Seragen Inc. stopped short a Phase II trial of a fusiontoxin molecule for psoriasis after one patient developed ablood clot. Further analysis will be needed before it isknown if the adverse event was drug related.
The double-blind placebo-controlled study of Interleukin-2 Fusion Toxin was stopped after treatment of 41 patientsin the study designed to enroll 60. Company officials saida complete analysis, which will include a look back atother studies of the toxin, should be completed in the firstquarter of 1996.
Seragen's stock (NASDAQ:SRGN) lost $1.63, or 28percent, Thursday to close at $4.25. About 842,000 shareswere traded compared to normal volume of well under50,000 shares. Company officials said they believe thenews released late Wednesday did not warrant a reductionin the stock of nearly 30 percent.
Jean Nichols, senior vice president of Hopkinton, Mass.-based Seragen, said company officials decidedtermination of the study, rather than putting a hold on it,was appropriate given the number of patients alreadytreated. Enough data should be available from this study,together with previous studies, to effectively design thenext trial, she said.
Nichols said the patient who developed a blood clot hasfully recovered.
"We're breaking the blind early and we should haveenough patients accrued to have meaningful data comingout of the study," said George Masters, vice chairman,president and CEO of Seragen.
Nichols said that assuming the analysis reveals theadverse event was not drug related, the company shouldbe in good shape to design a new Phase II study."Assuming all goes positively, we'll continue with ourpsoriasis trials and there won't be a huge impact on theprogram."
Seragen's fusion toxin molecules consist of a toxinfragment genetically fused to a hormone or growth factorthat target specific cell-surface receptors on disease-causing cells. In addition to the IL-2 toxin, Seragen has inclinical trials ongoing in an epidermal growth factor(EGF) fusion toxin for solid tumors.
Eli Lilly and Co., of Indianapolis, is collaborating withSeragen on development of the IL-2 Fusion Toxin in allcancer indications. They are in Phase III trials of the toxinin cutaneous T cell lymphoma (CTCL). Seragen has allrights in dermatological applications. The CTCL study isnot affected by the news in psoriasis.
Patients in the discontinued trial, which involved thosewith moderate to severe plaque-type psoriasis, receivedintravenous IL-2 Fusion Toxin or placebo three times aweek for four weeks, followed by a four-weekobservation period. Skin changes were assessed using apsoriasis index, physician assessment and a dermatologylife quality index. In an earlier study, disease severityscores decreased by a mean of 32 percent for thosecompleting two courses of therapy and 46 percent inthose completing three courses.
One of Seragen's concerns going forward, in addition toits analysis on the psoriasis data, is its cash position.
Seragen in June completed a $23.8 million loan guaranteeprogram that was secured by Boston University,Seragen's majority shareholder, and two individuals. Theguarantors were issued 10-year warrants to purchase 2.78million shares at $4.75 per share.
Masters said that loan should last the company until Sept.1, 1996. "We're looking at a number of financing optionsto take us beyond that," he said.
A positive in the financial picture is that Lilly is fundingall clinical development costs for the CTCL studies, aswell as additional studies where Lilly has rights. Masterssaid Seragen hopes to trigger a milestone payment in theLilly collaboration sometime late in 1996. n
-- Jim Shrine
(c) 1997 American Health Consultants. All rights reserved.