As the researchers behind Pfizer and Astellas' Padcev and Merck's Keytruda have taken victory laps on the heels of the positive readout of Keynote-905 study—also known as EV-303—terms like "transformational," "practice-changing" and "new standard of care" have been put to use.
With an FDA approval on Friday, the combination now has its official go-ahead as a perioperative treatment regimen for people with muscle-invasive bladder cancer (MIBC) who can't receive chemotherapy.
Padcev and Keytruda is the first and only approved perioperative treatment regimen for cisplatin-ineligible patients with MIBC, Pfizer said in a media statement Friday, meaning the pairing can be used before and after surgery.
The FDA approved the regimen based on findings from the Keynote-905/EV-303 trial, results from which were recently presented at the European Society for Medical Oncology congress in Berlin.
In the study, the PD-1/antibody-drug conjugate combo slashed patients' risk of death by a game-changing 50% when used before and after bladder removal surgery in those with previously untreated MIBC who were not eligible for—or who declined—cisplatin-based chemotherapy. The trial compared the perioperative treatment and surgery to surgery alone.
On the measure of event-free survival, the combo improved outcomes by 60% versus surgery alone, investigators said. "Events" in the endpoint were defined as progression of disease that precluded surgery, failure to undergo surgery, gross residual disease left behind during surgery, cancer recurrence and death.
“Today’s approval, granted months earlier than anticipated, ushers in a new era of treatment for cisplatin-ineligible patients with MIBC who have long been underserved by existing treatments," Pfizer's Chief Oncology Officer Jeff Legos, Ph.D., said in a press release.
The regimen stands to offer "a new standard of care for patients who rely solely on surgery," Legos added.
After a bladder removal surgery, half of patients with MIBC may experience recurrence and many cannot receive cisplatin, Mount Sinai Tisch Cancer Center's Director of Genitourinary Medical Oncology, Matthew Galsky, M.D., said in a statement provided by Pfizer. Galsky is an investigator in the EV-303 study.
The approval is "based on striking event-free and overall survival benefits" and may "represent an important practice-changing advance for these patients who’ve had no new options in decades," Galsky added.
The FDA approval covers the use of the original infused version of Keytruda and the newer subcutaneous Keytruda Qlex, according to the FDA's announcement.