Having been rejected by regulators in the USA last month, Arena Pharmaceuticals' obesity drug lorcaserin has received some good news with late-stage data showing that the treatment helps diabetics lose weight.

Arena and partner Eisai have reported top-line results from the one-year 604-patient BLOOM-DM trial which demonstrate statistically significant weight loss in obese and overweight patients with type 2 diabetes. In the trial, lorcaserin met all three of its co-primary efficacy endpoints.

Specifically, at week 52, 37.5% of patients treated with lorcaserin 10mg twice a day achieved at least 5% weight loss, compared with 16.1% on placebo. The data also showed that 16.3% of lorcaserin twice-daily patients enjoyed at least 10% weight reduction, compared to 4.4% for those taking placebo.

In addition, patients on the Arena/Eisai drug achieved statistically significant improvements in multiple secondary endpoints. Most strikingly, patients on lorcaserin saw a fall in HbA1c levels of 0.9% compared to 0.4% for placebo, and also showed a statistically significant improvement in fasting glucose levels.

The results are a real boost for Arena given that the US Food and Drug Administration issued a complete response letter regarding lorcaserin in October. The agency cited a number of reasons for its decision, notably concerns about efficacy and tumours found in animal studies, but it also said that it wanted to see the BLOOM-DM data.

Arena chief executive Jack Lief said the firm is looking  forward to reviewing the results with the FDA, especially as as "the efficacy results are aligned with the agency's categorical benchmark for weight management". He added on a conference call that the meeting will happen before the end of the year and Arena is looking at a European filing next year.

No new weight loss drug has been approved by the FDA since Roche's Xenical (orlistat) in 1999 and days after the rejection of lorcaserin, it declined to back Vivus' Qnexa (phentermine/topiramate). Orexigen Therapeutics' Contrave (sustained-release naltrexone/bupropion), partnered with Takeda, is scheduled to go in front of an advisory committee on December 7.