GLAXO WILL PROCEED WITH OTC ZANTAC BUT TIMETABLE UNCERTAIN, COMPANY TELLS ANALYSTS; RANITIDINE BISMUTH CITRATE FOR PEPTIC ULCER SET FOR 1994 FILING

Glaxo will proceed with the development of OTC ranitidine (Zantac) for the treatment of "episodic heartburn" following the restructuring of the company's agreement with Sandoz in October, Glaxo told analysts in New York City Dec. 11 during its annual R&D update.

Responding to a question about the status of OTC development for the H[2] antagonist, Richard Sykes, PhD, Glaxo Holdings' R&D director, said: "We certainly are going to do it. There's no question about that." Asked if Glaxo planned to proceed on the development with a partner, Sykes said "no . . . we'll develop it ourselves."

Glaxo has been very low key in the last year about the future of nonprescription ranitidine. The product was not discussed at all during the company's December 1990 R&D update for analysts. However, speculation about OTC ranitidine's future was renewed with the Oct. 11 announcement by Glaxo and Sandoz that they had restructured their December 1987 DynaCirc copromotion/OTC Zantac rights deal ("The Pink Sheet" Oct. 14, T&G-1).

Under the restructured deal, Glaxo assumed the right to develop OTC ranitidine and both Glaxo and Sandoz received independent marketing rights to the OTC product. In return, Glaxo will stop copromoting DynaCirc in 1993. The old agreement would have transferred DynaCirc ownership to Glaxo when OTC ranitidine was approved.

Glaxo is still uncertain about the timing of a submission to FDA for OTC ranitidine, Glaxo Research Institute Senior VP Medical Operations Peter Wise, MD, told the analysts.

The "exact timetable has not been worked out," Wise commented in response to an analyst's question. He called the "whole area" of OTC H[2] development "a bit fuzzy as far as the FDA is concerned." Outlining some of the regulatory uncertainties surrounding OTC H[2] antihistamines, Wise queried: "Will they ever approve one? If they do approve one, will it be of the 'therapeutic dose' or will it have to change to a much lower dose and have a clear separation between OTC doses and prescription doses?"

Wise said Glaxo is "going to start on a program looking at lower doses of Zantac for the OTC indication" of "episodic heartburn." Wise acknowledged that OTC development of the H[2] antagonist class is "a very difficult area in which to work; it's very subjective." Deferring any details about the development program for OTC Zantac, Wise added: "It's difficult to say how long it will take to first define a dose, and we don't know in fact what the FDA wants in the way of numbers of patients, how many attacks" to be included in clinical efficacy trials.

Sandoz said it had difficulties in its "extensive" clinical development work on OTC ranitidine and had set no NDA filing date for the product at the time of the restructuring of the Glaxo deal. Sandoz also said it had run into problems similar to those seen by SmithKline Beecham in its work to develop OTC cimetidine. One of the problems in developing an OTC product has been showing efficacy at doses lower than the prescription dose.

Prescription Zantac has received first approvals outside the U.S. for the treatment of nonsteroidal anti-inflammatory drug- associated gastric and duodenal ulcers and for prophylaxis of NSAID-associated duodenal ulcers, Sykes reported. "There's lots of activity still ongoing" with the company's mainstay drug, he said.

The company's work on new dosage forms of Zantac has begun to pay off outside the U.S., Sykes said. Efferverscent tablets developed for the French market are now for sale there and the new delivery form is currently being registered elsewhere. Soft gelatin capsules were developed and approved in Canada and are also being registered in other countries, Sykes said. Both versions could be possible delivery systems for an OTC version. Glaxo is also pursuing improved dosing regimens for oral and injectable Zantac. "All of these filings we hope will be going through the system in the next 12 months," Sykes said.

Ranitidine in combination with bismuth citrate is one of seven compounds involved in eight full development programs at the company. "Clinical trials are currently underway to determine whether healing rates are enhanced and remission is prolonged," Glaxo materials prepared for the meeting state. Glaxo is predicting the first registration filing for ranitidine bismuth citrate for peptic ulcer in 1994, a date on track with company predictions from a year ago.

Ranitidine bismuth citrate (GR 122311) for peptic acid diseases has been shown in studies to be efficacious in "decreasing 24-hour intragastric activity and the suppression of Helicobacter pylori," Glaxo said. H. pylori is the organism linked to gastritis, antritis and ulcers of the pylorus and gastric antrum. Two prospective case-control studies in the Oct. 17 issue of the New England Journal of Medicine also demonstrated that H. pylori is a risk factor for gastric cancer.

Sykes said that ranitidine bismuth citrate has the "same inhibition profile as Zantac" for acid secretion. Target indications for the compound are duodenal and gastric ulcer healing; the "prevention and treatment of NSAID-induced DU and GU ulcers"; and "relapse prevention." Sykes noted that "if we can repress the organism [H. pylori] then hopefully ulcers won't reoccur as they do with H[2]."