(Adds details about Roche, Novartis drug Xolair, comment from doctor)
ZURICH, Dec 4 (Reuters) - Novartis said on Tuesday it was taking its experimental medicine ligelizumab to late-stage trials after the drug showed signs of outperforming existing product Xolair in treating severe urticaria, also known as hives.
Xolair is sold by both Novartis and Roche, but has lost patent protection in Europe and the United States, leaving it exposed to rivals who are developing copies of the biological drug. None are yet on the market.
Novartis said it now plans two Phase III studies for ligelizumab with more than 2,000 patients who suffer from chronic spontaneous urticaria (CSU), an autoimmune disease that causes persistent itchy reddish welts on the skin.
"Despite existing treatment options, too many people continue to struggle with the debilitating and potentially painful symptoms of CSU," Marcus Maurer, a professor of dermatology and allergy at the Allergie-Centrum-Charite in Berlin, Germany, said in a statement from Novartis.
Roche is also developing a new drug, fenebrutinib, to fight CSU and has a Phase II trial, with an expected filing date of after 2021, according to its website.
Both companies are looking to develop a more advanced drug than Xolair as India's Glenmark Pharmaceuticals has a biosimilar copy in the works.
Xolair brought in 1.74 billion Swiss francs ($1.75 billion) for Roche last year and $920 million for Novartis.
($1 = 0.9960 Swiss francs)
(Reporting by John Miller; editing by Thomas Seythal and Susan Fenton)