Benefit/Risk Imbalance

This is a multicenter, open-label, Phase 1 study in participants with colorectal cancer (CRC) or gastric cancer to study the safety and tolerability of SC-007 and consists of Part A (dose regimen finding) in participants with CRC followed by Part A in participants with gastric cancer. Part B (dose expansion) will enroll participants into separate disease specific cohorts of CRC or gastric cancer.

Inclusion Criteria:

• Histologically or cytologically confirmed advanced metastatic or unresectable advanced colorectal cancer (CRC) or gastric cancer that is relapsed, refractory, or progressive after:
• CRC: at least 2 prior systemic regimens in the metastatic setting, and as appropriate in patients whose tumors are microsatellite instability-high (MSI-H), pembrolizumab as well.
• Gastric cancer (including gastric and EGJ cancers): at least 2 prior systemic regimens in adjuvant, advanced, or metastatic setting and, as appropriate, a human epidermal growth factor receptor 2 (HER2) targeted agent.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
• Adequate hematologic, hepatic, and renal function.

Exclusion Criteria:

• Any significant medical condition that, in the opinion of the investigator or sponsor, may place the participant at undue risk from the study.
• Has electrocardiogram (ECG) abnormalities that make QT interval corrected (QTc) evaluation difficult.
• Prior exposure to a pyrrolobenzodiazepine or indolinobenzodiazepine based drug.