UPDATE 2-US FDA staff question J&J, Zeltia cancer drug data
* FDA wants to know if benefits justify risks
* Will ask advisory panel for input on Wed
* J&J: Drug safe, effective for relapsed ovarian cancer
* Zeltia shares fall 19 pct
(Recasts, adds staff review of second drug, analyst and company comment, share prices)
WASHINGTON, July 13 (Reuters) - U.S. drug reviewers will ask outside advisers if a Johnson & Johnson (JNJ.N) and Zeltia (ZEL.MC) drug provides enough benefit to justify its approval for women with ovarian cancer, a memo released on Monday said.
Shares of Spanish biotechnology company Zeltia dropped 19 percent to 4.47 euros in Madrid trading.
Food and Drug Administration staff said discrepancies in radiology readings raised the question of whether patients' status was reliably measured in the main study of the drug, Yondelis. The study examined the time it took the cancer to worsen when patients were treated with a combination of Yondelis and another J&J cancer drug, Doxil.
Doxil is already approved for treating cancer, while Yondelis is not currently sold in the United States.
FDA staff said they would ask an advisory panel that meets Wednesday if the results "are reliable, are clinically significant, and are associated with an acceptable benefit:risk ratio."
The study found patients had about six more weeks without their cancer getting worse if they were treated with Doxil. FDA staff said they would ask the advisory panel if the extra six weeks "at a cost of additional toxicity is sufficient benefit for approval."
The main side effects included a decrease in white blood cells that can make patients vulnerable to infections, the FDA reviewers said. Cardiac problems also were higher in patients who received Yondelis.
CM Capital Markets equity analyst Flemming Barton said the staff review "casts doubts over Zeltia's flagship drug."
"This is bad news ... There was a lot of expectation that the FDA would give the green light right away," Barton said.
"But the stock has had a very good run, outperforming the broad market ahead of the FDA decision, so it's not so surprising there are sell orders in there now," he added. Continued...
