Arena reports positive results from Phase III obesity trial

Arena Pharmaceuticals has announced positive top-line results from Bloom, the first of two pivotal trials evaluating the safety and efficacy of lorcaserin for weight management.

Statistical significance (p<0.0001) was achieved on all three of the hierarchically ordered co-primary endpoints for patients treated with lorcaserin versus placebo, the company said. Treatment with lorcaserin was generally very well tolerated. An assessment of echocardiograms indicates no apparent drug-related effect on the development of FDA-defined valvulopathy over the two-year treatment period.

The hierarchically ordered endpoints were the proportion of patients achieving 5% or greater weight loss after 12 months, the difference in mean weight loss compared to placebo after 12 months, and the proportion of patients achieving 10% or greater weight loss after 12 months.

Compared to placebo, using an intent-to-treat last observation carried forward analysis, treatment with lorcaserin was associated with highly statistically significant (p<0.0001) categorical and average weight loss from baseline after 12 months: 47.5% of lorcaserin patients lost greater than or equal to 5% of their body weight from baseline compared to 20.3% in the placebo group. This result satisfies the efficacy benchmark in the most recent FDA draft guidance, said Arena.

Average weight loss of 5.8% of body weight, or 12.7 pounds, was achieved in the lorcaserin group, compared to 2.2% of body weight, or 4.7 pounds, in the placebo group. Statistical separation from placebo was observed by week two, the first post-baseline measurement. Approximately 22.6% of lorcaserin patients lost greater than or equal to 10% of their body weight from baseline, compared to 7.7% in the placebo group.

Lorcaserin patients who completed 52 weeks of treatment according to the protocol lost an average of 8.2% of body weight, or 17.9 pounds, compared to 3.4%, or 7.3 pounds, in the placebo group (p<0.0001), according to Arena.

Treatment with lorcaserin was also associated with statistically significant improvements in a range of secondary endpoints compared to treatment with placebo, including: total cholesterol, LDL cholesterol, triglycerides and blood pressure, said Arena.

Jack Lief, CEO of Arena, said: The positive outcome of the Bloom trial serves as a very significant milestone for Arena, demonstrating lorcaserin’s potential to provide a new treatment option for patients who need to lose weight and keep it off.