Novartis reported that FDA has approved Xolair (omalizumab) for the treatment of chronic idiopathic urticaria (CIU), a rare skin disease known as chronic spontaneous urticaria (CSU) outside of the US. In the US, Xolair is indicated for CIU in adults and adolescents (12 years of age and above) who remain symptomatic despite H1-antihistamine treatment. Until now, H1-antihistamines have been the only approved therapy for CIU in the US.
FDA approval is primarily based on positive and consistent results from two phase III studies, ASTERIA I and II, which involved CIU/CSU patients not responding to approved doses of H1-antihistamines. Xolair 300 mg and 150 mg met all primary endpoints across these studies, which also showed Xolair significantly improved itch and hives, including rapid itch relief, and in many cases completely cleared symptoms.
Results from three phase III studies for Xolair in CIU/CSU were announced in 2013. In all three studies, a significant proportion of patients became either completely free of itch and hives (range 34-44%; at 300 mg) or had their symptoms suppressed to minimal levels (52-66%; at 300 mg). In the ASTERIA II study, 44% of patients receiving Xolair 300 mg were itch-and hive-free after 12 weeks of treatment. In the ASTERIA I study, Xolair-treated patients experienced a rapid reduction in itch and hives as early as week one, with the therapeutic benefit sustained over 24 weeks of active treatment. In the GLACIAL study, more than half of patients had failed multiple therapies including H1-antihistamines (at up to four times the approved dose) and H2-antihistamines and/or leukotriene receptor antagonists (LTRAs). Patient response in GLACIAL was similar to that seen in ASTERIA I and II, leading to elimination or suppression of symptoms to minimal levels within two weeks of the start of treatment, and sustained throughout the 24 week treatment period.
Xolair was recently approved by European Commission as add-on therapy for CSU in adult and adolescent patients 12 years and above with inadequate response to H1-antihistamines. Xolair has also been approved for the treatment of refractory CSU in eight other countries: Egypt, Turkey, Guatemala, El Salvador, Bangladesh, Pakistan, Ecuador, and the Philippines. Regulatory reviews are currently ongoing in more than 20 countries, including Canada, Australia, and Switzerland. Novartis and Genentech are jointly developing Xolair.