Drug shows success in fights against smoking and obesity

Last month, there were health news headlines that seemed to offer a bright ray of hope for defeating difficult bad health habits.

A new pill, rimonabant, demonstrated promise in helping people both to lose weight and to quit smoking. But the scientists who authored the two key studies say that, although this drug could become a useful addition to these fights, the battles will not be easy.

"We have a drug that really attacks the two major killers in the United States," said Lowell Dale, MD, one of the lead investigators on the study that examined rimonabant and smoking cessation. He is also the associate medical director of the Mayo Clinic nicotine dependence center in Rochester, Minn. "But this is not a magic pill. People are still going to need counseling and discussion on lifestyle changes for this medicine work."

The medicine does, however, offer promise. Preliminary data from the phase III studies presented at the March American College of Cardiology annual scientific meeting in New Orleans found that, after one year, obese subjects on a calorie-controlled diet who took rimonabant lost an average 20 pounds. More than 44% of subjects who were on the drug lost at least 10% of their body weight, and the rate of metabolic syndrome was cut in half. Those on placebo lost an average five pounds, and only a tenth managed to lose 10% of their body weight.

For smokers motivated to quit, the drug doubled the smoking cessation rate. Those who quit also lost a pound on average, while those on placebo gained a couple of pounds.

"The promise of rimonabant is that it may provide an entirely new therapeutic strategy that targets the cause of multiple risk factors for a more integrated approach to cardiovascular disease risk management," said Jean Pierre Despres, PhD, one of the investigators on the weight-loss study and professor of human nutrition at Laval University in Quebec.

Lifestyle changes still involved

Physicians expressed reserved optimism in the wake of the news. Weight loss and smoking cessation long have been areas of fierce research with lots of unfulfilled hopes. And even if this medication passes all the hurdles, physicians caution that it still won't alleviate the need for patients to be motivated and to make difficult lifestyle changes.

In the weight-loss study, patients still had to cut calories either by reducing what they ate, exercising or both. The smokers in the cessation study already had attempted to quit and failed an average of four times.

"It improves people's ability to quit, but it certainly doesn't turn all smokers or overeaters into quitters," said Patrick Tranmer, MD, MPH, head of the family medicine department at the University of Illinois, Chicago. "It would probably become one more tool in an overall management strategy of behavior change."

Crossing patients' motivational divide is one of the biggest challenges physicians face. Experts say, however, that the drug could address one of many smokers' greatest barriers to quitting: The fear that they will gain weight.

"A core issue, particularly for women trying to quit, is concern about weight gain upon cessation," said Michael Fiore, MD, director of the Center for Tobacco Research and Intervention at the University of Wisconsin Medical School in Madison.

"If we could come up with a treatment that would blunt or eliminate weight gain [after cessation], that would be an enormous step forward," Dr. Fiore said.

But although the drug did result in some people quitting smoking and some people losing weight, the numbers were not sweeping. The average weight loss for those who were obese was 20 pounds. Many people needed to lose far more than that. It doubled the quit rate for smokers, but the rate of those successfully quitting on their own is already extremely low.

"Does that solve the public health problem of smoking? Probably no," Dr. Tranmer said.

Still, many maintain that if this pill makes it to the marketplace, it could be a positive force.

"I can't tell you how many people are on weight loss and can't lose five pounds," said Denise Bobovnyik, MD, a family physician in Canfield, Ohio. "Twenty pounds is realistic and can knock some people down from being a high-risk overweight person to someone who is near normal."

Physicians are also eager to see long-term data before making a judgment. Only a year of data was available from the weight-loss study, and 10 weeks was available for the cessation study.

Many doctors are interested in what this patient population looks like after a much longer period of time.

There are also unanswered questions about whether this drug would only be used acutely or would have to become a lifetime commitment.

"You don't know what the recidivism rate is going to be," Dr. Tranmer said. "How long are people going to maintain a benefit on this? How long would you have to take the medicine?"

Experts say that the drug, even with caveats and questions, still represents a significant advance. It's the first selective cannabinoid type-1 receptor antagonist, and attempts to reduce the overstimulation of this system that is believed to play a role in smoking and overeating.

It also represents a whole new way to attack a long-standing problem that bedevils many a physicians' practice.

"I'm very excited about any new medication that comes along and empowers the physician to be more effective in helping their patient" Dr. Fiore said. "We just need to see the data."

Additional data about rimonabant, which, if approved, will be marketed under the name Acomplia, are expected to be released later this year.

Notable side effects observed so far include nausea and upper respiratory tract infection.