BioCryst Pharmaceuticals Inc. has initiated a Phase III trial using atopical formation of BCX-34, an immunosuppressive drug designedfor the treatment of psoriasis.

BCX-34 is a small-molecule inhibitor of purine nucleosidephosphorylase, a human enzyme believed to be involved in theproliferation of T cells.

Psoriasis, a chronic and recurrent disease characterized by itchy,thick scaling or welt-covered portions of the skin afflictsapproximately 5 million people in the U.S.

John Higgins, vice president of corporate development, toldBioWorld Today, the Phase III double-blind, randomized, placebo-controlled trial will treat 350 patients with plaque psoriasis for 16weeks with a topical cream that contains a 1 percent drugconcentration.

The trial will have two patient groups of equal size, one receiving thedrug and the other a placebo. The trial _ managed by ResearchTriangle Park, N.C.-based Quintiles Transnational Corp. _ is beingadministered at 15 research centers throughout the U.S.

Oral Formulation In The Works

Additionally, BioCryst, of Birmingham, Ala., is using BCX-34 in aPhase I/II dose escalation trial with an oral formulation, also for thetreatment of psoriasis.

In this trial, said Higgins, cohorts of three to five patients withmoderate to severe stable plaque psoriasis will be dosed with BCX-34 contained in a gelatin capsule. Patients in the initial cohort willreceive a daily dose totaling 40 mg (20 mg per dose twice daily) for56 consecutive days. Subsequent cohorts of three to five patients willreceive a higher dose level, he explained, until the maximumtolerated dose is obtained.

"This study represents the first trial where psoriasis patients are beingtreated orally. We are excited because it is the second opportunity toobserve how oral BCX-34 will perform in humans in terms of safetyand pharmacological activity," Higgins said.

The company is currently conducting a multi-center Phase III clinicaltrial with topical BCX-34 for the treatment of cutaneous T celllymphoma (CTCL), a Phase I/II trial with an oral formation of BCX-34 to treat T cell cancers and a Phase I/II trial with topical BCX-34for the treatment of atopic dermatitis.

One Third Had Complete Remission

The results of a Phase II six-month, open-label trial of BCX-34demonstrated favorable responses in the topical treatment of CTCL in18 (75 percent) of the 24 patients with stage I-IIa disease.

Almost one-third (seven patients) had complete remissions, twoadditional patients were clinically clear of disease and nine patientsshowed partial remissions. The remaining six patients showed little orno improvement or got worse, Higgins said.

Phase I pharmacology data for oral formulation of BCX-34 fortreatment of T cell cancers was based on three patients with stage Iband IIb disease, who were administered oral and intravenousformulations of BCX-34. The goal of this trial, said Higgins, was tounderstand the pharmacology of orally administered BCX-34 todesign an oral dosing schedule for subsequent clinical trials.

Each patient received 36-42 mg intravenously, followed a week laterby the same dose orally, followed three weeks later by a five-dayconsecutive oral dosing program.

Higgins said BCX-34 show bioavailability of greater than 76 percentand was stable in vivo with minimal degradation after bothintravenous and oral administration. The study also showed thatBCX-34 was not significantly accumulated in vivo and no significanttoxicity was observed.

BioCryst had a public offering in December. Higgins said thecompany has $33 million in cash and 13.6 million shares outstanding.A net loss of $2.51 million or $0.23 per share was reported for thethird quarter of this year.

BioCryst's stock (NASDAQ:BCRX) closed Wednesday at $12.625, again of $0.375. n

-- Frances Bishopp

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