Is Genentech competent to develop a drug to treat peanut allergy?

Last year the Wall St. Journal published a page-one article (How Genentech, Novartis Stifled A Promising Drug) that described how an experimental drug for peanut allergy, Tanox, was killed in favor of development of Xolair.

Now Genentech has announced its cancellation of a peanut-allergy trial for Xolair. The trial was halted because of side-effects of the peanut antigen challenge in the control group. This is different from the typical situation in which a trial is halted because of a problem with the medication. Here, the problem is that the underlying allergy condition is so dangerous that the control group was at risk. From the Journal:

The South San Francisco, Calif., biotechnology company said two children in the 150-person trial experienced “severe hypersensitivity reactions” when given a trace amount of peanut protein, an initial step designed to gauge the severity of a patient’s allergies. Neither child had received the drug, called Xolair, the company said. Xolair is on the market, approved as a treatment for allergic asthma.

“We had always been very nervous about that study,” said Susan Desmond-Hellmann, head of product development for Genentech. “We are not going to do that anymore.”

Cancellation of the Xolair trial means that an approved treatment for peanut allergy remains years away at the earliest.

Xolair is already approved for asthma, and many people with peanut allergy have asthma, so there should be no huge problem getting the drug to the relevant patients. But it seems odd that the danger of being in the control group retards the availability of a medication.

Does Genentech know what it’s doing?

January 17, 2006

2 thoughts on “Is Genentech competent to develop a drug to treat peanut allergy?”

  1. The problem with the peanut antigen challenges was not difficult to foresee, though having gotten an emergency shot of epinephrine after a peanut antigen test I may be more attuned to such problems than others. However, there is also a problem here of excessive regulation that discourages advertising a medication for a condition too dangerous to test in a prospective trial.

    If a doctor has a patient with a huge sensitivity to peanuts it would probably be wise to put them on Xolair to prevent episodes of asthma following accidental exposure to allergens. The overlap is huge, as illustrated by this article (Sampson et al. (1992) N Engl J Med. 327:380):
    “We identified six children and adolescents who died of anaphylactic reactions to foods and seven others who nearly died and required intubation…. Of the 13 children and adolescents (age range, 2 to 17 years), 12 had asthma that was well controlled.”

    The best outcome for all concerned might be to publicize the oddness of this result and be thankful about the ability of doctors to prescribe off-label, or in this case prescribe with plausible deniability of being off-label.

  2. And this from NEJM, 2003

    N Engl J Med. 2003 Mar 13;34(11):986-93.

    “A 450-mg dose of TNX-901 [monoclonal anti-IgE, essentially Xolair] significantly and substantially increased the threshold of sensitivity to peanut on oral food challenge from a level equal to approximately half a peanut (178 mg) to one equal to almost nine peanuts (2805 mg), an effect that should translate into protection against most unintended ingestions of peanuts.

    On the basis of this study, I suspect some of my colleagues are already using Xolair for this off-lable indication (severe peanut allergy).

    I hope Genentech and the relevant regulatory bodies will get together and get this trial going.

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