Conditions: Solid Tumor
Allocation: NON_RANDOMIZED | Intervention model: PARALLEL
Enrollment: 119
Healthy volunteers: no

Brief summary:
This non-randomized, open-label, study will determine the highest safe dose of cobimetinib, how often it should be taken, how well participants with cancer tolerate cobimetinib and will assess the pharmacokinetic effect of midazolam and dextromethorphan on the study drug.

Detailed description:

Arms:
arm 1: Participants will receive cobimetinib (GDC-0973/XL518) at the starting dose of 0.05 mg/kg via solution or capsule, once daily for Days 1-21 of each 28-day cycle (21 days on drug followed by 7 days off treatment \[21/7 schedule\]). Treatment will continue until progressive disease (PD) or unacceptable toxicity for up to 1 year at the discretion of investigator and beyond 1 year with the agreement of the sponsor. arm 2: Participants will receive cobimetinib at the starting dose of 60 mg via solution or capsule, once daily for Days 1-14 of each 28-day cycle (14 days on drug followed by 14 days off treatment \[14/14 schedule\]). Treatment will continue until progressive disease (PD) or unacceptable toxicity for up to 1 year at the discretion of investigator and beyond 1 year with the agreement of the sponsor. arm 3: Participants will receive cobimetinib at the maximum tolerated dose (MTD) established in Stage 1, once daily for Days 1-21 of each 28-day cycle (21 days on drug followed by 7 days off treatment \[21/7 schedule\]). Treatment will continue until progressive disease (PD) or unacceptable toxicity for up to 1 year at the discretion of investigator and beyond 1 year with the agreement of the sponsor. arm 4: Participants will receive cobimetinib at the MTD established in Stage 1A, once daily for Days 1-14 of each 28-day cycle (14 days on drug followed by 14 days off treatment \[14/14 schedule\]). Treatment will continue until progressive disease (PD) or unacceptable toxicity for up to 1 year at the discretion of investigator and beyond 1 year with the agreement of the sponsor. arm 5: Participants will receive a single dose of midazolam (2 mg of midazolam syrup) and dextromethorphan (30 mg tablet) on Cycle 1 Day 1, in the absence of cobimetinib. After a 2-day washout period, participants will receive 21 consecutive daily doses of cobimetinib (60-mg) followed by a 7-day washout period. Participants will receive another single dose of midazolam and dextromethorphan on Cycle 1 Day 15, in the presence of steady-state cobimetinib concentrations. In Cycle 2 and beyond participants will receive cobimetinib alone, administered as a 60-mg daily dose for 21 consecutive days in 28-day cycles (21/7 schedule).

Interventions: intervention 1: cobimetinib intervention 2: dextromethorphan intervention 3: midazolam
Intervention descriptions: intervention 1: Repeating oral dose intervention 2: In Stage III only: single dose of dextromethorphan intervention 3: In Stage III only: single dose of midazolam

Protocol document: