ISIS-3 STUDY RESULTS UNCHANGED SINCE LAST REPORTED
-- INTERNATIONAL COMPARATIVE GUSTO TRIAL WELL UNDERWAY --
SOUTH SAN FRANCISCO, Calif., March 26 /PRNewswire/ -- The major findings of the ISIS-3 trial, published this week in The Lancet, remain unchanged since they were first publicly announced a year ago. Market research indicates that shifts in prescribing patterns in reaction to the findings of the ISIS-3 trial have already occurred during 1991, with market share of Genentech's Activase(R) (alteplase, recombinant) t-PA now stable at just over half of all patients administered thrombolytic therapy in the U.S.
In the United States, approximately 53 percent of patients currently treated with thrombolytics receive alteplase, 36 percent are prescribed streptokinase, and 11 percent receive APSAC.
"It is apparent from prescribing patterns that most physicians are as convinced as we are that Activase will reaffirm itself as having important clinical advantages in thrombolytic therapy," said G. Kirk Raab, president and chief executive officer of Genentech. "That is why we are helping to support such a large independent study as GUSTO, and that is why we continue to believe that the ISIS-3 findings are irrelevant to our product and to standard prescribing patterns for thrombolytic therapy in the U.S."
"Many of the critical questions left unanswered by ISIS-3 are now being addressed by the GUSTO study," according to Robert Califf, M.D., co-chairman of the new study and director of the Cardiac Care Unit at Duke University Medical Center. "The Gusto study will provide accurate comparative clinical data between thrombolytic therapies in the context of different methods of anticoagulation therapy," explains Dr. Califf.
Until the GUSTO trial is complete, Dr. Califf advises that whenever possible patients should be enrolled in the trial, but for patients at sites not participating in GUSTO, all thrombolytic agents should be available. Because the optimal approach is not clear, physicians should choose therapy based on clinical judgment and their interpretation of all published data.
Market Research Shows Physicians' View of Thrombolytic Therapy
In January, 1992, market research was conducted on behalf of Genentech among a random sample of 200 U.S. cardiologists and emergency physicians. This independent research revealed that:
-- More than 80 percent of U.S. cardiologists and emergency physicians still use Genentech's t-PA for some of their patients.
-- More than 80 percent of cardiologists and emergency physicians believe in the relationship between an early open artery and decreased mortality.
Key Issues in ISIS-3 Protocol Make GUSTO the Definitive Study
The major clinical questions left unanswered by the ISIS-3 data relate to problems inherent in the study's protocol, particularly its applicability to typical clinical practice in the United States. The questions include the following:
-- The study used Burroughs Wellcome's form of t-PA (duteplase), which is not the same product as alteplase, Genentech's t-PA, and the two versions of t-PA have never been compared in a head-to-head study.
-- Use of heparin was inconsistent with standard medical practice for alteplase in the United States (normally used intravenously with thrombolytics in the United States).
-- Stroke complications with duteplase cannot be extrapolated to alteplase -- alteplase is a different form of t-PA and the ISIS-3 findings are in marked contrast to the published results of U.S.-based clinical studies documenting the safety of alteplase (Genentech's t-PA).
Stroke Data from ISIS-3 Not Applicable to Activase
The safety of Activase has been well established in the double blind placebo-controlled studies conducted to obtain the product's labeling and marketing approval from the U.S. Food and Drug Administration. Further confirmation of the safety of Activase has been revealed in the Genentech-sponsored National Registry for Myocardial Infarction which is currently underway in 600 U.S. hospitals. Thus far, registry data have been collected on more than 17,000 patients who were treated with Activase. Of those patients, 98 percent received IV heparin and the total reported stroke rate for alteplase has been well below the rate reported in ISIS-3 for duteplase. While these stroke data were not collected in a randomized fashion, they do reflect actual usage of Activase among U.S. physicians.
GUSTO Should Answer Questions Left by ISIS-3
With no new data from the ISIS-3 publication in Lancet to clarify these questions, the medical community awaits the results of the 40,000- patient international clinical trial called GUSTO -- Global Utilization of Streptokinase and t-PA in Occluded Coronary Arteries. With more than 1,000 sites in the multicenter trial and about 15,000 patients already enrolled, the study is currently adding about 500 patients per week worldwide. It is scheduled to be completed in early 1993.
The trial is a four-arm study, and examines the two leading thrombolytic therapies (streptokinase and alteplase t-PA) in a manner consistent with U.S. medical practice. The GUSTO study includes adequate levels and monitoring of the anticoagulant heparin given intravenously (as is commonly practiced in the United States) as compared to unmonitored use of subcutaneous heparin (as was done in ISIS-3).
Genentech, Inc. (NYSE: GNE) is a leading biotechnology company that discovers, develops, manufactures and markets human pharmaceuticals for significant medical needs. The company has headquarters in South San Francisco and is traded on the New York and Pacific Stock Exchanges.
/CONTACT: Greg Baird, 415-266-6102, or Jim Weiss, 415-266-2742, both of Genentech, Inc./
(GNE) CO: Genentech, Inc. ST: California IN: MTC SU:
AH-KW -- NY065 -- 2109 03/26/92 16:07 EST