Related Party Transactions	12 Months Ended
Dec. 31, 2021
Related Party Transactions [Abstract]
Related Party Transactions	17. Related Party Transactions During the years ended December 31, 2021 and 2020, the Company paid $85,000 and $93,000, respectively, to David Schaffer, Ph.D., the co-founder, director and Chief Scientific Advisor of the Company for consulting services. In April 2019, the Company entered into two sponsored research agreements (“SRAs”) with the UC Regents to conduct research in a research facility on the U.C. Berkeley campus, under the direction of Dr. Schaffer. The SRAs have a three year term ending in May 2022. Under the SRAs, the Company has an option to license (on a royalty-bearing basis) all intellectual property generated under the SRAs. The total amount the Company is committed to pay to the UC Regents under the SRAs is $1.5 million, which was fully paid as of December 31, 2021. In March 2021, the Company entered into another sponsored research agreement with the UC Regents to conduct research in laboratories on the U.C. Berkeley campus that are under the direction of Dr. Schaffer and another U.C. Berkeley professor covering investigations into how machine learning approaches may enhance AAV capsid engineering (the “Machine Learning SRA”). Pursuant to the Machine Learning SRA, the Company has committed to pay the UC Regents a total of $1.4 million, of which $0.4 million was paid as of December 31, 2021. The Machine Learning SRA has a three-year term ending in 2024. Any patent prosecution costs incurred under the SRAs will also be borne by the Company. The Company can terminate the SRAs for convenience and without cause with 60 days’ notice. While the Machine Learning SRA is between the Company and the UC Regents, the payments under the SRA will be used to fund the lab under the direction of Dr. Schaffer. As of December 31, 2021 and 2020, accounts payable to the UC Regents related to the SRAs and Machine Learning SRA was $0.0 million and $0.2 million, respectively. In the years ended December 31, 2021 and 2020, the Company recorded $0.9 million and $0.5 million, respectively, of expense related to SRAs. In August 2019, the Company and uniQure entered into the amended uniQure Agreement and the Second uniQure Agreement. Under these agreements, the Company agreed to transfer incremental rights and services to uniQure in exchange for uniQure eliminating the exclusivity clause in the uniQure Agreement and transferring other rights back to the Company. Further details and the accounting for these agreements is discussed in Note 7. As of June 17, 2020, uniQure was no longer a related party of the Company.

Related Party Transactions

12 Months Ended

Dec. 31, 2021

17. Related Party Transactions

During the years ended December 31, 2021 and 2020, the Company paid $85,000 and $93,000, respectively, to David Schaffer, Ph.D., the co-founder, director and Chief Scientific Advisor of the Company for consulting services. In April 2019, the Company entered into two sponsored research agreements (“SRAs”) with the UC Regents to conduct research in a research facility on the U.C. Berkeley campus, under the direction of Dr. Schaffer. The SRAs have a three year term ending in May 2022. Under the SRAs, the Company has an option to license (on a royalty-bearing basis) all intellectual property generated under the SRAs. The total amount the Company is committed to pay to the UC Regents under the SRAs is $1.5 million, which was fully paid as of December 31, 2021. In March 2021, the Company entered into another sponsored research agreement with the UC Regents to conduct research in laboratories on the U.C. Berkeley campus that are under the direction of Dr. Schaffer and another U.C. Berkeley professor covering investigations into how machine learning approaches may enhance AAV capsid engineering (the “Machine Learning SRA”). Pursuant to the Machine Learning SRA, the Company has committed to pay the UC Regents a total of $1.4 million, of which $0.4 million was paid as of December 31, 2021. The Machine Learning SRA has a three-year term ending in 2024. Any patent prosecution costs incurred under the SRAs will also be borne by the Company. The Company can terminate the SRAs for convenience and without cause with 60 days’ notice. While the Machine Learning SRA is between the Company and the UC Regents, the payments under the SRA will be used to fund the lab under the direction of Dr. Schaffer. As of December 31, 2021 and 2020, accounts payable to the UC Regents related to the SRAs and Machine Learning SRA was $0.0 million and $0.2 million, respectively. In the years ended December 31, 2021 and 2020, the Company recorded $0.9 million and $0.5 million, respectively, of expense related to SRAs.

In August 2019, the Company and uniQure entered into the amended uniQure Agreement and the Second uniQure Agreement. Under these agreements, the Company agreed to transfer incremental rights and services to uniQure in exchange for uniQure eliminating the exclusivity clause in the uniQure Agreement and transferring other rights back to the Company. Further details and the accounting for these agreements is discussed in Note 7. As of June 17, 2020, uniQure was no longer a related party of the Company.