NAPROXEN OTC SWITCH WILL BE RECONSIDERED BY FDA ADVISORY COMMITTEES SEPT. 8; "FURTHER DEVELOPMENTS" IN SYNTEX/P&G APPLICATION WILL BE DISCUSSED, FDA SAYS

Syntex/Procter & Gamble's Rx-to-OTC switch application for naproxen will be reconsidered by FDA's Arthritis Drugs and Nonprescription Drugs Advisory Committees Sept. 8, just three months after the application was turned down by the same committees. FDA announced in an Aug. 24 Federal Register notice that a joint meeting of the two committees would "discuss further developments regarding [Syntex/P&G's] new drug application to switch naproxen...from prescription to over-the-counter status." Syntex/Procter & Gamble filed the NDA (20-204) in 1992 in support of naproxen sodium 220 mg as an OTC analgesic ingredient. By bringing the naproxen application back before the committee so quickly, Syntex and P&G will have a chance to salvage a relatively timely approval for the OTC version. The speedy turn- around also appears to reflect the support for a naproxen switch expressed by FDAers during the first committee review. The challenge for Syntex/P&G will be to convince the committees to reverse themselves so soon after rejecting the application. In a 7-4 split vote (with one abstention), the OTC and arthritis advisory 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 Pink Sheet" June 7, p. 6). During that meeting, however, FDA Pilot Drug Evaluation Staff Medical Officer John Harter, MD, expressed concern that the joint committee was using criteria beyond FDA's regulatory framework for turning down the application. At a June 2 closed session, the committee was asked by FDA to consider labeling and packaging for OTC naproxen sodium, as well as the possibility of Phase IV postmarketing studies. FDA's interest in that discussion indicates that the agency did not believe that eventual approval was out of the question. Based on the earlier advisory committee, the sponsors apparently have several approaches available to seek 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 tooth ache; and working with FDA to address outstanding dosage and half-life issues in the OTC labeling. Among the prominent reasons for rejecting the Syntex application in June, the committees objected to 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 a 220 mg naproxen sodium (Anaprox) formulation. 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 is too close to the prescription levels; and that the long half-life of the drug was not conducive 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. 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 Pink Sheet" June 15, 1992, T&G-2). 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.