Bayer pulls veil back on Xofigo-Zytiga combo study after deaths, fractures crop up

Bayer still plans to test Xofigo in additional prostate cancer trials.

Bayer thought it might be able to expand Xofigo in prostate cancer by testing it with Johnson & Johnson’s Zytiga. But that plan has hit a snag.

The German drugmaker unblinded a phase 3 study combining the two meds with steroids after an independent data monitoring committee identified more fractures and deaths in the Xofigo arm. Now, the company is raising the curtain on the study “to thoroughly analyze the data,” Mike Devoy, Bayer’s chief medical officer, said in a statement.

“It is important to note that, based on available data from previous trials as well as real-world use, the benefit-risk profile of Xofigo in its approved indication remains favorable,” he said.

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The trial had been testing the treatment trio against Zytiga and steroids alone in patients with a certain type of prechemo, bone-predominant castration-resistant prostate cancer. Xofigo is now approved for patients with castration-resistant prostate cancer, symptomatic bone metastases and no known visceral metastatic disease.

As one of five growth products Bayer has tapped for major success, Xofigo’s under a lot of pressure to come up big. To allay investors’ concerns after agreeing to a blockbuster deal with agrichemicals giant Monsanto, last year the German drugmaker upped its peak sales forecasts for the big 5—a group that also includes next-gen anticoagulant Xarelto, eye blockbuster Eylea, pulmonary arterial hypertension therapy Adempas and fellow oncology med Stivarga—to more than €10 billion from €7.5 billion.

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For the third quarter, though, that cohort brought in just €1.52 billion, which means Bayer still has a long way to go. And during the same period, Xofigo’s U.S. sales actually shrank compared with last year’s, checking in at €59 million versus 2016’s €60 million.

The company isn’t giving up on Xofigo’s expansion potential, however—even in prostate cancer. Bayer remains “committed to further exploring the potential” of Xofigo “across multiple tumor types with significant unmet need,” Devoy said.