Hey PGS, you still looking at this? Leerink downgraded on concerns about the ADT prevention trial for Acapodene, and it's been sailing down to possible breakdown territory ever since (good timing by Wilder to lighten). Both Leerink and Cowen are concerned about the power of the trial.
>>GTX Shares Fall on Study Concern
Monday April 30, 12:54 pm ET
GTX Shares Drop Over Analyst Concern for Structure of Portion of Acapodene Study
NEW YORK (AP) -- Shares of biotechnology company GTX Inc. stumbled Monday on concerns on the risks involved with a late-stage study of the company's prostate cancer drug Acapodene.
The drug is aimed at treating bone loss associated with androgen deprivation therapy in prostate cancer patients. The therapy is used to reduce levels of androgens (ADT therapy), such as testosterone, in the body in order to shrink prostate cancer. Another study is focusing on prostate cancer prevention.
Leerink Swann & Co. analyst Howard Liang downgraded the company to "Market Perform" from "Outperform" saying one of late-stage studies could be underpowered to detect statistically significant results.
Shares of GTX fell $1.62, or 7.2 percent, to $20.85 on the Nasdaq Stock Market in midday trading, but still remained near their 52-week high point. The stock has traded between $7.70 and $23.64 over the last year.
Despite Wall Street's view that the bone loss prevention study will likely work, based on previous results with similar compounds, Liang said there are a number of uncertainties. Primarily, he said, the study may be set up in a way that makes it difficult for the company to prove the drug is effective. There is also limited experience in establishing an assumed fracture rate to estimate the size of the study.
Also, men have a different baseline in bone mass than women, meaning previous results on women may not correlate into positive results in the current study.
"Bottom line -- the ADT trial is one that should work and is widely expected to work, but we simply lack this conviction and differ from the Street's view in this regard," Liang wrote.
Data from the Phase III clinical trials are expected during the fourth-quarter.
Cowen and Co. analyst Eric Schmidt took a more optimistic view of the drug's prospects but still mentioned some caution, citing positive interim results in the late stage study, in a report detailing prostate cancer drug development.
"Our experts view interim Phase III data on acapodene as 'spot-on', demonstrating a favorable effect on bone density that they believe will translate into fracture reduction," he wrote.
The biggest risk to success, though, is the powering of the trial, which is based upon previous assumptions for effectiveness, he wrote.<<
I don't understand what Schmidt means by that last sentence What previous assumptions is he talking about? How does this square with my notes from the UBS presentation of last October?
"In the prevention trial there is an event driven interim efficacy analysis that if successful (50% reduction in prostate cancer), will result in NDA. Powered at 89% for p=.001. That's the late '07 date given above."
Message 22953292
Does this mean the FDA is looking for p=.001 in order to approve based on the interim look? I gather it does, since the low p value is used yo keep from giving up too much alpha for the final look, yes? In which case . . . 89% isn't that bad, though one would like to see middle 90s.
So far, only the secondary endpoints have been unblinded, and I imagine you noticed they seem to be hitting them all easily. Do you share any of these analysts' concerns? Wilder?
Tempted to buy here on anticipation of good results, though may bail or hedge before they show up -- I've done horribly holding through binaries this year.
Cheers, Tuck |
