Pfizer, Merck KGaA scrap yet another Bavencio ovarian cancer trial

Pfizer and Merck KGaA have had a rough go at broadening immuno-oncology drug Bavencio's reach, and the pair are calling it quits on yet another late-stage trial—the third to bite the dust in ovarian cancer alone. 

It's the latest blow for Bavencio (avelumab), the fourth-to-market PD-1/PD-L1 therapy that's competing with I-O blockbusters Keytruda and Opdivo. Tuesday, the companies said they would nix a study evaluating a Bavencio-chemo combo—followed by treatment with a pairing of Bavencio and Pfizer PARP contender Talzenna—in previously untreated patients with stage III or stage IV disease.

As the drugmakers explained in a statement, multiple factors figured into the decision to discontinue the trial, dubbed Javelin Ovarian PARP 100. But not the least of which were poor results they rolled out in December showing that Bavencio, in tandem with and/or after chemo, couldn’t stave off cancer progression in previously untreated patients.

Those data prompted Pfizer and Merck KGaA to cancel the study they came from, known as Javelin Ovarian 100.

RELATED: Pfizer, Merck KGaA's Bavencio takes a hit with second ovarian cancer failure

“The alliance determined that the degree of benefit observed with avelumab in frontline ovarian cancer in that study does not support continuation of the Javelin Ovarian PARP 100 trial in an unselected patient population and emphasizes the need to better understand the role of immunotherapy in ovarian cancer,” the companies said in a statement.

Pfizer and Merck KGaA cited other reasons for yanking the trial, too—including “the rapidly changing treatment landscape” and the December approval of AstraZeneca and Merck’s Lynparza in the front-line ovarian cancer maintenance setting. But they didn’t make the move on account of any safety concerns, they stressed.

RELATED: AstraZeneca, Merck's Lynparza plows ahead in ovarian cancer with $1B-plus approval, phase 3 data

As far as the changing landscape goes, Pfizer has Talzenna’s PARP rivals to thank. Fourth-to-market Talzenna is the only member of the class on the market that doesn’t bear an ovarian cancer indication, and if it can eventually score a green light in the disease area, it’ll be chasing down Lynparza as well as GlaxoSmithKline’s Zejula and Clovis Oncology’s Rubraca.

Those drugs are also already in clinical trials for I-O combinations of their own. Merck, after shelling out major money for a 50% stake in Lynparza, is testing the drug alongside Keytruda in variety of cancers, including as an ovarian cancer maintenance regimen, and developer AstraZeneca is trialing Lynparza with its own checkpoint drug, Imfinzi, in ovarian cancer as well. Clovis, meanwhile, in 2017 teamed up with Bristol-Myers Squibb to test Rubraca in combination with Opdivo in certain settings, including ovarian cancer maintenance. 

Meanwhile, Bavencio’s ovarian cancer hardships have extended outside the first-line setting. Last November, its makers said it had come up short in a phase 3 study enrolling previously treated patients, failing both solo and in combination with chemo to keep disease at bay or extend patients’ lives. They ultimately scrapped that study, too. 

For that matter, the woes have extended outside ovarian cancer, too. Bavencio has missed the mark in a range of other trials: for one testing it in a range of solid tumors alongside an immuno-oncology candidate dubbed “4-1BB,” one in third-line gastric cancer and one in second-line lung cancer that Pfizer and Merck KGaA also discontinued. 

Those kinds of outcomes won’t help Bavencio, which is facing its own slew of tough competitors in the checkpoint inhibitor crowd. Merck’s Keytruda leads the field, with rivals such as Bristol-Myers Squibb’s Opdivo and Roche’s Tecentriq jockeying for position, too.