Amylin Pharmaceuticals, Inc announced positive results from a 28-week dose-ranging study of pramlintide/metreleptin, a combination treatment comprising pramlintide, an analog of the natural hormone amylin, and metreleptin, an analog of the natural hormone leptin, in overweight and obese patients. This phase-2 study successfully characterized patients who responded best to treatment and also provided important information to inform dose selection.

At 28 weeks, evaluable patients with a starting body mass index (BMI) less than 35 kg/m2 (n=149), and treated with the highest pramlintide/metreleptin doses, experienced significantly more weight loss on average (11 per cent; 22 pounds, p<0.01) than those receiving placebo (1.8 per cent; 4 pounds) or either agent alone (approximately 5 per cent; 10 pounds). Consistent with the physiologic role of leptin in regulating body fat, the weight loss in these patients was predominantly due to a reduction in fat mass (approximately 18 of the 22 pounds lost). These study results confirm previous phase-2 results with this combination therapy and provide a solid foundation for the company's ongoing obesity development programme.

In the overall evaluable study population, all of the pramlintide/metreleptin combination arms achieved more weight loss than placebo. The magnitude of weight loss was found to be dependent on dosage and baseline BMI. In a pre-specified analysis of evaluable patients with a starting BMI less than 35 kg/m2, weight loss with pramlintide/metreleptin was more than additive compared to that with pramlintide and metreleptin alone, a finding that was not observed in the overall evaluable population.

"Despite their best efforts with diet and exercise alone, most overweight or obese individuals experience progressive weight gain over time. To date, the only highly effective treatment option is surgical and limited to the minority of patients who have advanced to the most severe forms of obesity," said Steven R Smith, professor and assistant director of clinical research at the Pennington Biomedical Research Center. "Providing the over 80 million overweight and obese Americans who have a BMI less than 35 kg/m2 with safe treatment options that offer compelling weight loss would be a significant advancement in obesity drug development."

The combination therapy was well tolerated, and no cardiovascular or neuropsychiatric (such as anxiety or depression) safety signals were observed. Consistent with previous clinical experience, the most common side effects seen with pramlintide/metreleptin combination treatment were injection site adverse events and nausea, which were mostly mild or moderate and transient in nature.

"These findings provide us with valuable data that will inform our clinical and product development strategy moving forward," said Christian Weyer, vice president, corporate development, diabetes and obesity at Amylin Pharmaceuticals. "Our integrated neurohormonal approach to obesity provides a broad research and development platform that has the potential to yield transformational therapies that address a range of unmet patient needs across the various classes of obesity."

Pramlintide acetate is a synthetic analog of the natural hormone amylin, a neurohormone secreted by the pancreas that is known to play a role in the regulation of appetite, food intake and postprandial glucose concentrations.

Amylin Pharmaceuticals is a biopharmaceutical company committed to improving lives through the discovery, development and commercialization of innovative medicines.