Feb. 22, 2012: Albuquerque, New Mexico:
Qnexa Approved by FDA Advisory Panel
Qnexa may become the first new prescription weight loss medication to reach the US market in over a decade. Today an advisory panel to the FDA voted 20-2 to allow safety studies of the drug combination to occur AFTER the drug is brought to the US market. Although the FDA itself is not formally or legally bound by the recommendations of it advisory panels, it often follows their advice and I personally would bet the farm on the fact that Qnexa will ultimately be approved by FDA in April (when the final decision is due). After that, it should take several months to bring the actual product to the market where it will be available as a prescription-only (and perhaps controlled) substance.
Qnexa is Nothing New
The irony of all the hoopla over Qnexa is that the drug combination has been used for years by weight loss doctors around the country. Qnexa is nothing more than a combination of phentermine and topiramate in a single dosage unit. Phentermine has been on the market in the US since 1959 and topiramate for decades.
Do Phentermine and Topiramate Together Cause More Weight Loss Than Phentermine Alone?
According to Vivus, the manufacturer of Qnexa, the answer is yes. Vivus' studies suggest that the combination is significantly more effective than phentermine alone. According to a number of doctors who are familiar with the two-drug combination, the answer is "no".
Real-World Experience With Phentermine and Topiramate is Dissapointing
Doctors familiar with the two drug combination of phentermine and topiramate (and that includes myself) are generally not enthusiastic about Qnexa. In the real world it just doesn't work that well and the topiramate produces a lot of really unpleasant side effects in many patients.
Side Effects Include Memory Lapses, Foggy Thought, Drowsiness and Numbness in Fingers, Lips and Feet
Topiramate is a fairly unpleasant medication for most patients who take it and phentermine does little to improve the effect. Most of the patients who have taken the drug combination wanted to stop it (or did stop it) after one month.
Qnexa Will be EXPENSIVE and therefore Have Difficulty Competing With the Generic Two-Drug Combination
Both phentermine and topiramate have been generic medications for decades. Althought phentermine isn't cheap by generic standards, it is relatively so when compared to brand-name drugs. Furthermore, Vivus has dumped a lot of venture capital into Qnexa with no return so far and therefore they likely will price the drug at several hundred dollars per month. This is simply not viable and will, I think, doom the drug to obscurity.
Expect Lots of Qnexa Hype and Little Else
Everyone loves weight loss stories and the media will capitalize on this over the next several days, weeks and months as the Qnexa advertising Juggernaut rolls into high gear. By the end of summer, "Qnexa" will a household word in America. But, for reasons I have outlined above, it will all be forgotten in a few years. Anyone remember Meridia?
Mark Holland: Feb. 22, 2012