Tarextumab

The study consists of a Phase1b lead-in portion to determine the maximum tolerated dose (MTD) of OMP-59R5 (tarextumab) in combination with etoposide (EP) for 6 cycles followed a Phase 2, multi center, randomized, placebo-controlled portion comparing the efficacy and safety of OMP-59R5 in combination with EP for 6 cycles followed by single agent OMP-59R5 relative to EP alone for 6 cycles in subjects receiving first-line therapy for extensive stage small cell lung cancer.

This is an open-label Phase 1 dose escalation study of OMP-59R5 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 44 subjects will be enrolled at up to 2 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 intravenous (IV) infusions of OMP-59R5 at a assigned dosing schedule for 56 days. After 56 days, 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-59R5 every week until disease progression.
Dose escalation will be conducted to determine the maximum tolerated dose (MTD). No dose escalation or reduction will be allowed within a dose cohort. The first 2 subjects enrolled in a cohort will not be treated on the same day. 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. The first 2 subjects in each cohort will not be started on OMP-59R5 on the same day. If 1 of 3 subjects experiences 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 28 days. Dose escalation for newly enrolled subjects, if appropriate, will occur after all subjects in a cohort have completed their Day 28 DLT assessment. Subjects with stable disease or a response at Day 56 will be allowed to continue to receive weekly doses of OMP-59R5 until disease progression. An additional 14 subjects will be enrolled at the highest dose level that result in <2 of the 6 subjects experiencing a DLT.