FDA Approves Pembrolizumab for First-Line Treatment of Advanced Bladder Cancer

The FDA has granted full approval to pembrolizumab (Keytruda) for the treatment of patients with locally advanced or metastatic urothelial carcinoma (mUC) and are not deemed eligible for platinum-containing chemotherapy.

Pembrolizumab’s original indication had been granted an accelerated indication based off the tumor response rate and duration of response with continued approval remaining contingent upon certification of clinical benefit in confirmatory trials.

“While the treatment landscape has evolved, an unmet need remains for appropriate patients newly diagnosed with certain types of advanced urothelial carcinoma who are not eligible for platinum-containing chemotherapy,” Scot Ebbinghaus, MD, vice president, clinical research, Merck Research Laboratories, stated in a press release. “We are confident in the role [pembrolizumab] will continue to play for these patients who have few other treatment options and are working with urgency to advance studies to help more patients living with bladder and other types of cancer.”

Earlier this year, the drug was assessed by the FDA’s Oncologic Drugs Advisory Committee (ODAC) during an industry wide evaluation of accelerated approvals that had not yet met their post-marking requirements. ODAC members voted 5-3 to maintain the accelerated approval of pembrolizumab for the first-line bladder indication.

The following phase 3 KEYNOTE-361 trial, which evaluated pembrolizumab both as a monotherapy and in combination with chemotherapy for early treatment of patients with advanced or metastatic urothelial cancer and were fit to receive platinum-containing chemotherapy, did not achieve its pre-specified dual primary end points of overall or progression-free survival, in comparison with the current standard-of-care chemotherapy.

Pembrolizumab is also approved to treat patients with locally advanced or mUC following platinum-containing chemotherapy or within 12 months of neoadjuvant or adjuvant treatment with platinum-containing chemotherapy as well as for the treatment of patients with Bacillus Calmette-Guerin-unresponsive, high-risk, non-muscle invasive bladder cancer and are ineligible for or have chosen not to undergo cystectomy.

The humanized monoclonal antibody functions by blocking the interaction between PD-1 and its ligands, PD-L1 and PD-L2. Patients receiving pembrolizumab should be monitored for potential immunotherapy-related adverse events (irAEs). Liver enzymes, creatinine, and thyroid function should be assessed at baseline and revisited throughout treatment.

For serious irAEs, corticosteroid therapy should be administered (1 to 2 mg/kg/day prednisone or equivalent) until the grade is diminished to grade 1 or less. Pembrolizumab should be withheld or discontinued if the steroids do not improve symptoms.

Some AEs occur at a 10% higher rate in pediatric patients compared with adults, including pyrexia (33%), vomiting (30%), leukopenia (30%), upper respiratory tract infection (29%), neutropenia (26%), headache (25%), and Grade 3 anemia (17%).

References

1. FDA approves updated indication for Merck's KEYTRUDA (pembrolizumab) for the treatment of certain patients with urothelial carcinoma (bladder cancer). News release. Merck. August 31, 2021. Accessed August 31, 2021. https://bwnews.pr/3zCgh3N