SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company has a limited operating history and the sales and income potential of the Company’s business and market are unproven. The Company has experienced net losses and negative cash flows from operating activities since its inception. At March 31, 2022, the Company had an accumulated deficit of $395.4 million. The Company expects to continue to incur net losses into the foreseeable future. Successful transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support the Company’s cost structure. At March 31, 2022, the Company had cash, cash equivalents and restricted cash of $38.0 million. Based on the Company’s current business plan, management believes that existing cash and cash equivalents will not be sufficient to fund the Company’s obligations for twelve months from the issuance of these financial statements. The Company’s ability to execute its operating plan depends on its ability to obtain additional funding through equity offerings, debt financings or potential licensing and collaboration arrangements. The accompanying condensed consolidated financial statements have been prepared assuming the Company will continue as a going concern, which contemplates the realization of assets and settlement of liabilities in the normal course of business. However, the Company’s current working capital, anticipated operating expenses and net losses and the uncertainties surrounding its ability to raise additional capital as needed, as discussed below, raise substantial doubt about its ability to continue as a going concern for a period of one year following the date that these financial statements are issued. The condensed consolidated financial statements do not include any adjustments for the recovery and classification of assets or the amounts and classification of liabilities that might be necessary should the Company be unable to continue as a going concern. The Company plans to continue to fund its losses from operations through cash and cash equivalents on hand, as well as through future equity offerings, debt financings, other third party funding, and potential licensing or collaboration arrangements. There can be no assurance that additional funds will be available when needed from any source or, if available, will be available on terms that are acceptable to the Company. Even if the Company raises additional capital, it may also be required to modify, delay or abandon some of its plans which could have a material adverse effect on the Company’s business, operating results and financial condition and the Company’s ability to achieve its intended business objectives. Any of these actions could materially harm the Company’s business, results of operations and future prospects. In addition to the foregoing, the Company is monitoring closely the impact of the COVID-19 pandemic on its business and has taken steps designed to protect the health and safety of its employees while continuing its operations. Given the level of uncertainty regarding the duration and impact of the COVID-19 pandemic on capital markets and the United States, or U.S., economy, the Company is currently unable to assess the impact of the COVID-19 pandemic on its future access to capital. The Company is continuing to monitor the spread of COVID-19 and its potential impact on the Company's operations. The full extent to which the COVID-19 pandemic will impact the Company's business, results of operations, financial condition, clinical trials, and preclinical research will depend on future developments that are highly uncertain, including actions taken to contain or treat COVID-19 and their effectiveness, as well as the economic impact on national and international markets.
Unaudited Interim Financial Data	Unaudited Interim Financial Data The accompanying condensed consolidated financial statements are unaudited and have been prepared by the Company in accordance with U.S. generally accepted accounting principles, or GAAP, as found in the Accounting Standards Codification, or ASC, of the Financial Accounting Standards Board, or FASB. Certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. These interim condensed consolidated financial statements, in the opinion of management, reflect all normal recurring adjustments necessary for a fair presentation of the Company’s financial position and results of operations for the interim periods ended March 31, 2022 and 2021.
Basis of Consolidation	Basis of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	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 and the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of expenses during the reporting period. The Company evaluates its estimates and assumptions on an ongoing basis. The most significant estimates in the Company’s condensed consolidated financial statements relate to estimating the fair value of the Company’s stock options, estimated collaboration expenses and incurred expenses related to the Mundipharma Collaboration Agreement and Janssen Collaboration Agreement (each as defined below), certain accruals, including those related to nonclinical and clinical activities, and the Standalone Selling Price of performance obligations associated with license agreements. Although the estimates are based on the Company’s knowledge of current events, comparable companies, and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions.
Segment Information	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, the Chief Executive Officer, in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business as one operating segment.
Cash, Cash Equivalents, and Restricted Cash	Cash, Cash Equivalents, and Restricted Cash The Company considers all short-term investments purchased with a maturity of three months or less when acquired to be cash equivalents. Restricted cash represents cash that the Company is required to maintain on hand in order to maintain compliance with an operating covenant in the Third Amendment to the Company's Loan Agreement with Pacific Western Bank. See Note 4 for additional information.
Accounts Receivable	Accounts Receivable Accounts receivable are recorded at their net invoice value and are not interest bearing. The Company reserves specific receivables when collectability is no longer probable. These reserves are re-evaluated on a regular basis and are adjusted, as needed. Once a receivable is deemed to be uncollectable, such balance is recorded as an allowance for credit losses. No such allowance existed at March 31, 2022 or December 31, 2021.
Property and Equipment	Property and Equipment The Company records property and equipment at cost, which consists of lab equipment, computer equipment and software, office equipment, furniture and fixtures and leasehold improvements. Property and equipment is depreciated using the straight-line method over the estimated useful lives (generally three to seven years). Leasehold improvements are amortized over the lesser of their useful life or the remaining lease term, including any renewal periods that are deemed to be reasonably assured. Repair and maintenance costs are expensed as incurred.
Income Taxes	Income Taxes The Company follows the FASB ASC 740, Income Taxes, or ASC 740, in reporting deferred income taxes. ASC 740 requires a company to recognize deferred tax assets and liabilities for expected future income tax consequences of events that have been recognized in the Company’s condensed consolidated financial statements. Under this method, deferred tax assets and liabilities are determined based on temporary differences between financial statement carrying amounts and the tax basis of assets and liabilities using enacted tax rates in the years in which the temporary differences are expected to reverse. Valuation allowances are provided if, based on the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertain tax positions pursuant to ASC 740, which prescribes a recognition threshold and measurement process for financial statement recognition of uncertain tax positions taken or expected to be taken in a tax return. If the tax position meets this threshold, the benefit to be recognized is measured as the tax benefit having the highest likelihood of being realized upon ultimate settlement with the taxing authority. The Company recognizes interest accrued related to unrecognized tax benefits and penalties in the provision for income taxes.
Revenue Recognition	Revenue Recognition The Company recognizes revenue is accordance with ASC Topic 606, Revenue from Contracts with Customers, or Topic 606, which applies to all contracts with customers, except for elements of certain contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. Under Topic 606, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration that the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Topic 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations, and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. In a contract with multiple performance obligations, the Company must develop estimates and assumptions that require judgment to determine the underlying stand-alone selling price for each performance obligation, which determines how the transaction price is allocated among the performance obligations. The estimation of the stand-alone selling price(s) may include estimates regarding forecasted revenues or costs, development timelines, discount rates, and probabilities of technical and regulatory success. The Company evaluates each performance obligation to determine if it can be satisfied at a point in time or over time. Any change made to estimated progress towards completion of a performance obligation and, therefore, revenue recognized will be recorded as a change in estimate. In addition, variable consideration must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price. If a license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in a contract, the Company recognizes revenues from the transaction price allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from the allocated transaction price. The Company evaluates the measure of progress at each reporting period and, if necessary, adjusts the measure of performance and related revenue or expense recognition as a change in estimate. At the inception of each arrangement that includes milestone payments, the Company evaluates whether the milestones are considered probable of being reached. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s or a collaboration partner’s control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. At the end of each reporting period, the Company re-evaluates the probability of achievement of milestones that are within its or a collaboration partner’s control, such as operational developmental milestones and any related constraint, and, if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which will affect collaboration revenues and earnings in the period of adjustment. Revisions to the Company’s estimate of the transaction price may also result in negative collaboration revenues and earnings in the period of adjustment. For arrangements that include sales-based royalties, including commercial milestone payments based on the level of sales, and a license is deemed to be the predominant item to which the royalties relate, the Company will recognize revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied, or partially satisfied. To date, the Company has not recognized any royalty revenue from collaborative arrangements. In September 2019, the Company entered into a Collaboration and License Agreement, or the Mundipharma Collaboration Agreement, with Mundipharma Medical Company, or Mundipharma. The Company concluded that there were three significant performance obligations under the Mundipharma Collaboration Agreement: the license, the research and development services, and the clinical supply services, and that the obligations are distinct from each other. Revenue associated with the license was recognized upon delivery in September 2019. In March 2021, the Company entered into an exclusive worldwide license and collaboration agreement, or the Janssen Collaboration Agreement, with Janssen Pharmaceuticals, Inc., or Janssen, one of the Janssen Pharmaceutical Companies of Johnson & Johnson. The Company concluded that there were three significant performance obligations under the Janssen Collaboration Agreement: the license, the research and development services, and the clinical supply services, and that the obligations are distinct from each other. Revenue associated with the license was recognized upon delivery in May 2021. The Company concluded that progress towards completion of the research and development and clinical supply performance obligations related to the Mundipharma Collaboration Agreement is best measured in an amount proportional to the collaboration expenses incurred and the total estimated collaboration expenses. The Company periodically reviews and updates the estimated collaboration expenses, when appropriate, which may adjust revenue recognized for the period. While such changes to the Company’s estimates have no impact on the Company’s reported cash flows, the amount of revenue recorded in the period could be materially impacted. Revenue from research and development services for the Janssen Collaboration Agreement is recognized based on actual amounts billed as the underlying services are provided and billed at market rates. The transaction prices to be recognized as revenue under both the Mundipharma Collaboration Agreement and the Janssen Collaboration Agreement consist of upfront payments and estimated reimbursable research and development and clinical supply costs. Potential future payments for variable consideration, such as clinical, regulatory or commercial milestones, will be recognized when it is probable that, if recorded, a significant reversal will not take place. Potential future royalty payments will be recorded as revenue when the associated sales occur. See Note 7 for additional information.
Research and Development Costs	Research and Development Costs Research and development expenses consist of wages, benefits and stock-based compensation charges for research and development employees, scientific consultant fees, facilities and overhead expenses, laboratory supplies, manufacturing expenses, and nonclinical and clinical trial costs. The Company accrues nonclinical and clinical trial expenses based on work performed, which relies on estimates of total costs incurred based on patient enrollment, completion of studies, and other events. Costs incurred in purchasing technology assets and intellectual property are charged to research and development expense if the technology has not been conclusively proven to be feasible and has no alternative future use.
Preclinical and Clinical Trial Accruals	Preclinical and Clinical Trial Accruals The Company makes estimates of its accrued expenses as of each balance sheet date in the financial statements based on the facts and circumstances known at that time. Accrued expenses for preclinical studies and clinical trials are based on estimates of costs incurred and fees that may be associated with services provided by contract research organizations, or CROs, clinical trial investigational sites and other clinical trial-related activities. Payments under certain contracts with such parties depend on factors such as successful enrollment of patients, site initiation and the completion of clinical trial milestones. In accruing for these services, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If possible, the Company obtains information regarding unbilled services directly from these service providers. However, the Company may be required to estimate these services based on other available information. If the Company underestimates or overestimates the activities or fees associated with a study or service at a given point in time, adjustments to research and development expenses may be necessary in future periods. Historically, estimated accrued liabilities have approximated actual expense incurred. Subsequent changes in estimates may result in a material change in accruals.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for stock-based compensation expense related to stock options, restricted stock units, or RSUs, performance-based RSUs, or PRSUs, and Employee Stock Purchase Plan, or ESPP, rights by estimating the fair value on the date of grant. The Company estimates the fair value of stock options granted to employees and non-employees using the Black-Scholes option pricing model. The fair value of RSUs and PRSUs granted to employees is estimated based on the closing price of the Company's common stock on the date of grant. The assumptions included in the Black-Scholes option pricing model include (a) the risk-free interest rate, (b) the expected volatility of the Company's stock, (c) the expected term of the award, and (d) the expected dividend yield. The Company computed the expected volatility data using the daily close prices for the Company's common stock during the equivalent period of the calculated expected term of the Company's stock-based awards. The Company estimated the expected life of employee stock options using the “simplified” method, whereby the expected life equals the average of the vesting term and the original contractual term of the option. The risk-free interest rates for periods within the expected life of the option are based on the yields of zero-coupon U.S. treasury securities. The expected dividend yield of zero reflects that the Company has not paid cash dividends since inception and do not intend to pay cash dividends in the foreseeable future. For awards subject to time-based vesting conditions, including those with a graded vesting schedule, stock-based compensation expense is recognized using the straight-line method. For performance-based awards to employees, (i) the fair value of the award is determined on the grant date, (ii) the Company assesses the probability of the individual performance milestones under the award being achieved and (iii) the fair value of the shares subject to the milestone is expensed over the implicit service period commencing once management believes the performance criteria is probable of being met. The Company recognizes forfeitures related to stock-based compensation as they occur and any compensation cost previously recognized for awards for which the requisite service has not been completed is reversed in the period that the award is forfeited.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing the net loss allocable to common shares by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss allocable to common shares by the weighted-average number of common shares and dilutive stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. Dilutive common stock equivalents are comprised of warrants, Series X Convertible Preferred Stock, RSUs, PRSUs and options outstanding under the Company’s stock option plans. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company's net loss position.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company follows ASC 820-10 issued by the FASB with respect to fair value reporting for financial assets and liabilities. The guidance defines fair value, provides guidance for measuring fair value and requires certain disclosures. The guidance does not apply to measurements related to share-based payments. The guidance discusses valuation techniques such as the market approach (comparable market prices), the income approach (present value of future income or cash flow), and the cost approach (cost to replace the service capacity of an asset or replacement cost). The guidance establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. The Company’s financial instruments consist of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, accrued liabilities, lease liability, and a term loan. Fair value estimates of these instruments are made at each reporting period end based on relevant market information. These estimates may be subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. The carrying amount of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, and accrued liabilities are generally considered to be representative of their respective fair values because of the short-term nature of those instruments. Based on the borrowing rates available to the Company for loans with similar terms, which is considered a Level 2 input as described in Note 3, the Company believes that the fair value of the term loan approximates its carrying value.
Recently Issued Accounting Standards	Recently Issued Accounting Standards Recently Adopted Accounting Standards In August 2020, the FASB issued ASU 2020-06, "Accounting for Convertible Instruments and Contracts in an Entity's Own Equity," simplifies the accounting for certain convertible instruments by removing the separation models for convertible debt with a cash conversion feature or convertible instruments with a beneficial conversion feature. As a result, more convertible debt instruments will be reported as a single liability instrument with no separate accounting for embedded conversion features. Additionally, this ASU amends the diluted EPS calculation for convertible instruments by requiring the use of the if-converted method. The treasury stock method is no longer available. Entities may adopt this ASU using either a full or modified retrospective approach, and it is effective for interim and annual reporting periods beginning after December 15, 2021. Early adoption is permitted for interim and annual reporting periods beginning after December 15, 2020. The Company adopted ASU 2020-06 effective January 1, 2022. The adoption of this standard did not have a material impact on the Company's condensed consolidated financial statements.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

3 Months Ended

Mar. 31, 2022

The Company has a limited operating history and the sales and income potential of the Company’s business and market are unproven. The Company has experienced net losses and negative cash flows from operating activities since its inception. At March 31, 2022, the Company had an accumulated deficit of $395.4 million. The Company expects to continue to incur net losses into the foreseeable future. Successful transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support the Company’s cost structure.

At March 31, 2022, the Company had cash, cash equivalents and restricted cash of $38.0 million. Based on the Company’s current business plan, management believes that existing cash and cash equivalents will not be sufficient to fund the Company’s obligations for twelve months from the issuance of these financial statements. The Company’s ability to execute its operating plan depends on its ability to obtain additional funding through equity offerings, debt financings or potential licensing and collaboration arrangements. The accompanying condensed consolidated financial statements have been prepared assuming the Company will continue as a going concern, which contemplates the realization of assets and settlement of liabilities in the normal course of business. However, the Company’s current working capital, anticipated operating expenses and net losses and the uncertainties surrounding its ability to raise additional capital as needed, as discussed below, raise substantial doubt about its ability to continue as a going concern for a period of one year following the date that these financial statements are issued. The condensed consolidated financial statements do not include any adjustments for the recovery and classification of assets or the amounts and classification of liabilities that might be necessary should the Company be unable to continue as a going concern.

The Company plans to continue to fund its losses from operations through cash and cash equivalents on hand, as well as through future equity offerings, debt financings, other third party funding, and potential licensing or collaboration arrangements. There can be no assurance that additional funds will be available when needed from any source or, if available, will be available on terms that are acceptable to the Company. Even if the Company raises additional capital, it may also be required to modify, delay or abandon some of its plans which could have a material adverse effect on the Company’s business, operating results and financial condition and the Company’s ability to achieve its intended business objectives. Any of these actions could materially harm the Company’s business, results of operations and future prospects.

In addition to the foregoing, the Company is monitoring closely the impact of the COVID-19 pandemic on its business and has taken steps designed to protect the health and safety of its employees while continuing its operations. Given the level of uncertainty regarding the duration and impact of the COVID-19 pandemic on capital markets and the United States, or U.S., economy, the Company is currently unable to assess the impact of the COVID-19 pandemic on its future access to capital. The Company is continuing to monitor the spread of COVID-19 and its potential impact on the Company's operations. The full extent to which the COVID-19 pandemic will impact the Company's business, results of operations, financial condition, clinical trials, and preclinical research will depend on future developments that are highly uncertain,

including actions taken to contain or treat COVID-19 and their effectiveness, as well as the economic impact on national and international markets.

Unaudited Interim Financial Data

The accompanying condensed consolidated financial statements are unaudited and have been prepared by the Company in accordance with U.S. generally accepted accounting principles, or GAAP, as found in the Accounting Standards Codification, or ASC, of the Financial Accounting Standards Board, or FASB. Certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. These interim condensed consolidated financial statements, in the opinion of management, reflect all normal recurring adjustments necessary for a fair presentation of the Company’s financial position and results of operations for the interim periods ended March 31, 2022 and 2021.

Basis of Consolidation

The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation.

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 and the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of expenses during the reporting period. The Company evaluates its estimates and assumptions on an ongoing basis. The most significant estimates in the Company’s condensed consolidated financial statements relate to estimating the fair value of the Company’s stock options, estimated collaboration expenses and incurred expenses related to the Mundipharma Collaboration Agreement and Janssen Collaboration Agreement (each as defined below), certain accruals, including those related to nonclinical and clinical activities, and the Standalone Selling Price of performance obligations associated with license agreements. Although the estimates are based on the Company’s knowledge of current events, comparable companies, and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions.

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, the Chief Executive Officer, in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business as one operating segment.

Cash, Cash Equivalents, and Restricted Cash

The Company considers all short-term investments purchased with a maturity of three months or less when acquired to be cash equivalents.

Restricted cash represents cash that the Company is required to maintain on hand in order to maintain compliance with an operating covenant in the Third Amendment to the Company's Loan Agreement with Pacific Western Bank.

See Note 4 for additional information.

Accounts Receivable

Accounts receivable are recorded at their net invoice value and are not interest bearing. The Company reserves specific receivables when collectability is no longer probable. These reserves are re-evaluated on a regular basis and are adjusted, as needed. Once a receivable is deemed to be uncollectable, such balance is recorded as an allowance for credit losses. No such allowance existed at March 31, 2022 or December 31, 2021.

Property and Equipment

The Company records property and equipment at cost, which consists of lab equipment, computer equipment and software, office equipment, furniture and fixtures and leasehold improvements. Property and equipment is depreciated

using the straight-line method over the estimated useful lives (generally three to seven years). Leasehold improvements are amortized over the lesser of their useful life or the remaining lease term, including any renewal periods that are deemed to be reasonably assured. Repair and maintenance costs are expensed as incurred.

Income Taxes

The Company follows the FASB ASC 740, Income Taxes, or ASC 740, in reporting deferred income taxes. ASC 740 requires a company to recognize deferred tax assets and liabilities for expected future income tax consequences of events that have been recognized in the Company’s condensed consolidated financial statements. Under this method, deferred tax assets and liabilities are determined based on temporary differences between financial statement carrying amounts and the tax basis of assets and liabilities using enacted tax rates in the years in which the temporary differences are expected to reverse. Valuation allowances are provided if, based on the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized.

The Company accounts for uncertain tax positions pursuant to ASC 740, which prescribes a recognition threshold and measurement process for financial statement recognition of uncertain tax positions taken or expected to be taken in a tax return. If the tax position meets this threshold, the benefit to be recognized is measured as the tax benefit having the highest likelihood of being realized upon ultimate settlement with the taxing authority. The Company recognizes interest accrued related to unrecognized tax benefits and penalties in the provision for income taxes.

Revenue Recognition

The Company recognizes revenue is accordance with ASC Topic 606, Revenue from Contracts with Customers, or Topic 606, which applies to all contracts with customers, except for elements of certain contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. Under Topic 606, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration that the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Topic 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations, and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied.

In a contract with multiple performance obligations, the Company must develop estimates and assumptions that require judgment to determine the underlying stand-alone selling price for each performance obligation, which determines how the transaction price is allocated among the performance obligations. The estimation of the stand-alone selling price(s) may include estimates regarding forecasted revenues or costs, development timelines, discount rates, and probabilities of technical and regulatory success. The Company evaluates each performance obligation to determine if it can be satisfied at a point in time or over time. Any change made to estimated progress towards completion of a performance obligation and, therefore, revenue recognized will be recorded as a change in estimate. In addition, variable consideration must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price.

If a license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in a contract, the Company recognizes revenues from the transaction price allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from the allocated transaction price. The Company evaluates the measure of progress at each reporting period and, if necessary, adjusts the measure of performance and related revenue or expense recognition as a change in estimate.

At the inception of each arrangement that includes milestone payments, the Company evaluates whether the milestones are considered probable of being reached. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s or a collaboration partner’s control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. At the end of each reporting period, the Company re-evaluates the probability of achievement of milestones that are within its or a collaboration partner’s control, such as operational developmental milestones and any related constraint, and, if necessary, adjusts its estimate of the overall transaction price. Any such

adjustments are recorded on a cumulative catch-up basis, which will affect collaboration revenues and earnings in the period of adjustment. Revisions to the Company’s estimate of the transaction price may also result in negative collaboration revenues and earnings in the period of adjustment.

For arrangements that include sales-based royalties, including commercial milestone payments based on the level of sales, and a license is deemed to be the predominant item to which the royalties relate, the Company will recognize revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied, or partially satisfied. To date, the Company has not recognized any royalty revenue from collaborative arrangements.

In September 2019, the Company entered into a Collaboration and License Agreement, or the Mundipharma Collaboration Agreement, with Mundipharma Medical Company, or Mundipharma. The Company concluded that there were three significant performance obligations under the Mundipharma Collaboration Agreement: the license, the research and development services, and the clinical supply services, and that the obligations are distinct from each other. Revenue associated with the license was recognized upon delivery in September 2019.

In March 2021, the Company entered into an exclusive worldwide license and collaboration agreement, or the Janssen Collaboration Agreement, with Janssen Pharmaceuticals, Inc., or Janssen, one of the Janssen Pharmaceutical Companies of Johnson & Johnson. The Company concluded that there were three significant performance obligations under the Janssen Collaboration Agreement: the license, the research and development services, and the clinical supply services, and that the obligations are distinct from each other. Revenue associated with the license was recognized upon delivery in May 2021.

The Company concluded that progress towards completion of the research and development and clinical supply performance obligations related to the Mundipharma Collaboration Agreement is best measured in an amount proportional to the collaboration expenses incurred and the total estimated collaboration expenses. The Company periodically reviews and updates the estimated collaboration expenses, when appropriate, which may adjust revenue recognized for the period. While such changes to the Company’s estimates have no impact on the Company’s reported cash flows, the amount of revenue recorded in the period could be materially impacted. Revenue from research and development services for the Janssen Collaboration Agreement is recognized based on actual amounts billed as the underlying services are provided and billed at market rates. The transaction prices to be recognized as revenue under both the Mundipharma Collaboration Agreement and the Janssen Collaboration Agreement consist of upfront payments and estimated reimbursable research and development and clinical supply costs.

Potential future payments for variable consideration, such as clinical, regulatory or commercial milestones, will be recognized when it is probable that, if recorded, a significant reversal will not take place. Potential future royalty payments will be recorded as revenue when the associated sales occur.

See Note 7 for additional information.

Research and Development Costs

Research and development expenses consist of wages, benefits and stock-based compensation charges for research and development employees, scientific consultant fees, facilities and overhead expenses, laboratory supplies, manufacturing expenses, and nonclinical and clinical trial costs. The Company accrues nonclinical and clinical trial expenses based on work performed, which relies on estimates of total costs incurred based on patient enrollment, completion of studies, and other events.

Costs incurred in purchasing technology assets and intellectual property are charged to research and development expense if the technology has not been conclusively proven to be feasible and has no alternative future use.

Preclinical and Clinical Trial Accruals

The Company makes estimates of its accrued expenses as of each balance sheet date in the financial statements based on the facts and circumstances known at that time. Accrued expenses for preclinical studies and clinical trials are based on estimates of costs incurred and fees that may be associated with services provided by contract research organizations, or CROs, clinical trial investigational sites and other clinical trial-related activities. Payments under certain contracts with such parties depend on factors such as successful enrollment of patients, site initiation and the completion of clinical trial milestones. In accruing for these services, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If possible, the Company obtains information regarding unbilled services directly from these service providers. However, the Company may be required to estimate these services based on other available information. If the Company underestimates or overestimates the activities or fees associated with a study or service at a given point in time, adjustments to research and development expenses may be necessary in future

periods. Historically, estimated accrued liabilities have approximated actual expense incurred. Subsequent changes in estimates may result in a material change in accruals.

Stock-Based Compensation

The Company accounts for stock-based compensation expense related to stock options, restricted stock units, or RSUs, performance-based RSUs, or PRSUs, and Employee Stock Purchase Plan, or ESPP, rights by estimating the fair value on the date of grant. The Company estimates the fair value of stock options granted to employees and non-employees using the Black-Scholes option pricing model. The fair value of RSUs and PRSUs granted to employees is estimated based on the closing price of the Company's common stock on the date of grant.

The assumptions included in the Black-Scholes option pricing model include (a) the risk-free interest rate, (b) the expected volatility of the Company's stock, (c) the expected term of the award, and (d) the expected dividend yield. The Company computed the expected volatility data using the daily close prices for the Company's common stock during the equivalent period of the calculated expected term of the Company's stock-based awards. The Company estimated the expected life of employee stock options using the “simplified” method, whereby the expected life equals the average of the vesting term and the original contractual term of the option. The risk-free interest rates for periods within the expected life of the option are based on the yields of zero-coupon U.S. treasury securities. The expected dividend yield of zero reflects that the Company has not paid cash dividends since inception and do not intend to pay cash dividends in the foreseeable future.

For awards subject to time-based vesting conditions, including those with a graded vesting schedule, stock-based compensation expense is recognized using the straight-line method. For performance-based awards to employees, (i) the fair value of the award is determined on the grant date, (ii) the Company assesses the probability of the individual performance milestones under the award being achieved and (iii) the fair value of the shares subject to the milestone is expensed over the implicit service period commencing once management believes the performance criteria is probable of being met.

The Company recognizes forfeitures related to stock-based compensation as they occur and any compensation cost previously recognized for awards for which the requisite service has not been completed is reversed in the period that the award is forfeited.

Net Loss Per Share

Basic net loss per share is calculated by dividing the net loss allocable to common shares by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss allocable to common shares by the weighted-average number of common shares and dilutive stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. Dilutive common stock equivalents are comprised of warrants, Series X Convertible Preferred Stock, RSUs, PRSUs and options outstanding under the Company’s stock option plans. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company's net loss position.

Fair Value of Financial Instruments

The Company follows ASC 820-10 issued by the FASB with respect to fair value reporting for financial assets and liabilities. The guidance defines fair value, provides guidance for measuring fair value and requires certain disclosures. The guidance does not apply to measurements related to share-based payments. The guidance discusses valuation techniques such as the market approach (comparable market prices), the income approach (present value of future income or cash flow), and the cost approach (cost to replace the service capacity of an asset or replacement cost). The

guidance establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels.

The Company’s financial instruments consist of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, accrued liabilities, lease liability, and a term loan. Fair value estimates of these instruments are made at each reporting period end based on relevant market information. These estimates may be subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. The carrying amount of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, and accrued liabilities are generally considered to be representative of their respective fair values because of the short-term nature of those instruments. Based on the borrowing rates available to the Company for loans with similar terms, which is considered a Level 2 input as described in Note 3, the Company believes that the fair value of the term loan approximates its carrying value.

Recently Issued Accounting Standards

Recently Adopted Accounting Standards

In August 2020, the FASB issued ASU 2020-06, "Accounting for Convertible Instruments and Contracts in an Entity's Own Equity," simplifies the accounting for certain convertible instruments by removing the separation models for convertible debt with a cash conversion feature or convertible instruments with a beneficial conversion feature. As a result, more convertible debt instruments will be reported as a single liability instrument with no separate accounting for embedded conversion features. Additionally, this ASU amends the diluted EPS calculation for convertible instruments by requiring the use of the if-converted method. The treasury stock method is no longer available. Entities may adopt this ASU using either a full or modified retrospective approach, and it is effective for interim and annual reporting periods beginning after December 15, 2021. Early adoption is permitted for interim and annual reporting periods beginning after December 15, 2020. The Company adopted ASU 2020-06 effective January 1, 2022. The adoption of this standard did not have a material impact on the Company's condensed consolidated financial statements.