Swiss drug maker Ares-Serono Group won FDA approval Monday ofits recombinant human growth hormone, Serostim, to treat AIDSwasting, a potentially fatal condition in which HIV-infected patientslose too much muscle and organ tissue.

Serostim is identical to Ares-Serono's Saizen, which companyofficials expect will gain FDA approval in the next several weeks fortreatment of growth hormone deficiency in children. The Geneva-based company received an approvable letter for Saizen in April1996. (See BioWorld Today, May 1, 1996, p. 1.)

Although numerous companies are crowding the U.S. with growthhormone products for use as replacement therapy for children ofshort stature, Ares-Serono is the first to get approval of the hormoneto treat AIDS wasting, a potentially larger market for the drug.

About 160,000 AIDS patients are believed to suffer from wasting, orcachexia, in the U.S. About 20,000 children receive growth hormoneto offset their deficiencies and the annual patient price can run ashigh as $20,000.

Serostim's cost has not been determined, said Gina Cella, aspokeswoman for Ares-Serono's U.S. affiliate, Serono LaboratoriesInc. in Norwell, Mass.

"But we have committed to a price cap with the AIDS community,"she added. "The per-patient per-year cost will not exceed $36,000."

Cella said AIDS wasting occurs when the body's metabolism isreversed and lean body mass _ muscles and organ tissue _ areburned off instead of fat.

Therapies prior to Serostim concentrated on boosting appetite andcalorie intake, but those measures do not affect the abnormalmetabolism.

Clinical trials showed AIDS patients receiving Serostim experiencedsignificant increases in lean body mass and weight as well asimproved physical function. The data also showed body fatdecreased. However, the trials did not indicate Serostim affectedsurvival of AIDS patients suffering from cachexia.

In March 1996, an FDA advisory panel narrowly rejectedrecommending approval of Serostim. (See BioWorld Today, March5, 1996, p. 1.)

Cella said the advisory group's concerns about efficacy data from thetrials were answered, clearing the way for the FDA's acceleratedapproval.

A Phase IV study will have to be conducted to determinemaintenance dosing; that is, how often patients will take Serostim tokeep up their lean body mass after it is restored. To counteractwasting the drug is prescribed daily.

The most common side effects of Serostim experienced by patients inthe clinical studies were pain and stiffness as well as swelling ofhands and feet. Ares-Serono said the reactions were mild to moderateand subsided with continued treatments.

Cella said Ares-Serono will consider broadening Serostim's label totreat cachexia associated with other diseases, such as cancer.

As for Saizen _ the company's product to treat growth hormonedeficiency _ it faces tough competition from South San Francisco-based Genentech Inc.'s Protropin and Nutropin, which dominate 75percent of the $350 million U.S. market. Eli Lilly and Co., ofIndianapolis, accounts for the other 25 percent with Humatrope.

Three other companies have FDA-approved drugs for growthhormone deficiency. Genentech has kept two of the competingproducts off the market with patent infringement litigation. The third,Genotropin, is sold by Pharmacia & Upjohn Co., of Kalamazoo,Mich., which has a licensing agreement with Genentech.

Ares-Serono's growth hormone is made in mammalian cells and willface no court challenge from Genentech, which manufactures its drugin bacteria.

Cella said a price for Saizen has not been established. The worldwidemarket for growth hormone is estimated at $1.5 billion. Ares-Seronosells Saizen for growth hormone deficiency in 60 countries outsidethe U.S. and for Turner's syndrome in 30 countries.

In 1995, the company's growth hormone products generated $95.5million in revenues, which was 14 percent of Ares-Serono's $682million in total sales for the year.

Cella said the company is conducting clinical studies in Europe toseek approval there of Serostim for AIDS wasting. n

-- Charles Craig

(c) 1997 American Health Consultants. All rights reserved.

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