Thursday, Sep 30, 1993
New York -- September 30, 1993 --According to results of an international study of nearly 6,000 patients, heart attack victims who arrive at the hospital between six and 12 hours after the onset of symptoms can still significantly benefit from thrombolytic therapy with alteplase t-PA (recombinant tissue plasminogen activator).
Findings of the double-blind, placebo-controlled study known as LATE (Late Assessment of Thrombolytic Efficacy) were presented here today at an international symposium on heart disease sponsored by the New York Cardiological Society. The primary findings of LATE were published on September 25 in The Lancet and showed a significant decrease in 35-day mortality of 25.6 percent in patients treated with alteplase t-PA vs. placebo between six and 12 hours after symptom onset.
Although it is still crucial that heart attack patients seek treatment as early as possible, based on LATE's findings, many more heart attack patients each year may benefit from life-saving alteplase t-PA therapy. Genentech markets alteplase t-PA as Activase® (Alteplase, recombinant) in the United States.
The LATE trial was specifically designed to determine whether treatment with alteplase t-PA more than six but less than 24 hours after the onset of major heart attack symptoms (e.g., chest pain, nausea) reduces mortality. Patients were randomized and received infusions of either alteplase t-PA in a standard dose or placebo over three hours. All received aspirin and a majority also received intravenous heparin as anticoagulation therapy.
Although the overall mortality difference from six to 24 hours did not achieve statistical significance, a significant benefit was seen in the subgroup of patients treated between six and 12 hours after the onset of symptoms.
Mortality at 35 days was reduced 25.6 percent in patients treated with alteplase t-PA during this period as compared to placebo-treated patients; 8.9 percent vs. 11.97 percent respectively, a statistically significant difference (p=0.0229) that was maintained up to one year. Mortality reductions of this extent were also seen with alteplase t-PA in earlier trials (e.g., ASSET, Lancet 1988; 2:525-30) treating patients only up to six hours from the onset of heart attack symptoms.
The stroke rates of alteplase t-PA observed in this trial are consistent with that found in other thrombolytic trials with patients treated within only six hours from symptom onset. According to The Lancet article, "Although treatment with alteplase resulted in an excess of hemorrhagic strokes, by six months the number of disabled survivors was the same in both treatment groups and other clinical events were observed with similar frequency in the two groups..
"The results of LATE again confirm that use of thrombolytic therapy with alteplase t-PA can significantly reduce heart attack death rates," said Robert G. Wilcox, M.D., international coordinator of the LATE trial and one of the principal authors of The Lancet article. "And now we have a definitive trial providing a rationale for administering alteplase t-PA to patients who present between six and 12 hours from the onset of symptoms -- this may be encouraging news for a large number of potential heart attack victims.
The LATE study was independently conducted in 247 medical centers in the United States and 12 other countries with financial support from Genentech.
Genentech, Inc. 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, California and is traded on the New York and Pacific Stock Exchanges under the symbol GNE.
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