A Study of Vemurafenib and GDC-0973 (Cobimetinib) in Participants With BRAFV600E Mutation-Positive Metastatic Melanoma

A Phase IB, Open-Label, Dose-Escalation Study Evaluating the Safety, Tolerability and Pharmacokinetics of Vemurafenib in Combination With GDC-0973 (Cobimetinib) When Administered in BRAFV600E Mutation-Positive Patients Previously Treated (But Without Prior Exposure to BRAF or MEK Inhibitor Therapy) or Previously Untreated for Locally Advanced/Unresectable or Metastatic Melanoma or Those Who Have Progressed After Treatment With Vemurafenib

This open-label, dose-escalation study of vemurafenib in combination with cobimetinib will evaluate the safety, tolerability and pharmacokinetics in participants with BRAFV600 mutation-positive metastatic melanoma. Participants with previously untreated, BRAFV600E mutation-positive, locally advanced/unresectable or metastatic melanoma or those who have progressed on vemurafenib monotherapy immediately prior to enrolling in this trial are eligible. Participants will be assigned to different cohorts with escalating oral doses of vemurafenib and cobimetinib. This study consists of 2 stages, Stage 1 (Dose Escalation Stage [DES] and Cohort Expansion Stage [CES]) and the anticipated time on study treatment is until disease progression, unacceptable toxicity or any other discontinuation criterion is met.

Inclusion Criteria:

• Participants with histologically confirmed melanoma (unresectable Stage IIIc and Stage IV metastatic melanoma, as defined by American Joint Committee on Cancer [AJCC])

• Measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) Version (V) 1.1

• Eastern Cooperative Oncology Group (ECOG) Performance Status of less than or equal to (</=) 1

• Participants must

  1. be previously untreated for locally advanced/unresectable or metastatic melanoma or
  2. previously treated but without prior exposure to any BRAF or MEK inhibitor therapy or
  3. progressed on vemurafenib while participating in a Phase I (including clinical pharmacology studies), II, or III clinical study or expanded access programs (EAP) immediately prior to enrollment in this study or
  4. progressed on vemurafenib administered in a postmarketing setting immediately prior to enrollment in this study.

• Life expectancy >/=12 weeks

Exclusion Criteria:

• History of prior significant toxicity from another RAF or MEK pathway inhibitor requiring discontinuation of treatment
• Palliative radiotherapy within 2 weeks prior to first dose of study drug treatment
• Experimental therapy within 4 weeks prior to first dose of study drug treatment except vemurafenib
• Major surgery within 4 weeks of first dose of study drug treatment or planning a major surgery during the study