License, Collaboration and Service Agreements - Additional Information (Detail) $ / shares in Units, £ in Millions			1 Months Ended						3 Months Ended						6 Months Ended	9 Months Ended		12 Months Ended
	Sep. 21, 2022 USD ($) $ / shares shares	Jan. 15, 2021 USD ($)	Jun. 30, 2021 USD ($)	Nov. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2016 GBP (£)	May 31, 2016 USD ($)	Sep. 30, 2023 USD ($) $ / shares	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jun. 30, 2023 USD ($)	Sep. 30, 2023 USD ($) $ / shares shares	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) $ / shares	Jul. 31, 2023 USD ($)	Nov. 07, 2022 USD ($)	Oct. 31, 2017 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of stock, value									$ 220,000	$ 6,128,000						$ 220,000	$ 10,331,000
Common stock, par value | $ / shares									$ 0.001							$ 0.001		$ 0.001
Proceeds from sale of common stock to related party																$ 220,000	10,334,000
Revenue recognized									$ 23,382,000	1,082,000						24,910,000	2,225,000
Milestone payment									225,000,000							225,000,000
Research and development services performance obligation									8,800,000							8,800,000
Deferred revenue, current									13,873,000							13,873,000		$ 10,369,000
GSK SPA [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of stock, shares | shares	7,450,000
Issuance of stock, value	$ 10,300,000
Remaining transaction price allocated to the performance obligations									64,700,000							64,700,000
Milestone payment									21,200,000							21,200,000
Total Milestone									30,000,000							30,000,000
Initial Payments to Perform the Obligations																		66,000,000
Discount on Obligations																		1,300,000
GSK SPA [Member] | Research And Development Services Related To Upcoming Milestones [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized																19,000,000
GSK SPA [Member] | License and Know-How Transfer [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Remaining transaction price allocated to the performance obligations									64,700,000							64,700,000
Performance Obligation Allocated Transaction Price																45,700,000
Gates M R I [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reduction to research and development expense									0	0						0	0
Vertex License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement research and development expense related to achievement of regulatory milestones									0	0						$ 0	0
Contract termination period																10 years
Nonrefundable upfront payments								$ 500,000
Potential milestone payment upon achievement of specified clinical, regulatory and commercial milestones								$ 80,200,000
Contract termination period if no material development or commercialization occurs																1 year
GSK License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of stock, shares | shares	7,450,000
Issuance of stock, value	$ 1,300,000
Share price | $ / shares	$ 1.20805
Performance Obligation Allocated Transaction Price									23,200,000							$ 24,200,000
Deferred revenue, current									24,400,000							24,400,000
GSK License Agreement [Member] | Glaxo Smith Kline [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment																				$ 66,000,000
Reduction In Subsequent Payments by GSK to the Company																				50.00%
GSK License Agreement [Member] | GSK SPA [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment																			$ 30,000,000
Total Received Milestone									30,000,000							30,000,000
Meiji License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Nonrefundable upfront payments					$ 600,000
Sublicense fee payable to counter party									7,500,000							7,500,000
Potential milestone payments upon achievement of specified condition																					$ 1,000,000
License agreement fixed assets related payments														$ 1,600,000
Potential milestone payments upon completion and delivery of results of a clinical study																1,000,000
Future milestone payments																1,000,000
Total Received Milestone									30,000,000							30,000,000
Sublicence Fee Paid to Counter Party																		$ 6,600,000
Remaining Sublicence Fee Paid to Counter Party									900,000							900,000
Savior Service Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Impairment Expense									5,300,000							5,300,000
Savior Service Agreement [Member] | Prepaid Asset [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Non-refundable supervision fee related to commercial manufacturing facility				$ 2,000,000
Savior Service Agreement [Member] | Long-term Asset [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Service agreement additional payment related to facility build out costs															$ 5,300,000
Cantab Related Agreements [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Potential milestone payment upon achievement of specified commercial milestone							£ 5.0									6,100,000
License agreement research and development expense related to achievement of regulatory milestones									0	0						$ 0	0
Potential milestone payment upon achievement of specified clinical, regulatory and commercial milestones						$ 5,800,000
Everest License Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Period of option granted on an agreement																12 months
Upfront payment received													$ 3,000,000
Potential milestone payments upon completion and delivery of results of a clinical study												$ 2,000,000
Revenue recognized									0	0						$ 0	0
Milestone payment									34,000,000							34,000,000
Everest License Agreement [Member] | SPR 206 [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment received			$ 800,000										2,000,000
Potential milestone payments upon completion and delivery of results of a clinical study		$ 1,500,000									$ 700,000
Milestones payment received		$ 2,000,000
Everest License Agreement [Member] | SPR 741 [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment received													$ 1,000,000
Everest License Agreement [Member] | Maximum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Agreement termination period upon written notice		180 days
Everest License Agreement [Member] | Maximum [Member] | SPR 206 [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Receivable amount upon achievement of certain milestone		$ 38,000,000							59,500,000							$ 59,500,000
Everest License Agreement [Member] | Minimum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Agreement termination period upon written notice		90 days
Pfizer License and Share Purchase Agreements [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Receivable amount upon achievement of certain milestone										900,000							900,000
Milestones payment received										5,000,000
Issuance of stock, shares | shares																2,362,348
Issuance of stock, value																$ 27,500,000
Remaining transaction price allocated to the performance obligations									12,500,000							12,500,000
Revenue recognized									200,000	1,100,000						700,000	$ 1,500,000
Premium associated freestanding equity																12,500,000
Performance Obligation Allocated Transaction Price										5,000,000
Deferred revenue, current									$ 13,200,000							13,200,000
Pfizer License and Share Purchase Agreements [Member] | SPR 206 [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Receivable amount upon achievement of certain milestone																$ 80,000,000
Issuance of stock, shares | shares																2,362,348
Share price | $ / shares									$ 16.93							$ 16.93
Proceeds from sale of common stock to related party																$ 40,000,000
Pfizer License and Share Purchase Agreements [Member] | Research And Development Services Related To Upcoming Milestones [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Performance Obligation Allocated Transaction Price										$ 4,100,000						11,100,000
Pfizer License and Share Purchase Agreements [Member] | License and Know-How Transfer [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Performance Obligation Allocated Transaction Price																$ 1,400,000