GENENTECH’s ACTIMMUNE GAMMA INTERFERON TO BE LAUNCHED AS ORPHAN

GENENTECH's ACTIMMUNE GAMMA INTERFERON TO BE LAUNCHED AS ORPHAN product for chronic granulomatous disease, a condition affecting between 250 and 400 patients in the U.S. The product received FDA clearance on Dec. 20. The agency approved the drug one year to the day after Genentech's product license application was filed. Gamma interferon was granted orphan drug status for the chronic granulomatous disease (CGD) indication in September 1988. CGD is a rare inherited disorder in which the victim's white blood cells are unable to resist infection. Genentech already treats "most" of the patient population. In Phase III trials, 128 patients were followed in 13 centers worldwide (10 in the U.S.). An additional 90 patients have been treated with the drug on a compassionate basis in the U.S. The company will not disclose the price of the product until launch. Pricing for an orphan product is a thorny question when most of the treatable patients have been receiving therapy during trials. Actimmune will be the third recombinant DNA product to be marketed in-house by Genentech; the company already markets its Protropin human growth hormone and Activase (t-PA), a blood clot dissolving agent. Genentech developed two other products currently on the market: human insulin, licensed to Lilly, and alfa interferon, licensed to Genentech's new controlling shareholder, Hoffmann-La Roche, which markets the product as Roferon. Actimmune was recommended for approval by FDA's Biological Response Modifiers Committee on July 30 ("The Pink Sheet" Aug. 6, p. 9). Genentech presented Phase III data to the committee that showed that 77% of gamma interferon patients were free of infection after nine months on the drug, versus 30% on placebo. "Side effects observed in these trials, including headache, fever, rashes and chills, were common but transient," a Dec. 21 HHS press release says. As recommended by the committee, Genentech will conduct postmarketing studies to determine long-term effects of the drug, HHS said. Final labeling will recommend against the use of the drug in pregnant women, the release states. The final package insert is not yet available, the company said, due to some final "technicalities." Genentech is also investigating Actimmune for the treatment of small-cell lung cancer, malignant melanoma, and trauma-related infections. Phase III trials may be completed late next year, the company reported. A third indication sought for gamma interferon is for severe atopic dermatitis. A Phase II trial has just been completed, the company said, and will be reported early next year. Genentech is the first company to have a gamma interferon product approved by FDA, but several other companies are investigating the product. Biogen has an NDA pending for Immuneron for the treatment of renal cell carcinoma, and is also studying several other indications, including rheumatoid arthritis. Amgen has begun clinicals for treatment of infectious diseases with gamma interferon, and Exovir, Transgene, and Viragen are also developing the product for a variety of indications.