WEBWATCH

BY Shirley Butler

SEATTLE, March 2 /PRNewswire/

The U.S. Food and Drug Administration (FDA) issued an "approval letter" to Immunex Corporation (Nasdaq: IN4NX) today, indicating the agency's intention to support the use of NOVANTRONE(R) (mitoxantrone for injection concentrate) to treat multiple forms of multiple sclerosis (MS). The "approval letter" issued today follows a recommendation for approval made last month by the FDA's Peripheral and Central Nervous System Drugs Advisory Panel. "The FDA's approval letter brings physicians and their patients with MS one step closer to gaining access to this new approach to treating worsening forms of this disease," said Dawn Viveash, vice president, regulatory affairs. "Our productive interaction with the FDA will continue, as we work with officials of the agency to expeditiously fulfill the requirements of the approval process. We expect the new NOVANTRONE labeling to be consistent with the FDA panel's recommendations for treatment indications and safety." Physicians and patients will be advised that the use of NOVANTRONE has been associated with cardiotoxicity. This risk increases with cumulative dose and patients should be monitored for evidence of cardiotoxicity. Ordinarily, MS patients should not receive a cumulative dose greater than 140mg/m2. In the two-year clinical trial of patients with MS, side effects were generally manageable and primarily mild to moderate. The most frequently reported adverse events in patients receiving 12mg/m2 were nausea, alopecia (hair loss), upper respiratory tract infection, urinary tract infection, menstrual disorder, and transient neutropenia (a reduced number of white blood cells). Multiple sclerosis is a chronic, debilitating disease of the central nervous system. The symptoms of MS result when a breakdown occurs in the myelin sheath that insulates the nerve fibers of the brain and spinal cord, resulting in patches of scar tissue, or "sclerosis." When demyelination occurs, nerve impulses are slowed or halted which can cause symptoms ranging from numbness in the limbs to complete paralysis. NOVANTRONE acts in people with MS by suppressing the activity of certain white blood cells known as T cells, B cells and macrophages that are thought to lead the attack on the myelin sheath. NOVANTRONE is currently marketed to treat pain in patients with advanced hormone-refractory ferostate cancer in combination with corticosteroids and for initial therapy of acute nonlymphocytic leukemia. It is not approved for use in MS patients.