Xolair for Chronic Itch: Magic Bullet or Marketing Hype?

By Jonathan J. Darrow

Earlier this week, the New York Times reported that Xolair (omalizumab), a monoclonal antibody approved in 2003 to treat allergic asthma, had recently shown efficacy in relieving hives patients of chronic itch (See Laurie Tarkan, Drug to Treat Asthma Could Relieve Hives Patients of a Chronic Itch, Study Says, N.Y. Times, Feb. 25, 2013, at A5).  The article noted that a Phase 3 trial (usually, the final phase before FDA approval) showed that a monthly injection of Xolair “significantly reduced hives and itchiness.” Quoting the lead author of the study, the article reported that Xolair “is the magic bullet patients have been waiting for for the last 40 years.”  Is it?

An initial concern is the large number of conflicts of interest associated with the study. An examination of the Phase 3 trial as published in the New England Journal of Medicine (NEJM), on which the New York Times article is based, reveals that the trial was “[f]unded by Genentech and Novartis,” both of which sell Xolair.  The lead author and at least one other co-author of the study have received consulting fees from one or both companies, while another of the co-authors (Karin Rosen) is the medical director for Genentech.  Conflicts of interest, however, do not necessarily mean that the drug is in fact ineffective.  To determine efficacy, one must look at the evidence.

The NEJM study reports that test subjects received either placebo or Xolair at doses of either 75 mg, 150 mg, or 300 mg.  Starting from a baseline itch-severity score of about 14, the data were as follows:

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