License Agreement	12 Months Ended
Dec. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
License Agreement	Everest Collaboration In September 2023, the Company entered into a Collaboration and License Agreement (the “Everest License Agreement”) with Everest Medicines II (HK) Limited (“Everest”) pursuant to which, among other things, the Company granted to Everest an exclusive license to develop and commercialize one or more products containing the Company’s proprietary compound, zetomipzomib (the “Products”), in the licensed field in the Greater China region (Mainland China, Taiwan, Hong Kong and Macau), South Korea, Singapore, Malaysia, Thailand, Indonesia, Vietnam and the Philippines (the “Territory”). The licensed field includes all uses other than the diagnosis or treatment in humans of cancerous or pre-cancerous diseases or conditions. During the PALIZADE trial, Everest contributed their local regulatory and clinical trial expertise and were responsible for study costs in the Territory. Everest Medicines Limited is also a party to the Everest License Agreement solely for limited purposes, including to guarantee the performance by Everest of its obligations under the Everest License Agreement. Under the terms of the Everest License Agreement, the Company received one-time, irrecoverable, non-refundable and non-creditable upfront payment of $7.0 million in October 2023 and is entitled to receive certain variable payments for manufacturing supply services and milestone payments upon achievement of certain development, regulatory and commercial milestone events, for total potential milestone payments of up to $125.5 million. In addition, Everest will pay to the Company tiered royalties on the net sales of the Products in the Territory during the term of the Everest License Agreement ranging from the single digit to the low-teens, subject to certain reductions for patent expiration, generic competition and payments for licenses to third-party patents. The term of the Everest License Agreement will continue on a market-by-market basis until expiration of the relevant royalty term of the Products, unless terminated earlier. Everest has the right to terminate the Everest License Agreement for convenience at any time following the October 2024 termination of the PALIZADE clinical trial. The Company may terminate the Everest License Agreement if Everest challenges the Company’s patents or fails to perform any development or commercialization activities for a continuous period of more than twelve (12) months, subject to certain exceptions. In addition, either party may terminate the Everest License Agreement for the other party’s uncured breach or insolvency, and the Everest License Agreement will automatically terminate in the event of termination of the Company’s exclusive license agreement with Onyx Therapeutics, Inc. Under the terms of the Everest License Agreement, at the election of Everest, the Company may manufacture and provide clinical supply to Everest to use in development and commercialization in the Territory at the fully burdened manufacturing cost plus specified margins, as defined within the Everest License Agreement. Certain of these provisions were determined to be options to acquire additional goods or services at a price that approximates the stand-alone selling price for that good or service and therefore do not represent material rights, or separate performance obligations, within the context of the Everest License Agreement. The Company evaluated the Everest License Agreement and determined it was within the scope of ASC 606. The transaction price was determined to consist of the upfront payment of $7.0 million. License of Intellectual Property. The license to the Company’s intellectual property and associated know-how represents a distinct performance obligation. The license and associated know-how was transferred to Everest in the third quarter of 2023 to satisfy this performance obligation. The Company allocated the full transaction price to the license of the Company’s intellectual property and accordingly recognized collaboration revenue of $7.0 million during the year ended December 31, 2023. Milestone Payments. The potential development, regulatory and commercial milestone payments are paid upon achievement of certain milestones as defined in the Everest License Agreement. It was determined that their achievement is highly dependent on factors outside of the Company’s control. These payments have been fully constrained until the Company concludes that achievement of the milestone is probable and that recognition of revenue related to the milestone will not result in a significant reversal in amounts recognized in future periods and, as such, have been excluded from the transaction price. At the end of each subsequent reporting period, the Company will re-evaluate the probability of achievement of each milestone and any related constraint and, if necessary, adjust its estimate of the overall transaction price. As of December 31, 2025, the Company has not recognized any revenue associated with development, regulatory and commercial milestones. Royalties. Any consideration related to royalties will be recognized if and when the related sales occur, as they were determined to relate predominantly to the license granted to Everest and, therefore, have also been excluded from the transaction price. No royalty revenue was recognized as of December 31, 2025. In July 2024, the Company amended the Everest License Agreement to modify a development milestone and adjust certain payment terms relating to Everest’s responsibility for PALIZADE study costs in the Territory. As of December 31, 2025, the Company had an unbilled receivable of $1.7 million, representing reimbursement for payments made by the Company that is yet to be billed or due. The unbilled receivable was included in prepaid and other current assets in the Company’s Consolidated Balance Sheet as of December 31, 2025 and subsequently collected in January 2026. In connection with the cost-sharing arrangement with Everest, no contra research and development expense was recognized for the year ended December 31, 2025, and $3.6 million and $1.6 million was recognized as contra research and development expense for the years ended December 31, 2024 and 2023, respectively. License Agreement In June 2015, the Company entered into an exclusive license agreement with Onyx Therapeutics, Inc. (“Onyx”), a wholly owned subsidiary of Amgen, Inc., for a worldwide, exclusive license under certain patents, and a non-exclusive license to certain know-how, in each case controlled by Onyx and relating to the Company’s immunoproteasome program. The Company paid $5.0 million in milestone payments under the Onyx License Agreement in 2023 and may be required to make future payments of up to $167.5 million upon achievement of certain development and commercial milestones for zetomipzomib, as well as royalty payments in the mid to high single digits on future annual net sales, if any.

In September 2023, the Company entered into a Collaboration and License Agreement (the “Everest License Agreement”) with Everest Medicines II (HK) Limited (“Everest”) pursuant to which, among other things, the Company granted to Everest an exclusive license to develop and commercialize one or more products containing the Company’s proprietary compound, zetomipzomib (the “Products”), in the licensed field in the Greater China region (Mainland China, Taiwan, Hong Kong and Macau), South Korea, Singapore, Malaysia, Thailand, Indonesia, Vietnam and the Philippines (the “Territory”). The licensed field includes all uses other than the diagnosis or treatment in humans of cancerous or pre-cancerous diseases or conditions. During the PALIZADE trial, Everest contributed their local regulatory and clinical trial expertise and were responsible for study costs in the Territory. Everest Medicines Limited is also a party to the Everest License Agreement solely for limited purposes, including to guarantee the performance by Everest of its obligations under the Everest License Agreement.

Under the terms of the Everest License Agreement, the Company received one-time, irrecoverable, non-refundable and non-creditable upfront payment of $7.0 million in October 2023 and is entitled to receive certain variable payments for manufacturing supply services and milestone payments upon achievement of certain development, regulatory and commercial milestone events, for total potential milestone payments of up to $125.5 million. In addition, Everest will pay to the Company tiered royalties on the net sales of the Products in the Territory during the term of the Everest License Agreement ranging from the single digit to the low-teens, subject to certain reductions for patent expiration, generic competition and payments for licenses to third-party patents.

The term of the Everest License Agreement will continue on a market-by-market basis until expiration of the relevant royalty term of the Products, unless terminated earlier. Everest has the right to terminate the Everest License Agreement for convenience at any time following the October 2024 termination of the PALIZADE clinical trial. The Company may terminate the Everest License Agreement if Everest challenges the Company’s patents or fails to perform any development or commercialization activities for a continuous period of more than twelve (12) months, subject to certain exceptions. In addition, either party may terminate the Everest License Agreement for the other party’s uncured breach or insolvency, and the Everest License Agreement will automatically terminate in the event of termination of the Company’s exclusive license agreement with Onyx Therapeutics, Inc.

Under the terms of the Everest License Agreement, at the election of Everest, the Company may manufacture and provide clinical supply to Everest to use in development and commercialization in the Territory at the fully burdened manufacturing cost plus specified margins, as defined within the Everest License Agreement. Certain of these provisions were determined to be options to acquire additional goods or services at a price that approximates the stand-alone selling

price for that good or service and therefore do not represent material rights, or separate performance obligations, within the context of the Everest License Agreement. The Company evaluated the Everest License Agreement and determined it was within the scope of ASC 606. The transaction price was determined to consist of the upfront payment of $7.0 million.

License of Intellectual Property. The license to the Company’s intellectual property and associated know-how represents a distinct performance obligation. The license and associated know-how was transferred to Everest in the third quarter of 2023 to satisfy this performance obligation. The Company allocated the full transaction price to the license of the Company’s intellectual property and accordingly recognized collaboration revenue of $7.0 million during the year ended December 31, 2023.

Milestone Payments. The potential development, regulatory and commercial milestone payments are paid upon achievement of certain milestones as defined in the Everest License Agreement. It was determined that their achievement is highly dependent on factors outside of the Company’s control. These payments have been fully constrained until the Company concludes that achievement of the milestone is probable and that recognition of revenue related to the milestone will not result in a significant reversal in amounts recognized in future periods and, as such, have been excluded from the transaction price. At the end of each subsequent reporting period, the Company will re-evaluate the probability of achievement of each milestone and any related constraint and, if necessary, adjust its estimate of the overall transaction price. As of December 31, 2025, the Company has not recognized any revenue associated with development, regulatory and commercial milestones.

Royalties. Any consideration related to royalties will be recognized if and when the related sales occur, as they were determined to relate predominantly to the license granted to Everest and, therefore, have also been excluded from the transaction price. No royalty revenue was recognized as of December 31, 2025.

In July 2024, the Company amended the Everest License Agreement to modify a development milestone and adjust certain payment terms relating to Everest’s responsibility for PALIZADE study costs in the Territory. As of December 31, 2025, the Company had an unbilled receivable of $1.7 million, representing reimbursement for payments made by the Company that is yet to be billed or due. The unbilled receivable was included in prepaid and other current assets in the Company’s Consolidated Balance Sheet as of December 31, 2025 and subsequently collected in January 2026. In connection with the cost-sharing arrangement with Everest, no contra research and development expense was recognized for the year ended December 31, 2025, and $3.6 million and $1.6 million was recognized as contra research and development expense for the years ended December 31, 2024 and 2023, respectively.

In June 2015, the Company entered into an exclusive license agreement with Onyx Therapeutics, Inc. (“Onyx”), a wholly owned subsidiary of Amgen, Inc., for a worldwide, exclusive license under certain patents, and a non-exclusive license to certain know-how, in each case controlled by Onyx and relating to the Company’s immunoproteasome program. The Company paid $5.0 million in milestone payments under the Onyx License Agreement in 2023 and may be required to make future payments of up to $167.5 million upon achievement of certain development and commercial milestones for zetomipzomib, as well as royalty payments in the mid to high single digits on future annual net sales, if any.