PFIZER's CP-66,248 IS LEAD COMPOUND IN NEW NSAID CLASS OF IL-1 INHIBITORS; NDA FILING TARGET OF 1990 PUTS DRUG ON DECK TO FOLLOW FELDENE WHEN PATENT EXPIRES

Pfizer's nonsteroidal anti-inflammatory agent CP-66,248 has been tested in "some 400" arthritis patients as a one-a-day dosage in placebo-controlled clinical trials, Pfizer Central Research Labs President Barry Bloom, PhD, told a Prudential-Bache health care R&D conference Sept. 22 in New York City. "We are giving a high priority to its further development and we hope to be at the stage of regulatory filings by 1990," Bloom said. An NDA submission by 1990 would put Pfizer on track to have CP-66,248 on the market as exclusivity and patent protection run out for Feldene in 1992. CP-66,248 is Pfizer's lead compound among a group of interleukin-1 (IL-1) inhibitors under development. The company is studying the drug in osteoarthritis, rheumatoid arthritis and psoriasis. Describing the drug's mechanism of action, Bloom said that patients receiving the drug experienced within the synovial fluid of inflamed joints a reduction of interleukin-1, a substance which perpetuates the excessive immune response experienced by rheumatoid arthritis patients. IL-1 also causes the liver to produce a substance known as c-reactive protein. "We have confirmed our observation that CP-66,248 modifies IL-1 mediated processes by determining that patients show a prompt and substantial fall in circulating levels of c-reactive protein," he explained. "Interestingly enough, only corticosteroids and certain disease-remittive agents such as the gold derivatives have been shown to lower c-reactive protein levels consistently and substantially in rheumatoid arthritis patients." Commenting on a small clinical trial using CP-66,248 to treat psoriasis, Bloom noted that "initial results have been encouraging." He said Pfizer is "now undertaking a larger, controlled trial to confirm these preliminary efficacy observations." Thus far, the Pfizer exec added, no "serious side effect problems" have been observed in either the arthritis or psoriasis studies. In addition to the new anti-arthritic, Bloom discussed two antimicrobial agents that Pfizer has identified as development priorities, the once-daily oral antibiotic azithromycin and the broad-spectrum antifungal agent fluconazole. The company said it hopes to file NDAs for both products in 1989. Azithromycin, a modification of erythromycin, has a "propensity to leave the blood stream and achieve very high intracellular levels in tissues where infectious organisms reside," Bloom noted. "Azithromycin possesses excellent intrinsic activity against a broad range of pathogens important, for example, in upper and lower respiratory tract infections, in otitis media . . . and in sexually transmitted diseases." Commenting on the drug's efficacy, Bloom gave the example of nonspecific urethritis, the sexually transmitted disease caused by the chlamydia organism. "We find azithromycin able to eradicate this type of chlamydia infection when administered as a single, one-gram dose," Bloom said. He added that in certain respiratory infections, a 1-1/2 gm dose of azithromycin over five days has an effect similar to 15 gm erythromycin over 10 days. Fluconazole, widely marketed outside the U.S., is "clinically useful in treating a whole range of dermal and vaginal infections," Bloom remarked. The antifungal, Bloom added, is also "uniquely advantageous for the treatment and prophylaxis of serious systemic fungal infections" such as streptococcal meningitis "where there presently exists, in our judgment, a significant therapeutic void."