The news is a boost for the Spanish biotech company, which already sells Yondelis as a treatment for soft tissue sarcoma, a rare disease, and now hopes to address a much bigger commercial opportunity.

Bradley Monk, an oncologist from the University of California Irvine Medical Center, who led a Phase III trial of the drug, said Yondelis could be added to a short list of active drug therapies for recurrent ovarian cancer.

"These are exciting results because positive trials in recurrent ovarian cancer are rare and have almost always led to federally approved treatments," Monk said in a statement.

"This treatment undoubtedly will be evaluated carefully by the U.S. Food and Drug Administration and, if approved, will give women with ovarian cancer another much-needed option."

Zeltia`s drug is unusual in that is a synthetic version of a compound isolated from a type of sea squirt, a tubular marine animal. It works by binding to the DNA of cancer cells and blocking their ability to multiply.

The Spanish company had already announced that Yondelis, its first product to reach the market, had shown positive results in the pivotal trial.

But the actual results of the study, involving 672 women whose ovarian cancer had progressed after first-line treatment, were only disclosed at the annual meeting of the European Society of Medical Oncology (ESMO) in Stockholm.

Monk said the results showed those women given a combination of Yondelis and Johnson & Johnson`s (JNJ.N: Quote, Profile, Research, Stock Buzz) chemotherapy drug Doxil had no progression of their cancer for an average of 7.3 months, against 5.8 months for women treated only with Doxil.

In the case of women who had relapsed more than six months after getting first-line therapy, the median progression-free time was 9.2 months with Yondelis versus 7.5 months.

In common with other anti-cancer agents, this suggests Yondelis is most active in patients who have gone a long time since receiving initial chemotherapy treatment.

PEAK SALES

Zeltia plans to submit Yondelis for approval in Europe in the fourth quarter of this year. Its partner Johnson & Johnson (JNJ.N: Quote, Profile, Research, Stock Buzz) is expected to file in the United States by the end of the year as well.

The Spanish group has previously estimated that peak sales of Yondelis for ovarian cancer could be around 300 million euros ($420 million) in the European Union alone.

Sales of the drug as a treatment for soft tissue sarcoma are forecast to be about 30 million euros this year.

Yondelis, whose generic name is trabectedin, is currently approved for soft tissue sarcoma in Europe but not the U.S.

The product is also being studied in smaller, Phase II trials for prostate, breast and childhood cancers. (Editing by Will Waterman)

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