Seragen Inc. said Friday that it is putting its first product candidate inPhase III clinical trials, an interleukin-2 (IL-2) fusion toxin moleculefor the treatment of cutaneous T cell lymphoma (CTCL).
Two trials, at 18 sites, will run simultaneously. One study involvespatients in immediate need of therapy who have recurrent orpersistent disease despite systemic therapy with other agents. Theother is in those with less-advanced disease who have failed no morethan one topical and/or systemic therapy with another agent.
The drug is being developed in collaboration with Indianapolis-basedEli Lilly and Co., which has worldwide development, distributionand marketing rights to the product. Seragen, of Hopkinton, Mass.,has manufacturing rights and will get a percentage of end-user sales.
Fusion toxins consist of a toxin fragment genetically fused to ahormone or growth factor that targets specific cell-surface receptorson disease-causing cells.
"CTCL is the first of several IL-2 receptor-expressing cancers forwhich we intend to evaluate the clinical efficacy of IL-2 fusiontoxin," Homer Pearce, Lilly's vice president of cancer research andclinical investigation, said in a news release. "CTCL has a well-defined staging system with measurable clinical endpoints. Thismakes it a good target for our first joint trial of IL-2 fusion toxin incancer."
Helen Maslocka, Seragen's vice president for investorrelations/corporate communications, told BioWorld the trials areexpected to involve about 150 patients, but the breakdowns andexact numbers are not known because FDA recommendations arebeing incorporated into the protocol.
Treatment will entail a 10- to 15-minute intravenous infusionadministered daily for five days, then repeated every 21 days.Treatments may be administered for 12 months, or about 16 courses.
The trial with advanced-disease patients will be open-labeled anddesigned to evaluate safety, efficacy and pharmocokinetics. Theother is a randomized, double-blind, placebo-controlled study toevaluate efficacy of the fusion toxin in patients who do not needimmediate systemic treatment.
Tumor reduction is the primary endpoint, Maslocka said, with otherendpoints being physician assessment, biopsies and before/afterphotographs.
"Fusion toxins have shown significant promise in almost 500patients, in both autoimmune diseases and cancer," Maslocka said."We've tested the sickest patients in the diseases we've targeted.We're hopeful our Phase III study shows statistical significance, andwe have an agent that will be helpful to sufferers of this particulardisease."
Eight of 19 CTCL patients in a Phase I/II trial of IL-2 fusion toxinhad partial or complete responses, the company said.
The IL-2 fusion toxin is being tested in Phase I/II trials forchemotherapy-resistant lymphomas, psoriasis and recent-onset Type-1 diabetes. Phase I/II trials have been completed for severrheumatoid arthritis and HIV. Another agent, epidermal growthfactor (EGF) fusion toxin, is in Phase I/II trials for solid tumors.
Lilly has the option to gain rights to non-dermatological applications of the fusion toxins.
Seragen stock (NASDAQ:SRGN) was up 50 cents Friday, closing at$5.25 per share. n
-- Jim Shrine
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