ARENA Pharmaceuticals Inc on Saturday said the Food and Drug Administration has rejected the company's application for lorcaserin, one of three drugs seeking to become the first new FDA-approved prescription weight loss drug in more than a decade.
The federal agency's rejection came after an FDA panel of experts on Sept 16 recommended against approving lorcaserin in a 9-5 vote. Panelists raised concerns about tumours seen in rats in early stage testing, one of the factors that Arena Pharmaceuticals said the FDA had cited in a letter responding to the company's application.
After last month's FDA panel vote, shares of Arena plunged nearly 47 per cent, to US$1.99 (S$2.58). San Diego-based Arena currently has no drugs on the US market.
A group of Arena investors later launched a campaign arguing that the FDA panel's review had relied on faulty scientific data. On Friday, as the full FDA's review was expected to conclude, shares of Arena rose nearly 12 per cent to close at US$1.63.
Arena said on Saturday that the FDA determined 'that it cannot approve the application in its present form.' In addition to citing safety concerns about tumours, the FDA's letter said the agency found that lorcaserin's weight loss efficacy 'in overweight and obese individuals without type 2 diabetes is marginal,' Arena said.
Arena said the letter stated that the FDA may require additional clinical studies if the company can't provide further evidence to address the concern about tumours. -- AP