XML 36 R27.htm IDEA: XBRL DOCUMENT
v3.26.1

Leases (Tables) - 2026 Lease Operating Lease | 6 Months Ended
--- | ---
Jun. 30, 2026
Operating Leased Assets [Line Items] |
Summary of Supplemental Information Related to Leases | Supplemental information related to the 2026 Lease are as follows:
|  | Three Months Ended |
|  | June 30, 2026 |
|  | (in thousands) |
Cash paid for amounts included in the measurement of lease liabilities |  |  |
Operating cash flows from operating leases |  | $ | — |
|  | June 30, 2026 |
|  | (in thousands) |
Supplemental balance sheet information related to leases: |  |  |
Operating lease right-of-use assets |  | $ | 3,905 |
Current operating lease liabilities |  |  | 53 |
Non-current operating lease liabilities |  |  | 4,208 |
Total operating lease liabilities |  | $ | 4,261 |
Weighted-average remaining lease term (in years) |  |  |
Operating lease |  |  | 3.51 |
Weighted-average discount rate |  |  |
Operating lease |  |  | 10.87 | %
Schedule of Undiscounted Future Non-Cancelable Lease Payments |
|  | June 30, 2026 |
|  | (in thousands) |
Undiscounted future non-cancelable lease payments |  |  |
2027 |  | $ | 1,815 |
2028 |  |  | 1,900 |
2029 |  |  | 1,985 |
Total lease payments |  |  | 5,700 |
Less: Imputed interest |  |  | (1,083 | )
Less: Tenant improvement allowance |  |  | (356 | )
Present value of lease liabilities |  | $ | 4,261 |

X
- Definition Supplemental information related to leases. + References No definition available. + Details
Name: | ctmx_SupplementalInformationRelatedToLeasesTableTextBlock
Namespace Prefix: | ctmx_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of undiscounted cash flows of lessee's operating lease liability. Includes, but is not limited to, reconciliation of undiscounted cash flows to operating lease liability recognized in statement of financial position. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478964/842-20-50-6 + Details
Name: | us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
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 No definition available. + Details
Name: | us-gaap_OperatingLeasedAssetsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_LeaseContractualTermAxis=ctmx_TwoThousandTwentySixLeaseOperatingLeaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |