Acquisitions	3 Months Ended
Mar. 31, 2021
Business Combinations [Abstract]
Acquisitions	4.Acquisitions Acquisition of TomegaVax In September 2016, the Company entered into an agreement and plan of merger (“TomegaVax Merger Agreement”) to acquire all of the equity interests of TomegaVax. The primary asset purchased in the acquisition was an in-process cytomegalovirus vector-based vaccine platform for use in HBV, HIV, and TB. The acquisition was accounted for as an asset purchase. In connection with the entry into the TomegaVax Merger Agreement, the Company also entered into a letter agreement with TomegaVax (the “TomegaVax Letter Agreement”), which provides for certain payments to TomegaVax’s former stockholders before September 2024, in each case so long as the Company is continuing to pursue the development of the TomegaVax technology. Under the terms of the TomegaVax Letter Agreement, the Company will be required to pay to the former stockholders of TomegaVax milestone payments of up to an aggregate of $30.0 million if the per-share price of the Company’s publicly traded common stock, or implied price per share of the Company’s Series A-1 convertible preferred stock (or common stock upon conversion) upon a certain asset sale, merger or stock sale, is at least $45 (as adjusted in the case of any stock dividend, stock split or other similar recapitalization), with the amount of such payments determined by the share price and the stage of the Company’s clinical development at the time of the relevant event triggering the payment. The share price of the Company’s publicly traded common stock will be determined using the average of the daily volume-weighted average trading price of the Company’s common stock for each trading day during a consecutive 90-day period. The foregoing payments are payable (i) during any date after the completion of an initial public offering by the Company or any successor or affiliate controlling the TomegaVax technology, provided that no payment will be due before the first anniversary of the initial public offering, (ii) upon the sale of all assets related to the TomegaVax technology or (iii) upon a merger or stock sale of the Company or any successor or affiliate controlling the TomegaVax technology, in each case subject to certain conditions with respect to the timing of the payments. The payments under the TomegaVax Letter Agreement can be made in cash or shares of the Company’s common stock, at the discretion of the Company’s board of directors. In February 2021, the Company achieved one of the milestones related to the specified per-share price of its common stock, which resulted in a $10.0 million payable to TomegaVax’s former stockholders within 90 business days, subject to a 90-day grace period at the Company’s option in certain circumstances. The Company determined that the future milestone payments contain net settlement provisions and therefore, they were required to be accounted for as embedded derivatives under the relevant accounting guidance. As of March 31, 2021, the estimated fair value of the embedded derivative was $7.1 million. Acquisition of Humabs In August 2017, the Company acquired all of the outstanding equity of Humabs, a private Swiss company which discovers and develops monoclonal antibodies (“mAbs”) derived from individuals whose immune systems have successfully responded to major diseases. The Company acquired all of Humabs’ rights, title and interest in and to substantially all of the assets of Humabs except for rights under certain license agreements with third parties. The Company is obligated to pass-through to the former Humabs shareholders any amounts received by Humabs under such license agreements, net of any program expenses. The transaction was accounted for as an acquisition of a business. In addition to the cash payment and issuance of common stock to the former Humabs shareholders at the acquisition date, the Company also agreed to pay additional amounts in cash upon the achievement of specified milestone events: (i) up to $135.0 million upon the achievement of clinical, regulatory and commercial milestones for an HBV product; and (ii) up to $105.0 million upon the achievement of clinical, regulatory and commercial milestones for another product, which the Company elected as a severe acute respiratory syndrome coronavirus 2 (“SARS-CoV-2”) product. In May 2020, the Company achieved one of the specified clinical milestones for the HBV product. As such, the Company paid $10.0 million related to this milestone event in June 2020. In October 2020, the Company achieved another specified clinical milestone for the SARS-CoV-2 product and paid $10.0 million related to this milestone event. The estimated fair value of the remaining contingent consideration was $63.3 million as of March 31, 2021. Acquisition of Agenovir In January 2018, the Company entered into an agreement and plan of merger with Agenovir Corporation (“Agenovir”), under which the Company purchased all equity interests of Agenovir. The primary assets purchased in the acquisition were in-process research and development programs in human papillomavirus and HBV using CRISPR/Cas9. The acquisition was accounted for as an asset purchase. At the acquisition date, the Company paid cash and issued shares of Series A-2 convertible preferred stock to the former Agenovir stockholders. During a specified period following the closing of the Agenovir acquisition, the Company will be required to pay Agenovir’s former stockholders up to $135.0 million in the aggregate for the achievement of specified development, regulatory and commercial milestones for the first HBV product. None of the milestones have been achieved as of March 31, 2021, therefore no amounts were recognized relating to the contingent consideration.

Acquisitions

3 Months Ended

Mar. 31, 2021

4.Acquisitions

Acquisition of TomegaVax

In September 2016, the Company entered into an agreement and plan of merger (“TomegaVax Merger Agreement”) to acquire all of the equity interests of TomegaVax. The primary asset purchased in the acquisition was an in-process cytomegalovirus vector-based vaccine platform for use in HBV, HIV, and TB. The acquisition was accounted for as an asset purchase.

In connection with the entry into the TomegaVax Merger Agreement, the Company also entered into a letter agreement with TomegaVax (the “TomegaVax Letter Agreement”), which provides for certain payments to TomegaVax’s former stockholders before September 2024, in each case so long as the Company is continuing to pursue the development of the TomegaVax technology. Under the terms of the TomegaVax Letter Agreement, the Company will be required to pay to the former stockholders of TomegaVax milestone payments of up to an aggregate of $30.0 million if the per-share price of the Company’s publicly traded common stock, or implied price per share of the Company’s Series A-1 convertible preferred stock (or common stock upon conversion) upon a certain asset sale, merger or stock sale, is at least $45 (as adjusted in the case of any stock dividend, stock split or other similar recapitalization), with the amount of such payments determined by the share price and the stage of the Company’s clinical development at the time of the relevant event triggering the payment. The share price of the Company’s publicly traded common stock will be determined using the average of the daily volume-weighted average trading price of the Company’s common stock for each trading day during a consecutive 90-day period. The foregoing payments are payable (i) during any date after the completion of an initial public offering by the Company or any successor or affiliate controlling the TomegaVax technology, provided that no payment will be due before the first anniversary of the initial public offering, (ii) upon the sale of all assets related to the TomegaVax technology or (iii) upon a merger or stock sale of the Company or any successor or affiliate controlling the TomegaVax technology, in each case subject to certain conditions with respect to the timing of the payments. The payments under the TomegaVax Letter Agreement can be made in cash or shares of the Company’s common stock, at the discretion of the Company’s board of directors. In February 2021, the Company achieved one of the milestones related to the specified per-share price of its common stock, which resulted in a $10.0 million payable to TomegaVax’s former stockholders within 90 business days, subject to a 90-day grace period at the Company’s option in certain circumstances.

The Company determined that the future milestone payments contain net settlement provisions and therefore, they were required to be accounted for as embedded derivatives under the relevant accounting guidance. As of March 31, 2021, the estimated fair value of the embedded derivative was $7.1 million.

Acquisition of Humabs

In August 2017, the Company acquired all of the outstanding equity of Humabs, a private Swiss company which discovers and develops monoclonal antibodies (“mAbs”) derived from individuals whose immune systems have successfully responded to major diseases. The Company acquired all of Humabs’ rights, title and interest in and to substantially all of the assets of Humabs except for rights under certain license agreements with third parties. The Company is obligated to pass-through to the former Humabs shareholders any amounts received by Humabs under such license agreements, net of any program expenses. The transaction was accounted for as an acquisition of a business. In addition to the cash payment and issuance of common stock to the former Humabs shareholders at the acquisition date, the Company also agreed to pay additional amounts in cash upon the achievement of specified milestone events: (i) up to $135.0 million upon the achievement of clinical, regulatory and commercial milestones for an HBV product; and (ii) up to $105.0 million upon the achievement of clinical, regulatory and commercial milestones for another product, which the Company elected as a severe acute respiratory syndrome coronavirus 2 (“SARS-CoV-2”) product.

In May 2020, the Company achieved one of the specified clinical milestones for the HBV product. As such, the Company paid $10.0 million related to this milestone event in June 2020. In October 2020, the Company achieved another specified clinical milestone for the SARS-CoV-2 product and paid $10.0 million related to this milestone event. The estimated fair value of the remaining contingent consideration was $63.3 million as of March 31, 2021.

Acquisition of Agenovir

In January 2018, the Company entered into an agreement and plan of merger with Agenovir Corporation (“Agenovir”), under which the Company purchased all equity interests of Agenovir. The primary assets purchased in the acquisition were in-process research and development programs in human papillomavirus and HBV using CRISPR/Cas9. The acquisition was accounted for as an asset purchase.

At the acquisition date, the Company paid cash and issued shares of Series A-2 convertible preferred stock to the former Agenovir stockholders. During a specified period following the closing of the Agenovir acquisition, the Company will be required to pay Agenovir’s former stockholders up to $135.0 million in the aggregate for the achievement of specified development, regulatory and commercial milestones for the first HBV product.

None of the milestones have been achieved as of March 31, 2021, therefore no amounts were recognized relating to the contingent consideration.