By Lisa Seachrist

Washington Editor

InterMune Pharmaceuticals Inc., which is in registration for an initial public offering, received FDA approval to market Actimmune (interferon gamma-1b) injection to treat patients with severe malignant osteopetrosis, a life-threatening overgrowth of bony structures.

The approval is the first Palo Alto, Calif.-based InterMune has garnered. Genentech Inc., of South San Francisco, received approval to market the drug to treat chronic granulomatous disease in 1990. Since then, privately held InterMune has licensed all rights to the drug and begun development of it for other indications.

"It's exciting; there is a lot of potential for gamma interferon," said W. Scott Harkonen, president and CEO of InterMune. "We expect to launch Actimmune in this indication in the next four weeks."

Osteopetrosis is a rare genetic disease that primarily affects children. The excessive growth of bone causes patients to become blind and deaf as new bone growth puts pressure on the optic and auditory nerves. In addition, the bone growth fills the hollow spaces occupied by bone marrow. As a result, patients suffer anemia and serious infections. Children frequently die by the age of 10.

Currently, bone marrow transplantation is the only therapy that can cure the disease. However, the chance of a cure also comes with the risk of death as 50 percent of children who undergo bone marrow transplantation die following the procedure.

Actimmune slows the progression of the disease by reducing the activity of osteoclasts, or bone-forming cells, and reducing infection by improving immune function. The company also is developing the drug as a potential therapy for idiopathic pulmonary fibrosis, multidrug-resistant tuberculosis and systemic fungal infections.

InterMune filed earlier this month to go puiblic. It intends to gross about $82.5 million from the sale of 5.5 million shares at $14 to $16 each. (See BioWorld Today, Feb 4, 2000, p. 1.)