BURROUGHS WELLCOME's ZOVIRAX OTC SWITCH NDA FOR GENITAL HERPES

BURROUGHS WELLCOME's ZOVIRAX OTC SWITCH NDA FOR GENITAL HERPES will be submitted to FDA "sometime in August," Burroughs Wellcome President and CEO Philip Tracy reported at a July 28 meeting for securities analysts in New York City. Burroughs Wellcome will be seeking approval for OTC marketing of a Zovirax (acyclovir) oral dosage form for the treatment of recurrent genital herpes. "There are some ongoing studies in process that will be completed after the initial filing" and will be submitted in a supplemental NDA "as soon as they are completed," Tracy added. He noted that Burroughs Wellcome also is "beginning to examine" the prescription use of Zovirax in the U.S. for the treatment of cold sores. "Ultimately, our goal would be to seek an OTC indication for that as well," he said. In an article published in the May issue of Archives of Dermatology, researchers from Baylor College of Medicine observed that more than 20% of 400 patients given oral acyclovir 400 mg b.i.d. for more than five years remained recurrence free ("The Tan Sheet" May 24, In Brief). The study also found Zovirax therapy to be "well-tolerated" and not associated with serious side effects or cumulative toxicity. Once approved, an over-the-counter version of Zovirax will be sold by Warner-Wellcome Consumer Health Products, a newly formed joint venture between Burroughs Wellcome and Warner-Lambert (see story, p. 1). Announced on July 28, the Warner-Wellcome deal is at the letter-of-intent stage and would effectively join the OTC businesses of Warner-Lambert and Burroughs Wellcome by January 1994. Tracy explained that the alliance with Warner-Lambert "will allow us to launch Zovirax as a major OTC product more effectively than we could do by ourselves." Tracy foreshadowed the deal at a March meeting with analysts when he predicted that Burroughs Wellcome would likely have a marketing partner in the U.S. for OTC Zovirax as part of a larger OTC alliance ("The Tan Sheet" March 29, p. 1). Through the proposed joint venture, Warner-Lambert is gaining access to an OTC version of the "eighth largest-selling prescription drug in the world, with annual revenues exceeding $ 1 bil.," according to Burroughs Wellcome. Under a related agreement in principle, Warner-Lambert also gained marketing rights to future OTC versions of Glaxo's prescription drugs, including the anti-ulcer remedy Zantac (see preceding story). Combined, Zantac and Zovirax generate over $ 4 bil. in sales worldwide as prescription products. Regarding the treatment of Zovirax and other Rx-to-OTC switch products under the agreement, the originator company will "retain the majority of the resulting profit" in the U.S., W-L noted, but a 50-50 partnership will be pursued for Zovirax in Europe. Zovirax is already available over-the-counter in the U.K. and Germany as a topical treatment for cold sores. Burroughs Wellcome has speculated that another potential Rx-to-OTC switch for the company, albeit farther in the future, could be antihistamine Semprex-D (acrivastine), which has not yet been approved in the U.S. for prescription sale. The allergy drug received a favorable review from FDA's Pulmonary-Allergy Drugs Advisory Committee in April ("The Tan Sheet" May 3, In Brief). For other OTCs to be marketed by the joint venture in the U.S., Warner-Lambert will receive approximately 70% of the profits while Wellcome plc will receive about 30%. Profits in the rest of the world will be divided on an equal basis. "We believe that the transfer of Zovirax from Rx-to-OTC status will accelerate, particularly as governments look to curb their health care bills," Warner-Lambert Consumer Products Sector President John Walsh told the analysts. "An OTC formulation of Zovirax could eliminate thousands of doctors visits and greatly lessen the misery of herpes," he predicted. Walsh suggested that, if allowed over-the-counter worldwide, Zovirax "could emerge as a significant and cost-effective OTC remedy."