Anti-angiogenic therapy is a proven therapeutic target in refractory gastric and gastroesophageal junction adenocarcinoma. This trial assessed whether the addition of a high affinity angiogenesis inhibitor, ziv-aflibercept, could improve the efficacy of first-line mFOLFOX6 (oxaliplatin, leucovorin, and bolus plus infusional 5- fluorouracil) chemotherapy in metastatic esophagogastric adenocarcinoma.

In this study (ZAMEGA), patients with treatment-naïve esophagogastric adenocarcinoma were randomly assigned 2:1 in a multicenter, placebo-controlled double-blind trial to receive first-line mFOLFOX6 with or without ziv-aflibercept 4mg/kg every 2 weeks. Randomization was stratified by ECOG performance status (0-1 vs. 2) and primary site of disease (esophagus or GE junction vs stomach).

In patients with esophagogastric cancer, mFOLFOX6 is considered standard of care. Every person has molecules in their bloodstream called vascular endothelial growth factors (VEGFs). These molecules help grow and sustain new blood vessels needed by the human body. Cancer tumors hijack this mechanism because they need new blood vessels and oxygen to grow. Ziv-aflibercept is an antibody, a "targeted therapy" called a "VEGF Trap", that "traps" (binds) these VEGFs and prevents the cancer from using them to grow. Ziv-aflibercept has recently been approved by the FDA for patients with treatment-resistant colorectal cancer. Patients who received standard 5-fluoruracil based chemotherapy pus ziv-aflibercept lived significantly longer than those patients who received standard 5-fluoruracil alone.

The study was designed to have an 80% power, at a 0.20 significance level, to detect a difference in 6-month progression-free survival of 15%, between 65% and 50%. A one-sided log rank test was utilized and all patients treated with at least one dose of mFOLFOX6 and ziv-aflibercept/placebo were included in the statistical analysis.

Inclusion Criteria:

• Confirmed adenocarcinoma of esophagus, GE junction or gastric origin
• Disease is not amenable to curative resection and is unresectable, locally advanced or metastatic
• Have not received any prior chemotherapy, investigative or biologic agents for esophagogastric cancer except in the neoadjuvant or adjuvant setting
• Any major surgery must be completed at least 4 weeks prior to study entry, minor procedures must be completed at least 2 weeks prior to study entry
• Vascular access device insertion should be performed at least 1 week prior to study entry. A central line is recommended for all participants
• Willing to use adequate contraception prior to study entry, for the duration of study participation and for 3 months after the last dose of Ziv-aflibercept/placebo

Exclusion Criteria:

• History of hypertension unless adequately controlled
• Evidence of active bleeding from primary tumor at time of study entry
• Pregnant or breastfeeding
• Squamous cell carcinoma histology
• Prior treatment for advanced or metastatic disease
• Palliative radiation to < 25% of bone marrow must have been completed 2 weeks prior to study entry, palliative RT to > 25% must have been completed 4 weeks prior to study entry
• Known allergy to study agents
• Known dihydropyrimidine dehydrogenase deficiency or thymidylate kinase gene polymorphism predisposing participant to 5-FU toxicity
• History of symptomatic congestive heart failure
• Clinically significant peripheral arterial disease
• Grade 2 or higher sensory or motor neuropathy
• Serious unhealed wound, ulcers or bone fractures
• History of HIV positivity or hepatitis B or C
• History of abdominal fistula, wound dehiscence, GI perforation, intra abdominal abscess, uncontrolled GI bleeding or diverticulitis that required hospitalization within 6 months of study entry
• History of arterial thrombotic events
• History of CNS hemorrhage in past 6 months
• Use of warfarin
• History of prior or synchronous malignancy except if treated with curative intent more than 3 years prior to enrollment, or adequately treated non-melanoma skin cancers, cervical carcinoma in situ or prostatic intraepithelial neoplasia without evidence of prostate cancer
• Uncontrolled non-malignant illness
• Uncontrolled psychiatric illness

The analysis dataset is comprised of all randomized patients.

Adverse events were assessed day 1 of each cycle. Patients received a median (range) treatment duration (months) of 6.9 (0-23.3) and 6.4 (0-43.9) for mFOLFOX6/ziv-aflibercept and mFOLFOX6/placebo, respectively.

Maximum grade toxicity by type was first calculated. Serious AEs were defined as events with treatment attribution of possibly, probably or definitely and grade 3 or higher per CTCAEv4. All remaining events regardless of treatment attribution were classified as Other AEs. Per the source vocabulary (CTCAEv4.0) there is a category "Other, specify" for each system organ class. No further data is available to specify classification beyond this general term.