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License and Collaboration Agreement (Details) - USD ($) $ in Thousands |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | ---
May 07, 2019 | Dec. 31, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Jul. 13, 2017
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Upfront payments and fees |  | $ 23,792 |  |  |  | $ 23,792 |  |
Revenue recognized |  |  |  |  | $ 14,100 | 1,600 | $ 23,500 |
Costs to obtain or fulfill the contract that were capitalized |  | 0 |  |  | $ 0 | 0 | 0 |
License and Collaborative Revenue |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Development cost |  |  |  |  | 20.00% |  |  |
Second-Generation Analog, Phase 3 CD Clinical Trial Primary Clinical Endpoint [Member] |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Development cost |  |  |  |  | 80.00% |  |  |
Second Generation Analog Phase 2 Cd Clinical Trial Primary Clinical |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Development cost |  |  |  |  | 80.00% |  |  |
Phase 2 clinical trial | Additional services |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  | 100 |
First Amendment | Development, regulatory and sales milestone payments |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Eligible payment receivable | $ 1,000,000 |  |  |  |  |  |  |
First Amendment | Development, regulatory and sales milestone payments | Maximum |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Percentages on net product sales | 10.00% |  |  |  |  |  |  |
Janssen Biotech, Inc. | License and Collaborative Revenue |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Revenue |  |  |  |  | $ 27,100 |  |  |
Revenue recognized |  |  |  |  | 28,600 | 200 | 30,900 |
Janssen Biotech, Inc. | Additional services |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Revenue |  |  |  |  | $ 1,500 | 0 |  |
Janssen Biotech, Inc. | Second-Generation Analog, Phase 3 CD Clinical Trial Primary Clinical Endpoint [Member] |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Development cost |  |  |  |  | 20.00% |  |  |
Janssen Biotech, Inc. | License and Collaboration Agreement |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Increase (decrease) in transaction price |  |  |  |  | $ (14,300) | 37,900 |  |
Transaction price |  | 112,900 |  |  | 98,600 | 112,900 | 60,700 |
Revenue |  |  |  |  |  |  | $ 30,800 |
Janssen Biotech, Inc. | License and Collaboration Agreement | Upfront cash payment |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Upfront payments and fees |  |  |  |  |  |  |  | $ 50,000
Janssen Biotech, Inc. | First, second-generation compound | Milestone payment |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Amount payable upon the effectiveness of the First Amendment |  |  |  |  | $ 7,500 |  |  |
Janssen Biotech, Inc. | First, second-generation compound | Second-Generation Analog, Phase 3 CD Clinical Trial Primary Clinical Endpoint [Member] |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Research program cost |  |  |  |  | 100.00% |  |  |
Janssen Biotech, Inc. | Second and third, second-generation compounds | Second-Generation Analog, Phase 3 CD Clinical Trial Primary Clinical Endpoint [Member] |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Research program cost |  |  |  |  | 50.00% |  |  |
Janssen Biotech, Inc. | Thereafter | Second-Generation Analog, Phase 3 CD Clinical Trial Primary Clinical Endpoint [Member] |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Research program cost |  |  |  |  | 100.00% |  |  |
Janssen Biotech, Inc. | Second-Generation Phase 2b Milestone |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Amount payable upon the effectiveness of the First Amendment |  | $ 5,000 |  |  |  |  |  |
Janssen Biotech, Inc. | Second-Generation Phase 2b Milestone | Milestone payment |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Revenue recognized |  |  |  |  | $ 6,800 |  |  |
Janssen Biotech, Inc. | Phase 2 clinical trial | License and Collaborative Revenue |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Revenue |  |  |  |  | 17,900 |  |  |
Janssen Biotech, Inc. | First Amendment |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Increase (decrease) in transaction price |  |  |  |  |  | (9,400) |  |
Revenue recognized |  |  |  |  | 5,000 |  |  |
Janssen Biotech, Inc. | First Amendment | License and Collaborative Revenue |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Eligible amount received |  |  | $ 25,000 |  |  |  |  |
Revenue recognized |  |  | 25,000 |  |  |  |  |
Revenue following contract modification |  |  |  |  |  | $ 8,000 |  |
Revenue recognized from performance obligations in previous periods |  |  |  | $ 1,600 |  |  |  |
Janssen Biotech, Inc. | First Amendment | PTG-200, Phase 3 CD Clinical Trial Primary Clinical Endpoint |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Eligible payment receivable | $ 100,000 |  |  |  |  |  |  |
Janssen Biotech, Inc. | First Amendment | Second-Generation Analog, Phase 3 CD Clinical Trial Primary Clinical Endpoint [Member] |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Eligible payment receivable | $ 115,000 |  |  |  |  |  |  |
Janssen Biotech, Inc. | First Amendment | Second-Generation Phase 2b Milestone Payment |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Amount payable upon the effectiveness of the First Amendment |  |  |  |  | 50,000 |  |  |
Janssen Biotech, Inc. | Amended First Opt-in | Upfront cash payment |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Amount payable upon the effectiveness of the First Amendment |  |  |  |  | 50,000 |  |  |
Janssen Biotech, Inc. | Amended Second Opt-in | Upfront cash payment |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Amount payable upon the effectiveness of the First Amendment |  |  |  |  | 50,000 |  |  |
Janssen Biotech, Inc. | Estimated variable consideration | License and Collaborative Revenue |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Amount payable upon the effectiveness of the First Amendment |  |  |  |  | $ 7,500 |  |  |
Janssen Biotech, Inc. | Pro Forma | License and Collaborative Revenue |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Amount payable upon the effectiveness of the First Amendment |  |  | 25,000 |  |  |  |  |
Janssen Biotech, Inc. | Pro Forma | Milestone payment |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |
Amount payable upon the effectiveness of the First Amendment |  |  | $ 25,000 |  |  |  |  |

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