) -- Shares of


(VVUS) - Get Report


Arena Pharmaceuticals

(ARNA) - Get Report

rose Wednesday after



said it would provide medical benefit coverage for the companies' respective prescription weight-loss pills.

The nation's third-largest insurer issued a

policy bulletin update

on Tuesday in which Vivus' Qsymia and Arena's Belviq were added to a list of "medically necessary weight loss reduction medicines."

Aetna's coverage decision could provide a financial incentive for obese patients to consider weight-loss pills. For this reason, Vivus shares rose 13% to $11.70; Arena shares increased 3% to $9.16 in Wednesday trading

Approximately 30% of patients prescribed Qsymia choose not to pick up their prescription due to the high out-of-pocket cost. This high rate of prescription abandonment has been cited by Vivus executives as one of the significant reasons for the weight-loss pill's disappointing commercial launch.

Vivus said approximately 20% of patients were receiving insurance reimbursement coverage for Qsymia with an average co-pay of $60 per month. Aetna's decision to cover Qsymia and Arena's Belviq is a significant addition.

Aetna's coverage of Qsymia and Belviq is as a medical benefit and not a pharmacy benefit, and comes with other restrictions. The medicines will be considered medically necessary only for members who fail to lose at least one pound per week after at least six months on a weight-loss regimen that includes diet and exercise. Members also have to have a body mass index greater than 30 or a body mass index greater than 27 plus other risk factors.

-- Reported by Adam Feuerstein in Boston.

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Adam Feuerstein writes regularly for TheStreet. In keeping with company editorial policy, he doesn't own or short individual stocks, although he owns stock in TheStreet. He also doesn't invest in hedge funds or other private investment partnerships. Feuerstein appreciates your feedback;

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