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License, Collaboration and Service Agreements - Additional Information (Detail) $ / shares in Units, £ in Millions |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Jan. 15, 2021 USD ($) | Jun. 30, 2021 USD ($) | Feb. 28, 2021 USD ($) shares | Nov. 30, 2018 USD ($) | Jun. 30, 2017 USD ($) | Jun. 30, 2016 USD ($) | Jun. 30, 2016 GBP (£) | May 31, 2016 USD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Mar. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2021 USD ($) $ / shares shares | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Oct. 31, 2017 USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue recognized |  |  |  |  |  |  |  |  |  |  |  |  | $ 3,070,000 | $ 258,000 |  |
Proceeds from sale of common stock to related party |  |  |  |  |  |  |  |  |  |  |  |  | 7,831,000 | 13,166,000 |  |
Common stock issued, aggregate fair value |  |  |  |  |  |  |  |  |  |  |  |  | 7,831,000 | 77,929,000 |  |
Pfizer Inc [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Issuance of common stock and preferred stock net of offering costs, shares | shares |  |  | 2,362,348 |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock issued, aggregate fair value |  |  | $ 27,500 |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining Transaction Price Allocated To Performance Obligations |  |  |  |  |  |  |  |  |  |  |  |  | 12,500,000 |  |  |
Cantab Related Agreements [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Potential milestone payment upon achievement of specified clinical and regulatory milestones |  |  |  |  |  | $ 5,800,000 |  |  |  |  |  |  |  |  |  |
Potential milestone payment upon achievement of specified commercial milestone |  |  |  |  |  |  | £ 5.0 |  |  |  |  |  | 6,700,000 |  |  |
License agreement research and development expense related to achievement of regulatory milestones |  |  |  |  |  |  |  |  |  |  |  |  | $ 0 | 0 |  |
Contract termination period |  |  |  |  |  | 10 years | 10 years |  |  |  |  |  |  |  |  |
Vertex License Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
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 |  |  |  |  |  |  |  |
License agreement payment of research and development expense related to achievement of regulatory milestones |  |  |  |  |  |  |  |  |  |  |  |  | $ 0 | 900,000 |  |
Contract termination period if no material development or commercialization occurs |  |  |  |  |  |  |  |  |  |  |  |  | 1 year |  |  |
Meiji License Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Nonrefundable upfront payments |  |  |  |  | $ 600,000 |  |  |  |  |  |  |  |  |  |  |
Sublicense fee payable to counter party |  |  |  |  |  |  |  |  |  |  |  |  | $ 7,500,000 |  |  |
Potential milestone payments upon achievement of specified condition |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,000,000.0
License agreement fixed assets related payments |  |  |  |  |  |  |  |  |  |  |  | $ 1,600,000 |  |  |  |
Potential milestone payments upon completion and delivery of results of a clinical study |  |  |  |  |  |  |  |  |  |  |  |  | 1,000.0 |  |  |
Future milestone payments |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,000.0 |  |  |
Everest License Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Period of option granted on an agreement |  |  |  |  |  |  |  |  |  |  |  |  | 12 months |  |  |
Upfront payment received |  |  |  |  |  |  |  |  |  |  | $ 3,000,000.0 |  |  |  |  |
Potential milestone payments upon completion and delivery of results of a clinical study |  |  |  |  |  |  |  |  | $ 2,000,000.0 |  |  |  |  |  |  |
Upfront license fee |  |  |  |  |  |  |  |  |  |  |  |  | $ 2,000,000.0 |  |  |
Transaction price allocated to the performance obligations |  |  |  |  |  |  |  |  |  |  |  |  | 5,000,000.0 |  |  |
Performance obligations exclusive option to negotiate license |  |  |  |  |  |  |  |  |  |  |  |  | 1,000,000.0 |  |  |
Performance obligations related to research and development services milestone |  |  |  |  |  |  |  |  |  |  |  |  | 2,000,000.0 |  |  |
Revenue recognized |  |  |  |  |  |  |  |  |  |  |  |  | 1,300,000 | 300,000 |  |
Everest License Agreement [Member] | SPR206 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Upfront payment received |  | $ 800,000 |  |  |  |  |  |  |  |  | 2,000,000.0 |  |  |  |  |
Potential milestone payments upon completion and delivery of results of a clinical study | $ 1,500,000 | $ 700,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
milestones payment received | $ 1,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Everest License Agreement [Member] | SPR 741 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
License agreement research and development expense related to achievement of regulatory milestones |  |  |  |  |  |  |  |  |  | $ 100,000 |  |  |  |  | $ 3,600,000 |
License agreement payment of research and development expense related to achievement of regulatory milestones |  |  |  |  |  |  |  |  |  | $ 1,300 |  |  |  |  |  |
Upfront payment received |  |  |  |  |  |  |  |  |  |  | $ 1,000,000.0 |  |  |  |  |
Everest License Agreement [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Agreement termination period upon written notice | 180 days |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Everest License Agreement [Member] | Maximum [Member] | SPR206 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Receivable amount upon achievement of certain milestone | $ 38,000,000.0 |  |  |  |  |  |  |  |  |  |  |  | 59,500,000 |  |  |
Everest License Agreement [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Agreement termination period upon written notice | 90 days |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Pfizer License and Share Purchase Agreements [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue recognized |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,800,000 |  |  |
Issuance of common stock and preferred stock net of offering costs, shares | shares |  |  |  |  |  |  |  |  |  |  |  |  | 2,362,348 |  |  |
Common stock issued, aggregate fair value |  |  |  |  |  |  |  |  |  |  |  |  | $ 27,500,000 |  |  |
Associated premium as a freestanding equity-linked instrument under ASC 815 |  |  |  |  |  |  |  |  |  |  |  |  | 12,500,000 |  |  |
Remaining Transaction Price Allocated To Performance Obligations |  |  |  |  |  |  |  |  |  |  |  |  | 10,600,000 |  |  |
Pfizer License and Share Purchase Agreements [Member] | SPR206 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Upfront payment received |  |  |  |  |  |  |  |  |  |  |  |  | $ 0 |  |  |
Issuance of common stock and preferred stock net of offering costs, shares | shares |  |  |  |  |  |  |  |  |  |  |  |  | 2,362,348 |  |  |
Share price | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  | $ 16.93 |  |  |
Proceeds from sale of common stock to related party |  |  |  |  |  |  |  |  |  |  |  |  | $ 40,000,000.0 |  |  |
Receivable amount upon achievement of certain milestone |  |  |  |  |  |  |  |  |  |  |  |  | 80,000,000.0 |  |  |
Gates MRI [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reduction to research and development expense |  |  |  |  |  |  |  |  |  |  |  |  | 1,500,000 | $ 2,100,000 |  |
Savior Service Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Supervision fee amortization service period |  |  |  | 34 months |  |  |  |  |  |  |  |  |  |  |  |
Savior Service Agreement [Member] | Prepaid Expenses and Other Current Assets [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Non-refundable supervision fee related to commercial manufacturing facility |  |  |  | $ 2,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |
Savior Service Agreement [Member] | Long-term Asset [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Service agreement additional payment related to facility build out costs |  |  |  |  |  |  |  |  |  |  |  |  | $ 5,200,000 |  |  |

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