By Lisa Seachrist
Genentech Inc. and Alkermes Inc. announced that Nutropin Depot, their sustained-release formulation of somatropin (recombinant human growth hormone), increased the growth rates of children with growth hormone deficiency (GHD).
As a result of the Phase III results presented in at the annual meeting of the Endocrine Society, in San Diego, the companies intend to file a new drug application by the end of June.
¿We are on track to file by the end of this quarter,¿ said Betsy Rosenberg, spokeswoman for the South San Francisco-based Genentech. ¿By reducing the number of injections to 12 or 24 times a year, Nutropin Depot is a technological advance that increases convenience for patients and potentially enhances compliance.¿
Nutropin Depot combines Cambridge, Mass.-based Alkermes¿ ProLease delivery vehicle ¿ a polymeric microsphere which utilizes the same polymer used in dissolving sutures ¿ with Genentech¿s human growth hormone. The resulting product provides a sustained release of human growth hormone that allows for once-a-month or twice-a-month dosing regimens compared to daily injections to treat short children with growth hormone deficiencies. About 20,000 children in the U.S. suffer from GHD, which requires them to take daily injections of growth hormone.
In the pivotal Phase III study of Nutropin Depot, the companies studied 74 children with GHD who had not received any previous treatments for the disorder. The study evaluated two dosing forms ¿ once a month and twice a month ¿ with both groups receiving the same total dose. Results demonstrated that six-month growth rates of both rates improved over their baseline growth rates. The mean annualized growth rate was 8.4 centimeters per year, which is within the range of growth rates seen with daily growth hormone therapy.
Ninety-three percent of patients completed the six-month study, and 88 percent elected to continue on the extension study, which allowed for continuing therapy with Nutropin Depot. Rosenberg said there were no serious drug-related side effects.
The alliance between Alkermes and Genentech dates back to 1996, when Genentech agreed to pay up to $30 million to continue the clinical development of ProLease sustained drug technology. That collaboration has been expanded twice.
The ProLease drug delivery system lasts longer than drug delivery microcarriers, such as those based on liposomes. The heart of the technology is a polymer called polylactide-coglycolide. Proteins to be carried in the ProLease system are first lyophilized into a powder and suspended in a polymer solution in organic solvent. The suspension is then atomized to create droplets. The droplets are frozen, and excess solvent is extracted. The result is porous polymer particles that contain freeze-dried protein particles dispersed throughout.
Genentech¿s various recombinant growth hormones, Protropin, Nutropin and Nutropin AQ are approved for indications including pediatric GHD, Turner¿s syndrome and adult GHD.
GHD occurs when the production of growth hormone, secreted by the pituitary gland, is disrupted. Since growth hormone plays a critical role in stimulating body growth and is involved in the production of muscle and protein and in the breakdown of fats, hormone deficiency affects a number of bodily functions.
¿As is the case with the daily growth-hormone therapies, we are committed to focusing on Nutropin Depot in a number of indications in both pediatric and adult populations,¿ Rosenberg said.
Genentech¿s stock (NYSE:GNE) closed Monday at $82.1875, up $0.0625. Alkermes stock (NASDAQ:ALKS) closed at $23, down $2.375.