Arena Pharmaceuticals reported on March 17th that one-year data from a Phase III trial of its diet drug Lorcaserin showed that the drug does not appear to raise heart safety issues.

Safety has been a big issue with Lorcaserin because the drug targets a serotonin receptor in the brain similar to fenfluramine, one of the two components of the diet pill fen-phen which had to be withdrawn from the market a decade ago after being linked to heart-valve damage.

But an independent safety monitoring board approved continuation of Arena's phase III trial of Lorcaserin, which involves some 3,200 patients, after comparison of heart valve damage in those treated with the drug for 12 months found no significant differences compared to patients in the control group.

"The month-12 review of the echocardiographic data significantly adds to our confidence in Lorcaserin's cardiovascular safety profile," said Arena's chief medical officer William Shanahan.

The two-year BLOOM trial, evaluating a 10 mg dose of Lorcaserin twice daily, will continue for another year with Arena evaluating echocardiograms again at 18 and 24 months.

Arena is conducting two other clinical trials: the BLOSSOM trial, a one-year study on 10 mg and 20 mg doses of Lorcaserin in obese patients, and the BLOOM-DM on obese patients with type II diabetes.

Patients in those studies will receive echocardiograms at baseline, six months, and at the end of the study to assess heart valve function over time.