Note 14.    Contingencies

We have entered into the collaboration agreements described in Note 7, as well as various other collaboration agreements that are not individually, or in the aggregate, significant to our operating results or financial condition at this time. We may in the future seek to license additional rights relating to technologies or drug development candidates in connection with our drug discovery and development programs. Under these agreements, we may be required to pay upfront fees, milestone payments, and royalties on sales of future products.

In the ordinary course of our business, we may become involved in lawsuits, proceedings, and other disputes, including commercial, intellectual property, regulatory, employment, and other matters.  We record a reserve for these matters when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated.

Note 7.    License agreements

Novartis

In November 2009, we entered into a Collaboration and License Agreement with Novartis. Under the terms of the agreement, Novartis received exclusive development and commercialization rights outside of the United States to our JAK inhibitor ruxolitinib and certain back-up compounds for hematologic and oncology indications, including all hematological malignancies, solid tumors and myeloproliferative diseases. We retained exclusive development and commercialization rights to JAKAFI (ruxolitinib) in the United States and in certain other indications. Novartis also received worldwide exclusive development and commercialization rights to our MET inhibitor compound capmatinib and certain back-up compounds in all indications.

Under this agreement, we were initially eligible to receive up to $174.0 million for the achievement of development milestones, up to $495.0 million for the achievement of regulatory milestones and up to $500.0 million for the achievement of sales milestones. In addition, we are eligible to receive up to $75.0 million of additional potential development and regulatory milestones relating to graft-versus-host-disease (“GVHD”). We have recognized and received, in the aggregate, $157.0 million for the achievement of development milestones, $280.0 million for the achievement of regulatory milestones and $200.0 million for the achievement of sales milestones through March 31, 2022.

We also are eligible to receive tiered, double-digit royalties ranging from the upper-teens to the mid-twenties on future JAKAVI net sales outside of the United States, and tiered, worldwide royalties on TABRECTA net sales that range from 12% to 14%. We are obligated to pay to Novartis tiered royalties in the low single-digits on future JAKAFI net sales within the United States contingent on certain conditions. During the three months ended March 31, 2022 and 2021, such royalties on net sales within the United States totaled $21.7 million and $17.8 million, respectively, and were reflected in cost of product revenues on the condensed consolidated statements of operations. At March 31, 2022 and December 31, 2021, $162.1 million and $148.1 million, respectively, of accrued royalties were included in accrued and other current liabilities on the condensed consolidated balance sheets. Each company is responsible for costs relating to the development and commercialization of ruxolitinib in its respective territories, with costs of collaborative studies shared equally. Novartis is also responsible for all costs relating to the development and commercialization of capmatinib.

For the three months ended March 31, 2022 and 2021, we recorded $70.8 million and $65.6 million, respectively, of product royalty revenues related to Novartis net sales of JAKAVI outside the United States. For the three months ended March 31, 2022 and 2021, we recorded $3.5 million and $2.0 million, respectively, of product royalty revenues related to Novartis net sales of TABRECTA worldwide.

Lilly - Baricitinib

In December 2009, we entered into a License, Development and Commercialization Agreement with Lilly. Under the terms of the agreement, Lilly received exclusive worldwide development and commercialization rights to our JAK inhibitor baricitinib, and certain back-up compounds for inflammatory and autoimmune diseases.

Under this agreement, we were initially eligible to receive up to $150.0 million for the achievement of development milestones, up to $365.0 million for the achievement of regulatory milestones and up to $150.0 million for the achievement of sales milestones. We have recognized and received, in aggregate, $149.0 million for the achievement of development milestones, $265.0 million for the achievement of regulatory milestones and $50.0 million for the achievement of sales milestones through March 31, 2022.

In May 2020, we amended our agreement with Lilly to enable Lilly to develop and commercialize baricitinib for the treatment of COVID-19. As part of the amended agreement, in addition to the royalties described above, we will be entitled to receive additional royalty payments with rates in the low teens on global net sales of baricitinib for the treatment of COVID-19 that exceed a specified aggregate global net sales threshold.

Product royalty revenue related to Lilly net sales of OLUMIANT outside of the United States for the three months ended March 31, 2022 and 2021 was $48.0 million and $32.3 million, respectively.  

Lilly - Ruxolitinib

In March 2016, we entered into an amendment to the agreement with Lilly that amended the non-compete provision of the agreement to allow us to engage in the development and commercialization of ruxolitinib in the GVHD field. Lilly is eligible to receive up to $40.0 million in regulatory milestone payments relating to ruxolitinib in the GVHD field. In May 2019, the approval of JAKAFI in steroid-refractory acute GVHD triggered a $20.0 million milestone payment to Lilly. In March 2022, the positive recommendation from the European Medicines Agency for regulatory approval of ruxolitinib in the GVHD field triggered an additional $20.0 million milestone payment to Lilly, which was recorded as research and development expense in our condensed consolidated statements of operations.

Agenus

In January 2015, we entered into a License, Development and Commercialization Agreement with Agenus Inc. and its wholly-owned subsidiary, 4-Antibody AG (now known as Agenus Switzerland Inc.), which we collectively refer to as Agenus. Under this agreement, which was amended in February 2017, the parties have agreed to collaborate on the discovery of novel immuno-therapeutics using Agenus’ antibody discovery platforms. Under the terms of the amended agreement, we received exclusive worldwide development and commercialization rights to four checkpoint modulators directed against GITR, OX40, LAG-3 and TIM-3 as well as two undisclosed targets. Targets may be designated profit-share programs, where all costs and profits are shared equally by us and Agenus, or royalty-bearing programs, where we are responsible for all costs associated with discovery, preclinical, clinical development and commercialization activities.   There are currently no profit-share programs. For each royalty-bearing product other than GITR, OX40 and one undisclosed target, Agenus will be eligible to receive tiered royalties on global net sales ranging from 6% to 12%.  For GITR, OX40 and one undisclosed target, Agenus will be eligible to receive 15% royalties on global net sales. The agreement may be terminated by us for convenience upon 12 months’ notice and may also be terminated under certain other circumstances, including material breach.

As of March 31, 2022, we have paid Agenus milestones totaling $30.0 million and Agenus is eligible to receive up to an additional $500.0 million in future contingent development, regulatory and commercialization milestones across all programs in the collaboration.

In addition, in 2017 we also agreed to purchase 10.0 million shares of Agenus common stock for an aggregate purchase price of $60.0 million in cash, or $6.00 per share. The fair market value of our long term investment in Agenus as of March 31, 2022 and December 31, 2021 was $29.7 million and $38.9 million, respectively. In 2020, we sold an aggregate of approximately 3.7 million shares of Agenus common stock resulting in gross proceeds of approximately $17.2 million. In 2021, we sold an aggregate of approximately 2.0 million shares of Agenus common stock resulting in gross proceeds of approximately $10.5 million. As of March 31, 2022, we owned less than 5% of the outstanding shares of Agenus common stock.

We intend to hold the investment in Agenus for the foreseeable future and therefore, are accounting for our shares held in Agenus at fair value whereby the investment is marked to market through earnings in each reporting period. Given our intent to hold the investment for the foreseeable future, we have classified the investment within long term investments on the accompanying condensed consolidated balance sheets. For the three months ended March 31, 2022 and 2021, we recorded an unrealized loss of $9.2 million and $5.9 million, respectively, based on the change in fair value of Agenus Inc.’s common stock during the respective periods.

Merus

In December 2016, we entered into a Collaboration and License Agreement with Merus N.V. (“Merus”). Under this agreement, the parties have agreed to collaborate with respect to the research, discovery and development of bispecific antibodies utilizing Merus’ technology platform.  The collaboration encompasses up to ten independent programs.  

In January 2022, we decided to opt-out of the continued development of MCLA-145, a bispecific antibody targeting PD-L1 and CD137. We continue to collaborate with Merus and leverage the Merus platform to develop a pipeline of novel agents, as we continue to hold worldwide exclusive development and commercialization rights to up to ten additional programs. Of these ten additional programs, Merus retained the option, subject to certain conditions, to co-fund development of up to two such programs. If Merus exercises its co-funding option for a program, Merus would be responsible for funding 35% of the associated future global development costs and, for certain of such programs, would be responsible for reimbursing us for certain development costs incurred prior to the option exercise.  Merus will also have the right to participate in a specified proportion of detailing activities in the United States for one of those co-developed programs. All costs related to the co-funded collaboration programs are subject to joint research and development plans and overseen by a joint development committee, but we will have final determination as to such plans in cases of dispute. We will be responsible for all research, development and commercialization costs relating to all other programs.  

For each program as to which Merus does not have commercialization or development co-funding rights, Merus is eligible to receive up to $100.0 million in future contingent development and regulatory milestones, and up to $250.0 million in commercialization milestones as well as tiered royalties ranging from 6% to 10% of global net sales. For each program as to which Merus exercises its option to co-fund development, Merus is eligible to receive a 50% share of profits (or sustain 50% of any losses) in the United States and be eligible to receive tiered royalties ranging from 6% to 10% of net sales of products outside of the United States.  If Merus opts to cease co-funding a program as to which it exercised its co-development option, then Merus will no longer receive a share of profits in the United States but will be eligible to receive the same milestones from the co-funding termination date and the same tiered royalties described above with respect to programs where Merus does not have a right to co-fund development and, depending on the stage at which Merus chose to cease co-funding development costs, Merus will be eligible to receive additional royalties ranging up to 4% of net sales in the United States. As of March 31, 2022, we have paid Merus milestones totaling $2.0 million.

In addition, in 2016 we entered into a Share Subscription Agreement with Merus, pursuant to which we agreed to purchase 3.2 million common shares of Merus for an aggregate purchase price of $80.0 million in cash, or $25.00 per share. The fair market value of our total long term investment in Merus as of March 31, 2022 and December 31, 2021 was $93.9 million and $112.9 million, respectively. In January 2021, we purchased 350,000 common shares in Merus’ underwritten public offering of 4,848,485 common shares at the public offering price of $24.75 per share, or an aggregate purchase price of $8.7 million. As of March 31, 2022, we owned approximately 8% of the outstanding common shares of Merus.

We have concluded that we have the ability to exercise significant influence, but not control, over Merus based primarily on our ownership interest, the level of intra-entity transactions between us and Merus related to development expenses, as well as other qualitative factors.  We have elected the fair value option to account for our long term investment in Merus whereby the investment is marked to market through earnings in each reporting period.  We believe the fair value option to be the most appropriate accounting method to account for securities in publicly held collaborators for which we have significant influence. For the three months ended March 31, 2022 and 2021 we recorded an unrealized loss of $19.0 million and an unrealized gain of $9.4 million, respectively, based on the change in fair value of Merus’ common shares during the respective periods.  

Calithera

In January 2017, we entered into a Collaboration and License Agreement with Calithera Biosciences, Inc. (“Calithera”). Under this agreement, we received an exclusive, worldwide license to develop and commercialize small molecule arginase inhibitors, including INCB01158. We have agreed to co-fund 70% of the global development costs for the development of the licensed products for hematology and oncology indications. Calithera will have the right to conduct certain clinical development under the collaboration, including combination studies of a licensed product with a proprietary compound of Calithera. We will be entitled to 60% of the profits and losses from net sales of licensed product in the United States, and Calithera will have the right to co-detail licensed products in the United States, and we have agreed to pay Calithera tiered royalties ranging from the low to mid-double digits on net sales of licensed products outside the United States.

As of March 31, 2022, we have paid Calithera milestones totaling $12.0 million. Calithera delivered notice of its decision to opt out of its co-funding obligation, effective on September 30, 2020.  As a result, the U.S. profit sharing will no longer be in effect, we will be responsible for funding all of the development costs of INCB01158 and any other licensed products, and the agreement provides that we will pay Calithera tiered royalties ranging from the low to mid-double digits on net sales of licensed products both in the United States and outside the United States and additional royalties to reimburse Calithera for previously incurred development costs. Calithera is eligible to receive $720.0 million in potential future development, regulatory and sales milestone payments and will have no further rights to research, develop or co-detail INCB001158. We will have the right to take over the conduct of all activities related to the research, development and commercialization of INCB001158 for all indications in the hematology/oncology field.

In addition, in 2017, we entered into a Stock Purchase Agreement with Calithera for the purchase of 1.7 million common shares of Calithera for an aggregate purchase price of $8.0 million in cash, or $4.65 per share. The fair market value of our long term investment in Calithera at March 31, 2022 and December 31, 2021 was $0.7 million and $1.1 million, respectively. As of March 31, 2022, we owned approximately 2% of the outstanding shares of Calithera common stock.

We intend to hold the investment in Calithera for the foreseeable future and therefore, are accounting for our shares held in Calithera at fair value whereby the investment is marked to market through earnings in each reporting period. Given our intent to hold the investment for the foreseeable future, we have classified the investment within long term investments on the accompanying condensed consolidated balance sheets. For the three months ended March 31, 2022 and 2021 we recorded an unrealized loss of $0.5 million and $4.3 million, respectively, based on the change in fair value of Calithera’s common stock during the respective periods.

MacroGenics

In October 2017, we entered into a Global Collaboration and License Agreement with MacroGenics, Inc. (“MacroGenics”). Under this agreement, we received exclusive development and commercialization rights worldwide to MacroGenics’ INCMGA0012 (formerly MGA012), an investigational monoclonal antibody that inhibits PD-1. Except as set forth in the succeeding sentence, we have sole authority over and bear all costs and expenses in connection with the development and commercialization of INCMGA0012 in all indications, whether as a monotherapy or as part of a combination regimen. MacroGenics has retained the right to develop and commercialize, at its cost and expense, its pipeline assets in combination with INCMGA0012.  In addition, MacroGenics has the right to manufacture a portion of both companies’ global clinical and commercial supply needs of INCMGA0012.

As of March 31, 2022, we have paid MacroGenics developmental milestones totaling $70.0 million.  MacroGenics is eligible to receive up to an additional $365.0 million in future contingent development and regulatory milestones, and up to $330.0 million in sales milestones as well as tiered royalties ranging from 15% to 24% of global net sales.

Research and development expenses for the three months ended March 31, 2022 and 2021 also included $13.5 million and $13.6 million, respectively, of development costs incurred pursuant to the MacroGenics agreement. At March 31, 2022 and December 31, 2021, a total of $0.4 million and $0.7 million of such costs were included in accrued and other liabilities on the condensed consolidated balance sheets.  

Syros

In January 2018, we entered into a Target Discovery, Research Collaboration and Option Agreement with Syros Pharmaceuticals, Inc. (“Syros”). Under this agreement, Syros will use its proprietary gene control platform to identify novel therapeutic targets with a focus in myeloproliferative neoplasms and we have received options to obtain exclusive worldwide rights to intellectual property resulting from the collaboration for up to seven validated targets. We will have exclusive worldwide rights to develop and commercialize any therapies under the collaboration that modulate those validated targets. We have agreed to pay Syros up to $54.0 million in target selection and option exercise fees should we decide to exercise all of our options under the agreement. For products resulting from the collaboration against each of the seven selected and validated targets, we have agreed to pay up to $50.0 million in potential development and regulatory

milestones and up to $65.0 million in potential sales milestones. Syros is also eligible to receive low single-digit royalties on net sales of products resulting from the collaboration.

In addition, in 2018, we entered into a Stock Purchase Agreement with Syros for the purchase of 0.8 million shares of common stock of Syros for an aggregate purchase price of $10.0 million in cash, or $12.61 per share.  Subsequently in 2018, we entered into an Amended Stock Purchase Agreement with Syros for the purchase of an additional 0.1 million common shares of Syros for an aggregate purchase price of $1.4 million in cash, or $9.55 per share. The fair market value of our long term investment in Syros as of March 31, 2022 and December 31, 2021 was $1.1 million and $3.1 million, respectively. As of March 31, 2022, we owned less than 2% of the outstanding shares of Syros common stock.

We intend to hold the investment in Syros for the foreseeable future and therefore, are accounting for our shares held in Syros at fair value whereby the investment is marked to market through earnings in each reporting period.  Given our intent to hold the investment for the foreseeable future, we have classified the investment within long term investments on the accompanying condensed consolidated balance sheets.  For the three months ended March 31, 2022 and 2021, we recorded an unrealized loss of $1.9 million and $3.2 million, respectively, based on the change in fair value of Syros’ common stock during the respective periods.

Innovent

In December 2018, we entered into a Research Collaboration and Licensing Agreement with Innovent. Under the terms of this agreement, Innovent received exclusive development and commercialization rights to our clinical-stage product candidates pemigatinib, itacitinib and parsaclisib in hematology and oncology in mainland China, Hong Kong, Macau and Taiwan. We are eligible to receive up to an additional $94.0 million in potential development and regulatory milestones.

We recognize development and regulatory milestones upon confirmation of achievement of the event, as development and regulatory approvals are events not controllable by us but rather development activities of Innovent and decisions made by regulatory agencies. In March 2022, we recognized a $5.0 million milestone for approval of PEMAZYRE (pemigatinib) in China.

In the event of commercialization of the licensed molecule, we are eligible to receive up to $202.5 million in potential sales milestones from Innovent. We will recognize sales milestones in the corresponding period of the product sale upon confirmation of net sales milestone threshold achievement by Innovent. We are also eligible to receive tiered royalties from the high-teens to the low-twenties on future sales of products resulting from the collaboration. We retain an option to assist in the promotion of the three product candidates in the Innovent territories.

Zai Lab

In July 2019, we entered into a Collaboration and License Agreement with Zai Lab. Under the terms of this agreement, Zai Lab received development and exclusive commercialization rights to INCMGA0012 in hematology and oncology in mainland China, Hong Kong, Macau and Taiwan.

The agreement allows for Zai Lab to continue development of the licensed molecule and to submit the licensed molecule to authorities for regulatory approval within the agreement territory, upon which we are eligible for up to $22.5 million in potential development and regulatory milestones. We recognize development and regulatory milestones upon confirmation of achievement of the event, as development and regulatory approvals are events not controllable by us but rather development activities of Zai Lab and decisions made by regulatory agencies.

In the event of commercialization of the licensed molecule, we are eligible to receive up to $37.5 million in potential sales milestones from Zai Lab.  We will recognize sales milestones in the corresponding period of the product sale upon confirmation of net sales milestone threshold achievement by Zai Lab. We are also eligible to receive tiered royalties from the low to mid-twenties on future product sales resulting from the collaboration. We also retain an option to assist in the promotion of INCMGA0012 in Zai Lab’s licensed territories.

MorphoSys

In January 2020, we entered into a Collaboration and License Agreement with MorphoSys AG and MorphoSys US Inc., a wholly-owned subsidiary of MorphoSys AG (together with MorphoSys AG, “MorphoSys”), covering the worldwide development and commercialization of MOR208 (tafasitamab), an investigational Fc engineered monoclonal antibody directed against the target molecule CD19 that is currently in clinical development by MorphoSys. MorphoSys has exclusive worldwide development and commercialization rights to tafasitamab under a June 2010 collaboration and license agreement with Xencor, Inc.

Under the terms of the agreement, we received exclusive commercialization rights outside of the United States, and MorphoSys and we have co-commercialization rights in the United States, with respect to tafasitamab.  MorphoSys is responsible for leading the commercialization strategy and booking all revenue from sales of tafasitamab in the United States, and we and MorphoSys are both responsible for commercialization efforts in the United States and will share equally the profits and losses from the co-commercialization efforts. We will lead the commercialization strategy outside of the United States, and will be responsible for commercialization efforts and book all revenue from sales of tafasitamab outside of the United States, subject to our royalty payment obligations set forth below. We and MorphoSys have agreed to co-develop tafasitamab and to share development costs associated with global and U.S.-specific clinical trials, with Incyte responsible for 55% of such costs and MorphoSys responsible for 45% of such costs.  Each company is responsible for funding any independent development activities, and we are responsible for funding development activities specific to territories outside of the United States. All development costs related to the collaboration are subject to a joint development plan.  

MorphoSys is eligible to receive up to $740.0 million in future contingent development and regulatory milestones and up to $315.0 million in commercialization milestones as well as tiered royalties ranging from the mid-teens to mid-twenties of net sales outside of the United States. MorphoSys’ right to receive royalties in any particular country will expire upon the last to occur of (a) the expiration of patent rights in that particular country, (b) a specified period of time after the first post-marketing authorization sale of a licensed product comprising tafasitamab in that country, and (c) the expiration of any regulatory exclusivity for that licensed product in that country.

In addition, under the terms of the agreement and pursuant to a related purchase agreement, we agreed to purchase American Depositary Shares (“ADSs”), each representing 0.25 of an ordinary share of MorphoSys AG, for an aggregate purchase price of $150.0 million or $41.33 per ADS (such ADSs to be purchased, the “New ADSs”). The fair market value of our long term investment in MorphoSys as of March 31, 2022 and December 31, 2021, was $24.6 million and $34.2 million, respectively. As of March 31, 2022, we owned approximately 3% of the outstanding shares of MorphoSys common stock.

We intend to hold the investment in MorphoSys for the foreseeable future and therefore, are accounting for our shares held in MorphoSys at fair value whereby the investment is marked to market through earnings in each reporting period.  Given our intent to hold the investment for the foreseeable future, we have classified the investment within long term investments on the accompanying condensed consolidated balance sheets. For the three months ended March 31, 2022 and 2021, we recorded an unrealized loss of $9.6 million and $23.7 million, respectively, based on the change in fair  value of MorphoSys’ common stock during the respective periods.  

Our 50% share of the United States loss for the commercialization of tafasitamab for the three months ended March 31, 2022 and 2021 was $4.7 million and $10.5 million, respectively, and is recorded as collaboration loss sharing on the condensed consolidated statement of operations. Research and development expenses for the three months ended March 31, 2022 and 2021, includes $21.0 million and $14.9 million, respectively, related to our 55% share of the co-development costs for tafasitamab. At March 31, 2022 and December 31, 2021, $41.5 million and $21.5 million, respectively, was included in accrued and other liabilities on the condensed consolidated balance sheet for amounts due to MorphoSys under the agreement.

Nimble

In September 2020, we entered into a Collaboration and License Agreement with Nimble Therapeutics, Inc. (“Nimble”). Under the terms of this agreement, Nimble will utilize their peptide synthesis, screening and optimization platform for discovery and validation of peptides against specified targets. Under the agreement, Nimble is eligible to receive up to $8.0 million in future contingent discovery milestones and up to $127.0 million in future contingent development and regulatory milestones. Additionally, in the event of successful commercialization, Nimble is eligible to receive up to $130.0 million in future contingent sales milestones and tiered royalties on net sales in the low single digits.

InnoCare

In August 2021, we entered into a Collaboration and License Agreement with Sunny Investments Limited, a wholly-owned subsidiary of InnoCare Pharma Limited (“InnoCare”). InnoCare received development and exclusive commercialization rights to tafasitamab in hematology and oncology in mainland China, Hong Kong, Macau and Taiwan. In September 2021, we recognized an upfront payment under this agreement of $35.0 million upon our transfer of technology related to the licensed product candidate to InnoCare, which was recorded in milestone and contract revenues on the consolidated statement of operations for the year ended December 31, 2021. Under the terms of this agreement, we are eligible to receive up to an additional $45.0 million in potential development and regulatory milestones. We recognize development and regulatory milestones upon confirmation of achievement of the event, as development and regulatory approvals are events not controllable by us but rather development activities of InnoCare and decisions made by regulatory agencies. In the event of commercialization, we are eligible to receive up to $37.5 million in potential sales milestones from InnoCare.  We will recognize sales milestones in the corresponding period of the product sale upon confirmation of net sales milestone threshold achievement by InnoCare. We are also eligible to receive tiered royalties from the low to mid-twenties on future product sales resulting from the collaboration.

Syndax

In September 2021, we entered into a Collaboration and License Agreement with Syndax Pharmaceuticals, Inc. (“Syndax”), covering the worldwide development and commercialization of SNDX-6352 (“axatilimab”).  Axatilimab, currently in clinical development by Syndax, is a monoclonal antibody that blocks the colony stimulating factor-1 (CSF-1) receptor. Syndax has exclusive worldwide development and commercialization rights to axatilimab under a June 2016 license agreement with UCB Biopharma Sprl. The agreement became effective in December 2021.

Under the terms of the agreement, we received exclusive commercialization rights outside of the United States, and Syndax and we have co-commercialization rights in the United States, with respect to axatilimab. We will be responsible for leading the commercialization strategy and booking all revenue from sales of tafasitamab globally, and Syndax will have the option to co-commercialization axatilimab with Incyte in the United States. Incyte and Syndax will share equally the profits and losses from the co-commercialization efforts in the United States. Sales of axatilimab outside the United States will be subject to our royalty payment obligations to Syndax, as set forth below. We and Syndax have agreed to co-develop axatilimab and to share development costs associated with global and U.S.-specific clinical trials, with Incyte responsible for 55% of such costs and Syndax responsible for 45% of such costs.  Each company is responsible for funding any independent development activities. All development costs related to the collaboration are subject to a joint development plan.  

In December 2021, we paid Syndax an upfront, non-refundable payment of $117.0 million, which was recorded in research and development expense on the consolidated statement of operations for the year ended December 31, 2021. Syndax is eligible to receive up to $220.0 million in future contingent development and regulatory milestones and up to $230.0 million in sales milestones as well as tiered royalties ranging in the mid-teens on net sales in Europe and Japan and low double digit percentage on net sales in the rest of the world outside of the United States. Syndax’ right to receive royalties in any particular country will expire upon the last to occur of (a) the expiration of patent rights in that particular country, (b) a specified period of time after the first post-marketing authorization sale of a licensed product comprising tafasitamab in that country, and (c) the expiration of any regulatory exclusivity for that licensed product in that country.

In addition, under the terms of the agreement and pursuant to a related stock purchase agreement, we agreed to purchase approximately 1.4 million shares of common stock of Syndax for an aggregate purchase price of $35.0 million, or $24.62 per share. We agreed, subject to limited exceptions, not to sell or otherwise transfer any of the shares for a six month period after the closing date of the sale. We completed the purchase of the shares on December 9, 2021 when the closing price on The Nasdaq Stock Market was $17.48 per share. Of the $35.0 million aggregate purchase price paid, $24.8 million was allocated to our stock purchase and was recorded within long term investments and $10.2 million, representing premium paid on the purchase, was allocated to research and development expense on the consolidated statement of operations for the year ended December 31, 2021. The fair market value of our long term investment in Syndax as of March 31, 2022 and December 31, 2021 was $24.7 million and $31.1 million. As of March 31, 2022, we owned approximately 3% of the outstanding shares of Syndax common stock.

We intend to hold the investment in Syndax for the foreseeable future and therefore, are accounting for our shares held in Syndax at fair value whereby the investment is marked to market through earnings in each reporting period. Given our intent to hold the investment for the foreseeable future, we have classified the investment within long term investments on the accompanying condensed consolidated balance sheets. For the three months ended March 31, 2022, we recorded an unrealized loss of $6.4 million based on the change in fair value of Syndax’s common stock during the period.

Note 10.     Stock compensation

We recorded $43.8 million and $47.3 million, respectively, of stock compensation expense on the condensed consolidated statements of operations for the three months ended March 31, 2022 and 2021. Stock compensation expense included within our condensed consolidated statements of operations for the three months ended March 31, 2022 and 2021 included research and development expense of $26.3 million and $29.9 million, respectively. Stock compensation expense included within our condensed consolidated statements of operations for the three months ended March 31, 2022 and 2021 also included selling, general and administrative expense of $16.9 million and $17.2 million, respectively. Stock compensation expense included within our condensed consolidated statements of operations for the three months ended March 31, 2022 and 2021 also included cost of product revenues of $0.6 million and $0.2 million, respectively.

We utilized the Black-Scholes valuation model for estimating the fair value of the stock compensation granted for options, with the following weighted-average assumptions:

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The risk-free interest rate is derived from the U.S. Federal Reserve rate in effect at the time of grant. The expected life calculation is based on the observed and expected time to the exercise of options by our employees based on historical exercise patterns for similar type options. Expected volatility is based on the historical volatility of our common stock over the period commensurate with the expected life of the options. A dividend yield of zero is assumed based on the fact that we have never paid cash dividends and have no present intention to pay cash dividends. Nonemployee awards are measured on the grant date by estimating the fair value of the equity instruments to be issued using the expected term, similar to our employee awards.

Option activity under our 2010 Stock Incentive Plan (the “2010 Stock Plan”) was as follows:

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Our annual stock option grants generally have a 10-year term and vest over four years, with 25% vesting after one year and the remainder vesting in 36 equal monthly installments.

Restricted stock unit (“RSU”) and performance share (“PSU”) award activity under the 2010 Stock Plan was as follows:

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RSUs and PSUs are granted to our employees at the share price on the date of grant. Each RSU represents the right to acquire one share of our common stock. Each RSU granted in connection with our annual equity awards will vest 25% annually over four years, while each RSU granted as outstanding merit awards or as part of retention award programs will vest in a single installment at the end of four years.

We grant PSUs with performance and/or service-based milestones with graded and/or cliff vesting over three to four years. The shares of our common stock into which each PSU may convert is subject to a multiplier based on the level at which the financial, developmental and market performance conditions are achieved over the service period. Compensation expense for PSUs with financial and developmental performance conditions is recorded over the estimated service period for each milestone when the performance conditions are deemed probable of achievement. For PSUs containing performance conditions which were not deemed probable of achievement, no stock compensation expense is recorded. Compensation expense for PSUs with market performance conditions is calculated using a Monte Carlo simulation model as of the date of grant and recorded over the requisite service period. For the three months ended March 31, 2022 and 2021, we recorded $1.8 million and $2.6 million, respectively, of stock compensation expense for PSUs on our condensed consolidated statements of operations.

The following table summarizes our shares available for grant under the 2010 Stock Plan. Each RSU and PSU grant reduces the available share pool by 2 shares.

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Based on our historical experience of employee turnover, we have assumed an annualized forfeiture rate of 5% for our options, RSUs and PSUs. Under the true-up provisions of the stock compensation guidance, we will record additional expense if the actual forfeiture rate is lower than we estimated, and will record a recovery of prior expense if the actual forfeiture is higher than we estimated.

Total compensation cost of options granted but not yet vested, as of March 31, 2022, was $68.0 million, which is expected to be recognized over the weighted average period of approximately 1.2 years. Total compensation cost of RSUs granted but not yet vested, as of March 31, 2022, was $153.8 million, which is expected to be recognized over the weighted average period of approximately 1.9 years.  Total compensation cost of PSUs granted but not yet vested, as of March 31, 2022, was $25.1 million, which is expected to be recognized over the weighted average period of 1.6 years, should the underlying performance conditions be deemed probable of achievement.

Note 9.     Accrued and other current liabilities

Accrued and other current liabilities consisted of the following (in thousands):

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Our inventory balance consists of the following (in thousands):