agreement for a portion of our laboratory and office space. The term of the sublease commenced on July 1, 2019 and expires on December 31, 2021. Our lease payments for the remainder of the term of the sublease will be $0.1 million per month.

On December 4, 2020, we entered into a lease agreement for additional office and laboratory space. The lease has a term of 8.5 years, with lease payments that begin six months after the premises are ready for occupancy and will be $0.4 million per month, increasing up to $0.5 million during the term of the lease. We have two options to extend the term of the lease, each for a period of an additional five years. We expect the premises to be ready for occupancy in the second half of 2021.

Critical accounting policies and significant judgments and estimates

Our consolidated financial statements are prepared in accordance with generally accepted accounting principles in the United States. The preparation of our consolidated financial statements and related disclosures requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, costs and expenses, and the disclosure of contingent assets and liabilities in our financial statements. We base our estimates on historical experience, known trends and events and various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. We evaluate our estimates and assumptions on an ongoing basis. Our actual results may differ from these estimates under different assumptions or conditions.

While our significant accounting policies are described in more detail in Note 2 to our consolidated financial statements, we believe that the following accounting policies are those most critical to the judgments and estimates used in the preparation of our consolidated financial statements.

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Accrued research and development expenses

As part of the process of preparing our financial statements, we are required to estimate our accrued research and development expenses. This process involves reviewing open contracts and purchase orders, communicating with our applicable personnel to identify services that have been performed on our behalf and estimating the level of service performed and the associated cost incurred for the service when we have not yet been invoiced or otherwise notified of actual costs. The majority of our service providers invoice us in arrears for services performed, on a pre-determined schedule or when contractual milestones are met; however, some require advance payments. We make estimates of our accrued expenses as of each balance sheet date in the financial statements based on facts and circumstances known to us at that time. We periodically confirm the accuracy of these estimates with the service providers and make adjustments, if necessary. Examples of estimated accrued research and development expenses include fees paid to:

• vendors in connection with preclinical development activities;

• CROs and investigative sites in connection with research activities; and

• CMOs in connection with the production of research materials.

We measure the expense recognized based on our estimates of the services received and efforts expended pursuant to quotes and contracts with multiple CMOs and CROs that supply, conduct and manage preclinical studies on our behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows. There may be instances in which payments made to our vendors will exceed the level of services provided and result in a prepayment of the expense. Payments under some of these contracts depend on factors such as the successful enrollment of patients and the achievement of specified milestones. In accruing service fees, we estimate the time period over which services will be performed and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from the estimate, we adjust the accrual or the amount of prepaid expenses accordingly. Although we do not expect our estimates to be materially different from amounts actually incurred, our understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in changes in estimates that increase or decrease amounts recognized in any particular period. To date, there have not been any material adjustments to our prior estimates of accrued research and development expenses.

Stock-based compensation

We measure stock-based awards granted to employees and directors based on fair value on the date of the grant using the Black-Scholes option-pricing model for options. Compensation expense for those awards is recognized over the requisite service period, which is generally the vesting period of the respective award. We use the straight-line method to record the expense of awards with service-based vesting conditions. We use the graded-vesting method to record the expense of awards with both service-based and performance-based vesting conditions, commencing when achievement of the performance condition becomes probable.

The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model, which uses as inputs the fair value of our common stock and assumptions we make for the volatility of our common stock, the expected term of our stock options, the risk-free interest rate for a period that approximates the expected term of our stock options and our expected dividend yield.

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Prior to our IPO, there was no public market for our common stock, and consequently, the estimated fair value of our common stock was determined by our board of directors as of the date of each option grant, with input from management, considering third-party valuations of our common stock as well as our board of directors’ assessment of additional objective and subjective factors that it believed were relevant and which may have changed from the date of the most recent third-party valuation through the date of the grant. Since our IPO, we have determined the fair market value of our common stock using the closing price of our common stock as reported on the Nasdaq Global Select Market.

Off-balance sheet arrangements

We did not have during the periods presented, and we do not currently have, any off-balance sheet arrangements, as defined in the rules and regulations of the Securities and Exchange Commission.

Recently issued accounting pronouncements

Refer to Note 2, “Summary of Significant Accounting Policies,” in the accompanying notes to the consolidated financial statements for a discussion of recent accounting pronouncements.

Emerging growth company and smaller reporting company status

We are an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act, or JOBS Act, and may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies. We may take advantage of these exemptions until we are no longer an “emerging growth company.” Section 107 of the JOBS Act provides that an “emerging growth company” can take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. We have elected to use the extended transition period for complying with new or revised accounting standards and as a result of this election, our financial statements may not be comparable to companies that comply with public company effective dates. We may take advantage of these exemptions until December 31, 2025 or until such earlier time that we are no longer an “emerging growth company.”

We are also a “smaller reporting company” as defined in Rule 12b-2 under the Exchange Act. We may continue to be a smaller reporting company if either (i) the market value of our shares held by non-affiliates is less than $250 million or (ii) our annual revenue is less than $100 million during the most recently completed fiscal year and the market value of our shares held by non-affiliates is less than $700 million as of the last business day of our most recently completed second fiscal quarter. If we are a smaller reporting company at the time we cease to be an emerging growth company, we may continue to rely on exemptions from certain disclosure requirements that are available to smaller reporting companies.

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Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

We are a smaller reporting company as defined by Rule 12b‐2 of the Exchange Act and are not required to provide the information required under this item.

Item 8. Financial Statements and Supplementary Data.

The financial statements required to be filed pursuant to this Item 8 are appended to this Annual Report on Form 10-K. An index of those financial statements is found in Item 15 of Part IV of this Annual Report on Form 10-K.

Item 9. Changes in and Disagreements With Accountants on Accounting and Financial Disclosure.

None.

Item 9A. Controls and Procedures.

Evaluation of Disclosure Controls and Procedures

Our management, under the supervision and with the participation of our Chief Executive Officer and Vice President, Accounting & Administration (our principal executive officer and principal financial officer, respectively), evaluated the effectiveness of our disclosure controls and procedures as of December 31, 2020. The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act means controls and other procedures of an issuer that are designed to ensure that information required to be disclosed by an issuer in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by an issuer in the reports that it files or submits under the Exchange Act is accumulated and communicated to the issuer’s management, including its principal executive and principal financial officers, or persons performing similar functions, as appropriate to allow timely decisions regarding required disclosure.

Management recognizes that any disclosure controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives and management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures. Based on the evaluation of our disclosure controls and procedures as of December 31, 2020, our Chief Executive Officer and Vice President, Accounting & Administration concluded that, as of such date, our disclosure controls and procedures were effective at the reasonable assurance level.

Exemption from Management’s Report on Internal Control over Financial Reporting

This Annual Report on Form 10-K does not include a report of management’s assessment regarding internal control over financial reporting or an attestation report of our independent registered public accounting firm due to a transition period established by rules of the SEC for newly public companies.

Changes in Internal Control over Financial Reporting

There were no changes in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d‐15(f) under the Exchange Act) that occurred during the three months ended December 31, 2020 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Item 9B. Other Information.

None.

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PART III

Item 10. Directors, Executive Officers and Corporate Governance.

Except to the extent provided below, the information required by this Item 10 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2021 Annual Meeting of Stockholders which we intend to file not later than 120 days after the end of our fiscal year ended December 31, 2020 and is incorporated herein by reference.

We have adopted a written code of business conduct and ethics that applies to our directors, officers, employees and designated agents, including our principal executive officer, principal financial officer, principal accounting officer, or persons performing similar functions. A current copy of the code is posted on the investor relations section of our website, which is located at http://www.dyne-tx.com. If we make any substantive amendments to, or grant any waivers from, the code of business conduct and ethics for any officer or director, we will disclose the nature of such amendment or waiver on our website.

Item 11. Executive Compensation.

The information required by this Item 11 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2021 Annual Meeting of Stockholders and is incorporated herein by reference.

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters.

The information required by this Item 12 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2021 Annual Meeting of Stockholders and is incorporated herein by reference.

Item 13. Certain Relationships and Related Transactions, and Director Independence.

The information required by this Item 13 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2021 Annual Meeting of Stockholders and is incorporated herein by reference.

Item 14. Principal Accounting Fees and Services.

The information required by this Item 14 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2021 Annual Meeting of Stockholders and is incorporated herein by reference.

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PART IV

Item 15. Exhibits, Financial Statement Schedules.

(1) Consolidated Financial Statements

The following documents are included on pages F-1 through F-24 attached hereto and are filed as part of this Annual Report on Form 10-K.

Report of Independent Registered Public Accounting Firm F-2

Consolidated Balance Sheets F-3

Consolidated Statements of Operations and Comprehensive Loss F-4

Consolidated Statements of Cash Flows F-6

Notes to Consolidated Financial Statements F-7

(2) Financial Statement Schedules

All financial statement schedules have been omitted because they are either not required or not applicable or the information is included in the consolidated financial statements or the notes thereto.

(3) Exhibits

The following is a list of exhibits filed as part of this Annual Report on Form 10-K.

Exhibit Number Description

4.3* Description of Securities Registered Under Section 12 of the Exchange Act

141

142

21.1* Subsidiaries of the Registrant

101.INS XBRL Instance Document

101.SCH XBRL Taxonomy Extension Schema Document

101.CAL XBRL Taxonomy Extension Calculation Linkbase Document

101.DEF XBRL Taxonomy Extension Definition Linkbase Document

101.LAB XBRL Taxonomy Extension Label Linkbase Document

101.PRE XBRL Taxonomy Extension Presentation Linkbase Document

* Filed herewith.

143

Item 16. Form 10-K Summary

None.

144

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this Report to be signed on its behalf by the undersigned, thereunto duly authorized.

Company Name

Date: March 4, 2021 By: /s/ Joshua Brumm

Joshua Brumm

President and Chief Executive Officer

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, this Report has been signed below by the following persons on behalf of the Registrant in the capacities and on the dates indicated.

Name Title Date

Joshua Brumm

Richard Scalzo

/s/ Jason Rhodes Director and Chairman of the Board March 4, 2021

Jason Rhodes

/s/ Ed Hurwitz Director March 4, 2021

Ed Hurwitz

/s/ Dirk Kersten Director March 4, 2021

Dirk Kersten

/s/ Lawrence Klein Director March 4, 2021

Lawrence Klein, Ph.D.

/s/ David Lubner Director March 4, 2021

David Lubner

/s/ Catherine Stehman-Breen Director March 4, 2021

Catherine Stehman-Breen, M.D.

145

Index to Consolidated Financial Statements

Report of Independent Registered Public Accounting Firm F-2

Consolidated Balance Sheets F-3

Consolidated Statements of Operations and Comprehensive Loss F-4

Consolidated Statements of Cash Flows F-6

Notes to Consolidated Financial Statements F-7

Report of Independent Registered Public Accounting Firm

To the stockholders and board of directors of Dyne Therapeutics, Inc.

Opinion on the financial statements

We have audited the accompanying consolidated balance sheets of Dyne Therapeutics, Inc. and subsidiary (the “Company”) as of December 31, 2020 and 2019, and the related consolidated statements of operations and comprehensive loss, redeemable convertible preferred stock and stockholders’ equity (deficit), and cash flows for the years then ended and the related notes to the financial statements (collectively referred to as the “financial statements”). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2020 and 2019, and the results of its operations and its cash flows for each of the years then ended, in conformity with accounting principles generally accepted in the United States of America.

Basis for opinion

These financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulation of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits, we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company’s internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

/s/ Deloitte & Touche LLP

Boston, Massachusetts

March 4, 2021

We have served as the Company’s auditor since 2020.

F-2

Dyne Therapeutics, Inc.

Consolidated Balance Sheets

December 31,

(in thousands, except share and per share data) 2020 2019

Assets

Current assets:

Marketable securities 44,462 —

Prepaid expenses and other current assets 3,773 127

Restricted cash and other assets 2,301 191

Liabilities and Stockholders’ Equity

Current liabilities:

Accrued expenses and other current liabilities 7,527 1,102

Deferred rent — 42

Commitments and contingencies (Note 12)

Stockholders’ equity

Convertible preferred stock (Note 7) — 27,429

Accumulated other comprehensive loss (27 ) —

Total liabilities and stockholders’ equity $ 353,334 $ 16,436

The accompanying notes are an integral part of these financial statements.

F-3

Dyne Therapeutics, Inc.

Consolidated Statements of Operations and Comprehensive Loss

Year Ended December 31,

(in thousands, except share and per share data) 2020 2019

Operating expenses:

Other (expense) income:

Interest expense (396 ) —

Change in fair value of preferred stock tranche obligations — (1,323 )

Change in success fee obligation (450 ) —

Total other (expense) income, net (790 ) (1,033 )

Net loss per share, basic and diluted $ (4.13 ) $ (6.08 )

Comprehensive loss:

Other comprehensive loss:

Unrealized losses on marketable securities (27 ) —

The accompanying notes are an integral part of these financial statements.

F-4

Dyne Therapeutics, Inc.

Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders’ Equity (Deficit)

(in thousands, except share data) Shares Amount Shares Amount Shares Amount

Settlement of Tranche Right I — (1,621 ) — — — — — — — —

Stock-based compensation — — — — — — 26 — — 26

Vesting of restricted shares — — — — 476,131 — — — — —

Exercise of stock options — — — — 32,197 — 30 — — 30

Stock-based compensation — — — — — — 6,591 — — 6,591

Vesting of restricted shares — — — — 282,153 — — — — —

Unrealized gains on marketable securities — — — — (27 ) — (27 )

The accompanying notes are an integral part of these financial statements.

F-5

Dyne Therapeutics, Inc.

Consolidated Statements of Cash Flows

Year Ended December 31,

Cash flows from operating activities:

Adjustments to reconcile net loss to net cash used in operating activities:

Stock-based compensation expense 6,591 26

Depreciation and amortization expense 700 271

Amortization of debt discount 64 —

Amortization (accretion) of premium (discount) on marketable securities 12 —

Changes in fair value of preferred stock tranche obligations — 1,323

Changes in success fee obligation 450 —

Changes in operating assets and liabilities:

Prepaid expenses and other assets (3,455 ) (284 )

Accounts payable and other liabilities 8,567 1,689

Net cash used in operating activities (46,508 ) (11,834 )

Cash flows from investing activities:

Purchases of property and equipment (1,161 ) (1,647 )

Purchases of marketable securities (44,500 ) —

Net cash used in investing activities (45,661 ) (1,647 )

Cash flows from financing activities:

Settlement of success fee obligation (450 ) —

Proceeds from issuance of debt, net of issuance costs 9,936 —

Repayment of debt (10,000 ) —

Proceeds from exercise of stock options 30 —

Net cash provided by financing activities 380,690 19,989

Net increase in cash, cash equivalents and restricted cash 288,521 6,508

Cash, cash equivalents and restricted cash, beginning of year 14,632 8,124

Cash, cash equivalents and restricted cash, end of year $ 303,153 $ 14,632

Supplemental cash flow information:

Cash paid for interest and taxes $ 328 $ —

Supplemental disclosure of non-cash investing and financing information:

Conversion of convertible preferred stock to common stock $ 162,215 $ —

Settlement of Tranche Right I $ — $ 1,621

The accompanying notes are an integral part of these financial statements.

F-6

Dyne Therapeutics, Inc.

Notes to Consolidated Financial Statements

1. Nature of business and basis of presentation

Dyne Therapeutics, Inc. (the “Company”) is building a leading muscle disease company focused on advancing innovative life-transforming therapeutics for people living with genetically driven diseases that was incorporated in Delaware on December 1, 2017 and has a principal place of business in Waltham, Massachusetts.

The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, risks of failure of preclinical studies and clinical trials, the need to obtain marketing approval for its product candidates, fluctuations in operating results, compliance with government regulations, the ability to establish clinical- and commercial-scale manufacturing processes, the impact of the COVID-19 pandemic and the ability to secure additional capital to fund operations. Programs currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization of a product. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales.

On September 21, 2020, the Company completed its initial public offering (“IPO”) pursuant to which it issued and sold 14,089,314 shares of its common stock, including 1,837,736 shares pursuant to the full exercise of the underwriters’ option to purchase additional shares, at a public offering price of $19.00 per share, resulting in net proceeds of $246.4 million, after deducting underwriting discounts and commissions and offering expenses. Upon the closing of the IPO, all of the Company’s then outstanding convertible preferred stock automatically converted into shares of common stock.

On January 25, 2021, the Company completed a follow-on public offering of common stock pursuant to which it issued and sold 6,000,000 shares of its common stock at a public offering price of $28.00 per share, resulting in net proceeds of $157.3 million, after deducting underwriting discounts and commissions and offering expenses.

The accompanying consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. Since inception, the Company has funded its operations with proceeds from the sales of preferred stock and common stock, including the IPO completed in September 2020 and the follow-on offering completed in January 2021. The Company expects to continue to generate operating losses for the foreseeable future. The Company expects that its cash, cash equivalents and marketable securities will be sufficient to fund its operating expenses and capital expenditure requirements for at least 12 months from the issuance of these consolidated financial statements.

To continue its development efforts, the Company will need to obtain substantial additional funding through public or private equity offerings, debt financings, collaborations, strategic alliances and/or licensing arrangements in order to fund its research and development and ongoing operating expenses. The Company may not be able to obtain financing on acceptable terms, when needed or at all, and the Company may not be able to enter into collaborations, strategic alliances or licensing arrangements. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. Any collaborations, strategic alliances or licensing arrangements may require the Company to relinquish rights to certain of its technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to the Company. If the Company is unable to obtain funding,

F-7

the Company could be forced to delay, limit, reduce or eliminate some or all of its research and development programs, pipeline expansion or future commercialization efforts or grant rights to develop and market product candidates, which could adversely affect its business prospects. Although management will continue to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations when needed or at all.

To date, the Company has not experienced material business disruptions, including with its vendors, as a result of the COVID-19 pandemic. In March 2020, the Company implemented a remote working policy for many of its employees and began restricting non-essential travel, and on May 18, 2020, when Massachusetts began its staged reopening plan, the Company began implementing a return-to-work plan, in accordance with the guidance and requirements of federal and state authorities. The Company expects to continue to take actions as may be required or recommended by government authorities or as it determines are in the best interests of its employees and other business partners. The Company is continuing to monitor the potential impact of the pandemic, but cannot be certain what the overall impact will be on its business, financial condition, results of operations and prospects.

2. Summary of significant accounting policies

The accompanying consolidated financial statements reflect the operations of the Company and the Company’s wholly owned subsidiary, Dyne Therapeutics Securities Corporation. Intercompany balances and transactions have been eliminated in consolidation. The accompanying consolidated financial statements have been prepared in conformity with generally accepted accounting principles (“GAAP”) in the United States of America. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”).

Use of estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the accrual of research and development expenses and stock-based compensation expense. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. On an ongoing basis, management evaluates its estimates, as there are changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results may differ from those estimates or assumptions.

Concentrations of credit risk and of significant suppliers

Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company believes the depository institutions in which the cash and cash equivalents are held are of high-credit quality. The Company maintains its cash equivalents in money market funds that invest in U.S. treasury securities. The Company’s marketable securities as of December 31, 2020 consisted of commercial paper and corporate debt securities. The Company has adopted an investment policy that limits the amounts the Company may invest in the securities of any single issuer with the exclusion of the U.S. government. The Company has not experienced any credit losses.

The Company is dependent on a small number of third-party suppliers for its drug substance and drug product. In particular, the Company relies, and expects to continue to rely, on third-party suppliers for certain materials and components required for the development of its programs and future production of any product candidates it may develop for its programs. These programs could be adversely affected by a significant interruption in the supply process.

F-8

Cash and cash equivalents

Cash includes cash in readily available checking accounts and cash equivalents include all highly liquid investments maturing within 90 days from the date of purchase.

Restricted cash

Amounts included in restricted cash represent amounts pledged as collateral for letters of credit required for security deposits on the Company’s leased facilities. Restricted cash totaled $2.3 million and $0.0 million at December 31, 2020 and 2019, respectively. These amounts are classified as restricted cash on the Company’s consolidated balance sheets.

Marketable securities

The Company’s marketable securities as of December 31, 2020 consisted of commercial paper, certificates of deposit and corporate debt securities and are classified as available-for-sale and are reported at fair value. Unrealized losses on available-for-sale debt securities are reported as a component of accumulated other comprehensive loss in stockholders’ equity. Realized gains and losses are based on the specific identification method and are included as a component of other income (expense), net in the consolidated statements of operations and comprehensive loss.

The Company evaluates its marketable securities with unrealized losses for other-than-temporary impairment. When assessing marketable securities for other-than-temporary declines in value, the Company considers such factors as, among other things, how significant the decline in value is as a percentage of the original cost, how long the market value of the investment has been less than its original cost, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value and market conditions in general. If any adjustment to fair value reflects a decline in the value of the investment that the Company considers to be “other than temporary,” the Company reduces the investment to fair value through a charge to the statement of operations and comprehensive loss. No such adjustments were necessary during the periods presented.

Deferred rent

Payment escalations, rent holidays and other lease incentives that may be included in lease agreements are accrued or deferred as appropriate such that rent expense for each lease is recognized on a straight-line basis over the respective lease term. Adjustments for such items are recorded as deferred rent and amortized over the respective lease terms.

Property and equipment

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization expense is recognized using the straight-line method over the estimated useful life of each asset as follows:

Estimated Useful Life

Laboratory equipment 3 years

Furnitures and fixtures 5 years

Computer equipment 3 years

Leasehold improvements Shorter of life of lease or 10 years

Costs for capital assets not yet placed into service are capitalized as construction-in-progress and depreciated once placed into service. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation and amortization are removed from the accounts and any resulting gain or loss is included in loss from operations. Expenditures for repairs and maintenance which do not improve or extend the life of the respective assets are charged to expense as incurred.

F-9

Impairment of long-lived assets

Long-lived assets consist of property and equipment. The Company evaluates the recoverability of its long-lived assets when circumstances indicate that an event of impairment may have occurred. The Company recognizes an impairment loss only if the carrying amount of a long-lived asset is not recoverable based on its undiscounted future cash flows. Impairment is measured based on the difference between the carrying value of the related assets and the fair value of such assets. The Company has not recorded any impairment charges in the periods presented in these financial statements.

Segment information

Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, or decision-making group, in making decisions on how to allocate resources and assess performance. The Company’s chief operating decision maker is the chief executive officer (“CEO”). The CEO views the Company’s operations and manages the business as one operating segment.

Research and development costs

Research and development costs are expensed as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including salaries and bonuses, stock-based compensation, employee benefits, facilities costs, laboratory supplies, depreciation and amortization, manufacturing expenses and external costs of vendors engaged to conduct preclinical development activities as well as the cost of licensing technology.

Upfront payments and milestone payments made for the licensing of technology are expensed as research and development expenses in the period in which they are incurred. Advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. The prepaid amounts are expensed as the related goods are consumed or the services are performed.

Research and manufacturing contract costs and accruals

The Company has entered into various research and development and manufacturing contracts. These agreements are generally cancelable, and related payments are recorded as the corresponding expenses are incurred. The Company records accruals for estimated ongoing costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the research studies and manufacturing activities, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs.

Patent costs

All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses.

Income taxes

The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the financial statements or in the Company’s tax returns. Deferred taxes are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect in the years in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it

F-10

believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies.

The Company accounts for uncertainty in income taxes recognized in the financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement.

Fair value measurements

Certain assets and liabilities are carried at fair value. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable:

• quoted prices for similar assets and liabilities in active markets;

Net loss per share

The Company follows the two-class method when computing net income (loss) per share as the Company has issued shares that meet the definition of participating securities. The two-class method determines net income (loss) per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. During periods of loss, the Company does not allocate loss to participating securities because they have no contractual obligation to share in the losses of the Company.

Basic net loss per share is computed by dividing the net income loss by the weighted average number of shares of common stock outstanding for the period. Diluted net loss is computed by adjusting net loss to

F-11

reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net loss per share is computed by dividing the diluted net loss by the weighted average number of shares of common stock outstanding for the period, including potential dilutive common shares assuming the dilutive effect of common stock equivalents.

Redeemable convertible preferred stock

The Company recorded redeemable convertible preferred stock at fair value upon issuance, net of any issuance costs. The Company classified stock that was redeemable in circumstances outside of the Company’s control outside of permanent equity. No accretion was recognized as the contingent events that could give rise to redemption were not deemed probable.

Stock-based compensation

The Company accounts for stock-based awards at fair value, and measures fair value using the Black-Scholes option-pricing model. Stock-based compensation costs are recognized as expense over the requisite service period, which is generally the vesting period, on a straight-line basis for all time-vested awards. Forfeitures are recognized as they occur.

Success fee obligation

The Company’s loan and security agreement (the “Loan Agreement”) entered into in 2020 required the Company to pay a success fee of $0.5 million upon the occurrence of a specified liquidity event, as described in the Loan Agreement, which included the Company’s IPO. The liability was initially deemed immaterial upon entering into the Loan Agreement and was subsequently remeasured to fair value at each reporting date. Following the completion of the IPO, the success fee of $0.5 million was paid in September 2020.

Comprehensive loss

Comprehensive loss includes net loss as well as other changes in stockholders’ equity that result from transactions and economic events other than those with stockholders. For the year ended December 31, 2020, the Company’s only element of other comprehensive loss was unrealized gains (losses) on marketable securities.

Accounting pronouncements issued and not adopted

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). The new standard requires that all lessees recognize the assets and liabilities that arise from leases on the balance sheet and disclose qualitative and quantitative information about its leasing arrangements. The Company plans to adopt ASU 2016-02 on January 1, 2021 using the modified retrospective approach transition method as of the date of adoption such that prior periods will not be restated. The Company will also elect a package of practical expedients, under which an entity need not reassess whether any expired or existing contracts are or contain leases, the lease classification for any expired or existing leases, or initial direct costs for any existing leases. The adoption of the new standard is expected to result in the recognition of material liabilities and right-of-use assets, however, the Company has not completed the assessment.

F-12

3. Marketable securities and fair value measurements

Marketable securities by security type at December 31, 2020 consisted of the following:

(in thousands) Amortized Cost Unrealized Gains Unrealized Losses Total

The Company did not have marketable securities as of December 31, 2019.

The following tables set forth by level, within the fair value hierarchy (see Note 2), the assets carried at fair value on a recurring basis for the periods presented:

Fair Value Measurements as of December 31, 2020

(in thousands) Level 1 Level 2 Level 3 Total

Assets:

Cash equivalents

Marketable securities

Fair Value Measurements as of December 31, 2019

(in thousands) Level 1 Level 2 Level 3 Total

Assets:

Cash equivalents

The fair value of U.S. government money market funds and commercial paper were determined by the Company based on quoted market prices, which represent a Level 1 measurement within the fair value hierarchy. Certificates of deposit and corporate debt securities were valued by the Company using quoted prices in active markets for similar securities, which represent a Level 2 measurement within the fair value hierarchy. During the years ended December 31, 2020 and 2019, there were no transfers between Level 1, Level 2 and Level 3.

The following table summarizes the scheduled maturity for the Company’s marketable securities at December 31, 2020:

(in thousands) December 31, 2020

Maturing in one year or less $ 28,623

Maturing after one year through two years 24,147

Maturing after two years —

There were no sales of marketable securities during the year ending December 31, 2020.

The fair value of the preferred stock tranche obligations in connection with the unfunded tranches associated with the Series A Preferred Stock Purchase Agreement (see Note 7) was determined based on significant inputs not observable in the market, which represents a Level 3 measurement within the fair

F-13

value hierarchy. The fair value of the preferred stock tranche obligations was determined by considering as inputs the future value of the Series A Preferred Stock, the difference between the future value of the Series A Preferred Stock and the contract price, the number of shares underlying the contract, the probability of achieving the funding of the tranches, expected timing of the tranche closing and the discount rate. The future value of Series A Preferred Stock was estimated by calibrating, or backsolving, to the price of the Series A Preferred Stock as set forth in the Series A Preferred Stock Purchase Agreement. The contractual price of the shares to be issued in addition to the number of shares underlying the contract are both provided for by the Series A Preferred Stock Purchase Agreement. The probability of achieving the funding of the tranches and the expected timing of those closings were estimates made by the Company. The discount rate was equal to the risk-free rate for the estimated timing of each tranche closing.

The fair value of the liability recognized in connection with the contingent success fee associated with the Loan Agreement (see Note 6) was determined based on significant inputs not observable in the market, which represents a Level 3 measurement within the fair value hierarchy. The fair value of the liability was determined using the probability-weighted expected return method (“PWERM”), which considered as inputs the probability of occurrence of a specified liquidity event, the expected timing of a liquidity event, the amount of the success fee and a risk-adjusted discount rate. The initial fair value of the liability was de minimis due to the low probability of the events probable of triggering payment. As of September 21, 2020, the closing date of the IPO, the event occurred and the probability increased to 100% and the discount rate was assessed to be 0%. Based on these inputs, the Company determined that the fair value of the derivative liability was $0.5 million as of September 21, 2020. Following the completion of the IPO, the success fee of $0.5 million was paid in September 2020.

The following table presents a roll-forward of the aggregate fair values of the Company’s liabilities for which fair value is determined by Level 3 inputs:

(in thousands) Preferred Stock Tranche Obligations Success Fee Obligation

Settlement of Tranche Right I 1,621 —

Change in fair value 1,323 —

Reclassification of Tranche Right II to equity (6,319 ) —

Initial fair value of success fee obligation — —

Change in fair value — 450

Settlement of derivative instrument — (450 )

Balance—December 31, 2020 $ — $ —

Financial instruments not recorded at fair value

The carrying values of cash, cash equivalents, accounts payable and accrued expenses that are reported on the balance sheets approximate their fair value due to the short-term nature of these assets and liabilities.

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4. Property and equipment

Property and equipment consisted of the following:

December 31,

Office and computer equipment 78 62

Leasehold improvements 14 14

Construction in process 105 —

Property and equipment—at cost 2,941 1,781

Less accumulated depreciation and amortization (995 ) (295 )

Property and equipment—net $ 1,946 $ 1,486

Depreciation expense totaled $0.7 million and $0.3 million for the years ended December 31, 2020 and 2019, respectively.

5. Accrued expenses and other current liabilities

Accrued expenses and other current liabilities consisted of the following:

December 31,

Consulting services 263 60

Legal services 325 —

6. Debt financing

On February 20, 2020, the Company entered into a Loan Agreement pursuant to which the lender made term loans to the Company in an aggregate principal amount of $10.0 million. Borrowings under the Loan Agreement were collateralized by substantially all of the Company’s assets, excluding intellectual property.

Interest on the outstanding loan balance accrued at a variable annual rate equal to the greater of (i) the lender’s prime rate plus 0.25% and (ii) 5.00%, and the Company was required to make interest-only payments on the loans on a monthly basis through August 2021. The outstanding borrowings were repaid in October 2020.

As part of the Loan Agreement, a success fee of $0.5 million was required in the event of a liquidation event, including an IPO. The success fee represented an embedded derivative which the Company bifurcated from the debt arrangement and carried at fair value. In September 2020, the Company completed its IPO and paid the success fee of $0.5 million.

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7. Convertible preferred stock

Since inception, the Company issued Series A convertible preferred stock (the “Series A Preferred Stock”) and Series B convertible preferred stock (the “Series B Preferred Stock”). Collectively the Series A Preferred Stock and the Series B Preferred Stock are referred to as the Preferred Stock.

Upon the closing of the IPO in September 2020, the Company’s Preferred Stock automatically converted into 28,086,375 shares of common stock.

Series A Preferred Stock

On November 29, 2018, the Company entered into the Series A Preferred Stock Purchase Agreement with its initial investors committing to purchase an aggregate of $50.0 million in shares of Series A Preferred Stock. At the initial closing, 12,500,000 shares of Series A Preferred Stock were issued by the Company at a purchase price of $1.00 per share, for gross cash proceeds of $7.5 million. Of the 12,500,000 shares issued, 5,000,000 shares were issued upon conversion of the then outstanding SAFEs, which had a fair value of $5.0 million. In April 2019, the Company issued an additional 20,000,000 shares of Series A Preferred Stock under the terms of the Series A Preferred Stock Purchase Agreement at a purchase price of $1.00 per share for total gross proceeds of $20.0 million. Issuance costs associated with each closing of the Series A Preferred Stock financing were $0.1 million. On March 18, 2020, the Company entered into a separate Series A Preferred Stock Purchase Agreement with an additional investor and issued 2,000,000 shares of Series A Preferred Stock at a purchase price $1.00 per share for gross cash proceeds of $2.0 million. In July 2020, the Company issued and sold 17,500,000 shares of Series A Preferred Stock at a price of $1.00 per share, for gross proceeds of $17.5 million.

Series B Preferred Stock

In August 2020, the Company issued and sold 41,159,724 shares of Series B Preferred Stock at a price of $2.81 per share for gross proceeds of $115.7 million.

Tranche Rights

Included in the terms of the November 2018 Series A Preferred Stock Purchase Agreement were certain rights (“Tranche Rights”) granted to the investors who purchased the Series A Preferred Stock purchased in November 2018. The Tranche Rights contingently obligated the investors to purchase, and the Company to sell, up to an aggregate of 37,500,000 shares of Series A Preferred Stock at $1.00 per share upon the satisfaction of specified research and development milestones by the Company. The Tranche Rights are also exercisable at the option of the holders of the Series A Preferred Stock. The Tranche Rights were divided into separate rights and obligations to purchase 20,000,000 shares (“Tranche Right I”) and 17,500,000 shares (“Tranche Right II”) based on the achievement of specified milestones for each tranche.

The Company concluded that the Tranche Rights met the definition of a freestanding financial instrument, as the Tranche Rights were legally detachable and separately exercisable from the Series A Preferred Stock. Therefore, the Company allocated the proceeds from the November 2018 issuance between the Tranche Rights and the Series A Preferred Stock. As the Series A Preferred Stock was redeemable upon a deemed liquidation event at the election of the holder-controlled Board, and therefore outside of the control of the Company, the Tranche Rights were initially classified as a liability and were initially recorded at their fair value of $3.4 million. The Tranche Rights were then remeasured at fair value at each reporting period, with changes in fair value recorded in the statement of operations. The estimated fair value of the Tranche Rights was determined at each reporting date using a probability-weighted present value model that considers the probability of closing a tranche, the estimated future value of the Series A Preferred Stock to be issued at each closing, and the investment required at each closing. Future values were converted to present value using a discount rate appropriate for probability-adjusted cash flows.

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In April 2019, Tranche Right I was settled when the Company closed on the issuance of 20,000,000 shares Series A Preferred Stock. The fair value of the Tranche Right I as of the closing date was reclassified from a liability to Series A Preferred Stock within equity.

In September 2019, the size of the Board was increased from five to six members, including three independent members, which allowed the Company to conclude that the redemption rights of the holders of the Series A Preferred Stock was within the control of the Company. As a result, the Company concluded that Tranche Right II qualified for equity classification as of that date. The preferred stock tranche obligation liability, with a fair value of $6.3 million, was reclassified into permanent equity and was no longer remeasured at fair value. In July 2020, Tranche Right II was settled when the Company closed on the issuance of 17,500,000 shares Series A Preferred Stock.

The Preferred Stock had the followings rights and privileges:

Dividends

Holders of the Preferred Stock were entitled to receive non-cumulative dividends when, as and if declared by the Board. The Company did not declare dividends on any class of preferred or common stock.

Liquidation

In the event of any liquidation, dissolution, or winding-up of the Company, which would include the sale of the Company, the Preferred Stock was senior to common stock.

Voting

The holders of the Preferred Stock were entitled to the number of votes equal to the number of shares of common stock into which the shares of Preferred Stock held by each holder were then convertible.

Conversion

The holders of the Preferred Stock were able to convert, at any time, each share of Preferred Stock into shares of common stock at the stated conversion price.

8. Equity

As of December 31, 2020, the Company’s restated certificate of incorporation authorized the Company to issue 200,000,000 shares of common stock, par value $0.0001 per share, and 10,000,000 shares of preferred stock, par value $0.0001 per share.

As of December 31, 2019, the Company had authorized 68,000,000 shares of common stock. The voting, dividend and liquidation rights of the holders of the Company’s common stock was subject to and qualified by the rights, powers and preferences of the holders of the Preferred Stock as set forth above.

9. Stock-based compensation

2018 Stock incentive plan

The Company’s 2018 Stock Incentive Plan (the “2018 Plan”) provided for the Company to sell or issue incentive stock options or nonqualified stock options, restricted stock, and other equity awards to employees, directors and consultants of the Company. The 2018 Plan was administered by the board of directors or, at the discretion of the board of directors, by a committee of the board of directors. The exercise prices, vesting and other restrictions were determined at the discretion of the board of directors.

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The total number of shares of common stock authorized under the 2018 Plan was 8,267,252 shares. Upon the effectiveness of the 2020 Plan, the Company ceased granting awards under the 2018 Plan, and the 1,928,487 shares of common stock remaining under the 2018 Plan became available for future issuance under the 2020 Plan.

2020 Stock incentive plan

In August 2020 the Company’s board of directors adopted and the Company’s stockholders approved the 2020 Plan (together with the 2018 Plan the “Plans”), which became effective on September 16, 2020. The 2020 Plan provides for the grant of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock units and other stock-based awards to employees, directors, consultants and advisors of the Company. The 2020 Plan is administered by the Company’s board of directors or by a committee appointed by the board of directors. Upon the effectiveness of the 2020 Plan, the Company ceased granting awards under the 2018 Plan. The number of shares initially reserved for issuance under the 2020 Plan was 4,884,233. The number of shares of common stock reserved for issuance under the 2020 Plan automatically increases on the first day of each fiscal year, beginning with the fiscal year commencing on January 1, 2021 and continuing for each fiscal year until, and including the fiscal year commencing on, January 1, 2030, in an amount equal to the lower of (1) 5% of the shares of common stock outstanding on such date and (2) an amount determined by the Company’s board of directors. On January 1, 2021, 2,272,345 shares were added to the shares reserved for issuance under the 2020 Plan in the first of these annual increases.

As of December 31, 2020, 3,237,244 shares remained available for future issuance under the 2020 Plan.

2020 Employee Stock Purchase Plan

In August 2020 the Company’s board of directors adopted and the Company’s stockholders approved the 2020 Employee Stock Purchase Plan (the “2020 ESPP”), which became effective September 16, 2020. The 2020 ESPP is administered by the Company’s board of directors or by a committee appointed by the board of directors. The 2020 ESPP initially provides participating employees with the opportunity to purchase up to an aggregate of 488,414 shares of common stock. The number of shares of common stock reserved for issuance under the 2020 ESPP will automatically increase on the first day of each fiscal year, beginning with the fiscal year commencing on January 1, 2021 and continuing for each fiscal year until, and including the fiscal year commencing on, January 1, 2030, in an amount equal to the lowest of (1) 1,953,656 shares of common stock, (2) 1% of the shares of common stock outstanding on such date, and (3) an amount determined by the board of directors. As of December 31, 2020, no offering periods have commenced under the 2020 ESPP and 488,414 shares remained available for issuance.

Stock option valuation

The Company typically grants stock options at exercise prices deemed by the Board to be equal to the fair value of the common stock at the time of grant. In the periods prior to the IPO, the fair value of the common stock was determined by the Board at each measurement date based on a variety of different factors, including the results obtained from independent third-party appraisals, the Company’s financial position and historical financial performance, the status of development of the Company’s programs, the current climate in the marketplace, the illiquid nature of the common stock, the effect of the rights and preferences of the preferred stockholders, and the prospects of a liquidity event, among others. In the periods following the IPO, the fair value is determined based upon the quoted price of the Company’s common stock.

The fair value of stock option grants is estimated using the Black-Scholes option-pricing model. The Company historically has been a private company and lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. For options with service-based vesting conditions, the expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future.

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The assumptions that the Company used to determine the grant-date fair value of options granted were as follows:

Expected volatility 75% 74%

Expected term (in years) 6 6

Expected dividend yield — —

Stock option activity

The following table summarizes the option activity:

The weighted-average grant date fair value of the options granted during the years ended December 31, 2020 and 2019 was $4.50 per share and $0.62 per share, respectively. As of December 31, 2020 there was $20.3 million of unrecognized compensation expense, which the Company expects to recognize over a weighted-average period of 2.71 years. Additionally, as of December 31, 2020, the Company has unrecognized compensation cost related to unvested stock-based awards with performance-based vesting conditions for which performance has not been deemed probable of $2.6 million.

Restricted stock units

A restricted stock unit (“RSU”) represents the right to receive one share of common stock upon vesting of the RSU. The Company grants RSUs with service conditions that vest in four equal annual installments provided that the employee remains employed with the Company. The Company also grants RSUs with performance conditions that vest upon the achievement of specified milestones. The fair value of each RSU is based on the closing price of the Company’s common stock on the date of grant. A summary of the Company’s RSU activity and related information for the 2020 Plan for the year ended December 31, 2020 is as follows:

Number of Shares Underlying RSUs Weighted Average Grant Date Fair Value

Issued and unvested as of January 1, 2020 — —

Vested — —

Forfeited — —

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As of December 31, 2020, there was $7.7 million of unrecognized compensation costs ​​​​​​​related to unvested RSUs, which are expected to be recognized over a weighted-average period of 2.75 years. Additionally, as of December 31, 2020, the Company has unrecognized compensation cost of $0.6 million related to unvested stock-based awards with performance-based vesting conditions for which performance has not been deemed probable.

Restricted common stock

During the year ended December 31, 2018, the Company granted restricted common stock with service-based vesting conditions. Shares of unvested restricted common stock may not be sold or transferred by the holder. These restrictions lapse according to the time-based vesting conditions of each award. The grant date fair value of these shares was immaterial. The following table summarizes the Company’s restricted common stock award activity for the year ended December 31, 2020:

Number of Restricted Shares

The Company recorded stock-based compensation expense in the following expense categories of its statements of operations:

Year Ended December 31,

Research and development $ 2,699 $ 13

General and administrative 3,892 13

10. Income taxes

There is no provision for income taxes because the Company has historically incurred net operating losses and maintains a full valuation allowance against its deferred tax assets. The reported amount of income tax expense/benefit for the years ended December 31, 2020 and 2019 differs from the amount that would result from applying domestic federal statutory rates to pretax losses primarily because of changes in the valuation allowance.

A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate is as follows:

Year Ended December 31,

Federal income tax expense at statutory rate 21 % 21 %

State taxes—net of federal benefit 5 6

Change in fair value of preferred stock tranche obligations — (2 )

Other permanent differences — (1 )

Federal & state R&D credits 1 4

Increase in valuation allowance (27 ) (28 )

Effective income tax rate 0 % 0 %

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Significant components of the Company’s net deferred tax assets at December 31, 2020 and 2019 are as follows:

Year Ended December 31,

Deferred tax assets:

Stock-based compensation $ 1,349 $ 1

Intangible assets — 12

Total net deferred tax assets 43 27

Deferred tax liabilities:

Fixed assets (43 ) (27 )

Total deferred tax liability (43 ) (27 )

Total deferred tax assets (liabilities) $ — $ —

As of December 31, 2020, the Company had federal and state net operating loss carryforwards of $69.1 million and $68.9 million, respectively. The federal net operating loss carryforwards are indefinite lived and the state net operating loss carryforwards begin to expire in 2038. As of December 31, 2020, the Company also had federal and state research and development tax credit carryforwards $0.8 million and $0.4 million, respectively, which begin to expire in 2039 and 2033, respectively.

Utilization of the net operating loss carryforwards and research and development tax credit carryforwards may be subject to a substantial annual limitation under Section 382 of the Internal Revenue Code of 1986 due to ownership changes that have occurred previously or that could occur in the future. These ownership changes may limit the amount of carryforwards that can be utilized annually to offset future taxable income. In general, an ownership change, as defined by Section 382, results from transactions increasing the ownership of certain stockholders or public groups in the stock of a corporation by more than 50% over a three-year period. The Company has not conducted a study to assess whether a change of control has occurred or whether there have been multiple changes of control since inception due to the significant complexity and cost associated with such a study. If the Company has experienced a change of control, as defined by Section 382, at any time since inception, utilization of the net operating loss carryforwards or research and development tax credit carryforwards would be subject to an annual limitation. Any limitation may result in expiration of a portion of the net operating loss carryforwards or research and development tax credit carryforwards before utilization. Further, until a study is completed and any limitation is known, no amounts are being presented as an uncertain tax position.

The Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets, which are comprised principally of net operating loss carryforwards and research and development tax credit carryforwards. Management has considered the Company’s history of cumulative net losses incurred since inception and its lack of commercialization of any products or generation of any revenue from product sales since inception and concluded that it is more likely than not that the Company will not recognize the benefits of its federal and state deferred tax assets. Accordingly, a full valuation allowance has been established against the net deferred tax assets as of December 31, 2020 and 2019. The increase in the valuation allowance for deferred tax assets during the years ended December 31, 2020 and 2019 totaled $16.3 million and $4.2 million, respectively, and related primarily to the increase in net operating loss carryforwards.

The Company’s policy is to record estimated interest and penalties related to uncertain tax positions in income tax expense. The Company has no amounts recorded for any unrecognized tax positions, accrued interest or penalties as of December 31, 2020 and 2019.

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The Company files tax returns as prescribed by the tax laws of the jurisdictions in which it operates, including the United States and the Commonwealth of Massachusetts. In the normal course of business, the Company is subject to examination by federal and state jurisdictions, where applicable. There are currently no pending tax examinations. The Company’s tax returns are open under statute from 2018 to the present.

11. Net loss per share

Basic and diluted net loss per share was calculated as follows:

Year Ended December 31,

(in thousands, except share and per share data) 2020 2019

Numerator:

Denominator:

Net loss per share—basic and diluted $ (4.13 ) $ (6.08 )

The following potentially dilutive common stock equivalents, presented based on amounts outstanding at each period end, were excluded from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect:

Year Ended December 31,

Unvested restricted stock units 403,355 —

Convertible preferred stock (as converted to common stock) — 9,798,298

12. Commitments and contingencies

Operating leases

In May 2019, the Company entered into a sublease agreement for laboratory and office space in Waltham, Massachusetts. The term of the sublease commenced on July 1, 2019 and expires on December 31, 2021.

In December 2020, the Company entered into a lease agreement (the “Lease”), pursuant to which the Company will lease approximately 68,187 square feet of additional office and laboratory space located in Waltham, Massachusetts (the “Premises”). The Lease will have a term of eight years and six months that will commence when the Premises are ready for occupancy. The Company’s obligation for the payment of base rent for the Premises begins six months after the commencement date and will be $0.4 million per month, increasing up to $0.5 million during the term of the Lease. The Company has two options to extend the term of the Lease, each for a period of an additional five years. The Company expects the Premises to be ready for occupancy in the second half of 2021.

Rent expense for the years ended December 31, 2020 and 2019 totaled $0.8 million and $0.7 million, respectively.

Future minimum lease payments under the non-cancelable operating leases consisted of the following as of December 31, 2020:

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Year Ending December 31, (in thousands)

Legal proceedings

The Company is not currently party to any material legal proceedings. At each reporting date, the Company evaluates whether a potential loss amount or a potential range of loss is probable and reasonably estimable under the provisions of the authoritative guidance that addresses accounting for contingencies. The Company expenses as incurred the costs related to any such legal proceedings.

Other contractual obligations

The Company enters into contracts in the normal course of business with third parties for preclinical research studies, clinical trials and testing and manufacturing services. These contracts typically do not contain minimum purchase commitments and are generally cancelable by the Company upon written notice. Payments due upon cancellation consist of payments for services provided or expenses incurred, including noncancelable obligations of the service providers, up to the date of cancellation and in the case of certain arrangements may include non-cancelable fees.

The Company has also entered into a license agreement (the “UMONS Agreement”) with the University of Mons (“UMONS”) in April 2020, pursuant to which UMONS granted to the Company an exclusive, worldwide license to certain patents and patent applications and a non-exclusive, worldwide license to existing, related know-how. Each of the issued patents licensed to the Company under the UMONS Agreement is scheduled to expire in 2031. The licenses under the UMONS Agreement confer on the Company the right to research, develop and commercialize products (“licensed products”), and to practice processes, in each case, covered by the licensed patents and existing, related know-how.

Under the UMONS Agreement, the Company is obligated to use commercially reasonable efforts to develop at least one licensed product and, to the extent regulatory approval is obtained in such jurisdictions, to commercialize at least one licensed product in the United States and the United Kingdom or a member country of the European Union. Unless terminated earlier, the UMONS Agreement will remain in effect until the last to expire of the licensed patent rights on a licensed product-by-licensed product and country-by-country basis. UMONS may terminate the UMONS Agreement in the event of a material breach by the Company and the Company’s failure to cure such breach within a specified time period. The Company may voluntarily terminate the UMONS Agreement with prior notice to UMONS.

In connection with the Company’s entry into the UMONS Agreement, the Company paid UMONS an upfront payment of €0.1 million. The Company also agreed to make milestone payments to UMONS upon the achievement of specified development and regulatory milestones up to a maximum aggregate total of €0.4 million for the first licensed product to achieve such milestones and up to a maximum aggregate total of €0.2 million for each subsequent licensed product to achieve each such milestones, as well as a low single-digit percentage royalty on net sales of licensed products by the Company, its affiliates and sublicensees. These royalty obligations continue on a licensed product-by-licensed product and country-by-country basis until the expiration of the last licensed patent rights covering such licensed product in such country. In addition, if the Company sublicenses rights under the UMONS Agreement, the Company is required to pay a low double-digit percentage of the sublicense revenue to UMONS. Additionally, if the Company chooses to file, prosecute or maintain any patents included in the licensed patent rights under the UMONS Agreement, it will be required to bear the full cost and expenses of preparing, filing, prosecuting and maintaining any such patents.

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No amounts have been accrued under this arrangement with respect to potential milestone payment obligations or royalty obligations given the uncertainty of achieving the specified milestones and commercial sales of any licensed products.

13. Subsequent events

For the year ended December 31, 2020, subsequent events were evaluated through March 4, 2021, the date on which the audited consolidated financial statements were issued.

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