Company seeks priority review of NOVATRONE in secondary progressive Multiple Sclerosis

SEATTLE - Immunex Corporation (NASDAQ:IMNX) announced today that it has filed a supplemental NDA with the U.S. Food and Drug Administration (FDA) for expanded labeling for NOVANTRONE® (mitoxantrone for injection concentrate) for the treatment of patients with secondary progressive Multiple Sclerosis (MS).

"There are 120,000 patients with secondary progressive MS for whom there are still no approved treatment options," said Peggy V. Phillips, senior vice president, pharmaceutical development for Immunex. "Patients with this form of the disease experience a steady worsening of their neurological function which can result in loss of control over movement of limbs and impaired vision and speech. We are pleased to be filing this and we have asked the FDA for priority review."

The results of the pivotal NOVANTRONE Phase III data submitted to the FDA today showed that NOVANTRONE had a statistically significant impact on relapse rate and disability progression in patients with secondary progressive MS. These clinical data were corroborated by positive magnetic resonance imaging (MRI) data.

This multicenter, placebo-controlled, randomized, observer-blind study of 194 patients compared two doses of NOVANTRONE -- 12 mg/m2 and 5 mg/m2 - with placebo. Each treatment was administered by short, IV infusion once every three months for two years. These results were reported at the September 1998 Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS).

Additional third-year follow-up data were presented in April of this year at the Annual Meeting of the American Academy of Neurology (AAN). These results showed that one year after treatment was stopped, patients who had been treated with NOVANTRONE experienced a sustained reduction in their number of attacks, and delay in their disab
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Contact: Lisa Crisera
criseral@immunex.com
206-389-4346
Immunex Corporation
2-Jun-1999