Partnerships	6 Months Ended
Jun. 30, 2024
Collaboration And License Agreement [Abstract]
Partnerships	8. Partnerships Asset Purchase Agreement with Ono Pharmaceutical Co., Ltd. On December 5, 2022, the Company and Ono, a Japan kabushiki kaisha, entered into an Asset Purchase Agreement pursuant to which the Company granted Ono the exclusive right, but not the obligation, to acquire the Company’s rights to itolizumab (the Option). These rights include all therapeutic indications and the rights to commercialize itolizumab in the United States, Canada, Australia, and New Zealand. In exchange for the Option, Ono paid the Company a one-time, upfront payment of an amount equal to JPY 3.5 billion, or $26.4 million. If Ono exercises the Option, Ono will pay the Company a one-time payment of an amount equal to JPY 5.0 billion, or approximately $35.0 million based on the currency exchange rate quoted by MUFG Bank, Ltd. on August 5, 2024. The Company is also eligible to receive up to $101.4 million upon the achievement of certain clinical, regulatory and commercialization milestones as well as continued reimbursement of itolizumab-related expenses and a markup on full time equivalent costs. The Company is responsible for conducting all research and development of itolizumab, which is being funded by Ono on a quarterly basis from July 1, 2022, through the option period. Unless terminated early, the option period will expire 90 days following the delivery of topline data from the EQUALISE clinical study in lupus nephritis (LN) and the results of the interim analysis from the Phase 3 EQUATOR clinical study in aGVHD. In April 2024, the Company delivered topline data from the EQUALISE clinical study in LN to Ono, and on August 1, 2024 we delivered the results of the interim analysis from the Phase 3 EQUATOR clinical study in aGVHD to Ono, which results in the expiration of Ono's option period on October 30, 2024. The Asset Purchase Agreement can be terminated at any time by Ono upon written notice, provided that in limited circumstances Ono will be obligated to continue to reimburse the Company for research and development costs and expenses of itolizumab for a certain period of time following such termination. If Ono does not timely exercise its Option, the Asset Purchase Agreement and the Option will automatically terminate. The Asset Purchase Agreement also contains customary termination rights for both parties for material breach and an outside date (subject to limited adjustments) that permits either party to terminate the Asset Purchase Agreement if the closing has not occurred by December 31, 2025. The Asset Purchase Agreement contains customary representations and warranties with respect to both the Company and Ono. Additionally, the Company is subject to customary obligations and covenants, including affirmative and negative operating covenants on the Company with respect to its business as it applies to the development and exploitation of itolizumab, exclusivity obligations that prohibit the Company, except in limited circumstances, including in connection with the sale of the Company, from pursuing a direct or indirect sale, license or other disposition of all or any portion of the Company's itolizumab program or any of the assets to be purchased pursuant to the Asset Purchase Agreement and indemnification obligations, which, except in limited circumstances, are subject to customary caps and deductibles. The Company applied ASC 808, Collaborative Arrangements, to the Asset Purchase Agreement and determined that the agreement is applicable to such guidance. The Company concluded that Ono represented a customer and applied relevant guidance from ASC 606, Revenue Recognition, (ASC 606) to evaluate the appropriate accounting for the Asset Purchase Agreement. In accordance with this guidance, the Company identified its performance obligations, including its grant of a license to Ono to certain of its intellectual property subject to certain conditions and the conduct of research and development services. The Company determined that its grant of a license to Ono to certain of its intellectual property subject to certain conditions was not distinct from other performance obligations because such grant is dependent on the conduct and results of the research and development services. Accordingly, the Company determined that all performance obligations should be accounted for as one combined performance obligation, and that the combined performance obligation is transferred over the expected term of the conduct of the research and development services. The Company also assessed, in connection with the upfront and non-creditable payment of JPY 3.5 billion or $25.8 million, invoiced on December 5, 2022, that there was not a significant financing component in the Asset Purchase Agreement. The Company received payment of $26.4 million related to this upfront payment in December 2022 which included a foreign currency realized gain of $0.6 million as the initial invoice for the upfront payment was denominated in JPY. The Company also assessed the effects of any variable elements under the Asset Purchase Agreement. Such assessment evaluated, among other things, the likelihood of receiving (i) option fees and (ii) various clinical, regulatory and commercial milestone payments. Based on its assessment, the Company concluded that, based on the likelihood of these variable components occurring, there was not a significant variable element included in the transaction price. Accordingly, the Company has not assigned a transaction price to any option fees or milestone payments under the Asset Purchase Agreement given the substantial uncertainty related to their achievement. In accordance with ASC 606, the Company determined that the initial transaction price under the Asset Purchase Agreement equals $102.6 million, consisting of the upfront and non-creditable payment of $25.8 million and the aggregate estimated research and development funding of $76.8 million over the estimated option period. The upfront payment of $25.8 million was recorded as deferred revenue and is being recognized as revenue over time in conjunction with the Company’s conduct of research and development services as the research and development services are the primary component of the combined performance obligations. Revenue associated with the upfront payment will be recognized based on actual research and development costs incurred as a percentage of the estimated total research and development costs to be incurred over the expected term of the option period. Reimbursable research and development costs will be recognized as revenue as incurred. The Company’s policy is to periodically review the estimated aggregate research and development funding over the estimated option period when facts and circumstances change. The Company’s review in the second quarter of 2024 resulted in a revised estimate of the aggregate research and development funding over the estimated option period from $76.8 million to $70.8 million and an update to the transaction price from $102.6 million to $96.6 million. The lower estimate of the aggregate research and development funding is primarily driven by a shortening of the option period as a result of delivery of the interim analysis of the EQUATOR clinical study to Ono earlier than previously anticipated. The effect of this change in estimate was to increase revenue related to the amortization of the upfront payment in each of the three and six-month periods ended June 30, 2024 by $1.3 million. The Company recognized revenue of $13.9 million and $24.5 million under the Asset Purchase Agreement during the three and six months ended June 30, 2024, respectively. The Company recognized revenue of $9.1 million and $18.0 million under the Asset Purchase Agreement during the three and six months ended June 30, 2023, respectively. Such revenue was comprised of $9.2 million and $17.2 million associated with development funding for the three and six months ended June 30, 2024, respectively, and $4.7 million and $7.3 million associated with the amortization of the upfront payment for the three and six months ended June 30, 2024, respectively. As of June 30, 2024, aggregate deferred revenue related to the Asset Purchase Agreement was $8.4 million, which was classified as short-term on the condensed consolidated balance sheet. As of June 30, 2024, the Company has received $53.1 million in cash related to aggregate development funding from Ono. Biocon Collaboration and License Agreement In May 2017, the Company entered into a collaboration and license agreement (which was amended in September 2018, April 2019, December 2019, April 2021 and November 2022), clinical supply agreement, investor rights agreement, and common stock purchase agreement (collectively License Agreements) with Biocon SA (subsequently assigned to Biocon Limited, or together, Biocon). Pursuant to the License Agreements, Biocon granted the Company an exclusive license to develop, make, have made, use, sell, have sold, offer for sale, import and otherwise exploit itolizumab and any pharmaceutical composition or preparation containing or comprising itolizumab that uses Biocon technology or Biocon know-how (collectively a Biocon Product) in the United States, Canada, Australia and New Zealand (collectively Equillium Territory). The Company also has the right to sublicense through multiple tiers to third parties, provided such sublicenses comply with the terms of the License Agreements and the Company provides Biocon a copy of each sublicense agreement within 30 days of execution. If the Company grants a third party a sublicense of its rights to develop and commercialize Biocon Products in Australia or New Zealand, the Company will be required to pay Biocon a high double-digit percentage of any upfront payment the Company receives from such sublicensee for such sublicense, as well as a high double-digit percentage of any additional payments the Company receives from such sublicensee for such sublicense, including but not limited to royalty payments on net sales of Biocon Products by such sublicensee. Under the License Agreements, the Company granted back to Biocon a license to use its technology and know-how related to itolizumab and Biocon Products in certain countries outside of the Equillium Territory. Pursuant to the License Agreements, Biocon agreed to be the Company’s exclusive supplier of itolizumab clinical drug product. Biocon will provide clinical drug product at no cost for up to three concurrent orphan indications until the Company’s first U.S. regulatory approval and all other clinical drug product at Biocon’s cost. In consideration of the rights granted to the Company by Biocon, the Company issued Biocon a total of 2,316,134 shares of its common stock. In addition, the Company is obligated to pay Biocon up to an aggregate of $30 million in regulatory milestone payments upon the achievement of certain regulatory approvals and up to an aggregate of $565 million in sales milestone payments upon the achievement of first commercial sale of product and specified levels of product sales. The Company is also required to pay royalties on tiers of aggregate annual net sales of Biocon Products by the Company, the Company's affiliates and the Company's sublicensees in the United States and Canada at percentages from the mid-single digits to sub-teen double-digits and on tiers of aggregate annual net sales of Biocon Products by the Company and the Company's affiliates (but not the Company's sublicensees) in Australia and New Zealand, in each case, subject to adjustments in certain circumstances. Biocon is also required to pay the Company royalties at comparable percentages for sales of itolizumab (EQ001) outside of the Equillium Territory if the approvals in such geographies included or referenced the Company’s data including data from certain of the Company’s clinical studies, subject to adjustments in certain circumstances. Should Ono exercise its option to acquire the Company's rights to itolizumab (EQ001), as described below, the aforementioned milestone payments and royalties potentially owed to Biocon would become Ono’s responsibility, and the potential royalties on sales of itolizumab outside of the Equillium Territory would be become Ono’s right. Under the License Agreements, net sales are calculated on a country-by-country basis and are subject to adjustments, including whether the Biocon Product is sold in the form of a combination product. As of June 30, 2024, the Company has not made or received payments in connection with the milestones or royalties within the agreement.

Partnerships

6 Months Ended

Jun. 30, 2024

Collaboration And License Agreement [Abstract]

8. Partnerships

Asset Purchase Agreement with Ono Pharmaceutical Co., Ltd.

On December 5, 2022, the Company and Ono, a Japan kabushiki kaisha, entered into an Asset Purchase Agreement pursuant to which the Company granted Ono the exclusive right, but not the obligation, to acquire the Company’s rights to itolizumab (the Option). These rights include all therapeutic indications and the rights to commercialize itolizumab in the United States, Canada, Australia, and New Zealand. In exchange for the Option, Ono paid the Company a one-time, upfront payment of an amount equal to JPY 3.5 billion, or $26.4 million.

If Ono exercises the Option, Ono will pay the Company a one-time payment of an amount equal to JPY 5.0 billion, or approximately $35.0 million based on the currency exchange rate quoted by MUFG Bank, Ltd. on August 5, 2024. The Company is also eligible to receive up to $101.4 million upon the achievement of certain clinical, regulatory and commercialization milestones as well as continued reimbursement of itolizumab-related expenses and a markup on full time equivalent costs.

The Company is responsible for conducting all research and development of itolizumab, which is being funded by Ono on a quarterly basis from July 1, 2022, through the option period. Unless terminated early, the option period will expire 90 days following the delivery of topline data from the EQUALISE clinical study in lupus nephritis (LN) and the results of the interim analysis from the Phase 3 EQUATOR clinical study in aGVHD. In April 2024, the Company delivered topline data from the EQUALISE clinical study in LN to Ono, and on August 1, 2024 we delivered the results of the interim analysis from the Phase 3 EQUATOR clinical study in aGVHD to Ono, which results in the expiration of Ono's option period on October 30, 2024.

The Asset Purchase Agreement can be terminated at any time by Ono upon written notice, provided that in limited circumstances Ono will be obligated to continue to reimburse the Company for research and development costs and expenses of itolizumab for a certain period of time following such termination. If Ono does not timely exercise its Option, the Asset Purchase Agreement and the Option will automatically terminate. The Asset Purchase Agreement also contains customary termination rights for both parties for material breach and an outside date (subject to limited adjustments) that permits either party to terminate the Asset Purchase Agreement if the closing has not occurred by December 31, 2025.

The Asset Purchase Agreement contains customary representations and warranties with respect to both the Company and Ono. Additionally, the Company is subject to customary obligations and covenants, including affirmative and negative operating covenants on the Company with respect to its business as it applies to the development and exploitation of itolizumab, exclusivity obligations that prohibit the Company, except in limited circumstances, including in connection with the sale of the Company, from pursuing a direct or indirect sale, license or other disposition of all or any portion of the Company's itolizumab program or any of the assets to be purchased pursuant to the Asset Purchase Agreement and indemnification obligations, which, except in limited circumstances, are subject to customary caps and deductibles.

The Company applied ASC 808, Collaborative Arrangements, to the Asset Purchase Agreement and determined that the agreement is applicable to such guidance. The Company concluded that Ono represented a customer and applied relevant guidance from ASC 606, Revenue Recognition, (ASC 606) to evaluate the appropriate accounting for the Asset Purchase Agreement. In accordance with this guidance, the Company identified its performance obligations, including its grant of a license to Ono to certain of its intellectual property subject to certain conditions and the conduct of research and development services. The Company determined that its grant of a license to Ono to certain of its intellectual property subject to certain conditions was not distinct from other performance obligations because such grant is dependent on the conduct and results of the research and development services. Accordingly, the Company determined that all performance obligations should be accounted for as one combined performance obligation, and that the combined performance obligation is transferred over the expected term of the conduct of the research and development services.

The Company also assessed, in connection with the upfront and non-creditable payment of JPY 3.5 billion or $25.8 million, invoiced on December 5, 2022, that there was not a significant financing component in the Asset Purchase Agreement. The Company received payment of $26.4 million related to this upfront payment in December 2022 which included a foreign currency realized gain of $0.6 million as the initial invoice for the upfront payment was denominated in JPY.

The Company also assessed the effects of any variable elements under the Asset Purchase Agreement. Such assessment evaluated, among other things, the likelihood of receiving (i) option fees and (ii) various clinical, regulatory and commercial milestone payments. Based on its assessment, the Company concluded that, based on the likelihood of these variable components occurring, there was not a significant variable element included in the transaction price. Accordingly, the Company has not assigned a transaction price to any option fees or milestone payments under the Asset Purchase Agreement given the substantial uncertainty related to their achievement.

In accordance with ASC 606, the Company determined that the initial transaction price under the Asset Purchase Agreement equals $102.6 million, consisting of the upfront and non-creditable payment of $25.8 million and the aggregate estimated research and development funding of $76.8 million over the estimated option period. The upfront payment of $25.8 million was recorded as deferred revenue and is being recognized as revenue over time in conjunction with the Company’s conduct of research and development services as the research and development services are the primary component of the combined performance obligations. Revenue associated with the upfront payment will be recognized based on actual research and development costs incurred as a percentage of the estimated total research and development costs to be incurred over the expected term of the option period. Reimbursable research and development costs will be recognized as revenue as incurred.

The Company’s policy is to periodically review the estimated aggregate research and development funding over the estimated option period when facts and circumstances change. The Company’s review in the second quarter of 2024 resulted in a revised estimate of the aggregate research and development funding over the estimated option period from $76.8 million to $70.8 million and an update to the transaction price from $102.6 million to $96.6 million. The lower estimate of the aggregate research and development funding is primarily driven by a shortening of the option period as a result of delivery of the interim analysis of the EQUATOR clinical study to Ono earlier than previously anticipated. The effect of this change in estimate was to increase revenue related to the amortization of the upfront payment in each of the three and six-month periods ended June 30, 2024 by $1.3 million.

The Company recognized revenue of $13.9 million and $24.5 million under the Asset Purchase Agreement during the three and six months ended June 30, 2024, respectively. The Company recognized revenue of $9.1 million and $18.0 million under the Asset Purchase Agreement during the three and six months ended June 30, 2023, respectively. Such revenue was comprised of $9.2 million and $17.2 million associated with development funding for the three and six months ended June 30, 2024, respectively, and $4.7 million and $7.3 million associated with the amortization of the upfront payment for the three and six months ended June 30, 2024, respectively. As of June 30, 2024, aggregate deferred revenue related to the Asset Purchase Agreement was $8.4 million, which was classified as short-term on the condensed consolidated balance sheet.

As of June 30, 2024, the Company has received $53.1 million in cash related to aggregate development funding from Ono.

Biocon Collaboration and License Agreement

In May 2017, the Company entered into a collaboration and license agreement (which was amended in September 2018, April 2019, December 2019, April 2021 and November 2022), clinical supply agreement, investor rights agreement, and common stock purchase agreement (collectively License Agreements) with Biocon SA (subsequently assigned to Biocon Limited, or together, Biocon). Pursuant to the License Agreements, Biocon granted the Company an exclusive license to develop, make, have made, use, sell, have sold, offer for sale, import and otherwise exploit itolizumab and any pharmaceutical composition or preparation containing or comprising itolizumab that uses Biocon technology or Biocon know-how (collectively a Biocon Product) in the United States, Canada, Australia and New Zealand (collectively Equillium Territory). The Company also has the right to sublicense through multiple tiers to third parties, provided such sublicenses comply with the terms of the License Agreements and the Company provides Biocon a copy of each sublicense agreement within 30 days of execution. If the Company grants a third party a sublicense of its rights to develop and commercialize Biocon Products in Australia or New Zealand, the Company will be required to pay Biocon a high double-digit percentage of any upfront payment the Company receives from such sublicensee for such sublicense, as well as a high double-digit percentage of any additional payments the Company receives from such sublicensee for such sublicense, including but not limited to royalty payments on net sales of Biocon Products by such sublicensee. Under the License Agreements, the Company granted back to Biocon a license to use its technology and know-how related to itolizumab and Biocon Products in certain countries outside of the Equillium Territory. Pursuant to the License Agreements, Biocon agreed to be the Company’s exclusive supplier of itolizumab clinical drug product. Biocon will provide clinical drug product at no cost for up to three concurrent orphan indications until the Company’s first U.S. regulatory approval and all other clinical drug product at Biocon’s cost.

In consideration of the rights granted to the Company by Biocon, the Company issued Biocon a total of 2,316,134 shares of its common stock.

In addition, the Company is obligated to pay Biocon up to an aggregate of $30 million in regulatory milestone payments upon the achievement of certain regulatory approvals and up to an aggregate of $565 million in sales milestone payments upon the achievement of first commercial sale of product and specified levels of product sales. The Company is also required to pay royalties on tiers of aggregate annual net sales of Biocon Products by the Company, the Company's affiliates and the Company's sublicensees in the United States and Canada at percentages from the mid-single digits to sub-teen double-digits and on tiers of aggregate annual net sales of Biocon Products by the Company and the Company's affiliates (but not the Company's sublicensees) in Australia and New Zealand, in each case, subject to adjustments in certain circumstances. Biocon is also required to pay the Company royalties at comparable percentages for sales of itolizumab (EQ001) outside of the Equillium Territory if the approvals in such geographies included or referenced the Company’s data including data from certain of the Company’s clinical studies, subject to adjustments in certain circumstances. Should Ono exercise its option to acquire the Company's rights to itolizumab (EQ001), as described below, the aforementioned milestone payments and royalties potentially owed to Biocon would become Ono’s responsibility, and the potential royalties on sales of itolizumab outside of the Equillium Territory would be become Ono’s right. Under the License Agreements, net sales are calculated on a country-by-country basis and are subject to adjustments, including whether the Biocon Product is sold in the form of a combination product. As of June 30, 2024, the Company has not made or received payments in connection with the milestones or royalties within the agreement.