Pfizer nixes multiple Bavencio tests in recent clinical program dump

In Pfizer’s most recent clinical program dump, the New York pharma pulled the plug on several studies of its Merck KGaA-shared immuno-oncology drug Bavencio.

Some cohorts of early- to mid-stage Javelin Medley trial testing Bavencio alongside investigational OX40 agonist PF-04518600 and/or anti-4-1BB drug utomilumab (PF-05082566) have ended, Pfizer revealed in its fourth-quarter pipeline upgrade.

Information is thin as to why Pfizer stopped the trials, described simply as tests in solid tumors. Other combo tests survived, including an ongoing investigator-sponsored phase 2 examining three Bavencio pairings—with PF-04518600, utomilumab and Pfizer-acquired Array BioPharma’s MEK inhibitor binimtinib—in triple-negative breast cancer. Its primary completion date is set in mid-2020, according to clinicaltrials.gov.

RELATED: Pfizer, Merck KGaA's Bavencio flunks study in hard-to-treat gastric cancer

Meanwhile, a phase 3 of Bavencio as maintenance therapy for prevention of stomach cancer progression after an initial round of chemo has officially ended. It’s no surprise, however; the drug failed to top continuation of chemo or best supportive care at prolonging patients’ lives—not even in PD-L1-positive population.

But Pfizer recently read out positively for another Bavencio first-line maintenance trial. A phase 3 dubbed Javelin Bladder 100—which has a similar design as the failed Javelin Gastric 100—showed Bavencio as a monotherapy could help locally advanced or metastatic urothelial cancer patients live significantly longer than best supportive care.

RELATED: Pfizer, Merck KGaA's Bavencio posts first-in-class bladder cancer win

It marks the first such win for an immuno-oncology agent in an area where chemo still constitutes the standard of care. At last year’s American Society of Clinical Oncology annual meeting, investigators also reported a phase 2 trial of Keytruda in the same frontline maintenance setting showed a response in 22% of bladder cancer patients, versus 12% in the placebo arm.

A phase 1 trial that combines Keytruda with Pfizer’s VEGFR inhibitor Inlyta appears as “discontinued.” But a Pfizer spokesperson told FiercePharma that it actually refers to a dose-finding trial in renal cell carcinoma that posted preliminary results in 2016. That early study led to the phase 3 that got the Keytruda-Inlyta pairing an FDA nod in previously untreated kidney cancer last April. The Bavencio-Inlyta regimen immediately followed with the same green light.

Editor's Corner: This story has been updated to clarify that only some cohorts in the Javelin Medley trial were stopped. And, rather than being nixed, the Keytruda-Inlyta phase 1 has already read out.