The U.S. Food and Drug Administration has  given the green light to a new treatment for chronic idiopathic urticarial (CIU), a form of chronic hives that last more than six weeks.

Drug company Genentech announced on Friday that FDA has given its approval on omalizumab (Xolair) for treating patients with CIU following positive results of pivotal  phase III studies ASTERIA I and II, which involved  patients with CIU who do not respond to H1-antihistamine therapy.

"This approval from the FDA is great news for patients in the US suffering from CIU, a skin disease known as CSU in other parts of the world," said David Epstein, Division Head of Novartis Pharmaceuticals, which co-developed and co-marketed the drug. "Up to 50% of patients do not respond to approved doses of H1-antihistamines, which up until now have been the only licensed treatment for CIU in the US."

Xolair can now be marketed and sold as an injectable therapy to patients who are at least 12 years old whose symptoms do not disappear with H1-antihistamine therapy. It is the first medicine that has gotten the approval of FDA for CIU treatment since H1-antihistamines.

"For CIU patients, it can take months or even years to get the right diagnosis and some relief," said Novartis Pharmaceuticals Corporation  President André Wyss, President. "Novartis is proud to have collaborated with clinicians to bring forward a new treatment option for those who suffer from this serious skin condition. This is part of our quest to deliver innovative medicines that address unmet need."

Genentech spokeswoman Allison Neves said that the monthly cost of Xolair would range from $780 and $1,560 depending on the dose. The official duration of the treatment, however, has not yet been established albeit patients who participated in clinical trials experienced positive results when they use Xolair once every four weeks for 12 weeks.

"CIU can be a frustrating condition for patients," said Mike Tringale, senior vice president at the Asthma and Allergy Foundation of America (AAFA). "This new use for Xolair gives hope to appropriate patients who can go for months or even years without getting satisfactory itch and hive reduction."

CIU is characterized by red, raised, itchy skin rashes that sometimes come with burning sensation.  It occurs without identifiable cause and may last for months and even years.