SAN DIEGO and WOODCLIFF LAKE, N.J., Oct. 23, 2010 /PRNewswire-FirstCall/ -- Arena Pharmaceuticals, Inc. (Nasdaq: ARNA) and Eisai Inc. announced that the US Food and Drug Administration (FDA) issued a Complete Response Letter (CRL) regarding Arena's New Drug Application (NDA) for lorcaserin. Lorcaserin is intended for weight management, including weight loss and maintenance of weight loss, in patients who are obese (Body Mass Index, or BMI, >/= 30) or patients who are overweight (BMI >/= 27) and have at least one weight-related co-morbid condition.
The FDA has completed its review of the NDA and determined that it cannot approve the application in its present form. In the CRL, the FDA outlined the non-clinical and clinical reasons for their decision.
The non-clinical issues identified by the FDA included diagnostic uncertainty in the classification of mammary masses in female rats, unresolved exposure-response relationship for lorcaserin-emergent mammary adenocarcinoma, and unidentified mode of action and unclear safety margin for lorcaserin-emergent brain astrocytoma.
The CRL included the following requests related to the non-clinical issues: provide a detailed accounting of all slides prepared from female rats that contributed to mammary tumor incidence data in each update to the FDA and to the final study report; in consultation with the FDA, identify an independent pathologist or group of pathologists to re-adjudicate all mammary and lung tissues (neoplastic and nonneoplastic lesions) from all female rats; demonstrate that the apparent increase in aggressiveness of adenocarcinoma in rats administered lorcaserin is reasonably irrelevant to human risk assessment; and provide additional data/information regarding the distribution of lorcaserin to the CNS in animals and human subjects that would clarify or provide a better estimate of astrocytoma exposure