NEW YORK (CNN/Money) - Xolair, a treatment for severe asthma from Swiss drug giant Novartis, was approved by European regulators on Thursday.

The European Commission granted market approval to Xolair, clearing the drug for sale in 25 member states, Novartis (up $0.51 to $53.79, Research) said.

Xolair, also known as omalizumab, has been available in the United States since 2003, when it was approved by the Food and Drug Administration. Novartis markets the drug in the U.S. with partners Genentech (down $1.80 to $87.72, Research), the biotech firm based in South San Francisco, Calif. and Houston-based biotech Tanox (down $0.03 to $13.92, Research). Genentech reported that Xolair sales totaled $81.6 million in the third quarter, and Novartis spokesman said this sum is disseminated among the partners.

Xolair is injected every two to four weeks. According to Novartis, clinical studies have shown that use of the drug reduced asthma-related emergency room visits by half.

Xolair targets an antibody that causes asthma symptoms and is a first-in-line medication, meaning that it is the first drug with its specific chemical function, said Novartis. The company considers Xolair to be the biggest breakthrough for asthma treatment in 15 years.

Novartis, based in Basel, Switzerland, reported $23.6 billion in sales for the first nine months of 2005, including $15 billion in drug sales. The company's top-selling products are Diovan, a treatment for hypertension that totaled $2.7 billion in sales for the first nine months of 2005, and the Gleevec/Glivec group of leukemia drugs, which totaled $1.6 billion in that time period.

To read about Novartis' third quarter earnings, click here.