Analysts eye generic threat as Vivus rolls out Qsymia

Vivus ($VVUS) has won an early weight-loss race in the marketplace. The company launched its Qsymia treatment, beating competitor Arena Pharmaceuticals' ($ARNA) Belviq by several months. But will it come out on top in the most important one--the contest for prescriptions and sales?

As analysts have pointed out, Qsymia has better back-up evidence, with patients losing up to 8.9% of their body weight in one study. Belviq's percentage runs at 3.7% on the high side. And FDA labeling on Belviq specifies that patients who haven't lost 5% of their body weight after 12 weeks of therapy should stop taking it. Qsymia's label has no such reservation.

But Qsymia is a combination of two older drugs--phentermine and topiramate--both of which are available as cheap generics. Analysts have also pointed out that doctors could choose to prescribe the two components as generics, rather than use the much more expensive brand.

Some pooh-pooh the danger; as The Street reports today, J.P. Morgan analyst Cory Kasimov believes, based on feedback from doctors, that generic substitution will be limited as long as Qsymia isn't cost-prohibitive. Vivus has priced Qsymia at $4 to $6 per day, compared with $1 to $3 per day for the generic combination, The Street notes.

The coming months will tell. Given the intense interest in the obesity market, sales figures will be tracked closely. Before Belviq ever hits pharmacy shelves, we'll have an idea how Qsymia is faring.

- see The Street's article
- get more from the Associated Press

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