This account is pending registration confirmation. Please click on the link within the confirmation email previously sent you to complete registration.
Need a new registration confirmation email? Click here
See Cramer's multi-million dollar portfolio for FREE and get his new book Get Rich Carefully! Learn More

Your Guide to Deciphering Medivation's Most Important Prostate Cancer Drug Trial

Median overall survival is a very commonly used barometer of a drug's efficacy, however, it's not ideal. The preferred way to measure survival is by calculating a hazard ratio, which compares survival of all patients on the drug being studied compared to survival of all patients on placebo or some comparative treatment.

A hazard ratio of 1 means survival, or the risk of death, is the same for both arms of the study. A lower hazard ration (less than 1) equates to an improvement in survival, or a reduction in the risk of death.

As I said above, J&J reported a survival hazard ratio of 0.79 for the Zytiga pre-chemo study, which means patients treated with Zytiga had a 21% reduction in the risk of death compared to placebo. (1 - 0.79 = .21)

I feel smarter already. Thanks. So, if Xtandi brings home a survival hazard ratio of less than 0.79 in the PREVAIL study, it's a win?

Call the Xtandi bogey a hazard ratio of 0.75 or less, which would be meaningfully better than Zytiga. An Xtandi hazard ratio of 0.75 would also imply a median overall survival benefit of 8-10 months compared to placebo (assuming the placebo arm comes in with a median overall survival in the range of 26-30 months.) That would be a nice improvement over the five-month median survival benefit seen with Zytiga.

One more important point to keep in mind: J&J's Zytiga must be given with a steroid, while Xtandi does not. Urologists, who treat a majority of prostate cancer patients, hate giving steroids. This is a big advantage for Xtandi.

What if Xtandi doesn't reach median overall survival when the results are announced?

Hmm. I think you're smarter than you're letting on. You raise a good point. We may not get median overall survival in the Xtandi arm but that would be a plus, not a minus, as long as the hazard ratio is strong.

You've written 700-plus words on Xtandi so far and no mention at all of biostatistics and p values. How is that possible?

Okay, now you're mocking me. We definitely want to see a statistically significant p value attached to the Xtandi results, which would be another point of differentiation from Zytiga. You may not remember, the Zytiga survival benefit was not statistically significant, although to be fair, the statistical miss did not deter FDA from approving the drug anyway for pre-chemo prostate cancer patients. Same can be said for Xtandi in the unlikely event that the survival benefit comes back with an errant p value, although it won't make investors very happy.

When will Medivation and Astellas announced results from the PREVAIL study?

Official guidance is "before the end of the year," but I suspect the end of September or October is more likely. That's just a hunch.

How can you write a story about prostate cancer and not mention Dendreon (DNDN) or Provenge?

Who? What?

-- Reported by Adam Feuerstein in Boston.

Stock quotes in this article: MDVN, JNJ, DNDN 
Adam Feuerstein writes regularly for TheStreet. In keeping with company editorial policy, he doesn't own or short individual stocks, although he owns stock in TheStreet. He also doesn't invest in hedge funds or other private investment partnerships. Feuerstein appreciates your feedback; click here to send him an email.

Select the service that is right for you!

COMPARE ALL SERVICES
Action Alerts PLUS
Try it NOW

Jim Cramer and Stephanie Link actively manage a real portfolio and reveal their money management tactics while giving advanced notice before every trade.

Product Features:
  • $2.5+ million portfolio
  • Large-cap and dividend focus
  • Intraday trade alerts from Cramer
  • Weekly roundups
TheStreet Quant Ratings
Try it NOW
Only $49.95/yr

Access the tool that DOMINATES the Russell 2000 and the S&P 500.

Product Features:
  • Buy, hold, or sell recommendations for over 4,300 stocks
  • Unlimited research reports on your favorite stocks
  • A custom stock screener
  • Upgrade/downgrade alerts
Stocks Under $10
Try it NOW

David Peltier, uncovers low dollar stocks with extraordinary upside potential that are flying under Wall Street's radar.

Product Features:
  • Model portfolio
  • Stocks trading below $10
  • Intraday trade alerts
  • Weekly roundups
Dividend Stock Advisor
Try it NOW

Jim Cramer's protege, David Peltier, identifies the best of breed dividend stocks that will pay a reliable AND significant income stream.

Product Features:
  • Diversified model portfolio of dividend stocks
  • Alerts when market news affect the portfolio
  • Bi-weekly updates with exact steps to take - BUY, HOLD, SELL
Real Money Pro
Try it NOW

All of Real Money, plus 15 more of Wall Street's sharpest minds delivering actionable trading ideas, a comprehensive look at the market, and fundamental and technical analysis.

Product Features:
  • Real Money + Doug Kass Plus 15 more Wall Street Pros
  • Intraday commentary & news
  • Ultra-actionable trading ideas
Options Profits
Try it NOW

Our options trading pros provide daily market commentary and over 100 monthly option trading ideas and strategies to help you become a well-seasoned trader.

Product Features:
  • 100+ monthly options trading ideas
  • Actionable options commentary & news
  • Real-time trading community
  • Options TV
To begin commenting right away, you can log in below using your Disqus, Facebook, Twitter, OpenID or Yahoo login credentials. Alternatively, you can post a comment as a "guest" just by entering an email address. Your use of the commenting tool is subject to multiple terms of service/use and privacy policies - see here for more details.
DOW 16,408.54 -16.31 -0.10%
S&P 500 1,864.85 +2.54 0.14%
NASDAQ 4,095.5160 +9.2910 0.23%

Brokerage Partners

Rates from Bankrate.com

  • Mortgage
  • Credit Cards
  • Auto
Advertising Partners

Free Newsletters from TheStreet

My Subscriptions:

After the Bell

Before the Bell

Booyah! Newsletter

Midday Bell

TheStreet Top 10 Stories

Winners & Losers

Register for Newsletters
Top Rated Stocks Top Rated Funds Top Rated ETFs