FDA Approves Merck’s KEYTRUDA (pembrolizumab) Plus Pemetrexed and Platinum Chemotherapy as First-Line Treatment for Adult Patients With Unresectable Advanced or Metastatic Malignant Pleural Mesothelioma (MPM)

Merck, known as MSD outside of the United States and Canada, today announced the U.S. Food and Drug Administration (FDA) has approved KEYTRUDA, Merck’s anti-PD-1 therapy, in combination with pemetrexed and platinum chemotherapy, for the first-line treatment of adult patients with unresectable advanced or metastatic malignant pleural mesothelioma (MPM).

The approval is based on data from the pivotal Phase 2/3 IND.227/KEYNOTE-483 trial. In IND.227/KEYNOTE-483, KEYTRUDA plus chemotherapy demonstrated a statistically significant improvement in overall survival (OS), reducing the risk of death by 21% (HR=0.79 [95% CI, 0.64-0.98]; p=0.0162) compared to chemotherapy alone at the trial’s pre-specified final analysis. Median OS was 17.3 months (95% CI, 14.4-21.3) for KEYTRUDA plus chemotherapy versus 16.1 months (95% CI, 13.1-18.2) for chemotherapy alone. KEYTRUDA plus chemotherapy also significantly improved progression-free survival (PFS) versus chemotherapy alone (HR=0.80 [95% CI, 0.65-0.99], p=0.0194; median PFS 7.1 months [95% CI, 6.9-8.1] versus 7.1 months [95% CI, 6.8-7.7], respectively). Overall response rate (ORR) was significantly higher for KEYTRUDA plus chemotherapy versus chemotherapy alone (52% [95% CI, 45.5-59.0] versus 29% [95% CI, 23.0-35.4], respectively; p<0.00001). Adverse reactions occurring in patients with MPM were generally similar to those in other patients receiving KEYTRUDA in combination with pemetrexed and platinum chemotherapy.

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, other transplant (including corneal graft) 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. Based on its mechanism of action, KEYTRUDA can cause fetal harm when administered to a pregnant woman.

“We’re pleased to offer a new first-line treatment option for adult patients with unresectable advanced or metastatic malignant pleural mesothelioma, a disease where prognoses are generally poor,” said Dr. Gregory Lubiniecki, vice president, oncology clinical research, Merck Research Laboratories. “This milestone underscores our commitment to advancing research for patients with difficult-to-treat tumors.”