With the prognosis for advanced prostate cancer patients so bleak, any treatment that yields even a minor increase in survival should result in decent sales. At least until the next drug comes along.

The winner, for now, appears to be sanofi-aventis (NYSE: SNY). Today the company released results for its tests of cabazitaxel in patients who had already failed the company's first-line treatment for advanced prostate cancer, Taxotere. Median patient survival was 15.1 months -- that is, half lived this long or longer -- a statistically significant 2.4 months longer than those given EMD Serono and OSI Pharmaceuticals' (Nasdaq: OSIP) Novantrone.

That's not a huge improvement. It's certainly no cure. But keep in mind that Novantrone isn't even approved to treat advanced prostate cancer, and the median patient survival in that group was slightly more than a year. There's clearly a need for something better, and cabazitaxel is an improvement on what's currently available.

As a second-line treatment, cabazitaxel will have to wait for patients to fail Taxotere -- and potentially Dendreon's (Nasdaq: DNDN) Provenge, if it's approved. But with these results, cabazitaxel should be able to capture most of the post-Taxotere/Provenge patients.

Sanofi plans to submit its marketing application to the Food and Drug Administration within the next few months. Given the unmet need, the FDA should certainly give cabazitaxel a six-month priority review, which should result in a decision by the end of the year.  Assuming nothing pops up when the full data set is presented at a medical conference on Friday, the drug looks good enough for an approval.

In order to gain any marketing traction, new competitors will have to beat that 2.4-month survival gap. Johnson & Johnson (NYSE: JNJ), Medivation (Nasdaq: MDVN), and OncoGenex Pharmaceuticals (Nasdaq: OGXI) are all testing drugs as second-line prostate cancer treatments.

For now, though, Sanofi is in the driver's seat. Others will be gunning for it, but Sanofi should have a head start talking to doctors, and the results from any new compounds will be compared against cabazitaxel.

Given the choice, I'd rather be chased than be the chaser. But only by a little.

Dividends are dumb -- except when they're not.

Johnson & Johnson is an Income Investor recommendation. To see how dividend-paying stocks can offer both secure income and the opportunity for growth, take a free 30-day look at this newsletter.

Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. Motley Fool Options has recommended a buy calls position on Johnson & Johnson's stock. The Fool has a disclosure policy.