Pfizer, Merck KGaA's Bavencio flunks another trial, this time in ovarian cancer

Pfizer and Merck KGaA's Bavencio has failed its fourth high-profile trial. (Pfizer)

Mark another tally for Pfizer and Merck KGaA’s Bavencio in the “loss” column.

Monday, the drugmakers reported that their immuno-oncology drug had failed a phase 3 trial in previously treated ovarian cancer patients, failing to stave off cancer progression or prolong life either on its own or in tandem with chemo.

As the companies were quick to point out, the trial enrolled “a population known to have disease that is challenging to treat” and one that’s often left out of phase 3 trials, Chris Boshoff, M.D., Ph.D., SVP and head of Immuno-Oncology, Early Development and Translational Oncology at Pfizer Global Product Development, said in a statement.

But it’s far from Bavencio’s only high-profile trial miss. The drug, which followed PD-1/PD-L1 rivals such as Merck’s Keytruda and Bristol-Myers Squibb’s Opdivo into an ultracompetitive immuno-oncology arena, has flunked a range of other trials: 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.

RELATED: Pfizer preps for Bristol-Myers Squibb showdown with Bavencio kidney cancer combination data

That’s not to say it’s all been bad news for Bavencio. Last month, its makers unveiled data showing that the contender, paired with Pfizer’s Inlyta, could keep kidney-cancer progression at bay in previously untreated patients by a median 13.8 months, compared with 8.4 months for Pfizer standard-of-care drug Sutent.

But the drug, which bears just two approvals, has still struggled to make the kind of inroads its peers have in the field, and before Monday’s news, the lung cancer flop in particular had industry watchers scratching their heads. Evercore ISI analyst Umer Raffat, for one, made the case that Bavencio “should get a pass” on its first two misses, but he couldn’t say the same for the third.

RELATED: Pfizer's Bavencio flops third key study, this time in lung cancer. Can crossover really explain it?

Meanwhile, the companies aren’t yet throwing in the towel on the ovarian cancer trial.

“Study results indicate potential clinical activity” of the Bavencio-chemo combo, and they’ll be “analyzed further,” Luciano Rossetti, M.D., EVP and global R&D head of Merck KGaA’s biopharma business, said in a statement.

The partners testing two Bavencio combos among previously untreated ovarian cancer patients. One phase 3 study features the Bavencio-chemo regimen, while the other combines the drug with a PARP inhibitor.