NEW YORK (CNNMoney.com) - Two drugs sold generically in the United States extend the life span of ovarian cancer patients when pumped into the abdominal cavity, according to a medical study released Thursday.

But even if this results in a surge in drug sales, it won't make much difference to the ledgers of the manufacturers, analysts say.

Paclitaxel and cisplatin can significantly increase the life span of patients with advanced ovarian cancer when pumped directly into the abdomen instead of just intravenously, according to study results reported in the New England Journal of Medicine.

However, any sales gain for the generic drugs would be diluted among several drug makers, including Bristol-Myers Squibb and Ivax Pharmaceuticals, and would not translate into a meaningful benefit to any single company, analysts say.

Paclitaxel is manufactured by Bristol-Myers Squibb (down $0.07 to $28.84, Research) under the brand name Taxol, which was a top-selling cancer drug when it still had patent protection in the U.S. Taxol sales totaled $1.6 billion for Bristol-Myers in 2000, its last full year with U.S. patent protection; in the third quarter of last year, the most recent report available, sales were $175 million out of $4.77 billion in company sales.

Since 2001, Ivax (down $0.13 to $31.19, Research) has manufactured paclitaxel as a generic drug under the name Onxol. Ivax, a Miami-based drug maker that is being acquired by the Israel's generic drug giant Teva Pharmaceuticals (down $0.28 to $42.94, Research), did not provide sales figures for Onxol. But analysts said that sales took a dive after the drug went generic, as they typically do.

"Ivax will benefit some, but the real benefit of this is spread out among a bunch of competitors," said Casey Alexander, analyst for Gilford Securities, Inc. "There is no one company that is going to make their year off of Taxol. It just doesn't generate that kind of leverage to any one company's bottom line."

"The price of Taxol has declined precipitously, probably 80 percent," said Alexander.

In addition to Bristol-Myers and Ivax, paclitaxel is also manufactured by Ohio-based Bedford Laboratories and Australian company Mayne Pharma, said Richard Watson, analyst for William Blair & Co.

Cisplatin, the other generic drug used in the ovarian cancer treatment, is manufactured by Bedford and Teva. Watson said a sales gain would not have a "impact fundamentally" any one of those companies.

Teva's acquisition of Ivax, which is expected to close Jan. 12, will make the Israeli drug maker the biggest producer of generics in the world. Sales in the third quarter were $1.32 billion.

"While [increased sales of paclitaxel] is not expected to move the needle on the global Teva platform, it's another growth factor" for the company that it might not have anticipated, said Andrew Forman, analyst for WR Hambrecht. "Teva's acquisition [of paclitaxel maker Ivax] looks very smart right up to the end."

To read about Bristol-Myers' pipeline plans for 2006, click here.