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v3.20.1

License, Clinical Trial and Sponsored Research Agreements - Licenses (Details) |  |  |  |  |  |  | 1 Months Ended | 12 Months Ended |  |  |
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Aug. 23, 2019 USD ($) | Aug. 02, 2018 USD ($) item | Mar. 17, 2018 USD ($) | Jan. 03, 2018 USD ($) | Nov. 28, 2017 USD ($) | Jul. 03, 2017 USD ($) | Feb. 28, 2019 USD ($) | May 31, 2017 USD ($) item | Feb. 28, 2017 USD ($) | Mar. 31, 2015 USD ($) item | Dec. 31, 2019 USD ($) shares | Dec. 31, 2018 USD ($) shares | Aug. 16, 2019 shares | Aug. 15, 2019 shares | Jul. 31, 2016 shares
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  | $ 6,273,000 | $ 3,360,000 |  |  |
Common stock, shares authorized | shares |  |  |  |  |  |  |  |  |  |  | 85,000,000 | 85,000,000 | 85,000,000 | 50,000,000 | 50,000,000
Research and development |  |  |  |  |  |  |  |  |  |  | $ 30,042,000 | $ 21,104,000 |  |  |
License Agreements [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  | 4,900,000 | 2,100,000 |  |  |
License Agreements [Member] | ST Jude XSCID [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  |  | 1,000,000 |  |  |
License Agreements [Member] | Fortress Pik Dividend [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  | 4,923,000 | 2,085,000 |  |  |
License Agreements [Member] | Ucla License [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  | 300,000 |  |  |  |
City Of Hope National Medical Center ("COH") [Member] | License Agreements [Member] | CD123 Product Or Process [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  | 250,000 | 0 |  |  |
City Of Hope National Medical Center ("COH") [Member] | License Agreements [Member] | CS1 Product Or Process [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  | 200,000 | 0 |  |  |
Upfront fees paid |  |  |  |  |  |  |  | $ 600,000 |  |  |  |  |  |  |
Number of milestones | item |  |  |  |  |  |  |  | 10 |  |  |  |  |  |  |
Milestones payable |  |  |  |  |  |  |  | $ 14,900,000 |  |  |  |  |  |  |
Annual maintenance fee payable |  |  |  |  |  |  |  | 50,000 |  |  |  |  |  |  |
City Of Hope National Medical Center ("COH") [Member] | License Agreements [Member] | PSCA Product Or Process [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  | 200,000 | 0 |  |  |
Upfront fees paid |  |  |  |  |  |  |  | $ 300,000 |  |  |  |  |  |  |
Number of milestones | item |  |  |  |  |  |  |  | 10 |  |  |  |  |  |  |
Milestones payable |  |  |  |  |  |  |  | $ 14,900,000 |  |  |  |  |  |  |
Annual maintenance fee payable |  |  |  |  |  |  |  | 50,000 |  |  |  |  |  |  |
City Of Hope National Medical Center ("COH") [Member] | License Agreements [Member] | HER2 Product Or Process [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  | 0 | 200,000 |  |  |
Upfront fees paid |  |  |  |  |  |  |  | 600,000 |  |  |  |  |  |  |
Annual maintenance fee payable |  |  |  |  |  |  |  | $ 50,000 |  |  |  |  |  |  |
City Of Hope National Medical Center ("COH") [Member] | License Agreements [Member] | Manufacturing |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  |  | 75,000 |  |  |
Upfront fees paid |  |  |  | $ 75,000 |  |  |  |  |  |  |  |  |  |  |
City Of Hope National Medical Center ("COH") [Member] | Arrangements Related To Developmental Milestones [Member] | HER2 Product Or Process [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of milestones | item |  |  |  |  |  |  |  | 10 |  |  |  |  |  |  |
Milestones payable |  |  |  |  |  |  |  | $ 14,900,000 |  |  |  |  |  |  |
City Of Hope National Medical Center ("COH") [Member] | Sponsored Research And Clinical Trial Agreements [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development |  |  |  |  |  |  |  |  |  |  | 6,143,000 | 5,719,000 |  |  |
City Of Hope National Medical Center ("COH") [Member] | Sponsored Research And Clinical Trial Agreements [Member] | CD123 Product Or Process [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development |  |  |  |  |  |  |  |  |  |  | 1,202,000 | 835,000 |  |  |
City Of Hope National Medical Center ("COH") [Member] | Sponsored Research And Clinical Trial Agreements [Member] | Il13r2 Product [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development |  |  |  |  |  |  |  |  |  |  | 876,000 | 1,056,000 |  |  |
City Of Hope National Medical Center ("COH") [Member] | Sponsored Research And Clinical Trial Agreements [Member] | Manufacturing |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Milestones payable |  |  |  | $ 900,000 |  |  |  |  |  |  |  |  |  |  |
Agreement term |  |  |  | 2 years |  |  |  |  |  |  |  |  |  |  |
Research and development |  |  |  |  |  |  |  |  |  |  | 457,000 | 458,000 |  |  |
City Of Hope National Medical Center ("COH") [Member] | Sponsored Research And Clinical Trial Agreements [Member] | ST Jude XSCID [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development |  |  |  |  |  |  |  |  |  |  | 777,000 |  |  |  |
City Of Hope, Original Agreement [Member] | Sponsored Research And Clinical Trial Agreements [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Milestones payable |  |  |  |  |  |  |  |  |  | $ 2,000,000 |  |  |  |  |
Number of installments | item |  |  |  |  |  |  |  |  |  | 4 |  |  |  |  |
Research and development |  |  |  |  |  |  |  |  |  |  | 2,000,000 |  |  |  |
City of Hope, Amended Agreement [Member] | CD123 Product Or Process [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development |  |  |  |  |  |  |  |  |  |  |  | 800,000 |  |  |
City of Hope, Amended Agreement [Member] | Il13r2 Product [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development |  |  |  |  |  |  |  |  |  |  |  | 1,100,000 |  |  |
City of Hope, Amended Agreement [Member] | License Agreements [Member] | CD123 Product Or Process [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Milestones payable |  |  |  |  |  |  |  |  | $ 14,500,000 |  |  |  |  |  |
Annual maintenance fee payable |  |  |  |  |  |  |  |  | 25,000 |  |  |  |  |  |
City of Hope, Amended Agreement [Member] | Sponsored Research And Clinical Trial Agreements [Member] | CD123 Product Or Process [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Upfront fees paid |  |  |  |  |  |  |  |  | 19,450 |  |  |  |  |  |
Milestones payable |  |  |  |  |  |  |  |  | 200,000 |  |  |  |  |  |
Contribution per patient |  |  |  |  |  |  |  |  | $ 97,490 |  |  |  |  |  |
Agreement term |  |  |  |  |  |  |  |  | 3 years |  |  |  |  |  |
Research and development |  |  |  |  |  |  |  |  |  |  | 1,200,000 |  |  |  |
City of Hope, Amended Agreement [Member] | Sponsored Research And Clinical Trial Agreements [Member] | Il13r2 Product [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Upfront fees paid |  |  |  |  |  |  |  |  | $ 9,300 |  |  |  |  |  |
Milestones payable |  |  |  |  |  |  |  |  | $ 200,000 |  |  |  |  |  |
Agreement term |  |  |  |  |  |  |  |  | 3 years |  |  |  |  |  |
Contribution toward patient costs |  |  |  |  |  |  |  |  | $ 100,000 |  |  |  |  |  |
Research and development |  |  |  |  |  |  |  |  |  |  | 900,000 |  |  |  |
St. Jude Children's Research Hospital [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research arrangement consideration of services |  |  |  |  |  |  |  |  |  |  | 800,000 |  |  |  |
St. Jude Children's Research Hospital [Member] | License Agreements [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  | 0 | 1,000,000 |  |  |
Upfront fees paid |  | $ 1,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Annual maintenance fee payable |  | $ 100,000 |  |  |  |  |  |  |  |  |  |  |  |  |
St. Jude Children's Research Hospital [Member] | Arrangements Related To Developmental Milestones [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of milestones | item |  | 5 |  |  |  |  |  |  |  |  |  |  |  |  |
Milestones payable |  | $ 13,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Nationwide Childrens Hospital [Member] | License Agreements [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  | 200,000 | 0 |  |  |
Upfront fees paid |  |  |  |  |  |  | $ 200,000 |  |  |  |  |  |  |  |
Milestones payable |  |  |  |  |  |  | $ 152,800,000 |  |  |  |  |  |  |  |
Calimmune [Member] | License Agreements [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  | 200,000 |  |  |  |
Upfront fees paid | $ 200,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Milestones payable | $ 1,200,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
University of California [Member] | License Agreements [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  | 300,000 |  |  |  |
Fred Hutchinson Cancer Research Center [Member] | Sponsored Research And Clinical Trial Agreements [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Milestones payable |  |  |  |  |  | $ 5,300,000 |  |  |  |  |  |  |  |  |
Research and development |  |  |  |  |  |  |  |  |  |  | 600,000 | 900,000 |  |  |
Fred Hutchinson Cancer Research Center [Member] | Sponsored Research And Clinical Trial Agreements [Member] | Manufacturing |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  |  |  |  |  | 200,000 | 400,000 |  |  |
Milestones payable |  |  | $ 600,000 |  |  |  |  |  |  |  |  |  |  |  |
Beth Israel Deaconess Medical Center Inc. ("BIDMC") [Member] | Sponsored Research And Clinical Trial Agreements [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Milestones payable |  |  |  |  | $ 800,000 |  |  |  |  |  |  |  |  |  |
Agreement term |  |  |  |  | 3 years |  |  |  |  |  |  |  |  |  |
Research and development |  |  |  |  |  |  |  |  |  |  | $ 100,000 | $ 100,000 |  |  |

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