Note 4 - Collaboration and License Agreement	6 Months Ended
Jun. 30, 2021
Notes to Financial Statements
Collaborative Arrangement Disclosure [Text Block]	4. Collaboration and License Agreement On November 6, 2020, the Company entered into a collaboration and license agreement (the “Agreement”) with 3D Medicines, whereby the Company granted 3D Medicines an exclusive license to develop and commercialize products that contain AVB-500 as the sole drug substance, for the diagnosis, treatment or prevention of human oncological diseases, in mainland China, Taiwan, Hong Kong and Macau (the “Territory”). Under the terms of the Agreement, the Company was paid $18 million and is eligible to receive from 3D Medicines cash payments of up to an aggregate of $207 million in clinical development, regulatory and commercial milestone payments. There can be no guarantee that any such milestones will in fact be met. The Company is obligated to make certain payments to The Board of Trustees of the Leland Stanford Junior University (“Stanford”) based on certain amounts received from 3D Medicines under the Agreement pursuant to the existing license agreement by and between the Company and Stanford, dated January 25, 2012, and as amended to date. For the six months ended June 30, 2021, the Company has paid amounts due to Stanford of $0.4 million. For the year ended December 31, 2020, the Company received payments of $12 million from 3D Medicines and during the three and six months ended June 30, 2021, the Company received payment of $6 million. The Company will also be entitled to receive tiered royalties ranging from low double digits to mid-teens on sales in the Territory, if any, of products containing AVB-500. Royalties are payable with respect to each jurisdiction in the Territory until the latest to occur of: (i) the last-to-expire of specified patent rights in such jurisdiction in the Territory; or (ii) ten (10) years after the first commercial sale of a product in such jurisdiction in the Territory. In addition, royalties payable under the Agreement will be subject to reduction on account of generic competition under certain specified conditions, with any such reductions capped at certain percentages of the amounts otherwise payable during the applicable royalty payment period. Under the terms and conditions of the Agreement, 3D Medicines will be solely responsible for the development and commercialization of licensed products in the Territory. If either the Company or 3D Medicines materially breaches the Agreement and does not cure such breach, the non-breaching party may terminate the Agreement in its entirety. Either party may also terminate the Agreement, upon written notice, if the other party files for bankruptcy, is dissolved or has a receiver appointed for substantially all of its property. The Company may terminate the Agreement if 3D Medicines, its affiliates or its sublicensees challenges the validity or enforceability of any of the Company’s patents covering any of the licensed compounds or products or ceases substantially all development and commercialization of licensed products in the Territory for a specified period, subject to certain exceptions. 3D Medicines may also terminate the Agreement for convenience provided certain notice is provided to the Company. The Agreement contemplates that the Company will enter into ancillary arrangements with 3D Medicines, including a clinical supply agreement and a manufacturing technology transfer agreement. The Company assessed this arrangement in accordance with ASC 606 and identified the following performance obligations: 1) license to intellectual property, AVB-500, and 2) research and development services, including conducting clinical trials. The Company concluded that each of these performance obligations were distinct because 3D Medicines can benefit from the good or service either on its own or together with other resources that are readily available, and each performance obligation is separately identifiable from other promises within the contract. The estimated total transaction price was allocated between performance obligations based on their relative standalone selling prices. The Company uses a discounted cash flow approach and an expected cost plus a margin approach to estimate the standalone selling price for the performance obligations. The Company allocated the $18.0 million transaction price of the upfront payments as such: $9.6 million to the research and development services performance obligation and $8.4 million to the license to intellectual property. Accordingly, the Company will recognize revenue related to the allocable research and development services obligation on a proportional performance basis as the underlying services are performed pursuant to the current development plan which is commensurate with the period and consistent with the pattern over which the Company’s research and development services obligation is satisfied. The Company will recognize the revenue related to the license to intellectual property at a point in time. This is due to the fact that the license was determined to be a functional license due to the current stage in development of AVB-500. AVB-500 has been developed, dosing levels have already been determined and the drug is currently in a Phase 3 clinical trial related to its PROC ovarian cancer trial. As of June 30, 2021, the Company has achieved a clinical milestone, no other clinical or regulatory milestones have been assessed as probable of being reached and thus have been fully constrained. The Company continues to re-assess the probability of achievement of future milestones at the end of each reporting period. The Company recognized in revenue $3.8 and $4.0 million related to the research and development services for the three and six months ended June 30, 2021 including $2.8 million related to the license to the intellectual property for the three and six months ended June 30, 2021. During the three months ended June 30, 2021, the Company adjusted its estimate of the overall transaction price as a result of the achievement of the $6 million development milestone. This adjustment resulted in a cumulative catch-up recorded to revenue in the three months ended June 30, 2021 of approximately $3.2 million. As of June 30, 2021, the Company had a contract liability balance of $8.3 million of which $4.0 million is classified as current and $4.3 million is classified as long-term, consisting of deferred revenue related to a portion of the payment received from 3D Medicines. Revenue recognized from the deferred revenue balance as of December 30, 2020 was $0.8 for the six months ended June 30, 2021. The service period for the future research and development services is expected to occur over the next 2 years.

Note 4 - Collaboration and License Agreement

6 Months Ended

Jun. 30, 2021

Collaborative Arrangement Disclosure [Text Block]

4. Collaboration and License Agreement

On November 6, 2020, the Company entered into a collaboration and license agreement (the “Agreement”) with 3D Medicines, whereby the Company granted 3D Medicines an exclusive license to develop and commercialize products that contain AVB-500 as the sole drug substance, for the diagnosis, treatment or prevention of human oncological diseases, in mainland China, Taiwan, Hong Kong and Macau (the “Territory”).

Under the terms of the Agreement, the Company was paid $18 million and is eligible to receive from 3D Medicines cash payments of up to an aggregate of $207 million in clinical development, regulatory and commercial milestone payments. There can be no guarantee that any such milestones will in fact be met. The Company is obligated to make certain payments to The Board of Trustees of the Leland Stanford Junior University (“Stanford”) based on certain amounts received from 3D Medicines under the Agreement pursuant to the existing license agreement by and between the Company and Stanford, dated January 25, 2012, and as amended to date. For the six months ended June 30, 2021, the Company has paid amounts due to Stanford of $0.4 million. For the year ended December 31, 2020, the Company received payments of $12 million from 3D Medicines and during the three and six months ended June 30, 2021, the Company received payment of $6 million.

The Company will also be entitled to receive tiered royalties ranging from low double digits to mid-teens on sales in the Territory, if any, of products containing AVB-500. Royalties are payable with respect to each jurisdiction in the Territory until the latest to occur of: (i) the last-to-expire of specified patent rights in such jurisdiction in the Territory; or (ii) ten (10) years after the first commercial sale of a product in such jurisdiction in the Territory. In addition, royalties payable under the Agreement will be subject to reduction on account of generic competition under certain specified conditions, with any such reductions capped at certain percentages of the amounts otherwise payable during the applicable royalty payment period.

Under the terms and conditions of the Agreement, 3D Medicines will be solely responsible for the development and commercialization of licensed products in the Territory.

If either the Company or 3D Medicines materially breaches the Agreement and does not cure such breach, the non-breaching party may terminate the Agreement in its entirety. Either party may also terminate the Agreement, upon written notice, if the other party files for bankruptcy, is dissolved or has a receiver appointed for substantially all of its property. The Company may terminate the Agreement if 3D Medicines, its affiliates or its sublicensees challenges the validity or enforceability of any of the Company’s patents covering any of the licensed compounds or products or ceases substantially all development and commercialization of licensed products in the Territory for a specified period, subject to certain exceptions. 3D Medicines may also terminate the Agreement for convenience provided certain notice is provided to the Company.

The Agreement contemplates that the Company will enter into ancillary arrangements with 3D Medicines, including a clinical supply agreement and a manufacturing technology transfer agreement.

The Company assessed this arrangement in accordance with ASC 606 and identified the following performance obligations: 1) license to intellectual property, AVB-500, and 2) research and development services, including conducting clinical trials. The Company concluded that each of these performance obligations were distinct because 3D Medicines can benefit from the good or service either on its own or together with other resources that are readily available, and each performance obligation is separately identifiable from other promises within the contract.

The estimated total transaction price was allocated between performance obligations based on their relative standalone selling prices. The Company uses a discounted cash flow approach and an expected cost plus a margin approach to estimate the standalone selling price for the performance obligations. The Company allocated the $18.0 million transaction price of the upfront payments as such: $9.6 million to the research and development services performance obligation and $8.4 million to the license to intellectual property. Accordingly, the Company will recognize revenue related to the allocable research and development services obligation on a proportional performance basis as the underlying services are performed pursuant to the current development plan which is commensurate with the period and consistent with the pattern over which the Company’s research and development services obligation is satisfied. The Company will recognize the revenue related to the license to intellectual property at a point in time. This is due to the fact that the license was determined to be a functional license due to the current stage in development of AVB-500. AVB-500 has been developed, dosing levels have already been determined and the drug is currently in a Phase 3 clinical trial related to its PROC ovarian cancer trial. As of June 30, 2021, the Company has achieved a clinical milestone, no other clinical or regulatory milestones have been assessed as probable of being reached and thus have been fully constrained. The Company continues to re-assess the probability of achievement of future milestones at the end of each reporting period.

The Company recognized in revenue $3.8 and $4.0 million related to the research and development services for the three and six months ended June 30, 2021 including $2.8 million related to the license to the intellectual property for the three and six months ended June 30, 2021. During the three months ended June 30, 2021, the Company adjusted its estimate of the overall transaction price as a result of the achievement of the $6 million development milestone. This adjustment resulted in a cumulative catch-up recorded to revenue in the three months ended June 30, 2021 of approximately $3.2 million. As of June 30, 2021, the Company had a contract liability balance of $8.3 million of which $4.0 million is classified as current and $4.3 million is classified as long-term, consisting of deferred revenue related to a portion of the payment received from 3D Medicines. Revenue recognized from the deferred revenue balance as of December 30, 2020 was $0.8 for the six months ended June 30, 2021. The service period for the future research and development services is expected to occur over the next 2 years.