Results from the second trial, reported in a poster by Dr. Nolte, came from a study with a similar design that randomized 784 patients at sites in both North America and Europe (J. Allergy Clin. Immunol. 2012 [doi:10.1016/j.jaci.2011.12.482]). This 52-week treatment study added a third active-treatment arm in which patients receive a daily pill containing 1.5 Amb a 1-U ragweed pollen. This low-dose pill did not produce a statistically-significant improvement in efficacy, compared with placebo. The 6 Amb a 1-U and 12 Amb a 1-U dosages resulted in a 19% and 24% average reduction in the total combined score during the peak ragweed season, statistically significant benefits for the study’s primary end point. The safety profile of the two highest doses also mimicked the first study, with no serious adverse effects and no systemic allergic reactions, anaphylaxis, or life-threatening effects. The type and severity of the treatment-related adverse effects were very similar to the first study. One patient in the second study received epinephrine, for a concomitant food-allergy reaction.
Both trials were sponsored by Merck, which is developing the oral ragweed-pollen desensitization pill. Dr. Creticos said that he has received research support from and has been a consultant to Merck as well as to several other drug companies. Dr. Nolte is an employee of Merck.