Lost in all the talk surrounding Sanofi-Sythelabo's (NYSE:SNY) attempts to acquire Aventis (NYSE:AVE) is the fact that the company just released great phase 3 data on a pill that would help stop two of the nation's biggest killers -- smoking and obesity.

The drug, rimonabant, or Acomplia, packs a wicked combination punch. It helped roughly one-third of smokers quit and without gaining weight. In non-smokers, it helps overweight people lose 20 pounds and more than three inches off their waists. Finally, Acomplia increased HDL, the so-called "good cholesterol" by 23% while reducing triglycerides by 16%. Weight loss alone usually does not increase HDL. Increasing HDL and modifying lipids other than LDL is a major goal of big pharma players like Pfizer (NYSE:PFE), Merck (NYSE:MRK), and Bristol Myers Squibb (NYSE:BMY) as their statin drugs go off patent.

While only slightly more than a third of smokers quit over a year, compared to nearly 21% of placebo-treated smokers, this is a significant result and compares favorably with other smoking cessation products. Importantly, patients lost an average of a half-pound while on Acomplia, whereas patients on placebo gained over 2 pounds. And, interestingly enough, overweight smokers lost the weight, while normal weight smokers did not.

I think the weight loss data in non-smokers were even more impressive. Nearly 75% of patients lost 5% of their body weight over one year, with 44% losing more than 10%. The weight loss coupled with the changes in their lipid profiles makes this drug candidate particularly promising. As an added bonus, C-reactive protein (CRP)--a marker for heart disease-- dropped by 27% and insulin sensitivity rose. Increasing insulin sensitivity is vital for preventing adult-onset diabetes (Type II diabetes) that afflicts many overweight people.

The drug seems to work on the same brain receptor that makes marijuana users crave food, scientifically termed the "munchies." Apparently, both tobacco and overeating also affect this Endocannabinoid System, sending into disarray. Acomplia blocks the receptors in the brain in order to restore the system to balance. Unfortunately for some users, the drug also causes dizziness and nausea, leading to a 15% dropout rate for the high-dose patients in the trial.

With obesity and smoking sending about 800,000 Americans total to their graves early every year, a drug that can help treat both conditions could be a major breakthrough. As long as there are no nasty Phen-Fen-like surprises, this could be a very popular treatment among the nearly one-quarter of Americans who smoke and the nearly two-thirds of Americans who are overweight. I would expect Acomplia to be available to patients around the second quarter of next year, so you have a whole year to load up on the cake and ice cream to see if this pill will really work.

Fool contributor David Nierengarten, Ph.D., works with a biotechnology venture capital fund. He often contributes to Fool.com, is an active member of the TMF community as DavidMN, and enjoys the Biotechnology discussion board. He doesn't own shares of companies listed.