New Kidney Cancer Drug OKd by FDA : Medicine: Approval is good news for patients in which the disease has spread, and for troubled Chiron Corp.

The U.S. Food and Drug Administration on Tuesday approved the nation’s first drug to treat kidney cancer that has spread beyond that organ, a disease that typically claims its victims within a year of diagnosis.

The approval of Proleukin--a genetically engineered “orphan drug” developed by biotechnology pioneer Cetus Corp., now part of Chiron Corp.--should buoy the hopes of the nearly 10,000 patients diagnosed each year with kidney cancer. To date, there has been no treatment once the cancer has spread.

It is also a boon for Chiron, which has suffered steep losses since buying Cetus last year in a stock swap valued at $660 million.

“This is the first approval for Chiron that we’ll sell on our own,” said Larry Kurtz, a spokesman for the company, which is based in the East Bay industrial city of Emeryville. The company’s other products are licensed or sold through joint ventures.

Kurtz said the product, which has been available in Europe for two years, is expected to generate first-year U.S. revenue of $15 million and ultimately could reel in $100 million annually if other uses are approved. A full course of treatment is expected to cost $6,000 to $8,000, not including the approximately $30,000 cost of the required hospitalization.

Industry analysts and medical experts said the approval bodes well for Chiron, the biotech industry and kidney cancer patients, despite the drug’s potentially deadly side effects.

“It’s very positive given the FDA’s problems with other biotech companies,” said John McCamant, publisher of the Medical Technology Stock Letter, a Berkeley newsletter that follows such stocks.

Stocks of biotech companies were slammed last month after the FDA declined to approve a highly anticipated product of Centocor Inc. to treat septic shock. Centocor, based in Malvern, Pa., has been in a heated battle with Xoma, based in Berkeley, to win approval of a treatment for septic shock.

McCamant said he expects Chiron to become profitable again within two quarters. For 1991, the company had a loss of $425 million on sales of $118.5 million. The results reflected a one-time, primarily non-cash charge relating to the Cetus purchase.

Robert Figlin, an associate professor of medicine at UCLA who served on an FDA advisory panel that reviewed the Proleukin test results, said the drug “will not work for all patients (but that) for those it helps, the help is significant.” In tests, it proved fatally toxic to about 4% of patients, he said. The injectable drug works by stimulating the immune system to fight the cancer.

Proleukin did not have an easy road to approval. Cetus began human clinical trials of the drug in 1984, with test treatments of kidney cancer coming the next year. The company, which had invested heavily in the drug in anticipation of relatively quick approval, filed its application to market the drug in November, 1988.

In a crushing blow, an FDA advisory panel in July, 1990, asked for more data and analysis. Last January, the committee reviewed the new data and recommended approval of the drug for treatment of kidney cancer. The agency’s approval less than four months later “shows that it can move quickly when it comes to life-threatening diseases,” McCamant said.

Proleukin, which Kurtz said will be shipped to hospitals later this month, is also being tested as a possible treatment for melanoma, AIDS and other diseases.