Pre-treatment IgE levels against Timothy grass and its allergen components (Phl p) were determined using the diagnostic tool ImmunoCAP-ISAC for a sub-set of 1,140 randomized North American study participants in a double-blind, placebo-controlled Grastek clinical trial. The participants were Timothy grass skin prick test positive and IgE positive. The total symptom plus medication score over the entire pollen season and treatment-related adverse events was determined by pre-treatment Phl p-IgE levels.
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July 2015“Results found subjects with detectable and higher pre-treatment Phl p-IgE trended toward higher efficacy and increased incidence of having at least one treatment-related adverse event,” Dr. Kaur said. These results indicate that pre-treatment levels of specific Phlp-IgE sensitization could continue to be explored to possibly further improve the patient benefit for allergen immunotherapy.
Further exploration may be necessary to identify optimal cutoff, she said. Future investigations will be needed to replicate these findings and also to examine the impact of more than one allergen component on efficacy and safety.
Epinephrine Use Evaluated in SLIT Tablets
Jennifer Maloney, MD, clinical director of respiratory and immunology, Merck Research Laboratories, Kenilworth, N.J., reported that her post hoc study evaluated the use of epinephrine among 8,804 participants in 16 clinical trials for three rapidly dissolving SLIT tablets, including Timothy grass (Merck’s Grastek), short-ragweed (Merck’s Ragwitek), and house dust mite (Merck’s MK-8237, an investi-gational product). Some participants had conjunctivitis, while others did not.
Epinephrine was used 13 times in grass SLIT tablet trials, eight of which were for SLIT tablet-related adverse events—four for systemic reactions and four for local events of pruritus and/or swelling in the mouth and/or throat. The remaining five administrations were unrelated to grass SLIT tablets. In ragweed trials, epinephrine was used nine times, four of which were SLIT tablet-related adverse events; in house dust mite trials, epinephrine was administered once for a SLIT tablet-related event.
Results found that for the 8,804 participants studied, epinephrine administrations were uncommon (event rate=0.1%), and 43% were for events that the investigator deemed unrelated to SLIT tablets, Dr. Maloney said.
“The data from my presentation indicates that epinephrine use is infrequent when treating side effects related to the Merck SLIT tablets,” Dr. Maloney added.
The Future of Treating Allergic Rhinitis with Immunotherapy
With the increased research in SLIT and the availability of sublingual tablets ap¬proved by the U.S. Food and Drug Administration, allergic rhinitis patients have gained more options in the method of immunotherapy methods. “SLIT is not for everyone, but having the option may increase the number of patients willing to undergo immunotherapy, especially those who cannot commit to the time requirements for regular injections in the office or for younger patients who have an aversion to needle sticks,” said Bryan D. Leatherman, MD, a specialist in sinus and allergy disorders as well as otolaryngology-head and neck surgery at Coastal Sinus and Allergy Center in Gulfport, Miss. “The safety profile of SLIT allows for home administration without as much risk of life-threatening anaphylactic reactions as home subcutaneous immunotherapy.”