FDA has delayed its final decision on approval of Eli Lilly & Co.'s (LLY) long-lasting antipsychotic drug Zyprexa. A detailed response letter has been sent to Eli Lilly & Co.'s (LLY), said the FDA spokeswoman Sandy Walsh.  On confirmation from Lilly Chief Executive John Lechleiter, such letters are usually sent when the U.S. Food and Drug Administration is not ready for acceptance of a drug.

ZYPREXA (olanzapine) is a psychotropic agent that belongs to the thienobenzodiazepine class. At present Zyprexa is usually given to patients suffering from Bipolar Disorder and Schizophrenia.

Earlier in February 2008, FDA had already rejected the application for the approval of Zyprexa and had asked for more information about the drug for the better understanding of the side effects of excessive sedation events that were noticed in about 1% of patients during clinical trials. A complete new response letter is expected to be submitted to FDA as per Eli Lilly & Co.'s (LLY).

European Union and New Zealand had already approved Zyprexa under the brand Zypadhera. But unfortunately Lilly requires much more efforts to impress FDA for the same. FDA insists on more detailed information ensuring the benefits of the drug surpassing its risks.

Lilly said in its statement, “Per the agency's request, Lilly is preparing a proposed Risk Evaluation and Mitigation Strategy (REMS), which will be submitted in the near future. We cannot speculate on the timing of a potential decision.”