Amgen’s star PhIII osteoporosis drug romo slammed by surprising cardio risk, a big plus for rival Radius drug

Amgen’s romosozumab, one of its top late-stage drug prospects aimed at osteoporosis, is in some serious trouble.

Late Sunday the big biotech $AMGN and its partner UCB announced what at first glance would appear to be happy news: the late-stage trial comparing romosozumab to Fosamax hit its primary and key secondary endpoints. But as you wind through the release, some big issues start to rise up that raise serious questions about its future — if it has one. And that could make a big difference for its newly approved rival at Radius Health $RDUS.

Big event one: There was a notable cardio risk imbalance between romo and Fosamax; 2.5% for romo and 1.9% for Fosamax.

Big event two: The FDA wants to evaluate the new set of head-to-head data in sizing up an approval. And that means no decision is expected this summer, as had been assumed earlier.

Amgen shares dropped 2.3% in pre-market trading, while UCB plunged 14.5%. Radius shares jumped about 15% on the news.

Umer Raffat at Evercore ISI spotted the significance quickly. He noted:

Amgen’s Ph 3 update on bone drug just now is clearly negative, and very surprising.  At this point, we are taking out all romo sales from the model.  Consensus has ~$800M peak for this drug – if you take it out (and bake in the partnership split with UCB), EPS revision of ~$0.32/share.  We suspect stock likely down ~3-4% on this.

That all sounded suspiciously like odanacatib, Merck’s osteoporosis drug which the pharma giant decided to shelve last fall after witnessing an increase risk of stroke for the drug. And Geoffrey Porges at Leerink calculated the odds of Amgen scrapping the drug.

We believe that the product now has only a 50/50 probability of coming to market at all, and these odds are subject to the results of discussions with specialists and investigators, as well as full disclosure of the nature and severity of the cardiovascular events observed in both studies.

Just a few weeks ago Radius won their first ever drug approval for abaloparatide, now being lined up for the osteoporosis market as Tymlos. Analysts like Geoffrey Porges had thought Radius may try to go after a unique market with a commercial strategy taking into account Eli Lilly’s aging Forteo with the rival romosozumab from Amgen and UCB being steered into a July 19 PDUFA date.

But that’s at the very least significantly delayed — Radius CEO Bob Ward said it never was a factor — as far as romo is concerned.

Last fall analysts were talking more about a straight shot at a quick approval for romo this summer — with some significant caveats. Romo — which targets the sclerostin protein — followed by Amgen’s Prolia (denosumab) clearly vaulted the bar in Phase III for reducing vertebral fractures, with a hefty 75% risk reduction compared to a placebo plus denosumab. Investigators also were able to show a better safety profile in its presentation at the annual confab of the American Society for Bone Mineral Research. And there was an increase in bone mineral density among the drug arm in the study, which recruited 7,180 high-prism postmenopausal women.

But the drug missed a key secondary endpoint. The drug did not significantly improve patients’ risk of non-vertebral fractures, leaving Radius Health — which has posted an 86% risk reduction in vertebral fractures — with a possible distinct advantage on that score.

Amgen and its partners at UCB didn’t ignore the situation today, after highlighting the positive.

Iris Loew-Friedrich

“We are impressed with the statistically significant superior fracture risk reduction of EVENITY over alendronate, a current standard of care in osteoporosis. When we think that patients who have had a fracture are highly likely to suffer another one, the importance of post-fracture care cannot be emphasized enough,” said Iris Loew-Friedrich, UCB’s chief medical officer. “We are working on understanding the observed cardiovascular safety signal and will continue to discuss these results with global regulators and experts in the field.”

This is a bad twist for Amgen. The biopharma player has had a series of issues, including a big backlash by payers targeting its PCSK9 drug. Watching another late-stage drug go under a cloud like this won’t help Amgen’s rep with analysts.

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Research Scientist - Immunology
Recursion Pharmaceuticals Salt Lake City, UT
Director of Operations
Atlas Venture Cambridge, MA

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