Merck KGaA, a German multinational chemical, pharmaceutical and life sciences company, and Pfizer, an American multinational pharmaceutical corporation, announced the initiation of two phase III studies of avelumab, an investigational, fully human anti-PD-L1 IgG1 monoclonal antibody, in treating advanced or metastatic gastric/gastro-esophageal junction (GEJ) cancers, which are aggressive cancers with poor survival rates. These pivotal trials are investigating avelumab in the first-line and third-line settings, with overall survival (OS) as the primary endpoint in both trials.

JAVELIN Gastric 100, a study comparing the switch from first-line chemotherapy to maintenance therapy with avelumab versus continuation of chemotherapy, is a multicenter, international, randomized, open-label phase III trial designed to evaluate the potential superiority (based on OS) of maintenance therapy with avelumab in patients with unresectable, locally advanced or metastatic gastric/GEJ cancers whose disease has not progressed with first-line platinum-based chemotherapy. This is currently the only phase III trial in gastric cancer that is designed to evaluate superiority of an immunotherapy compared with conventional platinum-based chemotherapy as a first-line maintenance treatment. The study will enroll 629 patients across more than 220 sites in Asia Pacific, Europe, North America and South America.

“The prognosis is generally poor for the majority of patients with advanced gastric cancers,” said Dr. Luciano Rossetti, global head of research & development of the biopharma business of Merck KGaA, Darmstadt, Germany.

“By initiating these two phase III trials in gastric and gastro-esophageal junction cancers, we are continuing the fight against cancer with an overarching goal of potentially improving survival for patients.”

The third-line study, JAVELIN Gastric 300, is a multicenter, international, randomized, open-label phase III trial designed to evaluate the potential superiority (based on OS) of avelumab in patients with unresectable, recurrent or metastatic gastric/GEJ cancers, compared with investigator’s choice of chemotherapy from a pre-specified list of therapeutic options. The study will enroll approximately 330 patients, spanning approximately 170 sites in Asia, Australia, Europe, North America and South America.

“We are continuing to investigate avelumab in cancers with high unmet need and where there is a strong rationale for immunotherapeutic intervention,” said Dr. Mace Rothenberg, senior vice president of clinical development and medical affairs and chief medical officer for Pfizer Oncology.

“Advanced gastric cancer is a challenging diagnosis to face as a patient, and we are dedicating significant resources to evaluate avelumab as a potential new treatment option for patients in multiple settings of this disease.”

The clinical development program for avelumab now includes more than 1,500 patients who have been treated across more than 15 tumor types, including breast cancer, gastric/GEJ cancers, head and neck cancer, Merkel cell carcinoma, melanoma, mesothelioma, non-small cell lung cancer, ovarian cancer, renal cell carcinoma and urothelial (e.g. bladder) cancer. Clinical trials for both of the gastric/GEJ phase III trials in North America will be conducted on behalf of Merck KGaA, Darmstadt, Germany, by EMD Serono, the company’s US and Canadian biopharma business.