Summit Therapeutics Inc

1. Nature of Business and Operations

Nature of Business and Operations

Summit Therapeutics Inc. (“we”, “Summit” or the “Company”) is a biopharmaceutical company focused on the discovery, development, and commercialization of patient-, physician-, caregiver- and societal-friendly medicinal therapies intended to improve quality of life, increase potential duration of life, and resolve serious unmet medical needs.

The Company’s current lead development candidate is ivonescimab, a novel, potential first-in-class bispecific antibody intending to combine the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects of an anti-VEGF compound into a single molecule. On December 5, 2022, the Company entered into a Collaboration and License Agreement (the “License Agreement”) with Akeso, Inc. and its affiliates (“Akeso”) pursuant to which the Company has in-licensed ivonescimab as further described in Note 7. Through the License Agreement, the Company obtained the rights to develop and commercialize ivonescimab in the United States, Canada, Europe, and Japan (the “Licensed Territory”). The License Agreement and transaction closed in January 2023 following customary waiting periods. The Company’s operations will be focused on the development of ivonescimab and other future activities, as the Company determines.

The Company has begun its development for ivonescimab in non-small cell lung cancer (“NSCLC”), specifically launching Phase III clinical trials in the following indications:

a) ivonescimab combined with chemotherapy in patients with epidermal growth factor receptor (“EGFR”)-mutated, locally advanced or metastatic non-squamous NSCLC who have progressed after treatment with a third-generation EGFR tyrosine kinase inhibitor (“TKI”) (“HARMONi”); and

b) ivonescimab combined with chemotherapy in first-line metastatic squamous NSCLC patients (“HARMONi-3”)

As of the date of these financial statements, both studies are enrolling patients.

The entry into the License Agreement with Akeso represents a significant change in the Company’s strategy and its future operations will be focused on the development of ivonescimab and other future activities as the Company determines. The Company’s portfolio also includes ridinilazole, a product candidate for treating patients suffering from Clostridioides difficile infection, also known as C. difficile infection, or CDI, and SMT-738, the first of a novel class of precision antibiotics for combating multidrug resistant infections, specifically carbapenem-resistant Enterobacteriaceae (“CRE”) infections. All prior development activities related to ridinilazole and SMT-738 have been terminated; the Company will continue to pursue partnerships for both assets.

2. Basis of Presentation and Use of Estimates

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States ("U.S. GAAP") and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission. Accordingly, certain information and disclosures required by U.S. GAAP for complete consolidated financial statements are not included herein. All intercompany accounts and transactions have been eliminated in consolidation. The interim financial data as of March 31, 2024 and for the three months ended March 31, 2024 are unaudited; however, in the opinion of management, the interim data includes all adjustments, consisting of normal recurring adjustments, necessary for a fair statement of the results for the interim periods. The condensed consolidated balance sheet presented as of December 31, 2023 has been derived from the consolidated audited financial statement as of that date. The results of the period are not necessarily indicative of full year results or any other interim period. These unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto of the Company which are included in the Company's Annual Report on Form 10-K for the year ended December 31, 2023 filed with the Securities and Exchange Commission on February 20, 2024. The financial results of the Company's activities are reported in United States Dollars

Our accounting policies are consistent with the Notes to the Consolidated Financial Statement in the Company's Annual Report on Form 10-K filed with the Securities and Exchange Commission, except as updated below:

Cash Equivalents

Cash equivalents consist of non-interest-bearing deposits denominated in the U.S. dollar and British pound, and the Company invested cash in money market funds and U.S. treasury securities. All highly liquid investments with a maturity date of 90 days or less at the date of purchase are considered to be cash equivalents. The appropriate classification of investments in securities as to whether it is classified as a cash equivalent is determined by the Company at the time of purchase.

Marketable Securities

Marketable securities consist of investments with original maturities greater than ninety days from the date of acquisition. The Company classifies investments with maturities of greater than 90 days as short-term, based on the liquid nature of the securities and because such marketable securities represent the investment of cash that is available for current operations. The Company considers its investment portfolio of investments as available-for-sale. Accordingly, these investments are recorded at fair value, which is based on quoted market prices or other observable inputs. Unrealized gains and losses are recorded as a component of other comprehensive income (loss). Realized gains and losses are determined on a specific identification basis and are included in other (expense) income. Amortization and accretion of discounts and premiums is also recorded in other (expense) income.

When the fair value is below the amortized cost of the asset, an estimate of expected credit losses is made, this estimate is limited to the amount by which fair value is less than amortized cost. The credit-related impairment amount is recognized in the condensed consolidated statements of operations and comprehensive loss and the remaining impairment amount and unrealized gains are reported as a component of accumulated other comprehensive income (loss) in shareholders’ equity. Credit losses are recognized through the use of an allowance for credit losses account and subsequent improvements in expected credit losses are recognized as a reversal of the allowance account. If the Company has the intent to sell the security or it is more likely than not that the Company will be required to sell the security prior to recovery of its amortized cost basis the allowance for credit loss is written off and the excess of the amortized cost basis of the asset over its fair value is recorded in the condensed consolidated statements of operations and comprehensive loss..

Use of Estimates

The preparation of these unaudited condensed consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities at the date of the unaudited condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. On an on-going basis, management evaluates its estimates and judgments, including those related to accrued research and development expenses, stock-based compensation, goodwill, other long-lived assets and income taxes. Management bases its estimates and judgments on historical experience and on various other factors that are believed to be 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. Actual results may differ from these estimates under different assumptions or conditions.

3. Summary of Significant Accounting Policies and Recently Issued or Adopted Accounting Pronouncements

Summary of Accounting Policies

The significant accounting policies used in the preparation of these condensed consolidated financial statements for the three months ended March 31, 2024 are consistent with those discussed in Note 4 to the consolidated financial statements in the Company's Annual Report on Form 10-K for the year ended December 31, 2023.

Recently Issued or Adopted Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board or other standard setting bodies that the Company adopts as of the specified effective date. The Company does not believe that the adoption of recently issued standards have or may have a material impact on the accompanying unaudited condensed consolidated financial statements.

4. Liquidity and Capital Resources

During the three months ended March 31, 2024, the Company incurred a net loss of $43,473 and cash flows used in operating activities for the three months ended March 31, 2024 was $30,134. As of March 31, 2024, the Company had an accumulated deficit of $1,036,731, cash and cash equivalents of $61,294, short-term investments in U.S. treasury securities of $95,386 and current and long-term U.K. research and development tax credits receivable of $1,157. The Company expects to continue to generate operating losses for the foreseeable future.

The Company has evaluated whether its cash, cash equivalents and U.K. research and development tax credits provide sufficient cash to fund its operating cash needs for the next twelve months from the date of issuance of these quarterly financials. The Company is investing in the clinical development of ivonescimab, including its ongoing clinical trials. In addition, the Company has a $100,000 promissory note and interest payable to a related party (refer to Note 14 for further details) that matures on April 1, 2025. In order to repay this promissory note, the Company intends to raise additional capital. As of the date of issuance of these condensed consolidated financial statements, additional capital has not yet been secured. These conditions raise substantial doubt about the Company’s ability to continue as a going concern for at least one year from the date these condensed consolidated financial statements are issued.

Until the Company can generate substantial revenue and achieve profitability, the Company will need to raise additional capital to fund its ongoing operations and capital needs. The Company continues to evaluate options to further finance its operating cash needs for its product candidates through a combination of some, or all, of the following: equity and debt offerings, collaborations, strategic alliances, grants and clinical trial support from government entities, philanthropic, non-government and not-for-profit organizations, and marketing, distribution or licensing arrangements. There is no assurance, however, that additional financing will be available when needed or that management of the Company will be able to obtain financing on terms acceptable to the Company. If the Company is unable to obtain funding when required in the future, the Company could be required to delay, reduce, or eliminate research and development programs, product portfolio expansion, or future commercialization efforts, which could adversely affect its business prospects.

The accompanying condensed consolidated financial statements are prepared assuming the Company will continue as a going concern, which contemplates the realization of assets and satisfaction of liabilities in the normal course of the business. The condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classifications of liabilities that might result from the outcome of this uncertainty.

5. Segment Reporting

The Company's chief operating decision makers (the "CODM function"), which are the Company's CEOs, Mr. Duggan and Dr. Zanganeh, utilize consolidated financial information to make decisions about allocating resources and assessing performance for the entire Company. The CODM function approves of key operating and strategic decisions, including key decisions in clinical development and clinical operating activities, entering into significant contracts, such as revenue contracts and collaboration agreements and approves the Company's consolidated operating budget. The CODM function views the Company's operations and manages its business as a single reportable operating segment. The Company's single operating segment covers the Company’s research and development activities, primarily comprising of oncology product research activities (including ivonescimab). As the Company operates asone operating segment, all required financial segment information can be found in these condensed consolidated financial statements.

The Company operates intwo geographic regions: the U.K. and the U.S. The following table summarizes the Company's long-lived assets, which include the Company's property and equipment, net and right-of-use assets by geography:

(1) The increase in long-lived assets as of March 31, 2024 as compared to December 31, 2023, is primarily due to $4,106 of net right-of use assets recorded as a result of the Company entering into a new lease agreement for their Miami, FL headquarters, partially offset by $534 of amortization expense for right-of-use assets relating to lease agreements for its office space in Menlo Park, CA.

6. Other Operating Income, net

The following table sets forth the components of other operating income, net by category:

Research and development tax credits

Income from tax credits, consist of R&D tax credits received in the U.K. The Company benefits from the Small and Medium Enterprise Program ("SME Program") U.K. research and development tax credit cash rebate regime, and The Research and Development Expenditure Credit ("The RDEC scheme"), a UK government tax incentive that promotes innovation amongst UK's larger businesses. Qualifying expenditures largely comprise of employment costs for research staff, consumables, a proportion of relevant, permitted sub-contract costs and certain internal overhead costs incurred as part of research projects for which the Company does not receive income. Tax credits related to the SME Program and The RDEC scheme are recorded as other operating income in the consolidated statements of operations and other comprehensive loss. Under these scheme, the Company receives cash payments that are not dependent on the Company’s pre-tax net income levels.

Based on criteria established by His Majesty’s Revenue and Customs ("HMRC"), a portion of expenditures being carried out in relation to the Company's pipeline research and development, clinical trials management and third-party manufacturing development activities are eligible for the SME regime and the Company expects such elements of research and development expenditure incurred in its UK entities will also continue to be eligible for the SME regime for future periods.

As of March 31, 2024, the current and non-current research and development tax credit receivable was $945 and $212, respectively. As of December 31, 2023, the current and non-current research and development tax credit receivable was $848 and $959, respectively.

CARB-X (as defined below)

In May 2021, the Company announced the selection of a new preclinical candidate, SMT-738, from the DDS-04 series for development in the fight against multi-drug resistant infections, specifically Carbapenem-resistant Enterobacteriaceae ("CRE") infections. Simultaneously, the Company announced it had received an award from the Trustees of Boston University under the Combating Antibiotic Resistant Bacteria Biopharmaceutical Accelerator program ("CARB-X") to progress this candidate through preclinical development and Phase Ia clinical trials. The award commits initial funding of up to $4,100, with the possibility of up to another $3,700 based on the achievement of future milestones. As of March 31, 2024, based on translation of historical foreign currency amounts in the period, the Company has recognized $2,920 of cumulative income since contract inception.

7. Akeso Collaboration and License Agreement

On December 5, 2022, the Company entered into a Collaboration and License Agreement (the “License Agreement”) with Akeso, Inc. and its affiliates (“Akeso”) pursuant to which the Company is in-licensing its breakthrough bispecific antibody, ivonescimab. The License Agreement and transaction closed in January 2023 following customary waiting periods.

Ivonescimab, known as AK112 in China and Australia, and also as SMT112 in the United States, Canada, Europe, and Japan, is a novel, potential first-in-class bispecific antibody intending to combine the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects of an anti-VEGF into a single molecule. Ivonescimab was engineered to bring two well established oncology targeted mechanisms together. Ivonescimab is currently in clinical development and, pursuant to the terms of the License Agreement, Summit will design and conduct the clinical trial activities to support regulatory filings in the Licensed Territory that Summit will submit.

Pursuant to the terms of the License Agreement, Summit will have final decision-making authority with respect to clinical development strategy and execution in the Licensed Territory. For co-joined studies in which both Summit and Akeso participate, mutual agreement is required for material decisions; Summit retains the exclusive decision making with respect to participating in, and continuing its participation in, co-joined studies. Pursuant to the terms of the License Agreement, Summit will have final decision making authority with respect to commercial strategy, pricing and reimbursement and other commercialization matters in the Licensed Territory. In connection with the License Agreement, the Company has also entered into a Supply Agreement with Akeso, pursuant to which Summit agrees to purchase a certain portion of drug substance for clinical and commercial supply. Summit is not assuming any liabilities (including contingent liabilities), acquiring any physical assets or trade names, or hiring or acquiring any employees from Akeso in connection with the License Agreement. Through the License Agreement, the Company obtained the rights to develop and commercialize ivonescimab in the United States, Canada, Europe, and Japan (the “Licensee Territory”).

In exchange for the rights obtained, an upfront payment of $500,000 was made to Akeso, of which $274,900 was paid in cash and, pursuant to the License Agreement and Issuance Agreement, Akeso elected to receive 10,000,000 shares of the Company's common stock in lieu of $25,100 cash. The remaining $200,000 amount of the upfront payment was paid on March 6, 2023.

The Company has accounted for the License Agreement to acquire therights to develop and commercialize ivonescimab as the acquisition of an asset. All of the consideration relates to ivonescimab and technological feasibility of the asset has not yet been established since ivonescimab is in clinical development. As such, the Company has expensed the consideration as in-process research and development upon closing of the transaction in the condensed consolidated statement of comprehensive loss. In-process research and development expense for the three months ended March 31, 2023 was $520,915, which is comprised of the $474,900 paid in cash, the fair value of the 10,000,000 shares of common stock on the date of closing the transaction of $45,900, and $115 of direct transactions costs incurred.

In addition to the payments already made to Akeso, under the License Agreement, there are additional potential milestone payments of up to $4,500,000, as Akeso will be eligible to receive regulatory milestones of up to $1,050,000 and commercial milestones of up to $3,450,000. In addition, Akeso will be eligible to receive low double-digit royalties on net sales.

8. Other Expense, net

The following table sets forth the components of other (expense) income:

(1) During the three months ended March 31, 2023, the Company dissolved certain dormant entities and as a result, $419 of cumulative foreign currency translation adjustments were re-classified from accumulated other comprehensive loss relating to these entities.

For the three months ended March 31, 2024, other expense, net primarily consisted of loan interest expense incurred related to the $100,000 promissory note and for the three months ended March 31, 2023, other expense, net primarily consisted of loan interest expense incurred related to the $520,000 promissory notes, as described in Note 14. These amounts for both periods are partially offset by investment income related to the Company's money market funds and short-term investments in U.S. treasury securities.

9. Net Loss per Share

The following table sets forth the computation of basic and diluted net loss per share:

Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period. Diluted net loss per share is computed by dividing the diluted net loss by the weighted-average number of common shares outstanding for the period, including potentially dilutive common shares. Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods, as the inclusion of all potential common share equivalents outstanding would have been anti-dilutive.

The following potentially dilutive securities were excluded from the computation of the diluted net loss per share of common stock for the periods presented because their effect would have been anti-dilutive:

Stock options that are outstanding and contain performance-based or market-based vesting criteria for which the performance or market conditions have not been met are excluded from the presentation of common stock equivalents outstanding in the chart above

10. Fair Value Measurements and Short-Term Investments

In accordance with the provisions of fair value accounting, a fair value measurement assumes that the transaction to sell an asset or transfer a liability occurs in the principal market for the asset or liability or, in the absence of a principal market, the most advantageous market for the asset or liability and defines fair value based on the exit price model.

The fair value measurement guidance establishes a fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The guidance describes three levels of inputs that may be used to measure fair value:

Level 1

Quoted prices in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis.

Level 2

Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 2 assets and liabilities include debt securities with quoted prices that are traded less frequently than exchange-traded instruments or securities or derivative contracts that are valued using a pricing model with inputs that are observable in the market or can be derived principally from or corroborated by observable market data.

Level 3

Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation.

In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the Company categorizes such assets and liabilities based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset.

The following tables sets forth the Company’s fair value hierarchy for its assets and liabilities that are measured at fair value on a recurring basis as of March 31, 2024 and December 31, 2023:

The tables above do not include cash at March 31, 2024 and December 31, 2023 of $4,191 and $11,068, respectively.

The Company believes that the carrying amounts of prepaid expenses, other current assets, accounts payable, and accrued expenses approximates their fair values due to the short-term nature of those instruments. The carrying value of the Company’s promissory note approximates its fair value and the current interest rate of the note outstanding when compared to market interest rates (which represents a Level 2 measurement). Refer to Note 14 for further details.

The following table sets forth the Company’s short-term investments as of March 31, 2024 and December 31, 2023, which have a contractual maturity of less than one year:

11. Goodwill

Goodwill

As of March 31, 2024 and December 31, 2023, goodwill was $1,875 and $1,893, respectively. Changes in the gross carrying amount of goodwill during the three months ended March 31, 2024 as compared to December 31, 2023, are the result of changes in foreign currency. As of December 31, 2023, the Company performed its annual impairment assessment of goodwill and determined that it is more likely than not that the fair value of the reporting unit exceeds its carrying amount. There have beenno cumulative goodwill impairments recognized during the three months ended March 31, 2024.

12. Leases

The Company has operating leases for real estate. The Company does not have any finance leases.

During the three months ended March 31, 2024, the Company recorded $4,216 of additional right-of-use assets related to a new lease for office space that commenced during the period for its Miami, Florida headquarter location. Total future lease payments as of March 31, 2024, which include base rent and sales tax are approximately $4,814 on an undiscounted basis. This lease commenced on February 1, 2024 and has a term of 64 months. As of March 31, 2024 the Company has $317 of restricted cash associated with an irrevocable letter of credit required by the landlord to enter into this lease. There wereno new right-of-use assets recorded during the three month period ended March 31, 2023. The carrying value of the right-of-use assets as of March 31, 2024 and December 31, 2023 was $9,373 and $5,859, respectively.

13. Research and Development Prepaid Expenses and Accrued Liabilities

Included within prepaid expenses and other current assets at March 31, 2024 and December 31, 2023 is $4,351 and $1,466, respectively, of prepayments relating to research and development expenditures. Included within accrued liabilities at March 31, 2024 and December 31, 2023 is $6,074 and $7,289, respectively, relating to research and development expenditures.

These amounts are determined based on the estimated costs to complete each study or activity, the estimation of the current stage of completion and the invoices received, as well as predetermined milestones which are not reflective of the current stage of development for prepaid expenses. However, prepaid expenses decrease and accrued liabilities increase as the activities progress, and if actual costs incurred exceed the prepaid expense, an accrual will be recorded for the liability. The key sensitivity is the estimated current stage of completion of each study or activity, which is based on information received from the supplier and the Company’s operational knowledge of the work completed under those contracts.

14. Promissory Note Payable to Related Parties

Non-current promissory note payable to related parties was $100,000 as of March 31, 2024 and December 31, 2023.

December 2022 Promissory Note

On December 6, 2022, the Company entered into a Note Purchase Agreement (the "Note Purchase Agreement"), with Mr. Duggan and Dr. Zanganeh, pursuant to which the Company agreed to sell to each of Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the aggregate amount of $520,000. Pursuant to the Note Purchase Agreement, the Company issued to Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the amount of $400,000 (the "Duggan February Note") and $20,000 (the "Zanganeh Note"), respectively, which would mature and become due on February 15, 2023 and an unsecured promissory note to Mr. Duggan in the amount of $100,000 (the “Duggan September Note” and together with the Duggan February Note and the Zanganeh Note, the “December 2022 Notes”), which was originally due on September 15, 2023. The maturity dates of the December 2022 Notes could be extended one or more times at the Company’s election, but in no event to a date later than September 6, 2024. In addition, if the Company consummates a public offering, then upon the later to occur of (i)five business days after the Company receives the net cash proceeds therefrom or (ii) May 15, 2023, the Duggan February Note and the Zanganeh Note shall be prepaid by an amount equal to the lesser of (a)100% of the amount of the net proceeds of such offering and (b) the outstanding principal amount on such Notes.

On January 19, 2023, the Company provided notice to extend the term of the Duggan February Note and Duggan September Note to a maturity date of September 6, 2024. Furthermore, on January 19, 2023, the Company and Mr. Duggan rectified the Duggan February Note and Duggan September Note in order to correctly reflect the parties’ intent that the Company may only prepay (i) the Duggan February Note following the completion of a public rights offering to be conducted by Summit in the approximate amount of $500,000, or a similar capital raise, in an amount equal to the lesser of (x) the net proceeds of the Rights Offering or such capital raise or (y) the full amount outstanding of the Duggan February Note, and (ii) Duggan September Note following the completion of a capital raising transaction subsequent to the 2023 Rights Offering in an amount equal to the lesser of (A) the net proceeds of such capital raise or (B) the full amount outstanding of the Duggan September Note. Following the issuance of thetwo new Promissory Notes (the “Duggan Promissory Notes”), the Duggan February Note and Duggan September Note were marked as “cancelled” on their face and replaced in their entirety by the Duggan Promissory Notes (together with the Zanganeh Note, the "Notes").

On February 15, 2023, the $20,000 Zanganeh Note matured and the Company repaid the outstanding principal balance. In connection with the closing of the 2023 Rights Offering, the $400,000 Duggan Promissory Note matured and became due, and the Company satisfied all principal and accrued interest thereunder using a combination of a portion of the cash proceeds from the 2023 Rights Offering and the extinguishment of a portion of the amount due equal to the subscription price for shares subscribed by Mr. Duggan in the 2023 Rights Offering.

The Notes accrued interest at an initial rate of 7.5%. All interest on the Notes was paid on the date of signing for the period through February 15, 2023. Such prepaid interest was paid in a number of shares of the Company’s common stock, par value $0.01 (“Common Stock”) equal to the dollar amount of such prepaid interest, divided by $0.7913 (the consolidated closing bid price immediately preceding the time the Company entered into the Note Purchase Agreement, plus $0.01), which was 9,720,291 shares. For all applicable periods following February 15, 2023, interest shall accrue on the outstanding principal balance of the Notes at the US prime interest rate, as reported in the Wall Street Journal, plus 50 basis points, as adjusted monthly, for three months immediately following February 15, 2023, and thereafter at the US prime rate plus 300 basis points, as adjusted monthly. Such accrued interest shall be paid in cash, quarterly in arrears, on each of March 31, June 30, September 30 and December 31.

Debt issuance costs associated with the Notes were $44 and were capitalized as part of the carrying value of the promissory notes payable to related parties.

On February 17, 2024, the Duggan February Note was amended and restated to extend the maturity date from September 6, 2024 to April 1, 2025. For all applicable periods commencing February 17, 2024, interest shall accrue on the outstanding principal balance at the greater of 12% or the US prime interest rate, as reported in the Wall Street Journal plus 350 basis points, as adjusted monthly, compounded quarterly. Interest shall be paid upon maturity of the loan.

The debt discount is amortized to interest expense using an effective interest rate method. The effective interest rate of the Duggan February Note and Zanganeh Note was 8.9% and the effective interest rate of the Duggan September Note is 12.4%.

During the three months ended March 31, 2024 and 2023, the Company incurred interest expense of $3,121 and $8,327, respectively. Interest expense incurred during the three months ended March 31, 2023 included amortized imputed interest of $761. As of March 31, 2024, accrued interest was $1,740 and was recorded in other long-term liabilities. As of December 31, 2023, accrued interest was $120 and was recorded in accrued liabilities.

The estimated future principal payments are $0 and $100,000 for 2024 and 2025, respectively, as the note matures on April 1, 2025.

15. Stock-Based Compensation and Warrants

The Company currently grants stock options to employees and directors under the 2020 Stock Incentive Plan (the "2020 Plan") and formerly, the Company granted stock options under the 2016 Long Term Incentive Plan (the "2016 Plan"). The 2020 Plan is administered by the Compensation Committee of the Company's Board of Directors. The 2020 Plan is intended to attract and retain employees and directors and provide an incentive for these individuals to assist the Company to achieve long-range performance goals and to enable these individuals to participate in the long-term growth of the Company.

On October 12, 2023, the Company's stockholders approved an increase in the number of shares of the Company's common stock issuable under the Plan by 70,000,000 shares.

The following table summarizes the Company's time-based stock option activity for the three months ended March 31, 2024:

The total intrinsic value of all outstanding time-based stock options and exercisable stock options at March 31, 2024 was $113,727 and $3,146, respectively The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock.

The following table summarizes the Company's performance-based stock option activity for the three months ended March 31, 2024:

The total intrinsic value of all performance-based stock options at March 31, 2024 was $117,019.

As of March 31, 2024, total unrecognized compensation expense related to performance-based stock options that were deemed probable of vesting was approximately $11,313 which excludes 37,223,376 of unvested performance-based stock options that were deemed not-probable of vesting totaling unrecognized stock-based compensation expense of $44,816.

The total stock-based compensation expense included in the Company's condensed consolidated statements of operations and comprehensive loss was as follows:

The following summarizes share-based compensation expense associated with each of the Company's stock-based compensation arrangements:

Warrants

The Company had outstanding and exercisable 5,015,642 warrants with a weighted average exercise price of $1.57 as of March 31, 2024 and December 31, 2023.

16. Related Party Transactions

July 25, 2022 First Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc.

On July 25, 2022 the Company entered into a first amendment, dated July 19, 2022, to its existing sublease agreement with Maky Zanganeh and Associates, Inc. ("MZA"), consisting of 4,500 square feet of office space at 2882 Sand Hill Road, Menlo Park, California. The existing sublease term, which was set to expire on September 30, 2022, was extended for a period ofthirty-nine months from October 1, 2022 through December 31, 2025. The rent payable under the terms of the sublease is equivalent to the proportionate share of the net payable by MZA to the third-party landlord, based on the square footage of office space sublet by the Company, and no mark-up has been applied. During the three months ended March 31, 2024 and 2023, payments of $195 and $189, respectively, were made pursuant to the first amendment to the Sublease Agreement.

July 29, 2022 Second Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc.

On July 29, 2022, the Company entered into a second amendment, dated August 1, 2022, to its existing sublease agreement with MZA, described above. The second amendment was effective as of August 1, 2022 and expires on December 31, 2025. The second amendment includes an additional 1,277 square feet (the "Expansion Premises") of office space at 2882 Sand Hill Road, Menlo Park, California. The rent payable under the terms of the sublease is equivalent to the proportionate share of the net payable by MZA to the third-party landlord, based on the square footage of office space sublet by the Company, and no mark-up has been applied. During the three months ended March 31, 2024 and 2023, payments of $55 and $54 respectively, were made pursuant to the second amendment to the Sublease Agreement.

December 6, 2022 Note Purchase Agreement

Akeso License Agreement

Upon the closing of the License Agreement, the Board of Directors (the “Board”) of the Company appointed Dr. Yu (Michelle) Xia to serve as a member of the Board pursuant to the terms of the License Agreement. Dr. Xia is the founder of Akeso, Inc. ("Akeso"), and has been the chairwoman, president and CEO of Akeso since its inception in 2012. For details on the License Agreement, see Note 7. Furthermore, in connection with the License Agreement, the Company also entered into a Supply Agreement with Akeso, pursuant to which Summit agreed to purchase a certain portion of drug substance for clinical and commercial supply (the “Supply Agreement”).

2023 Rights Offering

On December 6, 2022, the Company announced a rights offering for its existing shareholders to participate in the purchase of additional shares of its Common Stock for $1.05 per share. The 2023 Rights Offering commenced on February 7, 2023 and the associated subscription rights expired on March 1, 2023. Aggregate gross proceeds from the 2023 Rights Offering were $500,000 from the sale of 476,190,471 shares of the Company's common stock and issuance costs were $619. Mr. Duggan and Dr. Zanganeh fully subscribed to their respective basic subscription rights at a price of $1.05 per share. To satisfy the $395,314 subscription price for the shares subscribed by Mr. Duggan in the 2023 Rights Offering, Mr. Duggan agreed with the Company to extinguish a portion of the amount due and payable to him by the Company at the closing of the 2023 Rights Offering pursuant to the $400,000 Duggan Promissory Note in an amount equal to the subscription price.

Private Placement

On October 16, 2023, the Company announced the appointment of Mr. Manmeet Soni as its Chief Operating Officer, effective immediately. Mr. Soni has been a part of the Company's Board of Directors since 2019. He will remain a member of the Board of Directors. In conjunction with his appointment, Mr. Soni entered into a share purchase agreement with the Company to invest $5,000 in shares of common stock via a private placement. The transaction was effective October 13, 2023 with a closing price of $1.68, resulting in the purchase of 2,976,190 shares of the Company's common stock.

17. Commitments and Contingencies

Lease Commitments

There were no material changes to the Company's lease commitments that were disclosed in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2023 filed with the Securities and Exchange Commission on February 20, 2024, other than the new lease for the Miami, FL headquarter location as described in Note 12.

Debt Commitments

Other Commitments

The Company enters into contracts in the normal course of business with various third parties for clinical trials, preclinical research studies and testing, manufacturing and other services and products for operating purposes. Most contracts provide for termination upon notice, and therefore are cancellable contracts. The majority of these commitments are due withinone year. There have been no material changes to the Company's other contractual commitments that were disclosed in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2023.

Indemnifications

The Company's certificate of incorporation provides that it will indemnify the directors and officers to the fullest extent permitted by Delaware law. In addition, the Company has entered into indemnification agreements with all of the directors and executive officers. These indemnification agreements may require the Company, among other things, to indemnify each such director or executive officer for some expenses, including attorneys’ fees, judgments, fines, and settlement amounts incurred by him or her in any action or proceeding arising out of his or her service as one of the Company's directors or executive officers. The Company believes the fair value for these indemnification obligations is minimal. Accordingly, the Company has not recognized any liabilities relating to these obligations as of March 31, 2024 and December 31, 2023.

Legal Proceedings

The Company is not currently subject to any material legal proceedings.