Shire and Noven Pharmaceuticals received an “approvable” letter from the FDA for their experimental attention deficit hyperactivity disorder (ADHD) patch, pending more information, the firms said.The FDA asked for data clarification, in addition to more details on the kinds of post-marketing studies that would be conducted, Shire and Noven explained in a statement.“Shire is now initiating dialogue with FDA to address these issues,” said the company, which markets ADHD pill Adderall.Daytrana, the proposed name for the methylphenidate transdermal system, is an investigational transdermal patch formulation designed for once-daily use to treat ADHD in children. Earlier this month an outside panel of experts, convened by the FDA, recommended the agency approve the patch, though with the caveat that the drug should contain a strong recommendation to physicians to try oral therapies first until more information is known about skin reactions.One medical reviewer on the panel, Robert Levin, had recommended that the agency reject the patch because of side effects. But he reversed his position, saying he had obtained information suggesting that most side effects of the patch were similar to those seen with some oral ADHD drugs, with the exception of a small increase in tics.The companies submitted an amended NDA for a nine-hour Daytrana in June, after the FDA rejected a 12-hour patch in 2003 due to concerns of overmedicating.Shire, which acquired the global license to market Daytrana from Noven, said it hopes to reach a final agreement with the FDA that would allow it to launch the patch during the first half of 2006.