By Charles Craig
Less than three weeks after an FDA advisory panel recommended approval of Genentech Inc.'s Nutropin for Turner's syndrome, the agency cleared the growth hormone for marketing Tuesday to treat the rare female disorder affecting about 50,000 U.S. women.
Nutropin, first marketed in 1993, already was approved for treatment of children suffering from growth failure caused by inadequate levels of the hormone and chronic renal insufficiency.
A slightly different version of Nutropin, called Protropin, was approved in 1985 and also is sold by Genentech to treat growth hormone deficiencies in short children. Nutropin and Protropin sales in 1995 totaled $219.4 million.
Genentech's stock (NYSE:GNE) Tuesday near closing was trading at $53.625, which was unchanged from Monday.
The application for expansion of Nutropin's label to include Turner's syndrome was a joint submission with Eli Lilly and Co., of Indianapolis, for approval of its growth hormone, Humatrope, for the same indication. Nutropin and Humatrope are identical products. Humatrope was approved in 1987 for growth hormone deficiencies.
The FDA's Endocrinologic and Metabolic Drug Advisory Committee recommended approval of both Nutropin and Humatrope for Turner's syndrome. (See BioWorld Today, Dec. 12, 1996, p. 1.)
Officials of Lilly, whose offices were closed Tuesday, could not be reached to determine if the FDA cleared its growth hormone for the disease. FDA representatives did not return telephone calls.
Turner's syndrome, which affects females exclusively, can cause numerous problems, most notably short stature. Treatment with growth hormone is effective during childhood when girls are still growing. About one in 2,500 girls are born with the disorder, which is characterized by mutations in one of two X chromosomes.
The average annual cost of Nutropin is $16,000 to $18,000 per patient. The expansion of the label to include Turner's syndrome is not expected to have a significant financial impact on Genentech's sales.
In a prepared statement, Genentech's president and CEO, Arthur Levinson, said Tuesday, "After more than 12 years of research, today's clearance provides Turner's syndrome patients with a long-awaited treatment."
The expansion of the Nutropin label also helps Genentech's sales efforts as the U.S. market becomes more crowded with growth hormone products. Another boost came in January 1996 when Genentech got approval of a liquid version of Nutropin for more convenient use of the drug. Through the first nine months of this year, Nutropin and Protropin accounted for two-thirds of growth hormone sales in the U.S.
Genentech and Lilly had the U.S. growth hormone market to themselves until 1995. Novo Nordisk A/S, of Bagsvaerd, Denmark, and Bio-Technology General Corp., of Iselin, N.J., received FDA approval of their growth hormones in May 1995. But Genentech's patent infringement litigation blocked them from selling in the U.S.
Novo Nordisk won the latest round in court in December 1996 when the U.S. District Court of Appeals cleared the way for the company to begin selling its growth hormone by issuing a stay of a lower court's preliminary injunction.
Pharmacia & Upjohn, of Kalamazoo, also won FDA approval of its growth hormone in 1995 and Ares-Serono Group, of Geneva, Switzerland, was cleared for marketing its product in the U.S. in 1996.
Ares-Serono makes its growth hormone by a method different from Genentech and will face no court challenge. Pharmacia & Upjohn also will not end up in litigation with Genentech based on a 1985 agreement. *