KEYTRUDA approved for gastric or gastroesophageal junction adenocarcinoma

May 6, 2021

KEYTRUDA is the first anti-PD-1 therapy approved in combination with trastuzumab and chemotherapy for the first-line treatment of these patients.

Merck, known as MSD outside the United States and Canada, have announced that the U.S. Food and Drug Administration (FDA) has approved KEYTRUDA, MSD’s anti-PD-1 therapy, in combination with trastuzumab, fluoropyrimidine- and platinum-containing chemotherapy, for the first-line treatment of patients with locally advanced unresectable or metastatic HER2-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma.

This indication is approved under accelerated approval based on tumour response rate and durability of response; continued approval for this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials. This approval is based on data from the ongoing Phase 3 KEYNOTE-811 trial, in which KEYTRUDA in combination with trastuzumab and either 5-fluorouracil plus cisplatin or capecitabine plus oxaliplatin demonstrated a statistically significant objective response rate (ORR) of 74% (95% CI, 66-82) for patients who received the regimen with KEYTRUDA versus 52% (95% CI, 43-61) for those who received trastuzumab and chemotherapy alone (p<0.0001). For patients who received the regimen with KEYTRUDA, the complete response rate was 11% and the partial response rate was 63%. For patients who received trastuzumab and chemotherapy alone, the complete response rate was 3.1% and the partial response rate was 49%.

This is the first time an anti-PD-1 therapy has been approved in combination with anti-HER2 therapy and chemotherapy as a first-line treatment for these patients

Dr. Roy Baynes, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories

Immune-mediated adverse reactions, which may be severe or fatal, can occur in any organ system or tissue and can affect more than one body system simultaneously. Immune-mediated adverse reactions can occur at any time during or after treatment with KEYTRUDA, including pneumonitis, colitis, hepatitis, endocrinopathies, nephritis, dermatologic reactions, solid organ transplant rejection, and complications of allogeneic hematopoietic stem cell transplantation. Important immune-mediated adverse reactions listed here may not include all possible severe and fatal immune-mediated adverse reactions. Early identification and management of immune-mediated adverse reactions are essential to ensure safe use of KEYTRUDA. Based on the severity of the adverse reaction, KEYTRUDA should be withheld or permanently discontinued and corticosteroids administered if appropriate. KEYTRUDA can also cause severe or life-threatening infusion-related reactions.

“Today’s approval marks an important milestone, as this is the first time an anti-PD-1 therapy has been approved in combination with anti-HER2 therapy and chemotherapy as a first-line treatment for these patients,” said Dr. Roy Baynes, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories. “From the start of KEYTRUDA’s development, we have thoughtfully pursued novel combinations to help more patients with cancer. We are pleased to bring a new first-line combination regimen with KEYTRUDA that has shown meaningful improvement in ORR over standard treatment to patients with HER2-positive gastric and GEJ cancer.”

This submission was reviewed under the FDA’s Real-Time Oncology Review (RTOR) pilot program.

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