But in an Arena study published online this week in the journal Circulation: Cardiovascular Imaging, evaluation of over 5, 200 patients in phase 3 trials of 52 weeks of lorcaserin (10 mg, twice daily) or placebo showed only a slight difference in heart valve problems: 2.04% for placebo and 2.37% for lorcaserin.

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There was no statistically significant difference in the development of FDA-defined valve abnormalities between Belviq and placebo-treated patients.

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On a conference call, Arena Chief Executive Jack Lief said that there were heart valve problems seen in the trial, but that in the end he expects no difference between Arena's drug and placebo when it comes to this side effect.

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