Orexigen Therapeutics, Inc., a biopharmaceutical company focused on the treatment of obesity, has resubmitted the Contrave New Drug Application (NDA) to the US Food and Drug Administration (FDA). Investigational drug Contrave (naltrexone sustained release (SR)/bupropion SR) is being developed for weight loss and maintenance of weight loss.

The resubmission follows the November 25, 2013 announcement of the successful interim analysis of the Light Study, the Contrave cardiovascular outcomes trial (CVOT), which is being conducted under a Special Protocol Assessment with the FDA. In January 2011, Orexigen received a Complete Response Letter (CRL) from the FDA detailing a single approval deficiency—the need to conduct a clinical trial of sufficient size and duration to exclude excess risk of major adverse cardiovascular events. In less than three years, Orexigen negotiated with FDA a feasible CVOT design, enrolled the CVOT, and generated safety data responsive to the CRL.

"Resubmitting the Contrave NDA is an exciting moment for Orexigen," said Michael Narachi, CEO of Orexigen. "I am proud of our team and admire their determination to bring Contrave forward to help patients with obesity."

Narachi continued: "This resubmission sets in motion the first of four potential key catalysts in 2014. With the successful Light Study interim analysis, we are confident in the prospect for approvals next year in the United States and in Europe. If Contrave is approved, we look forward to a well-executed US launch by Takeda. Additionally, we anticipate making progress next year in our discussions with potential partners for Contrave for territories outside North America."

By agreement with the FDA, the independent Data Monitoring Committee's summary report of the Light Study interim analysis formed the basis of the resubmission of the NDA. The interim analysis clinical study report (CSR) will be supplied to the FDA within 60 days of the NDA resubmission. The review period for the resubmission is expected to be six months.

The Contrave Light Study is a double-blind, placebo-controlled cardiovascular outcomes trial that randomized approximately 8,900 patients. The primary objective of the Light Study, which Orexigen is conducting under a Special Protocol Assessment with the FDA at approximately 260 clinical sites in the United States, is to rule out excess cardiovascular risk in overweight and obese patients receiving Contrave. In November 2013 Orexigen announced successful results of the interim analysis of the Light Study, stating that it met the prespecified criteria to exclude a hazard ratio of 2.0, using the upper bound of the 95% confidence interval, for excess risk of major adverse cardiovascular events (MACE) in patients receiving Contrave as compared to placebo.

Contrave (naltrexone sustained release (SR)/bupropion SR) is an investigational medication being evaluated for weight loss and maintenance of weight loss. Prior to initiation of the Light Study, Contrave was studied in clinical trials enrolling more than 4,500 people. In these clinical trials, 53 per cent of study participants taking Contrave and 21 per cent of those taking placebo lost five percent or more of their body weight over the 12 month trial duration. Many patients saw improvements in cholesterol levels, and blood sugar control. Those who combined Contrave with intensive diet and exercise experienced the most reduction in body weight. There is no guarantee that Contrave will help patients lose weight.

In the Contrave phase III clinical development programme, the most frequent adverse events in patients on Contrave were nausea, constipation, headache, vomiting, dizziness, insomnia, dry mouth, and diarrhoea. These were mostly mild to moderate in severity.

Orexigen has licensed North American Contrave rights to Takeda Pharmaceuticals. Orexigen owns Contrave rights in Europe and throughout the rest of the world outside of North America and will seek a partner to commercialize Contrave in those territories. In October 2013, Orexigen submitted a Marketing Authorization Application (MAA) for Contrave to the European Medicines Agency (EMA).