A negative heart safety signal picked up in a clinical trial of Amgen's (AMGN) osteoporosis drug Evenity means the product will not be approved and on the U.S. market this year, as previously expected, the company said Sunday.

Evenity was already under FDA consideration with a marketing decision expected on July 19. But with questions now raised about the drug's heart safety risk, U.S. regulators want a look at safety data from the new clinical trial as part of the agency's review.

As a result, Amgen "does not expect approval of Evenity in the U.S. to occur in 2017," the company said. A timetable for how long the drug's approval might be delayed was not offered.

"Amgen's phase III update on bone drug [Evenity] just now is clearly negative and very surprising," wrote Evercore ISI analyst Umer Raffat, in a quick email to clients on Sunday night. "At this point, we are taking out all [Evenity] sales from the model. Consensus has approximately $800 million peak for this drug... We suspect stock likely down approximately 3-4% on this."

Amgen shares are down about 2% in early Monday trading. The stock closed Friday at $156.51.

In the phase III study known as ARCH, the incidence of positively adjudicated cardiovascular serious adverse events as 12 months was 2.5% in the Evenity-treated patients compared to 1.9% in the group of patients treated with alendronate, a generic osteoporosis drug that served as the active comparator in the study.

"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," said Iris Loew-Friedrich, chief medical officer of UCB, the Brussels-based drug maker that is co-developing Evenity with Amgen.

Amgen's osteoporosis setback will likely be seen as a providing a commercial boost to Radius Health (RDUS) , which secured U.S. approval in April for a competing osteoporosis drug, Tymlos.

Radius Health rose 17% in early Monday trading, but quickly retreated to a gain of just 10%. 

Amgen's such a good company with a solid 3% dividend yield, but it just seems to be "snake bitten," TheStreet's Jim Cramer, manager of the Action Alerts PLUS portfolio, said on CNBC's "Mad Dash" segment. And while this news is bad for Amgen, it's good for Radius -- as indicated by the stock's rally. Radius Health now has a much more clear runway for its treatment, Cramer said.

The osteoporosis market is a big one and that makes Radius an attractive takeover candidate, he added. A big drug company can acquire Radius and add its osteoporosis treatment to its own portfolio of products. It may not happen, but it's certainly not impossible, Cramer reasoned.

Updated from 7:19 ET to include Jim Cramer's comments, written by Bret Kenwell.

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