NAPROXEN OTC SWITCH WILL BE RECONSIDERED BY FDA ADVISORY COMMITTEES

NAPROXEN OTC SWITCH WILL BE RECONSIDERED BY FDA ADVISORY COMMITTEES on Sept. 8, only three months after the application was turned down by a joint meeting of FDA's Arthritis Drugs and Nonprescription Drugs Advisory Committees in June. FDA announced in an Aug. 24 Federal Register notice that a joint meeting of the two committees would "discuss further developments regarding [Syntex/Procter & Gamble's] new drug application to switch naproxen . . . from prescription to over-the-counter status." Syntex/P&G filed the NDA (20-204) in 1992 to support of naproxen sodium 220 mg as an OTC analgesic ingredient. Naproxen's quick return to the advisory committees may provide Syntex and P&G with a chance to salvage a relatively timely approval for the OTC switch. The speedy turn-around also appears to reflect support for the switch at FDA. Syntex and P&G still appear to have an outside chance of having an OTC naproxen product on the market before the naproxen patent expires in December. Syntex has said it expects to receive three years of exclusivity for the OTC formulation. The challenge for Syntex/P&G will be to convince the committees to reverse their earlier vote on the application. In a 7-4 split vote (with one abstention), the OTC and arthritis committees concluded on June 2 that data "about the effectiveness and adverse effects of naproxen" were insufficient to support its approval as an Rx-to-OTC switch ("The Tan Sheet" June 7, pp. 1-5). However, during that meeting, FDA Pilot Drug Evaluation Staff Medical Officer John Harter, MD, expressed concern that the joint committee was considering issues outside of FDA's regulatory framework for OTC analgesics in arriving at its reasons for turning down the application. Harter also indicated that the committees' "divided" response could be seen by the agency as supporting either an approval or rejection of the application "because we have experts that would take either side of that issue." The committee was asked by Harter to consider labeling and packaging for OTC naproxen sodium, as well as the possibility of Phase IV postmarketing studies, at a June 2 closed session following the vote. Based on the earlier advisory committee, the two companies apparently have several options to select from if they choose to push for an approval, including: conducting Phase IV studies to buttress efficacy for several of the indications that appeared inconclusive in the NDA clinical trials; agreeing to an approval for the three indications supported by the NDA data -- musculoskeletal aches and pains, dysmenorrhea and toothache; and working with FDA to address outstanding dosage and half-life issues in the OTC labeling. Among the committees' reasons for rejecting the Syntex application in June was the company's use of a naproxen formulation (Naprosyn) in most of the clinical trials conducted to support the switch to OTC marketing. Responding to FDA's concern about the relatively slow onset of action of the naproxen formulation, the company later changed its application to support an approval for its 220 mg naproxen sodium formulation (Anaprox). Other objections raised by the committees included: that naproxen did not demonstrate efficacy in all the pain models indicated in general analgesic claims; that the recommended OTC dosing of 220 mg too nearly approximated prescription levels; and that the long half-life of the drug was not conductive to OTC use. Some committee members also expressed reservations about allowing another analgesic onto the OTC market, given the three alternatives already available: aspirin, acetaminophen and ibuprofen. The advisory committees are also scheduled to discuss on Sept. 8 whether aspirin and other OTC nonsteroidal anti-inflammatory drugs (including naproxen) should carry a warning label regarding toxicities associated with alcohol (see following story).