Pfizer nixes multiple Bavencio tests in recent clinical program dump

Some cohorts of a phase 2 trial that tests Pfizer and Merck KGaA's Bavencio alongside experimental OX40 agonist PF-04518600 and/or anti-4-1BB/CD137 drug utomilumab (PF-05082566) have been terminated. (Pfizer)

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

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.