STERLING WINTHROP TO FILE ACUPAQUE (IODIXINOL) NDA SHORTLY: IMAGING AGENT COULD SUCCEED TOP-SELLER OMNIPAQUE; FOUR CANCER NDA FILINGS FORECAST BY 1997

Sterling Winthrop plans to submit an NDA for Acupaque (iodixinol), an X-ray and computed tomography imaging agent, "in late December or very early next year," Sterling Winthrop Pharmaceuticals Research Division President Eugene Cordes, PhD, told a Dec. 17 securities analysts meeting in New York City. Acupaque "has promise to be an improved successor product to the current gold standard," Sterling Winthrop's top-selling product, Omnipaque (iohexol), Cordes maintained. Acupaque "is expected to be the first nonionic, dimeric radiopaque approved for use in the U.S.," Cordes said. The only other similar agent under development is Berlex' iotrolan, Cordes said. Iotrolan is in Phase II. "Our formulation of Acupaque is iso-osmotic with blood and balanced with respect to the ratio of sodium and calcium ions. When all our planned studies are complete, we expect Acupaque to demonstrate superior cardiovascular safety," Cordes said. Materials distributed at the meeting state that the "potential for improved renal safety" is also being studied. Sterling expects Omnipaque sales to top $500 mil. in 1992, Chairman and CEO Louis Mattis said. The product will show "double digit increases in both sales and earnings this year and increased market share despite intense competition," Mattis declared. Sterling is forecasting that its Omniscan (gadodiamide) non- ionic magnetic resonance imaging agent will be approved "early next year." Supplemental NDAs for Omniscan at higher doses for central nervous system and body indications will be filed "soon," Cordes said. "Clinical studies suggest that we will be able to move to higher doses, increasing diagnostic efficacy, without dose-limiting side effects," he added. Earlier-stage diagnostics include an intracellular magnetic resonance imaging (MRI) contrast agent for the liver (WIN-59010) and a lymphography agent employing Sterling's proprietary "nanoparticulate" technology. Phase III studies of WIN-59010 will begin "early next year," Cordes said. "We plan to submit an NDA in 1994." The lymphography agent is scheduled to enter clinical trials next year. Sterling unveiled its new "nanoparticle" micronization technology developed in conjunction with Kodak researchers at the Dec. 17 meeting. Nanoparticles are less than 400 nm in diameter, or about one-tenth the size previously available with small- particle technology, Cordes explained. Sterling initially has applied the new technology to its off- patent endometriosis drug Danocrine (danazol). Clinical studies have shown the drug to have better bioavailability in the new formulation, Cordes said. The company hopes to file an NDA for the drug in 1994. A patent covering all pharmaceutical uses of nanoparticulate formulations of crystalline drugs has been granted to Sterling/Kodak, Cordes said. Sterling indicated that it will pursue licensing agreements with the technology. Other nanoparticulate formulations under development include an unnamed elastase inhibitor, an antiviral agent, indomethacin and naproxen. Syntex and Procter & Gamble are developing an OTC naproxen, which would be another non-aspirin ingredient to compete against Sterling's Bayer line in the OTC analgesic market. Sterling's pursuit of a novel naproxen formulation represents an effort "to combat and improve upon the competition," the company said. Sterling unveiled its restructured R&D program at the Dec. 17 meeting, which was billed as "the first pharmaceutical development briefing" since Sterling was acquired by Kodak in 1988. The only other meeting Sterling has held with analysts since 1988 was to outline its joint venture arrangement with Sanofi early in 1991 ("The Pink Sheet" Jan. 14, 1991, p. 3). Sterling has 30 compounds under development, Pharmaceuticals Group President Jacques Rejeange said. The firm is focusing its R&D on three core areas: diagnostic imaging, oncology and chronic inflammatory diseases. Sterling is preparing to enter the oncology therapeutics arena on the strength of four new drugs for which it expects to file NDAs by 1997. Sterling's Cordes described the oncology program as "beginning from ground zero in 1987." The first anticipated NDA filing is in 1995 for mitoguazone, a cytotoxic agent for treatment of non- Hodgkin's lymphoma. The drug, now in Phase II/III trials for lymphoma, "is not significantly myelosuppressive," Sterling said, suggesting that it is a promising candidate for use in a number of combination therapies. Possible additional indications include prostate cancer. Mitoguazone is licensed from the Cancer Treatment and Research Center in San Antonio. Another cytotoxic agent, datelliptium, has "elicited complete or partial responses in a subset of patients with breast cancer resistant to conventional treatment with Adriamycin," Cordes reported. Additional Phase II trials to determine optimum dosing are slated for spring 1993 with a 1996 NDA filing target date. Tirapazamine is the oncology drug in development with the largest market potential, Cordes said. The compound is initially being developed for use in combination with radiation therapy to treat brain tumors. Phase I trials in the U.S. and the U.K. suggest tirapazamine is well-tolerated by cancer patients; Phase II studies should be under way in 1993 with a possible NDA filing in 1996. Sterling expects the hypoxic cell cytotoxic agent to be "significantly more effective and less toxic" than DuPont's SR2508 radiation enhancer. Cordes estimated $500 mil.-plus sales for the drug based on its use ultimately in combination with all cancer radiotherapy. A fourth cancer product, zanoterone, is a novel steroidal androgen antagonist under development for prostate cancer. Efficacy data from Phase II trials will be available in the second quarter of 1993. Sterling hopes to file an NDA in early 1997, Cordes said. Zanoterone is also under development for benign prostatic hyperplasia, Cordes told the analysts. Phase III studies could begin in 1993 with an NDA filing for BPH possible by 1996, Cordes said. Another endocrine project for Sterling is Sanofi's tiludronate, under development for Paget's disease and osteoporosis. Phase III trials will begin next year, and an NDA for Paget's could follow in 1994, Cordes said. An NDA for osteoporosis could be filed by 1997, he added. BPH and osteoporosis are both hot areas for drug development. Merck recently launched the first FDA-approved BPH treatment, Proscar (finasteride). Merck is also developing a bisphosphonate for osteoporosis Fosamax (alendronate). Pfizer also has an osteoporosis candidate, residronate, licensed from Procter & Gamble earlier this year. Sterling's largest developmental effort in terms of clinical resources appears to be the platelet aggregation inhibitor clopidogrel. The drug is currently in Phase III trials slated to enroll 15,000 patients worldwide, Cordes said. Clopidogrel was developed by Sanofi, whose initial effort in the category is ticlopidine, marketed in the U.S. by Syntex as Ticlid. Ticlid, however, has not performed well in its first year on the market due to a requirement for blood monitoring of patients because of a 1%-2% incidence of neutropenia. "In experience in well over 1,000 patients on clopidogrel, we have seen only one patient with neutropenia," Cordes reported. Sterling's objective with the massive Phase III trial is "to demonstrate efficacy superior to that of 325 mg aspirin with a safety profile comparable to that of aspirin" for the prevention of stroke, myocardial infarction and peripheral arterial disease, Cordes said. An NDA is slated for 1997. The final product highlighted by Cordes was Sterling's polyethylene glycol succinate conjugated superoxide dismutase (PEG SOD) for head trauma. Sterling expects its early Phase II results to be published early in 1993. The company is conducting two 450- patient Phase II/III trials: one began in November, one will begin early next year. An NDA could be filed in 1995, Cordes said, noting that Upjohn is developing potential competing products: the lazaroids, such as Freedox (tirilazad).