Strategic considerations

This is a multicenter, open-label, Phase 1 study of SC-006 given as a single agent and in combination with ABBV-181 in participants with advanced colorectal cancer (CRC), and consists of Part A (single agent SC-006 dose regimen finding), followed by Part B (single agent SC-006 dose expansion), and Part C (SC-006 and ABBV-181 combination escalation and expansion). Part A (dose regimen finding) will involve dose escalation and possible dose interval modification to define the maximum tolerated dose (MTD) and/or recommended Part B dose and schedule. Part B (dose expansion) will enroll additional participants who will be treated with a study drug dose at or below the MTD determined in Part A. Part C is dose escalation of SC-006 and fixed dose of ABBV-181 in combination. Recommended dose cohort of SC-006 with ABBV-181 will be expanded.

Inclusion Criteria:

• Participants with histologically or cytologically confirmed advanced metastatic or unresectable colorectal cancer (CRC) that is relapsed, refractory, or progressive following at least 2 prior systemic regimens in the metastatic setting.
• Participants with an Eastern Cooperative Oncology Group (ECOG) of 0 - 1.
• Participants with adequate hematologic, hepatic, and renal function.

Exclusion Criteria:

• Participants with prior exposure to a pyrrolobenzodiazepine or indolinobenzodiazepine based drug.

Additional Exclusion Criteria for the SC-006 and ABBV-181 Combination Treatment Regimen:

• History of inflammatory bowel disease
• Active autoimmune disease, with exception of psoriasis not requiring systemic treatment, vitiligo, type 1 diabetes mellitus and hypothyroidism
• History of primary immunodeficiency, allogenic bone marrow transplantation, solid organ transplantation, or previous clinical diagnosis of tuberculosis
• History of immune-mediated pneumonitis
• Current or prior use of immunosuppressive medication within 14 days prior to the first dose of study treatment