Grass pill (Grazax) continues to prove the effectiveness of Sublingual therapy.

Grazax, available in Europe but not in the U.S., is a fast-dissolving sublingual tablet taken once a day. A clinical trial to support U.S. approval of the immunotherapy is now underway. It may well revolutionize the way we treat allergies.

The randomized, phase III study reported by Dr. Emminger began several months before the 2005 grass pollen season and included 634 patients in eight European countries. Active treatment ended in 2007 but the study remains blinded and participants will be followed through 2009.

Adults 15 to 65 years old were included in the trial if they had a minimum two-year history of confirmed grass pollen allergy, no other perennial or seasonal allergies that overlapped with grass pollen season, and FEV1 lung function values of at least 70% predicted.

"This was a real test for [the Grazax] tablet," Dr. Emminger said. In the 2007 season, median rhinovirus symptom scores were 3.2 for patients taking placebo compared with 2.0 for those taking Grazax. The percentage difference was nearly identical in the 2005 and 2006 seasons, although the absolute symptom scores declined in both groups as time went on. Dr. Emminger said this resulted from a combination of reduced average pollen counts and different patterns in rescue medication usage.

By the third year, Grazax still appeared to cause more adverse effects than placebo, but the difference was less stark. Only 19% of patients receiving Grazax reported adverse effects in 2005, compared with 9% of the placebo group. The bottom line is that the side effect profile was minimal, it worked, and the positive effects seem to last for years.

Dr. Emminger explained that the Grazax regimen is unlike most other allergic immunotherapies, which start with small doses and gradually build up. With Grazax, patients start with the full dose from day one, she said. The only problem I see with this is the one size fits all design. Our SLIT is not only based on what you are allergic to, but also how allergic you are. That allows us to start at the appropriate dose and then build to the maximum dose. This avoids unnecessary reactions and allows for more rapid dose escalation.