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

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You should read the following discussion and analysis of our financial condition and results of operations together with the consolidated financial statements and related notes included elsewhere in this Annual Report. This discussion contains forward-looking statements based upon current expectations that involve risks and uncertainties. Our actual results may differ materially from those anticipated in these forward-looking statements as a result of various factors, including those discussed in “Item 1A. Risk Factors” and in other parts of this Annual Report.

Overview

Our most advanced clinical asset, rusfertide (generic name for PTG-300) is an injectable hepcidin mimetic in development for the potential treatment of erythrocytosis, iron overload and other blood disorders. Hepcidin is a key hormone in regulating iron equilibrium and is critical to the proper development of red blood cells. Rusfertide mimics the effect of the natural hormone hepcidin, but with greater potency, solubility and stability. We initiated Phase 2 proof of concept (“POC”) studies in the blood disorders polycythemia vera (“PV”) in the third quarter of 2019 and hereditary hemochromatosis (“HH”) in January 2020. In December 2020, we presented four posters and one oral presentation relating to rusfertide at the American Society for Hematology’s virtual annual meeting, including updated interim Phase 2 results for rusfertide in PV. We believe these interim results provide evidence regarding the potential of rusfertide to eliminate the need for phlebotomy by controlling hematocrit levels below 45% on an individual patient basis. Rusfertide has a unique mechanism of action in the potential treatment of PV, which may enable it to decrease and maintain hematocrit levels within the range of recommended clinical guidelines without causing the iron deficiency that may occur with frequent phlebotomy.

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We selected PV as our first indication for potential pivotal study in rusfertide and expect to complete patient enrollment in the ongoing Phase 2 clinical trial by mid-2021. We are consulting with regulatory authorities in the first half of 2021 to discuss the registrational clinical development plan. In June 2020, the U.S. Food and Drug Administration (“FDA”) granted orphan drug designation for rusfertide for the treatment of PV. In October 2020, the European Medicines Agency granted orphan drug designation for rusfertide for the treatment of PV. In December 2020, the FDA granted Fast Track designation for rusfertide for the treatment of PV. In addition, we expect to disclose preliminary data from our Phase 2 POC study in HH, our second indication, in the second half of 2021. We discontinued development of rusfertide for anemia associated with beta-thalassemia and myelodysplastic syndromes during the first half of 2020.

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Our clinical assets PTG-943 and PTG-200 are orally delivered investigational drugs currently in development for inflammatory bowel disease (“IBD”), a gastrointestinal (“GI”) disease consisting primarily of ulcerative colitis (“UC”) and Crohn’s disease (“CD”), that are designed to block biological pathways currently targeted by marketed injectable antibody drugs. Our orally stable peptide approach may offer targeted delivery to the GI tissue compartment. We believe that, compared to antibody drugs, these product candidates have the potential to provide improved safety due to minimal exposure in the blood, increased convenience and compliance due to oral delivery, and the opportunity for the earlier introduction of targeted oral therapy. As a result, if successfully developed and approved, we believe they may transform the existing treatment paradigm for IBD.

PN-943 is an investigational, orally delivered, gut-restricted alpha-4-beta-7 (“α4β7”) specific integrin antagonist. We developed PN-943 as a potentially more potent orally delivered, gut-restricted α4β7 backup compound to PTG-100, our first-generation orally delivered gut-restricted α4β7 inhibitor that was being developed for treatment of IBD. In 2019, we completed a Phase 1 single ascending dose (“SAD”) and multiple ascending dose (“MAD”) clinical study of PN-943 in healthy volunteers to evaluate safety, pharmacokinetics and pharmacodynamics. The pharmacodynamic results indicated that the administration of PN-943 was well tolerated and showed results of target engagement that were

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suggestive of higher potency for PN-943 as compared to PTG-100. We submitted a U.S. Investigational New Drug application (“IND”) with the FDA for PN-943 in December 2019, which took effect in January 2020, and we initiated a Phase 2 POC study in UC in the second quarter of 2020 which is expected to be completed in 2022, subject to delays related to the COVID-19 pandemic.

PTG-200 (also referenced as JNJ-67864238) is an investigational, orally delivered, gut-restricted Interleukin-23 receptor (“IL-23R”) antagonist for the treatment of IBD. In May 2017, we entered into a worldwide license and collaboration agreement with Janssen Biotech, Inc. (“Janssen”), a Johnson & Johnson company, to co-develop and co-detail PTG-200 and certain related compounds for all indications, including IBD. The agreement with Janssen was amended in May 2019 to expand the collaboration by supporting efforts towards second-generation IL- 23R antagonists, triggering a $25.0 million milestone payment to us. In January 2020, as part of the expanded research collaboration, we announced the identification and nomination of an orally delivered IL-23R antagonist peptide as a second-generation development candidate, triggering a $5.0 million milestone payment to us. Janssen initiated a global Phase 2 POC clinical study for PTG-200 in moderate-to-severe CD in the fourth quarter of 2019. Due to the uncertain effect on the timing of clinical trials caused by the COVID-19 pandemic, we have suspended guidance on a timeline for completion of the PTG-200 Phase 2 study. In October 2020, we announced the selection of two second-generation IL-R antagonists for advancement into clinical development, PN-235 (also referenced as JNJ-77242113) and PN-232 (also referenced as JNJ-75105186). A Phase 1 study was initiated for PN-235 in December 2020 and is expected to be completed in 2021. PN-232 is in the late preclinical stage and we expect to initiate and complete a Phase 1 study for PN-232 in 2021. The advancement of three different oral co-development candidates provides us with several strategic options for development in multiple indications. We are also continuing our joint research efforts to identify additional IL-23R antagonists.

Our clinical assets are all derived from our proprietary discovery platform. Our platform enables us to engineer novel, structurally constrained peptides that are designed to retain key advantages of both orally delivered small molecules and injectable antibody drugs in an effort to overcome many of their limitations as therapeutic agents. Importantly, constrained peptides can be designed to potentially alleviate the fundamental instability inherent in traditional peptides to allow different delivery forms, such as oral, subcutaneous, intravenous, and rectal. We continue to use our peptide technology platform to discover product candidates against targets in disease areas with significant unmet medical needs.

COVID-19 Business Impact

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We are subject to risks and uncertainties as a result of the COVID-19 pandemic. We are continuing to closely monitor the impact of the COVID-19 pandemic on our business and have taken and continue to take proactive efforts to protect the health and safety of our patients, study investigators, clinical research staff and employees, and to maintain business continuity. The extent of the impact of the COVID-19 pandemic on our activities is highly uncertain and difficult to predict, as the pandemic and the response to the pandemic continue to evolve. Capital markets and economies worldwide have been significantly impacted by the COVID-19 pandemic, and the pandemic has contributed to a global economic recession. Such economic disruption could have a material adverse effect on our business. Policymakers around the globe have responded with fiscal policy actions to support the healthcare industry and economy as a whole. The magnitude and overall effectiveness of these actions remains uncertain.

The severity of the impact of the COVID-19 pandemic on our activities will depend on a number of factors, including, but not limited to, the duration and severity of the pandemic, including the severity of any additional periods of increases or spikes in the number of cases in the areas we, our suppliers and our manufacturers operate and areas where our clinical trial sites are located. Accordingly, the extent and severity of the impact on our existing and planned clinical trials, manufacturing, collaboration activities and operations is uncertain and cannot be fully predicted. We have experienced delays in our existing and planned clinical trials due to the worldwide impacts of the pandemic. Our future results of operations and liquidity could be adversely impacted by further delays in existing and planned clinical trials and collaboration activities, continued difficulty in recruiting patients for these clinical trials, delays in manufacturing and collaboration activities, supply chain disruptions, the ongoing impact on operating activities and employees, and the ongoing impact of any initiatives or programs that we may undertake to address financial and operational challenges. As

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of the date of issuance of this Annual Report on Form 10-K, the extent to which the COVID-19 pandemic may materially impact our future financial condition, liquidity or results of operations is uncertain.

Operations

We have incurred net losses in each year since inception and we do not anticipate achieving sustained profitability in the foreseeable future. Our net losses were $66.2 million, $77.2 million and $38.9 million for the years ended December 31, 2020, 2019 and 2018, respectively. As of December 31, 2020, we had an accumulated deficit of $283.8 million. Substantially all of our net losses have resulted from costs incurred in connection with our research and development programs and from general and administrative costs associated with our operations. We expect to continue to incur significant research, development and other expenses related to our ongoing operations, product development, including clinical development activities under our worldwide license and collaboration agreement with Janssen, and pre-commercialization activities. As a result, we expect to continue to incur losses in the future as we continue our development of, and seek regulatory approval for, our product candidates.

Janssen License and Collaboration Agreement

On May 26, 2017, we and Janssen, one of the Janssen Pharmaceutical Companies of Johnson & Johnson, entered into an exclusive license and collaboration agreement for the clinical development, manufacture and potential commercialization of PTG-200 worldwide for the treatment of CD and UC (the “Janssen License and Collaboration Agreement”), which was subsequently amended effective May 7, 2019 (the “First Amendment”). The First Amendment expanded the scope of the Janssen License and Collaboration Agreement by supporting efforts towards identifying and development second-generation compounds. Janssen is a related party to us as Johnson & Johnson Innovation - JJDC, Inc., a significant stockholder of ours, and Janssen are both subsidiaries of Johnson & Johnson. During the third quarter of 2017, we received a non-refundable, upfront cash payment of $50.0 million from Janssen. During the second quarter of 2019, we received a non-refundable cash payment of $25.0 million upon execution of the First Amendment. During the first quarter of 2020, we received a cash payment of $5.0 million upon the successful nomination of a second-generation development candidate. See Note 3 to the Consolidated Financial Statements included elsewhere in this Annual Report on Form 10-K for additional information.

Critical Accounting Polices and Estimates

Our management’s discussion and analysis of our financial condition and results of operations is based on our consolidated financial statements, which have been prepared in accordance with United States generally accepted accounting principles. The preparation of these consolidated financial statements requires us 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 consolidated financial statements, as well as the reported revenue generated and expenses incurred during the reporting periods. Our estimates are based on our historical experience and on various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions. We believe that the accounting policies discussed below are critical to understanding our historical and future performance, as these policies relate to the more significant areas involving management’s judgments and estimates.

Use of Estimates

Due to the COVID-19 pandemic, there has been uncertainty and disruption in the global economy and financial markets. We have taken into consideration any known COVD-19 impacts in our accounting estimates to date and are not aware of any additional specific events or circumstances that would require any additional updates to our estimates or judgments or a revision of the carrying value of our assets or liabilities as of the date of issuance of this Annual Report on Form 10-K. These estimates may change as new events occur and additional information is obtained. Actual results could differ materially from these estimates under different assumptions or conditions.

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Leases

We adopted Accounting Standards Codification Topic 842, Leases, (“ASC 842”) effective January 1, 2019. We determine if an arrangement is a lease at inception. Pursuant to ASC 842, operating leases are included in operating lease right-of-use (“ROU”) assets, operating lease liabilities, and noncurrent operating lease liabilities on the consolidated balance sheets. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. If our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives and initial direct costs incurred. Lease terms include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term.

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We record tenant improvement allowances as a reduction to the ROU asset with the impact of the decrease recognized prospectively over the remaining lease term. The leasehold improvements will be amortized over the shorter of their useful life or the remaining term of the lease.

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Revenue Recognition

We follow Accounting Standards Codification Topic 606, Revenue from Contracts with Customers (“ASC 606”). Under ASC 606, we recognize revenue when our customer obtains control of promised goods or services, in an amount that reflects the consideration which we expect to receive in exchange for those goods or services. To determine revenue recognition for arrangements that we determine are within the scope of ASC 606, we perform 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) we satisfy a performance obligation. We apply the five-step model to contracts when it is probable that we will collect the consideration we are entitled to in exchange for the goods or services we transfer to the customer. At contract inception, we assess the goods or services promised within each contract, determine those that are performance obligations, and assess whether each promised good or service is distinct. We then recognize as revenue the amount of the transaction price that is allocated to the respective performance obligations when (or as) the performance obligations are satisfied. We constrain our estimate of the transaction price up to the amount (the “variable consideration constraint”) that a significant reversal of recognized revenue is not probable.

Licenses of intellectual property: If a license to our intellectual property is determined to be distinct from the other performance obligations identified in an arrangement, we recognize revenue from non-refundable, upfront fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. For licenses that are bundled with other promises, we utilize 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 proportional performance for purposes of recognizing revenue from non-refundable, upfront fees. We evaluate the measure of proportional performance each reporting period and, if necessary, adjust the measure of performance and related revenue recognition.

Milestone payments: At the inception of each arrangement or amendment that includes development, regulatory or commercial milestone payments, we evaluate whether the milestones are considered probable of being reached and estimate the amount to be included in the transaction price. ASC 606 suggests two alternatives to use when estimating the amount of variable consideration: the expected value method and the most likely amount method. Under the expected value method, an entity considers the sum of probability-weighted amounts in a range of possible consideration amounts. Under the most likely amount method, an entity considers the single most likely amount in a range of possible consideration amounts. Whichever method is used, it should be consistently applied throughout the life of the contract; however, it is not necessary for us to use the same approach for all contracts. We expect to use the most likely amount method for development and regulatory milestone payments. 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 our control or the control of the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. If there is more than one performance obligation, the transaction price is then allocated to

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each performance obligation on a relative stand-alone selling price basis. We recognize revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, we re-evaluate the probability or achievement of each such milestone and any related constraint, and if necessary, adjust our estimates of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment.

Royalties: For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, we 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).

Upfront payments and fees are recorded as deferred revenue upon receipt or when due and may require deferral of revenue recognition to a future period until we perform our obligations under these arrangements. Amounts payable to us are recorded as accounts receivable when our right to consideration is unconditional. Amounts payable to us and not yet billed to the collaboration partner are recorded as contract assets. We do not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less.

Contractual cost sharing payments made to a customer or collaboration partner are accounted for as a reduction to the transaction price if such payments are not related to distinct goods or services received from the customer or collaboration partner.

Contracts may be amended to account for changes in contract specifications and requirements. Contract modifications exist when the amendment either creates new, or changes existing, enforceable rights and obligations. When contract modifications create new performance obligations and the increase in consideration approximates the standalone selling price for goods and services related to such new performance obligations as adjusted for specific facts and circumstances of the contract, the modification is considered to be a separate contract and revenue is recognized prospectively. If a contract modification is not accounted for as a separate contract, we account for the promised goods or services not yet transferred at the date of the contract modification (the remaining promised goods or services) prospectively, as if it were a termination of the existing contract and the creation of a new contract, if the remaining goods or services are distinct from the goods or services transferred on or before the date of the contract modification. We account for a contract modification as if it were a part of the existing contract if the remaining goods or services are not distinct and, therefore, form part of a single performance obligation that is partially satisfied at the date of the contract modification. In such case the effect that the contract modification has on the transaction price, and on the entity’s measure of progress toward complete satisfaction of the performance obligation, is recognized as an adjustment to revenue (either as an increase in or a reduction of revenue) at the date of the contract modification (the adjustment to revenue is made on a cumulative catch-up basis).

The period between when we transfer control of promised goods or services and when we receive payment is expected to be one year or less, which is consistent with our historical experience. Upfront payment contract liabilities resulting from our license and collaboration agreements do not represent a financing component as the payment is not financing the transfer of goods and services, and the technology underlying the licenses granted reflects research and development expenses already incurred by us. As such, we do not adjust our revenues for the effects of a significant financing component.

Research and Development Costs

Research and development costs are expensed as incurred, unless there is an alternate future use in other research and development projects or otherwise. Research and development costs include salaries and benefits, stock-based compensation expense, laboratory supplies and facility-related overhead, outside contracted services including clinical trial costs, manufacturing and process development costs for both clinical and pre-clinical materials, research costs, development milestone payments under license and collaboration agreements, and other consulting services.

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We accrue for estimated costs of research and development activities conducted by third-party service providers, which include the conduct of pre-clinical studies and clinical trials, and contract manufacturing activities. We record the estimated costs of research and development activities based upon the estimated services provided but not yet invoiced and includes these costs in accrued expenses and other payables in the consolidated balance sheets and within research and development expense in the consolidated statements of operations. We accrue for these costs based on factors such as estimates of the work completed and in accordance with agreements established with its third-party service providers. As actual costs become known, we adjust our accrued liabilities. We have not experienced any material differences between accrued liabilities and actual costs incurred. However, the status and timing of actual services performed, number of patients enrolled, the rate of patient enrollment and number and location of sites activated may vary from our estimates, resulting in adjustments to expense in future periods. Changes in these estimates that result in material changes to our accruals could materially affect our results of operations.

We have received orphan drug designation from the U.S. Food and Drug Administration (“FDA”) for our clinical asset rusfertide (generic name for PTG-300) for the treatment of PV and beta-thalassemia and may qualify for a related 25% U.S. Federal income tax credit on qualifying clinical study expenditures.

Stock-Based Compensation

We recognize compensation costs related to stock options accounted for under Accounting Standards Codification Topic 718 – “Stock Compensation” based on the estimated fair value of the awards on the date of grant. We estimate the fair value, and the resulting stock-based compensation expense, using the Black-Scholes option-pricing model. The estimated fair value of the stock-based awards is generally recognized on a straight-line basis over the requisite service period, which is generally the vesting period of the respective awards.

The Black-Scholes option-pricing model requires the use of subjective assumptions which determine the fair value of stock-based awards. Expected volatility generally requires significant judgement to determine. Prior to January 1, 2020, our expected volatility was estimated based on the average volatility for comparable publicly traded biopharmaceutical companies over a period equal to the expected term of the stock option grants. Beginning January 1, 2020, our expected volatility was estimated based upon a mix of 75% of the average volatility for comparable publicly traded biopharmaceutical companies over a period equal to the expected term of the stock option grants and 25% of the volatility of our own stock price since our initial public offering in August 2016. These comparable companies are chosen based on their similar size, stage in the life cycle, or area of specialty. We will continue to apply this process until a longer period of historical information regarding the volatility of our own stock price becomes available.

Income Taxes

We use the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial reporting and the tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. We assess the likelihood that the resulting deferred tax assets will be realized. A valuation allowance is provided when it is more likely than not that all or some portion of a deferred tax asset will not be realized.

At December 31, 2020, our total gross deferred tax assets were $72.9 million and our gross deferred tax liabilities were $1.0 million. Due to our lack of earnings history and uncertainties surrounding our ability to generate future taxable income, our net deferred tax assets have been offset by a valuation allowance of $71.9 million. The deferred tax assets were primarily comprised of federal and state tax net operating loss and tax credit carryforwards. At December 31, 2020, we had $222.8 million of federal net operating loss carryforwards and $214.3 million of state net operating loss carryforwards. $78.7 million of the federal net operating loss carryforwards will begin to expire in 2033, if not utilized, and the remaining $144.1 million have no expiration date. The state net operating loss carryforwards will begin to expire in 2035, if not utilized. As of December 31, 2020, we also had accumulated Australian tax losses of AUD 3.7 million ($2.8 million) available for carry forward against future earnings, which under relevant tax laws do not expire but may not be available under certain circumstances.

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Utilization of the net operating loss carryforwards may be subject to a substantial annual limitation due to ownership changes that may have occurred or that could occur in the future, as required by Section 382 of the Internal Revenue Code (the “Code”), and similar state provisions. These ownership change limitations may limit the amount of net operating loss carryforwards and other tax attributes that can be utilized annually to offset future taxable income and tax, respectively. In general, an “ownership change” as defined by Section 382 of the Code results from a transaction or series of transactions over a three-year period resulting in an ownership change of more than 50 percentage points (by value) of the outstanding stock of a company by certain stockholders.

Recent Accounting Pronouncements

Information regarding recent accounting pronouncements applicable to us is included in Note 2 to the Consolidated Financial Statements included elsewhere in this Annual Report on Form 10-K.

Components of Our Results of Operations

License and Collaboration Revenue

Our license and collaboration revenue is derived from payments we receive under the Janssen License and Collaboration Agreement. See Note 3 to the Consolidated Financial Statements included elsewhere in this Annual Report on Form 10-K for additional information.

Research and Development Expenses

Research and development expenses represent costs incurred to conduct research, such as the discovery and development of our product candidates. We recognize all research and development costs as they are incurred, unless there is an alternative future use in other research and development projects or otherwise. Non-refundable advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when payment has been made. In instances where we enter into agreements with third parties to provide research and development services to us, costs are expensed as services are performed. Amounts due under such arrangements may be either fixed fee or fee for service and may include upfront payments, monthly payments, and payments upon the completion of milestones or the receipt of deliverables.

Research and development expenses consist primarily of the following:

We recognize the funds from grants under government programs as a reduction of research and development expenses when the related research costs are incurred. In addition, we recognize the funds related to our Australian

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research and development refundable cash tax incentive that are not subject to refund provisions as a reduction of research and development expenses. The research and development tax incentives are recognized when there is reasonable assurance that the incentives will be received, the relevant expenditure has been incurred and the amount of the consideration can be reliably measured. We evaluate our eligibility under the tax incentive program as of each balance sheet date and make accruals and related adjustments based on the most current and relevant data available. We may alternatively be eligible for a taxable credit in the form of a non-cash tax incentive.

We allocate direct costs and indirect costs incurred to product candidates when they enter clinical development. For product candidates in clinical development, direct costs consist primarily of clinical, pre-clinical, and drug discovery costs, costs of supplying drug substance and drug product for use in clinical and pre-clinical studies, including clinical manufacturing costs, contract research organization fees, and other contracted services pertaining to specific clinical and pre-clinical studies. Indirect costs allocated to our product candidates on a program specific basis include research and development employee salaries, benefits, and stock-based compensation, and indirect overhead and other administrative support costs. Program-specific costs are unallocated when the clinical expenses are incurred for our early stage research and drug discovery projects, our internal resources, employees and infrastructure are not tied to any one research or drug discovery project and are typically deployed across multiple projects. As such, we do not provide financial information regarding the costs incurred for early stage pre-clinical and drug discovery programs on a program-specific basis prior to the clinical development stage.

The following table summarizes our research and development expenses incurred during the periods indicated:

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​ ​ Year Ended December 31,

​ ​ ​ (Dollars in thousands)

Clinical and development expense — PN-235 ​ ​ 317 ​ ​ — ​ ​ —

Milestone payment obligation to former collaboration partner ​ ​ — ​ ​ — ​ ​ 500

Pre-clinical and drug discovery research expense ​ ​ 18,453 ​ ​ 4,162 ​ ​ 9,837

Grants and tax incentives expense reimbursement, net ​ (1,478) ​ (110) ​ (2,230)

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We expect our research and development expenses will increase as we progress our product candidates into later stage clinical trials, expand the number of ongoing clinical trials, advance development activities under the Janssen License and Collaboration Agreement, advance our discovery research projects into the pre-clinical stage and continue our early-stage research. The process of conducting research, identifying potential product candidates and conducting pre-clinical and clinical trials necessary to obtain regulatory approval is costly and time intensive. We may never succeed in achieving marketing approval for our product candidates regardless of our costs and efforts. The probability of success of our product candidates may be affected by numerous factors, including pre-clinical data, clinical data, competition, manufacturing capability, our ability to receive, and the timing of, regulatory approvals, market conditions, and our ability to successfully commercialize our products if they are approved for marketing. As a result, we are unable to determine the duration and completion costs of our research and development projects or when and to what extent we will generate revenue from the commercialization and sale of any of our product candidates. Our research and development programs are subject to change from time to time as we evaluate our priorities and available resources.

General and Administrative Expenses

General and administrative expenses consist of personnel costs, allocated facilities costs and other expenses for outside professional services, including legal, human resources, audit and accounting services, and pre-commercial selling and marketing costs. Personnel costs consist of salaries, benefits and stock-based compensation. Allocated expenses consist of expenses for rent and maintenance of facilities, information technology, depreciation and amortization expense and other supplies. We expect to continue to incur expenses to support our continued operations as

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a public company, including expenses related to existing and future compliance with rules and regulations of the SEC and those of the national securities exchange on which our securities are traded, insurance expenses, investor relations, professional services and general overhead and administrative costs.

Interest Income

Interest income consists of interest earned on our cash, cash equivalents, and marketable securities, which is comprised of contractual interest, premium amortization and discount accretion.

Interest Expense

Interest expense consists of interest recognized on our long-term debt, which is comprised of contractual interest, amortization of origination fees and other issuance costs, and accretion of final payment fees.

Loss on Early Repayment of Debt

Loss on early repayment of debt consists of prepayment and final payment fees paid upon the early repayment of our long-term debt.

Other Expense, Net

Other expense, net consists primarily of amounts related to foreign exchange gains and losses and related items.

Results of Operations

Comparison of the Year ended December 31, 2020 and 2019

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​ ​ Year Ended December 31, ​ Dollar ​ %

​ ​ (Dollars in thousands) ​ ​

Operating expenses: ​ ​ ​ ​ ​

Loss on early repayment of debt ​ ​ (585) ​ ​ — ​ ​ (585) 100

Other expense, net ​ ​ (46) ​ ​ (1) ​ ​ (45) ​ *

(1) Includes $4.1 million and $4.4 million of non-cash stock-based compensation expense for the year ended December 31, 2020 and 2019, respectively.

(2) Includes $3.8 million and $4.0 million of non-cash stock-based compensation expense for the year ended December 31, 2020 and 2019, respectively.

*Percentage not meaningful

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License and Collaboration Revenue

License and collaboration revenue increased $28.4 million from $0.2 million for the year ended December 31, 2019 to $28.6 million for the year ended December 31, 2020. The increase in license and collaboration revenue was primarily due to an update in the amounts forecast for future services remaining to be performed under the Janssen License and Collaboration Agreement, correspondingly increasing our overall cumulative percentage of completion of our performance obligation during year ended December 31, 2020, coupled with continued performance and delivery of services under the ongoing Janssen License and Collaboration Agreement. The increase in license and collaboration revenue for the year ended December 31, 2020 also included the impact of a one-time cumulative adjustment related to the application of revenue recognition principles following the May 2019 amendment of the Janssen License and Collaboration Agreement that reduced 2019 revenue by $9.4 million. The contract modification resulted in an increase in the transaction price and additional deliverables under the initial performance obligation, leading to an overall corresponding decrease in the cumulative percentage of completion of our performance obligation for the Janssen License and Collaboration Agreement during the second quarter of 2019.

We determined that the transaction price of the Janssen License and Collaboration Agreement was $98.6 million as of December 31, 2020, a decrease of $14.3 million from the transaction price of $112.9 million at December 31, 2019. In order to determine the transaction price, we evaluated all payments expected to be received during the duration of the contract, net of development costs reimbursement expected to be payable to Janssen. We determined that the transaction price includes the $50.0 million upfront payment, the $25.0 million payment received upon the effectiveness of the First Amendment, the $5.0 million payment triggered by the successful nomination of a second-generation compound, $17.9 million of reimbursement from Janssen for services performed for PTG-200 Phase 2 and for second-generation compound research costs and other services, and estimated variable consideration consisting of a $7.5 million milestone payment subject to the completion of a Phase 1 study for a second-generation compound, offset by $6.8 million of net cost reimbursement to Janssen for services performed. The decrease in transaction price from December 31, 2019 to December 31, 2020 was due primarily to a decrease in the forecast of remaining services to be provided under the initial performance obligation. We re-evaluate the transaction price each reporting period and as uncertain events are resolved or other changes in circumstances occur.

Research and Development Expenses

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​ ​ Year Ended December 31, ​ Dollar ​ %

​ ​ (Dollars in thousands) ​ ​

Clinical and development expense — PN-235 ​ ​ 317 ​ ​ — ​ ​ 317 100

*Percentage not meaningful

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Research and development expenses increased $9.5 million, or 15%, from $65.0 million for the year ended December 31, 2019 to $74.5 million for the year ended December 31, 2020. The increase included a $14.3 million increase in pre-clinical and discovery research expenses, including pre-clinical costs related to our second-generation research collaboration efforts with Janssen, a $2.4 million increase in PN-943 clinical trial and development expenses following the initiation of the Phase 2 trial in UC in 2020, a $2.1 million increase in rusfertide clinical trial and development expenses, including the ongoing Phase 2 trials in PV and HH, and $0.3 million of Phase 1 clinical trial and development expenses for PN-235. These increases were partially offset by a decrease of $8.5 million for PTG-200 clinical trial and development expenses under the Janssen License and Collaboration Agreement due to timing of

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deliverables and related cost sharing arrangements, and the impact of a $1.3 million reversal of previously recorded reductions to research and development expenses in connection with the tax incentive from Australia in 2019. Research and development expenses for the year ended December 31, 2020 included increased personnel costs due to an increase in research and development headcount from 54 full-time equivalent employees at December 31, 2019 to 59 full-time equivalent employees at December 31, 2020.

General and Administrative Expenses

General and administrative expenses increased $2.9 million, or 18%, from $15.7 million for the year ended December 31, 2019 to $18.6 million for the year ended December 31, 2020 primarily due to increases of $1.4 million in compensation-related expenses to support the growth of our operations, $1.3 million in legal expenses and $0.8 million in insurance expense, partially offset by a $0.6 decrease in other expenses, including accounting fees, market research, recruiting fees and travel expense.

Interest Income

Interest income decreased $1.9 million, or 68%, from $2.8 million for the year ended December 31, 2019 to $0.9 million for the year ended December 31, 2020. This decrease was primarily due to the declining interest rate environment and a change in the mix of marketable securities compared to the prior year period, despite higher interest-earning asset balances.

Interest Expense

Interest expense increased $0.4 million, or 254%, from $0.2 million for the year ended December 31, 2019 to $0.6 million for the year ended December 31, 2020. Interest expense reflects contractual interest, amortization of origination fees and other issuance costs, and accretion of final payment fees on our term loan that funded in October 2019 and was repaid in full in June 2020.

Income Tax Expense

Income tax expense increased by $2.0 million, or 289%, from an income tax benefit of $0.7 million for the year ended December 31, 2019 to income tax expense of $1.3 million for the year ended December 31, 2020. Our effective income tax rate was (2.0)% for the year ended December 31, 2020 as compared to 0.9% for the year ended December 31, 2019. Our effective income tax rate differs from our federal statutory rate of 21% primarily because our losses cannot be benefited due to our full valuation allowance position. During the second quarter of 2020, our Australia subsidiary sold beneficial rights to discovery intellectual property to our U.S. entity, and the U.S. entity reimbursed the Australia subsidiary for certain direct development costs. Upon completion of the sale, we analyzed tax planning strategies and future income and concluded that a valuation allowance is necessary for our Australia subsidiary. Income tax expense for year ended December 31, 2020 reflects this sale of intellectual property rights, cost reimbursements and related adjustments to the deferred tax asset, establishing a valuation allowance and certain uncertain tax position liabilities. Income tax benefit for the year ended December 31, 2019 included a discrete tax benefit of approximately $1.1 million for the 2017 Australia refundable R&D tax offset.

​

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Comparison of the Years ended December 31, 2019 and 2018

​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​ ​ Year Ended December 31, ​ Dollar ​ %

​ ​ (Dollars in thousands) ​ ​

Operating expenses: ​ ​ ​ ​ ​ ​ ​

Interest expense ​ ​ (169) ​ ​ — ​ ​ (169) ​ 100

Other expense, net ​ ​ (1) ​ ​ (20) ​ ​ 19 ​ (95)

(1) Includes $4.4 million and $3.4 million of non-cash stock-based compensation expense for the year ended December 31, 2019 and 2018, respectively.

(2) Includes $4.0 million and $3.5 million of non-cash stock-based compensation expense for the year ended December 31, 2019 and 2018, respectively.

​

License and Collaboration Revenue

License and collaboration revenue decreased $30.7 million, or 99%, from $30.9 million for the year ended December 31, 2018 to $0.2 million for the year ended December 31, 2019. The decrease in license and collaboration revenue was primarily due to a contract modification for the First Amendment to the Janssen License and Collaboration Agreement and the related cumulative catchup adjustment during the second quarter of 2019. The contract modification resulted in an increase in the transaction price and additional deliverables under the performance obligation, leading to an overall corresponding decrease in the cumulative percentage of completion of our performance obligation for the Janssen License and Collaboration Agreement.

We determined that the transaction price of the Janssen License and Collaboration Agreement was $112.9 million as of December 31, 2019, an increase of $52.2 million from the transaction price of $60.7 million at December 31, 2018. In order to determine the transaction price, we evaluated all payments to be received during the duration of the contract, net of Phase 2 development costs reimbursement expected to be payable to Janssen. We determined that the transaction price includes the $50.0 million upfront payment, the $25.0 million payment received upon the effectiveness of the First Amendment, the $5.0 million payment triggered by the successful nomination of a second-generation compound, $18.3 million of reimbursement from Janssen for services performed for PTG-200 Phase 2 and for second-generation compound research costs and other services, and $14.6 million of estimated variable consideration, which includes a $7.5 million milestone payment subject to the completion of a Phase 1 study for a second-generation compound. The increase in transaction price from December 31, 2018 to December 31, 2019 was due to an increase in fixed and variable consideration related to the contract modification for First Amendment to the Janssen License and Collaboration Agreement effective May 7, 2019.

​

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Research and Development Expenses

​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​ ​ Year Ended December 31, ​ Dollar ​ %

​ ​ (Dollars in thousands) ​ ​

*Percentage not meaningful

Research and development expenses increased $5.5 million, or 9%, from $59.5 million for the year ended December 31, 2018 to $65.0 million for the year ended December 31, 2019. The increase included $20.4 million of PN-943 clinical trial and development expenses, an increase of $16.0 million in rusfertide clinical trial and development expenses and a $1.3 million reversal of previously recorded reductions to research and development expenses in connection with the tax incentive from Australia, partially offset by a decrease of $20.1 million in PTG-100 clinical trial and development expenses due to the halting of further development during 2018 and related credit adjustments, a decrease of $6.7 million for PTG-200 clinical trial and development expenses under the Janssen License and Collaboration Agreement due to timing of deliverables and a decrease of $5.7 million in pre-clinical and discovery research expenses. Research and development expenses for the year ended December 31, 2019 included increased personnel costs due to an increase in research and development headcount from 49 employees at December 31, 2018 to 54 employees at December 31, 2019.

General and Administrative Expenses

General and administrative expenses increased $2.0 million, or 15%, from $13.7 million for the year ended December 31, 2018 to $15.7 million for the year ended December 31, 2019 primarily due to increases of $1.0 million in personnel costs to support the growth of our operations, $0.7 million in professional fees and $0.3 million in insurance expense. The increase in personnel costs for the year ended December 31, 2019 reflected an increase in general and administrative headcount from 15 employees at December 31, 2018 to 19 employees at December 31, 2019.

Interest Income

Interest income increased $0.2 million, or 10%, from $2.6 million for the year ended December 31, 2018 to $2.8 million for the year ended December 31, 2019 primarily due to higher interest income related to an increase in marketable securities balances.

Income Tax Benefit

Income tax benefit decreased $0.1 million, or 14%, from $0.8 million for the year ended December 31, 2018, representing an effective income tax rate of 2.0%, to $0.7 million for the year ended December 31, 2019, representing an effective income tax rate of 0.9%. Our effective income tax rate differs from our federal statutory rate of 21%, primarily because our U.S. loss cannot be benefited due to the full valuation allowance position and reduced by foreign taxes.

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Liquidity and Capital Resources

Liquidity and Capital Expenditures

As of December 31, 2020, we had $307.8 million of cash, cash equivalents and marketable securities and an accumulated deficit of $283.8 million. Our operations have been financed primarily by net proceeds from the sale of shares of our capital stock and payments under the Janssen License and Collaboration Agreement. During the third quarter of 2017 we received a non-refundable, upfront payment of $50.0 million from Janssen. During the second quarter of 2019, we received a nonrefundable $25.0 million payment from Janssen upon execution of the First Amendment. During the first quarter of 2020, we received a nonrefundable $5.0 million payment from Janssen.

​

In September 2017, we filed a registration statement on Form S-3 with the Securities and Exchange Commission (File No. 333-220314) that was declared effective as of October 5, 2017 and permits the offering, issuance, and sale by us of up to a maximum aggregate offering price of $200.0 million of our common stock, preferred stock and certain debt securities (the “2017 Form S-3”). Up to a maximum of $50.0 million of the maximum aggregate offering price of $200.0 million could be issued and sold pursuant to an at-the-market (“ATM”) financing facility under a sales agreement (the “2017 Sales Agreement”). The 2017 Sales Agreement was terminated in 2019. During the year ended December 31, 2019, prior to the termination of the 2017 Sales Agreement, we sold 2,846,641 shares of our common stock for net proceeds of $34.5 million, after deducting issuance costs. We sold 151,273 shares of our common stock pursuant to the 2017 Sales Agreement during the year ended December 31, 2018 for net proceeds of $1.5 million, after deducting issuance costs. The 2017 Form S-3 expired in October 2020.

In August 2018, we entered into a Securities Purchase Agreement with certain accredited investors (each, an “Investor” and, collectively, the “Investors”), pursuant to which we sold an aggregate of 2,750,000 shares of our common stock at a price of $8.00 per share, for aggregate net proceeds of $21.7 million, after deducting offering expenses payable by us. In a concurrent private placement, we issued the Investors warrants to purchase an aggregate of 2,750,000 shares of our common stock (each, a “Warrant” and, collectively, the “Warrants”). Each Warrant is exercisable from August 8, 2018 through August 8, 2023. Warrants to purchase 1,375,000 shares of our common stock have an exercise price of $10.00 per share and Warrants to purchase 1,375,000 shares of our common stock have an exercise price of $15.00 per share. The exercise price and number of shares of common stock issuable upon the exercise of the Warrants (the “Warrant Shares”) are subject to adjustment in the event of any stock dividends and splits, reverse stock split, recapitalization, reorganization or similar transaction, as described in the Warrants. Under certain circumstances, the Warrants may be exercisable on a “cashless” basis. In connection with the issuance and sale of the common stock and Warrants, we granted the Investors certain registration rights with respect to the Warrants and the Warrant Shares. The common stock and Warrants are classified as equity in accordance with Accounting Standards Codification Topic 480, Distinguishing Liabilities from Equity (“ASC 480”), and the net proceeds from the transaction were recorded as a credit to additional paid-in capital. As of December 31, 2020, none of the Warrants have been exercised.

In December 2018, we entered into an exchange agreement (the “Exchange Agreement”) with an Investor and its affiliates (the “Exchanging Stockholders”), pursuant to which we exchanged an aggregate of 1,000,000 shares of our common stock, par value $0.00001 per share, owned by the Exchanging Stockholders for pre-funded warrants (the “Exchange Warrants”) to purchase an aggregate of 1,000,000 shares of common stock (subject to adjustment in the event of any stock dividends and splits, reverse stock split, recapitalization, reorganization or similar transaction, as described in the Exchange Warrants), with an exercise price of $0.00001 per share. The Exchange Warrants will expire ten years from the date of issuance. The Exchange Warrants are exercisable at any time prior to expiration except that the Exchange Warrants cannot be exercised by the Exchanging Stockholders if, after giving effect thereto, the Exchanging Stockholders would beneficially own more than 9.99% of our common stock, subject to certain exceptions. In accordance with Accounting Standards Codification Topic 505, Equity, we recorded the retirement of the common stock exchanged as a reduction of common stock shares outstanding and a corresponding debit to additional paid-in-capital at the fair value of the Exchange Warrants on the issuance date. The Exchange Warrants are classified as equity in accordance with ASC 480, and fair value of the Exchange Warrants was recorded as a credit to additional paid-in capital and is not subject to remeasurement. We determined that the fair value of the Exchange Warrants is substantially similar to the fair value of the retired shares on the issuance date due to the negligible exercise price for the Exchange Warrants.

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During the year ended December 31, 2019, Exchange Warrants to purchase 600,000 shares were net exercised, resulting in the issuance of 599,997 shares of common stock. As of December 31, 2020, 400,000 of the Exchange Warrants remain unexercised.

In October 2019, we filed a registration statement on Form S-3 (File no. 333-234414) that was declared effective as of November 22, 2019 and permits the offering, issuance, and sale by us of up to a maximum aggregate offering price of $250.0 million of our common stock, preferred stock, debt securities and warrants (the “2019 Form S-3”). Up to a maximum of $75.0 million of the maximum aggregate offering price of $250.0 million may be issued and sold pursuant to an ATM financing facility under a sales agreement we entered into on November 27, 2019 (the “2019 Sales Agreement”). In May 2020, we completed an underwritten public offering of 7,000,000 shares of common stock at a public offering price of $14.00 per share and issued an additional 1,050,000 shares of our common stock at a price of $14.00 per share following the underwriters’ exercise of their option to purchase additional shares. Net proceeds, after deducting underwriting commissions and offering costs paid us, were $105.3 million. We sold 2,483,719 shares of our common stock pursuant to the 2019 Sales Agreement during the year ended December 31, 2020 for net proceeds of $41.9 million, after deducting issuance costs. As of December 31, 2020, a total of $94.2 million of common stock remained available for sale under the 2019 Form S-3, $31.9 million of which remained available for sale under the ATM financing facility.

In October 2019, we entered into a credit and security agreement pursuant to which the lenders party thereto agreed to make term loans available to us for working capital and general business purposes, in a principal amount of up to $50.0 million, including a $10.0 million term loan which was funded at closing (October 30, 2019), with the ability to access the remaining $40.0 million in two additional tranches of $20.0 million, subject to specified availability periods, the achievement of certain clinical development milestones, minimum cash requirements and other customary conditions. In June 2020, we prepaid the outstanding $10.0 million balance on the term loan as well as $0.6 million for related prepayment and exit fees. We did not exercise our option to borrow the $20.0 million second tranche of Term Loans, which expired on December 31, 2020, and therefore have one remaining $20.0 million tranche available under the Term Loan Credit Agreement and no related outstanding balance as of December 31, 2020. Additional information about this credit facility and our long-term debt is presented in Note 9 to the consolidated financial statements included elsewhere in this Annual Report on Form 10-K.

​

In December 2020, we filed an automatic registration statement on Form S-3ASR and an accompanying prospectus (Registration Statement No. 333-251254), pursuant to which we completed an underwritten public offering of 4,761,904 shares of common stock at a public offering price of $21.00 per share and issued an additional 714,285 shares of our common stock at a price of $21.00 per share following the underwriters’ exercise of their option to purchase additional shares. Net proceeds, after deducting underwriting commissions and offering costs paid by us, were $107.6 million. This Form S-3ASR expires in December 2023.

​

Our primary uses of cash are to fund operating expenses, primarily research and development expenditures and pre-commercialization costs. Cash used to fund operating expenses is impacted by the timing of when we pay these expenses, as reflected in the change in our outstanding accounts payable and accrued expenses.

We believe, based on our current operating plan and expected expenditures, that our existing cash, cash equivalents and marketable securities and access to our term loan facility will be sufficient to meet our anticipated operating and capital expenditure requirements for at least the next 12 months from the date of this filing. We have based this estimate on assumptions that may prove to be wrong, and we could utilize our available capital resources sooner than we currently expect. If our planned pre-clinical and clinical trials are successful, or our other product candidates enter clinical trials or advance beyond the discovery stage, we will need to raise additional funding, which may come from raising additional capital, seeking access to additional debt, and additional collaborative or other arrangements with corporate sources in order to further advance our product candidates towards potential regulatory approval, but such funding may not be available at terms acceptable to us, if at all. We will continue to require additional financing to advance our current product candidates through clinical development, to develop, acquire or in-license other potential

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product candidates and to fund operations for the foreseeable future. We anticipate that we will need to raise substantial additional funding, the requirements of which will depend on many factors, including:

● costs necessary to attract, hire and retain qualified personnel;

Adequate additional funding may not be available to us on acceptable terms, or at all. Any failure to raise capital as and when needed could have a negative impact on our financial condition and on our ability to pursue our business plans and strategies. Further, our operating plans may change, and we may need additional funds to meet operational needs and capital requirements for clinical trials, other research and development activities and pre-commercialization costs. If we do raise additional capital through public or private equity offerings or convertible debt securities, the ownership interest of our existing stockholders will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect our stockholders’ rights. If we raise additional capital through debt financing, we may be subject to covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. Because of the numerous risks and uncertainties associated with the development and commercialization of our product candidates, we are unable to estimate the amounts of increased capital outlays and operating expenditures associated with our current and anticipated product development programs.

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The following table summarizes our cash flows for the periods indicated:

​

​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​ ​ Year Ended December 31,

​ ​ (In thousands)

Cash (used in) provided by investing activities ​ (90,965) ​ (53,710) ​ 2,213

​

Cash Flows from Operating Activities

Cash used in operating activities for the year ended December 31, 2020 was $72.5 million, consisting or our net loss of $66.2 million and a net change of $19.0 million in net operating assets and liabilities, partially offset by non-cash charges of $12.7 million. Non-cash charges were primarily comprised of $7.9 million of stock-based compensation, $1.8 million of operating lease ROU asset amortization, a $1.4 million change in net deferred tax asset, $0.8 million of depreciation and amortization, a $0.6 million loss on early prepayment of long-term debt and $0.2 million of amortization of debt issuance costs and accretion of debt discount. The change in net operating assets and liabilities was primarily due to a decrease of $27.0 million in deferred revenue related to the Janssen License and Collaboration Agreement, a $1.9 million decrease in operating lease liability, a $1.1 million increase in prepaid expenses and other assets and a $1.0 million increase in Australia research and development refundable cash tax incentive receivable, partially offset by an increase of $5.8 million in accrued expenses and other liabilities, a decrease of $4.3 million in receivable from collaboration partner, an increase of $1.5 million in payable to collaboration partner, an increase of $0.3 million in accounts payable, and an increase of $0.1 million in other liability.

Cash used in operating activities for the year ended December 31, 2019 was $41.5 million, consisting of our net loss of $77.2 million, partially offset by a net change of $26.1 million in net operating assets and liabilities and non-cash charges of $9.5 million. The change in net operating assets and liabilities was primarily due to a net increase of $33.5 million in deferred revenue related to the Janssen License and Collaboration Agreement, a decrease of $1.4 million in research and development refundable cash tax incentive receivable and an increase of $1.1 million in accrued expenses and other payables, partially offset by an decrease of $3.0 million in accounts payable, an increase of $2.8 million in prepaid expenses and other assets, an increase of $2.2 million in receivable from collaboration partner and a decrease of $1.9 million in operating lease liability. Non-cash charges were primarily comprised of $8.4 million of stock-based compensation, $1.8 million of operating lease right-of-use asset amortization and $0.7 million of depreciation and amortization, partially offset by a $0.8 million increase in deferred tax assets and $0.6 million of net accretion of discount on marketable securities.

Cash used in operating activities for the year ended December 31, 2018 was $49.9 million, consisting of our net loss of $38.9 million and a net change of $18.0 million in net operating assets and liabilities, partially offset by non-cash charges of $7.0 million. The change in net operating assets and liabilities was primarily due to a net decrease of $23.5 million in deferred revenue related to the Janssen License and Collaboration Agreement and an increase of $2.8 million in receivable from collaboration partner, partially offset by an increase of $4.4 million in accounts payable, an increase of $1.9 million in accrued expenses and other payables, an increase of $1.1 million in payable to collaboration partner and a decrease of $1.1 million in prepaid expenses and other assets. Non-cash charges were primarily comprised of $6.9 million of stock-based compensation, $0.5 million of depreciation and amortization and $0.2 million of net amortization of premium on marketable securities, partially offset by a $0.7 million increase in deferred tax assets.

Cash Flows from Investing Activities

Cash used in investing activities for the year ended December 31, 2020 was $91.0 million, consisting of purchases of marketable securities of $280.0 million and purchases of property and equipment of $0.5 million, partially offset by proceeds from maturities of marketable securities of $189.5 million. Purchases of property and equipment were primarily related to purchases of laboratory equipment, furniture and computer equipment.

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Cash used in investing activities for the year ended December 31, 2019 was $53.7 million, consisting of purchases of marketable securities of $166.9 million and purchases of property and equipment of $1.0 million, partially offset by proceeds from maturities of marketable securities of $114.2 million. Purchases of property and equipment were primarily related to purchases of scientific equipment and leasehold improvements.

Cash provided by investing activities for the year ended December 31, 2018 was $2.2 million, consisting of proceeds from marketable securities of $73.8 million, partially offset by purchases of marketable securities of $71.1 million and purchases of property and equipment of $0.5 million. Purchases of property and equipment were primarily related to purchases of scientific equipment.

Cash Flows from Financing Activities

Cash provided by financing activities for the year ended December 31, 2020 was $247.6 million, consisting primarily of cash proceeds from our public offerings of common stock of $213.3 million, cash proceeds from ATM sales of $42.1 million, and proceeds from the issuance of common stock upon exercise of stock options and purchases of common stock under our employee stock purchase plan of $2.8 million, partially offset by early repayment of long-term debt of $10.5 million.

Cash provided by financing activities for the year ended December 31, 2019 was $46.0 million, consisting of $34.5 million of net proceeds from sales of common stock through our ATM financing facility, $9.8 million of net proceeds from long-term debt and $1.8 million from the issuance of common stock upon exercise of stock options and purchases of common stock under our employee stock purchase plan.

Cash provided by financing activities for the year ended December 31, 2018 was $24.1 million, consisting of $21.7 million of net proceeds from issuance of our common stock and warrants in a private placement, $1.5 million of net proceeds from sales through our ATM financing facility and $0.9 million from the issuance of common stock upon exercise of stock options and purchases of common stock under our employee stock purchase plan.

Contractual Obligations and Other Commitments

Our contractual obligations include minimum lease payments under our operating lease obligations. See Note 10 to the consolidated financial statements elsewhere in this Annual Report on Form 10-K for additional information.

​

We enter into agreements in the normal course of business with contract research organizations for clinical trials and with vendors for pre-clinical studies and other services and products for operating purposes, which are cancelable at any time by us, generally upon 30 to 60 days prior written notice.

Under the Janssen License and Collaboration Agreement, we share with Janssen certain development, regulatory and compound supply costs. The actual amounts that we pay Janssen or that Janssen pays us will depend on numerous factors, some of which are outside of our control and some of which are contingent upon the success of certain development and regulatory activities.

In June 2012, we entered into a Research Collaboration and License Agreement with Zealand Pharma A/S to identify, optimize and develop novel disulfide-rich peptides to discover a hepcidin mimetic. We amended this agreement on February 28, 2014, at which point Protagonist assumed responsibility for the development program. See “Item 3. Legal Proceedings”, “Item 7. Management’s Discussion and Analysis – Contractual Obligations and Other Commitments” and Note 7 and Note 11 to the Consolidated Financial Statements included elsewhere in this Annual Report on Form 10-K for additional information.

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​

Item 7A.Quantitative and Qualitative Disclosures about Market Risk

We are exposed to market risks in the ordinary course of our business. These risks primarily include interest rate sensitivities related to our investments and borrowings.

We had $307.8 million and $133.0 million in cash, cash equivalents and marketable securities at December 31, 2020 and December 31, 2019, respectively. Cash and cash equivalents consist of cash, money market funds, commercial paper and government bonds. Marketable securities consist of corporate bonds, commercial paper and government bonds. A portion of our investments may be subject to interest rate risk and could fall in value if market interest rates increase. Based on our interest rate sensitivity analysis, an immediate 1% increase in interest rates would increase our interest income by approximately $2.3 million, while an immediate 1% decrease in interest rates would decrease our interest income by approximately $0.4 million.

Approximately $1.0 million and $0.6 million of our cash balance was located in Australia at December 31, 2020 and December 31, 2019, respectively. Our expenses, except those related to our Australian operations, are generally denominated in U.S. dollars. For our operations in Australia, the majority of the expenses are denominated in Australian dollars. To date, we have not had a formal hedging program with respect to foreign currency, but we may do so in the future if our exposure to foreign currency becomes more significant. A 10% increase or decrease in current exchange rates would not have a material effect on our results of operations.

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Item 8.Financial Statements and Supplementary Data

PROTAGONIST THERAPEUTICS, INC.

INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

​ ​ ​

Audited Consolidated Financial Statements ​ Page

Reports of Independent Registered Public Accounting Firms ​ 75

Consolidated Balance Sheets ​ 77

Consolidated Statements of Operations ​ 78

Consolidated Statements of Comprehensive Loss ​ 79

Consolidated Statements of Stockholders’ Equity ​ 80

Consolidated Statements of Cash Flows ​ 81

Notes to the Consolidated Financial Statements ​ 82

​

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Report of Independent Registered Public Accounting Firm

​

To the Stockholders and the Board of Directors of Protagonist Therapeutics, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheet of Protagonist Therapeutics, Inc. (the Company) as of December 31, 2020, the related consolidated statements of operations, comprehensive loss, stockholders' equity and cash flows for the year ended December 31, 2020, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2020, and the results of its operations and its cash flows for the year then ended, in conformity with U.S. generally accepted accounting principles.

​

Basis for Opinion

​

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

​

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

​

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

​

​

/s/ Ernst & Young LLP

​

​

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

Redwood City, California

March 10, 2021

​

​

​

​

​

​

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Report of Independent Registered Public Accounting Firm

​

​

To the Board of Directors and Stockholders of Protagonist Therapeutics, Inc.

​

Opinion on the Financial Statements

​

We have audited the consolidated balance sheet of Protagonist Therapeutics, Inc. and its subsidiaries (the “Company”) as of December 31, 2019, and the related consolidated statements of operations, comprehensive loss, stockholders’ equity and cash flows for each of the two years in the period ended December 31, 2019, including the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position ofthe Company as of December 31, 2019, and the results of its operations and itscash flows for each of the two years in the period ended December 31, 2019in conformity with accounting principles generally accepted in the United States of America.

Change in Accounting Principle

​

As discussed in Note 2 to the consolidated financial statements, the Company changed the manner in which it accounts for leases in 2019.

​

Basis for Opinion

​

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

​

We conducted our audits of these consolidated financial statements in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud.

​

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

​

​

/s/ PricewaterhouseCoopers LLP

San Jose, California

March 10, 2020

​

We served as the Company's auditor from 2015 to 2019.

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PROTAGONIST THERAPEUTICS, INC.

Consolidated Balance Sheets

(In thousands, except share data)

​ ​ ​ ​ ​ ​ ​

​ ​ December 31,

Assets ​ ​ ​ ​ ​ ​

Current assets: ​ ​ ​ ​ ​ ​

Restricted cash - current ​ ​ 10 ​ ​ 10

Research and development tax incentive receivable ​ ​ 1,084 ​ ​ —

Prepaid expenses and other current assets ​ ​ 6,277 ​ ​ 5,529

Marketable securities - noncurrent ​ ​ 2,000 ​ ​ —

Property and equipment, net ​ ​ 1,462 ​ ​ 1,681

Restricted cash - noncurrent ​ ​ 450 ​ ​ 450

Operating lease right-of-use asset ​ ​ 4,950 ​ ​ 6,042

Deferred tax asset ​ ​ — ​ ​ 1,433

Liabilities and Stockholders’ Equity ​ ​ ​ ​ ​ ​

Current liabilities: ​ ​ ​ ​ ​

Payable to collaboration partner - related party ​ ​ 2,732 ​ ​ 1,262

Accrued expenses and other payables ​ ​ 18,498 ​ ​ 12,360

Deferred revenue - related party - current ​ ​ 14,477 ​ ​ 17,738

Operating lease liability - current ​ ​ 1,459 ​ ​ 1,256

Long-term debt, net ​ ​ — ​ ​ 9,794

Deferred revenue - related party - noncurrent ​ ​ — ​ ​ 23,792

Operating lease liability - noncurrent ​ ​ 4,500 ​ ​ 5,961

Other liabilities ​ ​ 121 ​ ​ —

Commitments and contingencies (Note 11) ​ ​ ​ ​ ​ ​

Stockholders’ equity: ​ ​ ​ ​ ​ ​

Accumulated other comprehensive gain (loss) ​ ​ 28 ​ ​ (221)

Total liabilities and stockholders’ equity ​ $ 324,468 ​ $ 154,917

​

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

​

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PROTAGONIST THERAPEUTICS, INC.

Consolidated Statements of Operations

(In thousands, except share and per share data)

​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​ ​ Year Ended December 31,

License and collaboration revenue - related party ​ $ 28,628 ​ $ 231 ​ $ 30,925

Operating expenses: ​ ​ ​ ​ ​ ​ ​ ​ ​

Interest expense ​ ​ (598) ​ ​ (169) ​ ​ —

Loss on early repayment of debt ​ ​ (585) ​ ​ — ​ ​ —

Other expense, net ​ ​ (46) ​ ​ (1) ​ ​ (20)

Loss before income tax (expense) benefit ​ ​ (64,845) ​ ​ (77,878) ​ ​ (39,723)

Income tax (expense) benefit ​ ​ (1,305) ​ ​ 691 ​ ​ 799

Net loss per share, basic and diluted ​ $ (1.92) ​ $ (2.98) ​ $ (1.74)

​

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

​

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PROTAGONIST THERAPEUTICS, INC.

Consolidated Statements of Comprehensive Loss

(In thousands)

​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​ ​ Year Ended December 31,

Other comprehensive loss: ​ ​ ​ ​ ​ ​ ​

Gain (loss) on translation of foreign operations ​ 266 ​ (44) ​ (322)

Unrealized (loss) gain on marketable securities ​ (17) ​ 56 ​ 95

​

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

​

​

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PROTAGONIST THERAPEUTICS, INC.

Consolidated Statements of Stockholders’ Equity

(In thousands, except share and per share data)

​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​ ​ ​ ​ ​ ​ Accumulated ​ ​ ​ ​

​ ​ ​ ​ Additional ​ Other ​ ​ ​ Total

​ ​ Common ​ Paid-In ​ Comprehensive ​ Accumulated ​ Stockholders’

​ ​ Stock Capital Gain (Loss) Deficit Equity

​ Shares Amount ​ ​ ​ ​ ​ ​ ​ ​ ​

Stock-based compensation expense ​ — — ​ 6,919 — ​ — 6,919

Other comprehensive loss ​ — — ​ — (227) ​ — (227)

Stock-based compensation expense ​ — — ​ 8,353 — ​ — 8,353

Other comprehensive gain ​ — — ​ — 12 ​ — 12

Stock-based compensation expense ​ — — ​ 7,899 — ​ — 7,899

Other comprehensive gain ​ — — ​ — 249 ​ — 249

​

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

​

​

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PROTAGONIST THERAPEUTICS, INC.

Consolidated Statements of Cash Flows

(In thousands)

​

​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​ ​ Year Ended December 31,

Cash Flows from Operating Activities ​ ​ ​ ​

Operating lease right-of-use asset amortization ​ ​ 1,775 ​ ​ 1,792 ​ ​ —

Depreciation and amortization ​ ​ 789 ​ ​ 703 ​ ​ 527

Loss on early repayment of debt ​ ​ 585 ​ ​ — ​ ​ —

Gain on disposal of property and equipment ​ ​ — ​ ​ 8 ​ ​ —

Change in deferred tax asset ​ ​ 1,438 ​ ​ (775) ​ ​ (658)

Changes in operating assets and liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​

Research and development tax incentive receivable ​ ​ (990) ​ ​ 1,411 ​ ​ (236)

Prepaid expenses and other assets ​ ​ (1,102) ​ ​ (2,820) ​ ​ 1,117

Payable to collaboration partner - related party ​ ​ 1,471 ​ ​ 201 ​ ​ 1,061

Accrued expenses and other payables ​ ​ 5,840 ​ ​ 1,098 ​ ​ 1,911

Operating lease liability ​ ​ (1,941) ​ ​ (1,885) ​ ​ —

Other liability ​ ​ 121 ​ ​ — ​ ​ —

Net cash used in operating activities ​ ​ (72,484) ​ ​ (41,527) ​ ​ (49,947)

Cash Flows from Investing Activities ​ ​ ​ ​ ​ ​ ​ ​ ​

Purchases of property and equipment ​ ​ (471) ​ ​ (967) ​ ​ (486)

Cash Flows from Financing Activities ​ ​ ​ ​ ​ ​ ​ ​ ​

Issuance costs related to long-term debt ​ ​ (14) ​ ​ — ​ ​ —

Early repayment of long-term debt ​ ​ (10,524) ​ ​ — ​ ​ —

Supplemental Disclosure of Cash Flow Information: ​ ​ ​ ​ ​ ​ ​ ​ ​

Cash paid for interest ​ $ 438 ​ $ 70 ​ $ —

​

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

​

​

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PROTAGONIST THERAPEUTICS, INC.

Notes to Consolidated Financial Statements

Note 1. Organization and Description of Business

Protagonist Therapeutics, Inc. (the “Company”) is headquartered in Newark, California. The Company is a clinical-stage biopharmaceutical company that utilizes a proprietary technology platform to discover and develop novel peptide-based therapeutics to address significant unmet medical needs and transform existing treatment paradigms for patients. Protagonist Pty Limited (“Protagonist Australia”) is a wholly-owned subsidiary of the Company and is located in Brisbane, Queensland, Australia. Protagonist Australia was incorporated in Australia in September 2001. The Company manages its operations as a single operating segment.

Liquidity

The Company has incurred net losses from operations since inception and has an accumulated deficit of $283.8 million as of December 31, 2020. The Company’s ultimate success depends on the outcome of its research and development and collaboration activities. The Company expects to incur additional losses in the future and anticipates the need to raise additional capital to continue to execute its long-range business plan. Since the Company’s initial public offering in August 2016, it has financed its operations primarily through offerings of common stock and payments received under a license and collaboration agreement.

Risks and Uncertainties

The Company is subject to risks and uncertainties as a result of the COVID-19 pandemic. The Company is continuing to closely monitor the impact of the COVID-19 pandemic on its business and has taken and continues to take proactive efforts to protect the health and safety of its patients, clinical research staff and employees, and to maintain business continuity. The extent of the impact of the COVID-19 pandemic on the Company's activities is highly uncertain and difficult to predict, as the response to the pandemic is ongoing and information continues to evolve. Capital markets and economies worldwide have been negatively impacted by the COVID-19 pandemic, which has contributed to the current global economic recession. Such economic disruption could have a material adverse effect on the Company’s business. Policymakers around the globe have responded with fiscal policy actions to support the healthcare industry and economy as a whole. The magnitude and overall effectiveness of these actions remains uncertain.

The severity of the impact of the COVID-19 pandemic on the Company's activities will depend on a number of factors, including, but not limited to, the duration and severity of the pandemic, including the severity of any additional periods of increases or spikes in the number of cases in the areas the Company and its suppliers operate and areas where the Company’s clinical trial sites are located. Accordingly, the extent and severity of the impact on the Company's existing and planned clinical trials, manufacturing, collaboration activities and operations, is uncertain and cannot be fully predicted. The Company has experienced delays in its existing and planned clinical trials due to the worldwide impacts of the pandemic. The Company's future results of operations and liquidity could be adversely impacted by further delays in existing and planned clinical trials, continued difficulty in recruiting patients for these clinical trials, delays in manufacturing and collaboration activities, supply chain disruptions, the ongoing impact on its operating activities and employees, and the ongoing impact of any initiatives or programs that the Company may undertake to address financial and operational challenges. As of the date of issuance of these consolidated financial statements, the extent to which the COVID-19 pandemic may materially impact the Company's future financial condition, liquidity or results of operations remains uncertain.

​

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Note2. Summary of Significant Accounting Policies

Basis of Presentation and Consolidation

The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiary, Protagonist Australia, and have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). All intercompany balances and transactions have been eliminated upon consolidation.

The financial statements of Protagonist Australia use the Australian dollar as the functional currency since the majority of expense transactions occur in such currency. Gains and losses from foreign currency transactions were not material for all periods presented. The re-measurement from Australian dollar to U.S. dollars is outlined below:

Foreign currency translation gains and losses are reported as a component of stockholders’ equity in accumulated other comprehensive loss on the consolidated balance sheets.

Use of Estimates

The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates, assumptions and judgments that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, accruals for research and development activities, stock-based compensation, income taxes, marketable securities and leases. Estimates related to revenue recognition include actual costs incurred versus total estimated costs of the Company’s deliverables to determine percentage of completion in addition to the application and estimates of potential revenue constraints in the determination of the transaction price under its license and collaboration agreements. Management bases these estimates on historical and anticipated results, trends and various other assumptions that the Company believes are reasonable under the circumstances, including assumptions as to forecasted amounts and future events. Actual results may differ significantly from those estimates.

Due to the COVID-19 pandemic, there has been uncertainty and disruption in the global economy and financial markets. The Company has taken into consideration any known COVID-19 impacts in its accounting estimates to date and is not aware of any additional specific events or circumstances that would require any additional updates to its estimates or judgments or a revision of the carrying value of its assets or liabilities as of the date of issuance of this Annual Report on Form 10-K. These estimates may change as new events occur and additional information is obtained. Actual results could differ materially from these estimates under different assumptions or conditions.

Concentrations of Credit Risk

Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash, cash equivalents and marketable securities. Substantially all of the Company’s cash is held by two financial institutions that management believes are of high credit quality. Such deposits may, at times, exceed federally insured limits. The primary focus of the Company’s investment strategy is to preserve capital and to meet liquidity requirements. The Company’s cash equivalents and marketable securities are managed by external managers within the guidelines of the Company’s investment policy. The Company’s investment policy addresses the level of credit exposure by limiting concentration in

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any one corporate issuer and establishing a minimum allowable credit rating. To manage its credit risk exposure, the Company maintains its portfolio of cash equivalents and marketable securities in fixed income securities denominated and payable in U.S. dollars. Permissible investments of fixed income securities include obligations of the U.S. government and its agencies, money market instruments including commercial paper and negotiable certificates of deposit, and highly rated corporate debt obligations and money market funds.

Cash Equivalents

Cash equivalents that are readily convertible to cash are stated at cost, which approximates fair value. The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents.

Restricted Cash

Restricted cash consists of cash balances primarily held as security in connection with a letter of credit related to the Company’s facility lease entered into in March 2017 and the Company’s corporate credit card.

Cash as Reported in Consolidated Statements of Cash Flows

Cash as reported in the consolidated statements of cash flows includes the aggregate amounts of cash and cash equivalents and the restricted cash as presented on the consolidated balance sheets.

Cash as reported in the consolidated statements of cash flows consists of (in thousands):

​

​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​ ​ December 31,

Restricted cash - current ​ 10 ​ 10 ​ 10

Restricted cash - noncurrent ​ 450 ​ 450 ​ 450

​

Marketable Securities

All marketable securities have been classified as “available-for-sale” and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its marketable securities at the time of purchase and reevaluates such designation as of each balance sheet date. Short-term marketable securities have maturities greater than three months but not longer than 365 days as of the balance sheet date. Long-term marketable securities have maturities of 365 days or longer as of the balance sheet date. Unrealized gains and losses are excluded from earnings and are reported as a component of comprehensive loss. Realized gains and losses and declines in fair value judged to be other than temporary, if any, on available-for-sale securities are included in interest income. The cost of securities sold is based on the specific-identification method. Interest on marketable securities is included in interest income.

Fair Value of Financial Instruments

Fair value accounting is applied to all financial assets and liabilities that are recognized or disclosed at fair value in the consolidated financial statements on a recurring basis (at least annually). The carrying amount of the Company’s financial instruments, including cash equivalents, receivable from collaboration partner, accounts payable, payable to collaboration partner and accrued expenses and other payables approximate fair value due to their short-term maturities. See Note 4. to the Consolidated Financial Statements for additional information regarding the fair value of the Company’s other financial assets and liabilities.

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Property and Equipment

Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, ranging from three to five years. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful lives of the assets. Maintenance and repairs are charged to expense as incurred. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the consolidated balance sheet and any resulting gain or loss is reflected in operations in the period realized.

Leases

The Company adopted Accounting Standards Codification Topic 842, Leases, (“ASC 842”) effective January 1, 2019. The Company determines if an arrangement is a lease at inception. Pursuant to ASC 842, operating leases are included in operating lease right-of-use (“ROU”) assets, operating lease liabilities, and noncurrent operating lease liabilities on the consolidated balance sheets. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. If the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives and initial direct costs incurred. Lease terms include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term.

​

The Company records tenant improvement allowances as a reduction to the ROU asset with the impact of the decrease recognized prospectively over the remaining lease term. The leasehold improvements will be amortized over the shorter of their useful life or the remaining term of the lease.

​

Impairment of Long-Lived Assets

The Company reviews long-lived assets, primarily comprised of property, equipment and operating lease right-of-use assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amount to the future net cash flows which the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying amount of the assets exceeds the projected discounted future net cash flows arising from the asset. There have been no such impairments of long-lived assets for any of the periods presented.

Long Term Debt

The Company accounts for interest on its long-term debt under the effective interest method, with interest expense comprised of contractual interest, amortization of origination fees and other issuance costs, and accretion of final payment fees.

Comprehensive Loss

Comprehensive loss includes net loss as well as other changes in stockholders’ equity that result from transactions and economic events other than those from stockholders. The Company’s foreign currency translation and unrealized gains and losses on available-for-sale securities represent the only components of other comprehensive loss that are excluded from reported net loss and that are presented in the consolidated statements of comprehensive loss.

Income Taxes

The Company uses the asset and liability method to account for income taxes in accordance with the authoritative guidance for income taxes. Under this method, deferred tax assets and liabilities are determined based on future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities

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and their respective tax bases, and tax loss and credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates applied to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance is established when necessary to reduce deferred tax assets to the amount expected to be realized.

The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than a 50% likelihood of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. The Company records interest and penalties related to unrecognized tax benefits in income tax expense. To date, there have been no interest or penalties recorded in relation to unrecognized tax benefits.

Revenue Recognition

The Company follows Accounting Standards Codification Topic 606, Revenue from Contracts with Customers (“ASC 606”). Under ASC 606, the Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, the Company 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 Company satisfies a performance obligation. The Company applies the five-step model to contracts when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, the Company assesses the goods or services promised within each contract, 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 obligations when (or as) the performance obligations are satisfied. The Company constrains its estimate of the transaction price up to the amount (the “variable consideration constraint”) that a significant reversal of recognized revenue is not probable.

​

Licenses of intellectual property: If a license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in an arrangement, the Company recognizes revenue from non-refundable, upfront fees allocated to the license when the license is transferred to the customer and the customer 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 proportional performance for purposes of recognizing revenue from non-refundable, upfront fees. The Company evaluates the measure of proportional performance each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition.

​

Milestone payments: At the inception of each arrangement or amendment that includes development, regulatory or commercial milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price. ASC 606 suggests two alternatives to use when estimating the amount of variable consideration: the expected value method and the most likely amount method. Under the expected value method, an entity considers the sum of probability-weighted amounts in a range of possible consideration amounts. Under the most likely amount method, an entity considers the single most likely amount in a range of possible consideration amounts. Whichever method is used, it should be consistently applied throughout the life of the contract; however, it is not necessary for the Company to use the same approach for all contracts. The Company expects to use the most likely amount method for development and regulatory milestone payments. 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 control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. If there is more than one performance obligation, the transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis. The Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability or achievement of each such milestone and any

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related constraint, and if necessary, adjusts its estimates of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment.

Royalties: For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes 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).

Upfront payments and fees are recorded as deferred revenue upon receipt or when due and may require deferral of revenue recognition to a future period until the Company performs its obligations under these arrangements. Amounts payable to the Company are recorded as accounts receivable when the Company’s right to consideration is unconditional. Amounts payable to the Company and not yet billed to the collaboration partner are recorded as contract assets. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less.

Contractual cost sharing payments made to a customer or collaboration partner are accounted for as a reduction to the transaction price if such payments are not related to distinct goods or services received from the customer or collaboration partner.

Contracts may be amended to account for changes in contract specifications and requirements. Contract modifications exist when the amendment either creates new, or changes existing, enforceable rights and obligations. When contract modifications create new performance obligations and the increase in consideration approximates the standalone selling price for goods and services related to such new performance obligations as adjusted for specific facts and circumstances of the contract, the modification is considered to be a separate contract. If a contract modification is not accounted for as a separate contract, the Company accounts for the promised goods or services not yet transferred at the date of the contract modification (the remaining promised goods or services) prospectively, as if it were a termination of the existing contract and the creation of a new contract, if the remaining goods or services are distinct from the goods or services transferred on or before the date of the contract modification. The Company accounts for a contract modification as if it were a part of the existing contract if the remaining goods or services are not distinct and, therefore, form part of a single performance obligation that is partially satisfied at the date of the contract modification. In such case the effect that the contract modification has on the transaction price, and on the entity’s measure of progress toward complete satisfaction of the performance obligation, is recognized as an adjustment to revenue (either as an increase in or a reduction of revenue) at the date of the contract modification (the adjustment to revenue is made on a cumulative catch-up basis).

The period between when the Company transfers control of promised goods or services and when the Company receives payment is expected to be one year or less, which is consistent with the Company’s historical experience. Upfront payment contract liabilities resulting from the Company’s license and collaboration agreements do not represent a financing component as the payment is not financing the transfer of goods and services, and the technology underlying the licenses granted reflects research and development expenses already incurred by the Company. As such, the Company does not adjust its revenues for the effects of a significant financing component.

Research and Development Costs

Research and development costs are expensed as incurred, unless there is an alternate future use in other research and development projects or otherwise. Research and development costs include salaries and benefits, stock-based compensation expense, laboratory supplies and facility-related overhead, outside contracted services including clinical trial costs, manufacturing and process development costs for both clinical and pre-clinical materials, research costs, development milestone payments under license and collaboration agreements, and other consulting services.

The Company accrues for estimated costs of research and development activities conducted by third-party service providers, which include the conduct of pre-clinical studies and clinical trials, and contract manufacturing activities. The Company records the estimated costs of research and development activities based upon the estimated services provided

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but not yet invoiced and includes these costs in accrued expenses and other payables in the consolidated balance sheets and within research and development expense in the consolidated statements of operations. The Company accrues for these costs based on factors such as estimates of the work completed and in accordance with agreements established with its third-party service providers. As actual costs become known, the Company adjusts its accrued liabilities. The Company has not experienced any material differences between accrued liabilities and actual costs incurred. However, the status and timing of actual services performed, number of patients enrolled, the rate of patient enrollment and number and location of sites activated may vary from the Company’s estimates, resulting in adjustments to expense in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect the Company’s results of operations.

The Company has received orphan drug designation from the U.S. Food and Drug Administration (“FDA”) for its clinical asset rusfertide (generic name for PTG-300) for the treatment of polycythemia vera and beta-thalassemia and may qualify for a related 25% U.S. Federal income tax credit on qualifying clinical study expenditures.

Research and Development Tax Incentive

The Company is eligible under the AusIndustry research and development tax incentive program to obtain either a refundable cash tax incentive or a taxable credit in the form of a non-cash tax incentive from the Australian Taxation Office (“ATO”). The refundable cash tax incentive is available to the Company on the basis of specific criteria with which the Company must comply. Specifically, the Company must have annual turnover of less than AUD 20.0 million and cannot be controlled by income tax exempt entities. The refundable cash tax incentive is recognized as a reduction to research and development expense when the right to receive has been attained and funds are considered to be collectible. The tax incentive is denominated in Australian dollars and, therefore, the related receivable is remeasured into U.S. dollars as of each reporting date. The Company may alternatively be eligible for a taxable credit in the form of a non-cash tax incentive in years when the annual turnover exceeds the limit. The Company evaluates its eligibility under tax incentive programs as of each balance sheet date and makes accrual and related adjustments based on the most current and relevant data available.

Small Business Innovation Research (“SBIR”) Grants

The Company has received SBIR grants from the National Institutes of Health (“NIH”) in support of its research activities. The Company recognizes a reduction to research and development expenses when expenses related to grants have been incurred and the grant funds become contractually due from NIH.

Stock-based Compensation

The Company measures its stock-based awards made to its equity plan participants based on the estimated fair values of the awards as of the grant date. For stock option awards, the Company uses the Black-Scholes option-pricing model to estimate fair values. For restricted stock unit awards, the estimated fair value is generally the fair market value of the underlying stock on the grant date. Stock-based compensation expense is recognized over the requisite service period and is based on the value of the portion of stock-based payment awards that is ultimately expected to vest. The Company recognizes forfeitures of stock-based awards as they occur.

Net Loss per Share

Basic net loss per share is calculated by dividing the Company’s net loss by the weighted average number of shares of common stock and Exchange Warrants outstanding during the period, without consideration of potentially dilutive securities. In accordance with Accounting Standards Codification Topic 260, Earnings Per Share, the Exchange Warrants are included in the computation of basic net loss per share because the exercise price is negligible and they are fully vested and exercisable after the original issuance date. Diluted net loss per share is the same as basic net loss per share for all periods presented since the effect of potentially dilutive securities is anti-dilutive given the net loss of the Company in each period. See Note 12. Stockholders' Equity for additional information regarding the Exchange Warrants.

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Recently Adopted Accounting Pronouncements

In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2018-13, Fair Value Measurement (Topic 820) – Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, which modifies the disclosure requirements on fair value measurements and is intended to improve the effectiveness of disclosures, including the consideration of costs and benefits. The Company adopted this guidance as of January 1, 2020. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements or disclosures.

In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606, which is intended to clarify the circumstances under which certain transactions in collaborative arrangements should be accounted for under the revenue recognition standard. Certain transactions between collaboration arrangement participants should be accounted for as revenue under ASC Topic 606 when the collaborative arrangement participant is a customer in the context of a unit of account. This guidance is effective for fiscal years and interim periods within those years beginning after December 15, 2019. The Company adopted this guidance as of January 1, 2020. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements and disclosures.

Recently Issued Accounting Pronouncements Not Yet Adopted as of December 31, 2020

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326), which is intended to provide financial statement users with more useful information about expected credit losses on financial assets held by a reporting entity at each reporting date. The new standard replaces the existing incurred loss impairment methodology with a methodology that requires consideration of a broader range of reasonable and supportable forward-looking information to estimate all expected credit losses. This guidance was originally effective for fiscal years and interim periods within those years beginning after December 15, 2019, with early adoption permitted for fiscal years and interim periods within those years beginning after December 15, 2018. In November 2019, the FASB issued ASU No. 2019-10, Financial Instruments – Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842): Effective Dates, which amended the mandatory effective date of ASU No. 2016-13 for smaller reporting companies. Based on the Company’s status as a smaller reporting company as of November 15, 2019, ASU 2016-13 is effective for the Company for fiscal years and interim periods beginning after December 15, 2022. The Company is currently evaluating the impact of this new guidance on its consolidated financial statements and disclosures.

In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which removes certain exceptions and amends certain requirements in the existing income tax guidance to ease accounting requirements. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020 and must be applied on a retrospective basis. The Company does not expect the adoption of this guidance to have a material impact on its consolidated financial statements and disclosures.

Note 3. License and Collaboration Agreement

Agreement Terms

On May 26, 2017, the Company and Janssen Biotech, Inc., (“Janssen”), one of the Janssen Pharmaceutical Companies of Johnson & Johnson, entered into an exclusive license and collaboration agreement (the “Janssen License and Collaboration Agreement”) for the development, manufacture and potential commercialization of PTG-200 worldwide for the treatment of Crohn’s disease (“CD”) and ulcerative colitis (“UC”). Janssen is a related party to the Company as Johnson & Johnson Innovation - JJDC, Inc., a significant stockholder of the Company, and Janssen are both subsidiaries of Johnson & Johnson. PTG-200 is the Company’s orally delivered gut-restricted Interleukin 23 receptor (“IL-23R”) antagonist drug candidate currently in development. The Janssen License and Collaboration Agreement became effective on July 13, 2017. Upon the effectiveness of the agreement, the Company received a non-refundable, upfront cash payment of $50.0 million from Janssen.

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Under the Janssen License and Collaboration Agreement, the Company granted to Janssen an exclusive worldwide license to develop, manufacture and commercialize PTG-200 and related IL-23R compounds for all indications, including CD and UC. The Company was responsible, at its own expense, for the conduct of the Phase 1 clinical trial for PTG-200, and Janssen is responsible for the conduct of the Phase 2 clinical trial for PTG-200 in CD, including filing the U.S. Investigational New Drug application (“IND”). Development costs for the Phase 2 clinical trial are shared between the parties on an 80/20 basis, with Janssen assuming the larger share. Janssen submitted an IND for PTG-200 in CD during the second quarter of 2019, which took effect in July 2019. The Company initiated a Phase 2 clinical study for PTG-200 in CD with Janssen in the fourth quarter of 2019.

The Company entered into an amendment (the “First Amendment”) to the Janssen License and Collaboration Agreement effective May 7, 2019. The First Amendment builds upon the Company’s ongoing development collaboration with Janssen for PTG-200 and, upon the effectiveness of the First Amendment, the Company became eligible to receive a $25.0 million payment from Janssen, which was received during the second quarter of 2019. The First Amendment expanded the scope of the Janssen License and Collaboration Agreement by supporting research efforts towards identifying and developing second-generation IL-23R antagonists (“second-generation compounds”). Two second-generation IL-23R compounds have been nominated and are currently in development: PN-235, in a Phase 1 clinical study, and PN-232, in preclinical studies.

As part of the services added in the First Amendment, Janssen will pay certain costs and milestones related to advancing pre-clinical candidates from the second-generation research program through Phase 1 studies, including funding of a certain number of full-time equivalent employees (“FTEs”) at the Company for an agreed upon period of time. The Company will pay 100% of the costs for the preclinical studies and Phase 1 studies for the first second-generation compound, and 50% of the costs of the Phase 1 studies for the second and third second-generation compounds; thereafter Janssen will pay 100% of any further Phase 1 development costs. Development costs for the Phase 2 clinical trials for second-generation compounds are shared between the parties on an 80/20 basis, with Janssen assuming the larger share. The Company’s Phase 1 and Phase 2 development costs are also limited by overall spending caps. In December 2019, the Company became eligible to receive a $5.0 million payment trigged by the successful nomination of a second-generation development compound, which was received during the first quarter of 2020. The Company will be eligible to receive a $7.5 million milestone payment at the completion of a Phase 1 study for the first second-generation compound.

Prior to the effectiveness of the First Amendment, the Company had been eligible to receive a $25.0 million milestone payment upon Janssen’s filing of the IND. This amount had been considered constrained until a time at which the Company would have become eligible to receive the $25.0 million payment from Janssen. Payments to the Company for research and development services are generally billed and collected as services are performed or assets are delivered, including research activities and Phase 1 and Phase 2 development activities. Janssen bills the Company for its 20% share of the Phase 2 development costs as expenses are incurred by Janssen. Milestone payments are received after the related milestones are achieved.

Pursuant to the First Amendment, the Company will be eligible to receive clinical development, regulatory and sales milestones, if and as achieved, and/or payments relating to Janssen’s elections to maintain or expand its license rights. The next possible milestone or opt-in election events based on a Phase 2 clinical trial in CD are as follows:

• Janssen would make a $50.0 million milestone payment following dosing of the third patient in the first Phase 2b clinical trial for CD for a second-generation product.

Janssen can also then elect to receive exclusive, world-wide commercial rights for both PTG-200 and second-generation products following the Phase 2b completion date for PTG-200 or a second-generation product by paying a $50.0 million payment (the “Amended Second Opt-in Election”). The Company will also be eligible for certain additional milestone payments including a potential payment of either $100.0 million upon a Phase 3 CD clinical trial meeting a

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primary clinical endpoint with respect to PTG-200 or $115.0 million upon a Phase 3 CD clinical trial meeting a primary clinical endpoint with respect to a second-generation compound.

Pursuant to the First Amendment, the Company will be eligible to receive tiered royalties on net product sales at percentages ranging from mid-single digits to ten percent. Under the terms of the First Amendment, the Company will be eligible to receive up to an aggregate $1.0 billion in research, development, regulatory and sales milestones.

The Janssen License and Collaboration Agreement remains in effect until the royalty obligations cease following patent and regulatory expiry, unless terminated earlier. Upon a termination of the Janssen License and Collaboration Agreement, all rights revert back to the Company, and in certain circumstances, if such termination occurs during ongoing clinical trials, Janssen would, if requested, provide certain financial and operational support to the Company for the completion of such trials.

Revenue Recognition

The Company concluded that the amended Janssen License and Collaboration Agreement continued to contain a single performance obligation including the development license; second-generation compound research services; Phase 1 development services for PTG-200 and potential second-generation compounds; the Company’s services associated with Phase 2 development for PTG-200 until Phase 2a; the Company’s services associated with Phase 2 development for second-generation products until the dosing of the third patient in Phase 2b in CD or UC, or Phase 2 in an additional indication; and all other such services that the Company may perform at the request of Janssen to support the development of PTG-200, second-generation research services, or the development of second-generation compounds. The Company concluded that the Amended First Opt-in Election and the Amended Second Opt-in Election options are not considered to be material rights.

The Company determined that the license was not distinct from the added research and development services within the context of the agreement because the added research and development services significantly increase the utility of the intellectual property. The Company also determined that the remaining research and development services are not distinct from the partially delivered combined promise comprised under the agreement prior to the First Amendment of the development license and PTG-200 services, including compound supply and other services. Therefore, the First Amendment is treated as if it were part of the original Janssen License and Collaboration Agreement. The First Amendment was accounted for as if it were an extension of services under the initial Janssen License and Collaboration Agreement by applying a cumulative catch-up adjustment to revenue. As of the effective date of the First Amendment, the Company calculated the adjusted cumulative revenue under the amended Janssen License and Collaboration Agreement by updating the transaction price for the incremental consideration to be received, net of the incremental development cost reimbursement to be paid to Janssen, and an updated percentage complete, which resulted in a cumulative adjustment recorded during the year ended December 31, 2019 that reduced revenue by $9.4 million.

The contract duration is defined as the period in which parties to the contract have present enforceable rights and obligations. For revenue recognition purposes, the Company determined that the duration of the Janssen License and Collaboration Agreement, as amended, began on the effective date of July 13, 2017 and is estimated to end upon the later of end of Phase 2a for PTG-200 or upon dosing of the third patient in Phase 2b for a second-generation compound.

The Company uses the most likely amount method to estimate variable consideration included in the transaction price. Variable consideration after the First Amendment consists of future milestone payments and cost sharing payments from Janssen for agreed upon services, offset by development cost reimbursements payable to Janssen. Cost sharing payments from Janssen relate to the agreed upon services for development activities that the Company performs within the duration of the contract and are included in the transaction price at the Company’s share of estimated budgeted costs for these activities, including primarily internal full-time equivalent effort and third party contract costs. Cost sharing payments to Janssen relate to agreed upon services for Phase 2 activities that Janssen performs within the duration of the contract and are not a distinct service that Janssen transfers to the Company. Therefore, the consideration payable to Janssen is accounted for as a reduction in the transaction price.

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The Company concluded that the transaction price of the initial performance obligation under the Janssen License and Collaboration Agreement was $98.6 million as of December 31, 2020, a decrease of $14.3 million from the transaction price of $112.9 million at December 31, 2019 and an increase of $37.9 million from the transaction price of $60.7 million at December 31, 2018. In order to determine the transaction price, the Company evaluated all payments to be received during the duration of the contract, net of Phase 2 development costs reimbursement expected to be payable to Janssen. The Company determined that the transaction price of the initial performance obligation as of December 31, 2020 includes the $50.0 million upfront payment, the $25.0 million payment received upon the effectiveness of the First Amendment, the $5.0 million payment triggered by the successful nomination of a second-generation compound, $17.9 million of reimbursement from Janssen for services performed for PTG-200 Phase 2 and for second-generation compound research and development costs and other services, and estimated variable consideration consisting of a $7.5 million milestone payment subject to the completion of a Phase 1 study for a second-generation compound, partially offset by $6.8 million of net cost reimbursement to Janssen for services performed. The Company evaluated whether the variable component of the transaction price should be constrained to ensure that a significant reversal of revenue recognized on a cumulative basis as of December 31, 2020 is not probable. The Company concluded that the variable consideration constraint does not further decrease the estimated transaction price as of December 31, 2020. The additional potential development, regulatory and sales milestone payments after the completion of Phase 2a activities in UC and CD that the Company would be eligible to receive are currently outside the contract term as defined for revenue recognition purposes and as such have been excluded from the transaction price. Janssen has also opted in for certain additional services to be performed by the Company that are outside the initial performance obligation; revenue is recognized as these services are performed.

The Company re-evaluates the transaction price, including variable consideration, at the end of each reporting period and as uncertain events are resolved or other changes in circumstances occur. The Company and Janssen make quarterly cost sharing payments to one another in amounts necessary to ensure that each party bears its contractual share of the overall shared costs incurred.

The Company utilizes a cost-based input method to measure proportional performance and to calculate the corresponding amount of revenue to recognize. In applying the cost-based input method of revenue recognition, the Company uses actual costs incurred relative to expected costs to fulfill the combined performance obligation. These costs consist primarily of internal FTE effort and third-party contract costs. Revenue will be recognized based on actual costs incurred as a percentage of total estimated costs as the Company completes its performance obligations. A cost-based input method of revenue recognition requires management to make estimates of costs to complete the Company’s performance obligations. The Company believes this is the best measure of progress because other measures do not reflect how the Company transfers its performance obligation to Janssen. In making such estimates, significant judgment is required to evaluate assumptions related to cost estimates. The cumulative effect of revisions to estimated costs to complete the Company’s performance obligations will be recorded in the period in which changes are identified and amounts can be reasonably estimated. A significant change in these assumptions and estimates could have a material impact on the timing and amount of revenue recognized in future periods.

For the year ended December 31, 2020, the Company recognized $28.6 million of license and collaboration revenue. This amount included $27.1 million of the transaction price based on proportional performance and an update in forecasted amounts for future services remaining to be performed and recognized under the Janssen License and Collaboration Agreement. In addition, the Company recorded $1.5 million of revenue for the year ended December 31, 2020 related to additional services provided by the Company under the Janssen License and Collaboration Agreement.

For the year ended December 31, 2019, the Company recognized $0.2 million of license and collaboration revenue. This amount included a $9.4 million cumulative catchup adjustment as a reduction of revenue, offset by $8.0 million of license and collaboration revenue recognized following the contract modification for the First Amendment and $1.6 million of collaboration revenue recognized during the first quarter of 2019 under the original Janssen License and Collaboration Agreement prior to the effectiveness of the First Amendment. No revenue for additional services was recognized for the year ended December 31, 2019.

For the year ended December 31, 2018, the Company recognized $30.9 million of license and collaboration revenue. This amount included $30.8 million of the transaction price for the Janssen License and Collaboration

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Agreement recognized based on proportional performance, and $0.1 million, net, for other services related to Phase 2 activities performed by the Company on behalf of Janssen that were not included in the performance obligations identified under the Janssen License and Collaboration Agreement.

The following table presents changes in the Company’s contract assets and liabilities during the periods presented (in thousands):

​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​ ​ Balance at ​ ​ ​ ​ ​ Balance at

​ ​ Beginning of ​ ​ ​ ​ ​ End of

Year Ended December 31, 2020 Period ​ Additions Deductions Period

Contract assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Contract asset - related party ​ $ 800 ​ $ 342 ​ $ (1,142) ​ $ —

Contract liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​ ​ ​ ​ ​ ​ ​ ​ ​

​ ​ Balance at ​ ​ ​ ​ ​ ​ ​ Balance at

​ ​ Beginning of ​ ​ ​ ​ ​ End of

Year Ended December 31, 2019 Period ​ Additions Deductions Period

Contract assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Contract liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​

During the year ended December 31, 2020, the Company recognized revenue of $14.1 million from amounts included in the deferred revenue contract liability balance at the beginning of the year. During the year ended December 31, 2019, the Company recognized revenue of $1.6 million from amounts included in the deferred revenue contract liability balance at the beginning of the year, which represents the revenue recognized during the first quarter of 2019 prior to the effectiveness of the First Amendment. During the year ended December 31, 2018, the Company recognized $23.5 million in revenue from the deferred revenue contract liability balance at the beginning of the year. None of the costs to obtain or fulfill the contract were capitalized.

Note 4. Fair Value Measurements

Financial assets and liabilities are recorded at fair value. The accounting guidance for fair value provides a framework for measuring fair value, clarifies the definition of fair value and expands disclosures regarding fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value as follows:

Level 1—Inputs are unadjusted quoted prices in active markets for identical assets or liabilities at the measurement date.

Level 2—Inputs (other than quoted market prices included in Level 1) are either directly or indirectly observable for the asset or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life.

Level 3—Inputs reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.

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In determining fair value, the Company utilizes quoted market prices, broker or dealer quotations, or valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible and considers counterparty credit risk in its assessment of fair value.

The following table presents the fair value of the Company’s financial assets determined using the inputs defined above (in thousands).

​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​ Level 1 Level 2 Level 3 Total

Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​

​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

​ Level 1 Level 2 Level 3 Total

Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

U.S. Treasury and agency securities ​ — ​ 40,810 — 40,810