XML 48 R39.htm IDEA: XBRL DOCUMENT
v3.26.1

Collaboration and License Agreements - Regeneron Pharmaceuticals, Inc - Additional Information (Details) $ in Thousands |  | 1 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Nov. 16, 2022 USD ($) | Jul. 31, 2026 USD ($) | May 31, 2026 USD ($) Target | Jun. 30, 2026 USD ($) | Dec. 31, 2025 USD ($) | Jun. 30, 2025 USD ($) | Dec. 31, 2024 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] |  |  |  |  |  |  |
Deferred revenue |  |  |  | $ 54,690 | $ 28,467 | $ 32,291 | $ 94,063
Regeneron Pharmaceuticals, Inc |  |  |  |  |  |  |
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] |  |  |  |  |  |  |
Number of targets selected | Target |  |  | 2 |  |  |  |
Deferred revenue |  |  |  | 45,400 |  |  |
Collaborative Arrangement | Regeneron Pharmaceuticals, Inc |  |  |  |  |  |  |
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] |  |  |  |  |  |  |
Right to expand the number of additional collaboration target | Target |  |  | 8 |  |  |  |
Upfront payment received | $ 30,000 |  | $ 37,000 |  |  |  |
Collaboration and License Agreement | Regeneron Pharmaceuticals, Inc |  |  |  |  |  |  |
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] |  |  |  |  |  |  |
Upfront payment received |  | $ 37,000 | 37,000 |  |  |  |
Estimated research and development service fees |  |  | 10,000 |  |  |  |
Total transaction price |  |  | 56,400 |  |  |  |
Deferred revenue |  |  | 9,400 | 45,400 | 10,500 |  |
Amount due from customer |  |  |  | $ 37,500 | $ 800 |  |
Collaboration and License Agreement | Regeneron Pharmaceuticals, Inc | Maximum |  |  |  |  |  |  |
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] |  |  |  |  |  |  |
Contingent milestone payments receivable | 800,000 |  | 800,000 |  |  |  |
Additional milestone payment received | $ 1,200,000 |  |  |  |  |  |
Collaboration and License Agreement | Regeneron Agreement | Maximum |  |  |  |  |  |  |
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] |  |  |  |  |  |  |
Contingent milestone payments receivable |  |  | $ 4,000,000 |  |  |  |

X
- Definition Additional milestone payment received. + References No definition available. + Details
Name: | ctmx_AdditionalMilestonePaymentReceived
Namespace Prefix: | ctmx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Aggregate collaboration transaction amount. + References No definition available. + Details
Name: | ctmx_AggregateCollaborationTransactionAmount
Namespace Prefix: | ctmx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Future contingent milestone payment receivable. + References No definition available. + Details
Name: | ctmx_ContingentMilestonePaymentsReceivable
Namespace Prefix: | ctmx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of targets selected. + References No definition available. + Details
Name: | ctmx_NumberOfTargetsSelected
Namespace Prefix: | ctmx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Right to expand the number of additional collaboration target. + References No definition available. + Details
Name: | ctmx_RightToExpandNumberOfAdditionalCollaborationTarget
Namespace Prefix: | ctmx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Upfront consideration estimated research and development service fees. + References No definition available. + Details
Name: | ctmx_UpfrontConsiderationEstimatedResearchAndDevelopmentServiceFees
Namespace Prefix: | ctmx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 808 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479402/808-10-50-1 + Details
Name: | us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-11 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479837/606-10-45-3 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479837/606-10-45-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-8 + Details
Name: | us-gaap_ContractWithCustomerAssetNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-11 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479837/606-10-45-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-8 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479837/606-10-45-2 + Details
Name: | us-gaap_ContractWithCustomerLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Cash received from collaborators during the current period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 25 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-25 + Details
Name: | us-gaap_ProceedsFromCollaborators
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | srt_CounterpartyNameAxis=ctmx_RegeneronPharmaceuticalsIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=us-gaap_CollaborativeArrangementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=ctmx_CollaborationAndLicenseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=ctmx_RegeneronAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |