A Study of Ipatasertib (GDC-0068) in Combination With Fluoropyrimidine Plus Oxaliplatin in Participants With Advanced or Metastatic Gastric or Gastroesophageal Junction Cancer

A Randomized, Phase II, Placebo-controlled Study of Ipatasertib (GDC-0068), an Inhibitor to Akt, in Combination With Fluoropyrimidine Plus Oxaliplatin in Patients With Locally Advanced or Metastatic Gastric or Gastroesophageal Junction Adenocarcinoma

This multicenter, randomized, double-blind, placebo-controlled study will evaluate the efficacy of ipatasertib in combination with oxaliplatin, 5-fluorouracil, and leucovorin (modified FOLFOX6 [mFOLFOX6]) chemotherapy in participants with advanced or metastatic gastric or gastroesophageal junction (GEJ) cancer. Participants will be randomized to receive either ipatasertib or placebo orally daily on Days 1 to 7 of each 14-day cycle in combination with mFOLFOX6 on Day 1 of each cycle.

Inclusion Criteria:

• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
• Histologically documented, inoperable locally advanced or metastatic or recurrent gastric/GEJ adenocarcinoma, not amenable to curative therapy
• Measurable disease, according to RECIST v1.1
• Life expectancy greater than or equal to (>/=) 12 weeks
• Adequate hematologic and organ function

Exclusion Criteria:

• Previous chemotherapy for inoperable locally advanced or metastatic gastric/GEJ adenocarcinoma. Participants may have received prior neoadjuvant or adjuvant chemotherapy and/or radiation treatment for locally advanced gastric/GEJ adenocarcinoma, provided all treatments were completed >/= 6 months prior to randomization.
• Known human epidermal growth factor receptor 2 (HER2)-positive gastric/GEJ adenocarcinoma
• Radiation treatment within 28 days of randomization. Participants who have received palliative radiation treatment to peripheral sites (eg, bone metastases) within 28 days of randomization may be enrolled in the study if they have recovered from all acute, reversible effects and with notification of the Medical Monitor.
• Previous therapy for gastric/GEJ adenocarcinoma with Akt, phosphatidylinositol 3-kinase (PI3K), and/or mammalian target of rapamycin (mTOR) inhibitors
• Major surgical procedure, open biopsy, or significant traumatic injury within 28 days prior to randomization or anticipation of need for a major surgical procedure during the course of the study