Merck’s Keytruda Shows Survival Benefit as Adjuvant Therapy in Stage II Melanoma

On August 5th, Merck (known as MSD outside the United States and Canada) announced that it has sought a new sBLA for Keytruda as adjuvant therapy in adult and pediatric patients with surgically resected high-risk stage II melanoma. The decision is an outcome of a positive interim analysis from the Phase 3 KEYNOTE-716 trial. 

“This is an important milestone discovery, and we look forward to sharing these results with the medical community as soon as possible,” said Dr. Roy Baynes, Senior Vice President and Head of Global Clinical Development, Chief Medical Officer, Merck Laboratories.

Blockbuster Immunotherapy

Stage II melanoma is characterized by the presence of cancer cells in both the epidermis and the dermis layers of skin, signifying an increased risk of recurrence and disease dissemination.

Surgical excision is the treatment of choice for early cutaneous melanoma. However, according to Dr. Jason Luke, Director, Cancer Immunotherapeutics Center at UPMC Hillman Cancer Center, “the immunotherapy with Keytruda in earlier stages of melanoma can reduce the risk of recurrence in patients with complete resection.”

Keytruda, Merck’s blockbuster drug, is an anti-PD-1 therapy that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, activating T lymphocytes to attack tumors.

In the US, Keytruda is indicated for treating patients with unresectable or metastatic melanoma and melanomas with involvement of lymph nodes following complete resection. Keytruda has been approved in over 90 countries as adjuvant therapy in patients with resected stage III melanoma based on successful trial results.

KEYNOTE-716 Trial

The KEYNOTE-716 trial is a part of Merck’s expansive program investigating Keytruda in early disease states of four tumor types. It is the first Phase 3 study to evaluate the drug as adjuvant therapy solely for stage IIB and IIC melanoma. The study enrolled adult and pediatric patients (12 years and older) with melanoma following complete resection.

The first part of the study was a double-blind trial in which adult patients were randomized to receive either intravenous Keytruda at a dose of 200mg or a placebo every three weeks for up to 17 cycles for approximately one year. Pediatric patients were randomized to receive intravenous Keytruda at a dose of 2mg/kg with a maximum of 200 mg or placebo for the same period.

The second part of the study was an open-label trial in which eligible adult and pediatric patients received up to 35 additional cycles of Keytruda, translating to approximately two years. Eligibility was defined by recurrence after receiving placebo or after completing 17 cycles of Keytruda with recurrence after six months of treatment.

Results show that as compared to placebo, Keytruda registered an improvement in recurrence-free survival (primary endpoint) with no new safety signals (secondary endpoint) in melanoma patients. Merck will present detailed results at an upcoming medical meeting.

Author

Manju Bhaskar