License, Collaboration and Grant Award/ Subaward Agreements - Additional Information (Details) - USD ($) shares in Thousands		1 Months Ended				3 Months Ended		6 Months Ended		12 Months Ended
	Nov. 01, 2021	Jan. 31, 2022	Aug. 31, 2021	Aug. 31, 2017	May 31, 2016	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2017	Dec. 31, 2015	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2014
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Patent costs as general and administrative expense						$ 3,225,000	$ 3,381,000	$ 6,904,000	$ 6,174,000
Grant revenue						191,000	883,000	937,000	1,631,000
Deferred grant revenue						211,000		211,000				$ 0
The National Institute of Health (“NIH”) Grant Awards
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Grants awarded to researchers			$ 2,200,000
Grant revenue						800,000		900,000
Payable to subawardees			$ 700,000
Award payments received						100,000		600,000
Georgetown University
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Annual license maintenance fee to be paid and payment made											$ 10,000
MD Anderson Cancer Center
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development expense						100,000	0	$ 200,000	100,000
Aggregate cost													$ 800,000
Regents of the University of California
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Written notice of termination, period								60 years
Research and development expense						0	0		25,000,000
Upfront license fees paid					$ 500,000
Common stock shares issued					107,108
Annual license maintenance fees										$ 25,000,000
Worldwide sales milestones based on achievement of tiered revenue levels					$ 75,000,000.0
Patent costs as general and administrative expense						100,000	100,000	$ 100,000	200,000
Regents of the University of California | The National Institute of Health (“NIH”) Grant Awards
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research agreement term								5 years
University of California San Diego School of Medicine | The California Institute for Regenerative Medicine ("CIRM") Award
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Unbilled grant receivable						38,000,000		$ 38,000,000
Grants awarded to researchers				$ 18,300,000
Development milestones to be received under research sub award agreements throughout award project period				$ 14,600,000
Subaward payments received								700,000	2,200,000
Grant revenue						100,000	900,000	400,000	1,600,000
Related qualifying subaward costs						0	1,800,000	$ 500,000	3,300,000
Exclusive License Agreement | Georgetown University
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Written notice of termination, period								90 days
Days after receipt of notice, to pay failure amount								30 days
Days after receipt of notice for default in payment								60 days
Minimum period in days of written notice to terminate license agreement								60 days
Collaborative Arrangement | MD Anderson Cancer Center
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Potential regulatory milestone payments														$ 1,000,000.0
Research Agreement 2022 | Regents of the University of California | The National Institute of Health (“NIH”) Grant Awards
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research agreement term		4 years
Aggregate research agreement budget		$ 1,600,000
Research amount payable quarterly		125,000,000						$ 3,600,000
Other Research and Development Expense						100,000	100,000	300	300
Research Agreement 2023 | Regents of the University of California | The National Institute of Health (“NIH”) Grant Awards
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research amount payable quarterly		131,250,000
Research Agreement 2024 | Regents of the University of California | The National Institute of Health (“NIH”) Grant Awards
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research amount payable quarterly		$ 137,813,000
License Agreement | University of Tennessee Research Foundation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development expense						$ 100,000	$ 100,000	$ 200,000	$ 100,000
CVR Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Period Which Payment Of Percentage Of Net Proceeds Would Be Payable Under C V R	15 years
Period Which Grant Sale Or Transfer Of Rights To Company Sard Or Sarm Technology Could Trigger Payment Under Cvr Agreement	10 years
Percentage Of NetSales	5.00%
Maximum | Regents of the University of California
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Potential regulatory milestone payments					12,500,000
Maximum | Exclusive License Agreement | Georgetown University
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Potential milestone payments											$ 200,000
Minimum | Regents of the University of California
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Potential regulatory milestone payments					10,000,000.0
Advance licensed assets					$ 1,000,000.0