This is an open-label Phase 1 dose escalation study of OMP-21M18 in subjects with previously treated solid tumors for which there is no remaining standard curative therapy and no therapy with a demonstrated survival benefit. Up to 30 subjects will be enrolled at up to 4 centers. Subjects will be assessed for safety, immunogenicity, pharmacokinetics, biomarkers, and efficacy. No formal interim analyses will be performed. Prior to enrollment, subjects will undergo screening to determine study eligibility. Upon enrollment, subjects will receive weekly intravenous (IV) infusions of OMP-21M18 for 9 weeks. After 9 weeks of treatment, subjects will be assessed for disease status. If there is no evidence of disease progression or if the tumor is smaller, then subjects may continue to receive IV infusions of OMP-21M18 every other week until disease progression.
Dose escalation will be conducted to determine the maximum tolerated dose (MTD). The dose levels of OMP 21M18 will be 0.5, 1.0, 2.5, 5, and 10 mg/kg administered IV weekly for 9 doses. No dose escalation or reduction will be allowed within a dose cohort. The dose may be administered at any time during the day. Three subjects will be treated at each dose level if no dose-limiting toxicities (DLTs) are observed. If 1 of 3 subjects experience a DLT, that dose level will be expanded to 6 subjects. If 2 or more subjects experience a DLT, no further subjects will be dosed at that level and 3 additional subjects will be added to the preceding dose cohort unless 6 subjects have already been treated at that dose level. Subjects will be assessed for DLTs from the time of the first dose through 7 days after administration of the 4th dose, but prior to administration of the 5th dose (i.e., Days 0-28). Dose escalation, if appropriate, will occur after all subjects in a cohort have completed their Day 28 DLT assessment.
