Some of the year’s most significant scientific research was reviewed by Harold S. Nelson, MD, Professor of Medicine at National Jewish Health, Denver, CO. The studies showed considerable advances in subcutaneous immunotherapy, allergen extract application by patch, and the mechanisms of subcutaneous and sublingual immunotherapy (SLIT), to name a few.
Good Safety Profile for Subcutaneous Immunotherapy
Year-1 outcomes of the ACAAI/ American Academy of Allergy, Asthma & Immunology collaborative study examining systemic reactions to subcutaneous immuno therapy were generally positive.1
Physician members of the 2 organizations were asked to complete a webbased survey reporting the number of injections administered in their practices, the number of injections or skin tests associated with fatal reactions, and all severe but nonfatal systemic reactions. They were also asked to record fatal reactions in their clinical practices in the preceding 12 months.
Of 1922 prescribers of immunotherapy, 806 physicians responded. “So there was about 50% reporting,” Dr Nelson said. No fatal reactions were reported with this therapy; 6 previously unreported fatalities from 2001 to 2007 were reported, but none had occurred during the preceding 12 months. Of the 8052 systemic reactions reported (0.1% of visits), only 265 were severe or life-threatening reactions. “This represented an incidence of only 3 for every 100,000 injections,” he said.
Grass Allergy Immunotherapy Tablet Shows Cost-effective Persistent Improvement
A study of the long-term clinical efficacy in grass pollen–induced rhinoconjunctivitis after treatment with a standardized grass allergy immunotherapy tablet suggests a cost-effective persistence of effect after 3 years.2 A group of 257 grass-sensitive adults received daily treatment with sublingual grass pollen tablets for 3 years. After completing treatment, they were followed through a grass pollen season. In the year after treatment was discontinued, sustained reduction was seen in symptom scores (26%), medication scores (29%), Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ; 23%), and percentage of symptomand medication-free days (27%). The researchers noted that there was persisting improvement in symptom and medication scores, RQLQ, and symptom- free and medication-free days for the first year without treatment after 3 years of high-dose SLIT.
Sublingual Immunotherapy Efficacy
David Skoner and colleagues reported on a study in which they randomized 115 subjects with ragweed rhinoconjunctivitis to a 1-day updosing and daily maintenance SLIT with placebo, medium-dose, or high-dose ragweed extract.3 The researchers concluded that SLIT employing US-standardized short ragweed extracts at cumulative doses 10 and 100 times those given subcutaneously can reduce symptom/ medication scores in patients with ragweed rhinoconjunctivitis.
Epicutaneous Allergen Administration
A double-blind study of epicutaneous (patch) allergen administration as a novel method of allergen-specific immunotherapy was conducted in 37 grass-sensitive adults in Zurich, Switzerland.4 Before and during the 2006 grass pollen season, patients had 13 weekly patches applied to tape stripped sites (2 in clinic and 11 by patient). The patches remained on the patients’ skin for 48 hours, and clinical response was assessed for the grass pollen seasons of 2006 and 2007, without further treatment
The application of the patches significantly increased allergen tolerance on nasal provocation after the 2006 and 2007 grass pollen seasons. The application also resulted in significantly improved symptoms of allergic rhinitis, compared with placebo, for both seasons.
Patches in a Pediatric Population
A study of grass transcutaneous immunotherapy in children with seasonal rhinoconjunctivitis also had a positive outcome. In this study, 15 children received grass transcutaneous immunotherapy, as well as placebo patches, from February to April.5 The patches contained grass pollen extract with 11.25 μg of major allergen, 50% petroleum jelly, and <3% salicylic acid. They were applied once weekly for 12 weeks and were removed after 24 hours.
The patches were well tolerated and reduced symptoms and medication use during the grass pollen season.
Initial High Cost May Lower Overall Cost of Therapy
Pretreatment with omalizumab affected the tolerability of specific immunotherapy in allergic asthma in a study of 248 patients reported by Massanari and colleagues.6 These findings would seem to indicate that increasing initial cost yields a clinically meaningful outcome.
The group of 248 patients with at least moderate persistent, allergic asthma were randomized to omalizumab or to placebo for 3 months, followed by cluster immunotherapy with cat, dog, or mite extracts (8 visits over 4 weeks). Maintenance therapy was continued for 2 months without further omalizumab.
Patients who were pretreated with omalizumab had significantly reduced systemic allergic reactions from immunotherapy, resulting in a clinically meaningful shift in the severity of systemic allergic reactions from immunotherapy. A significantly higher proportion of omalizumab patients were able to reach the target maintenance dose of immunotherapy, and overall, omalizumab was well tolerated.
References
- Bernstein DI, Epstein T, Murphy-Berendts K, Liss GM. Surveillance of systemic reactions to subcutaneous immunotherapy injections. Ann Allergy Asthma Immunol. 2010;104:530-535.
- Durham SR, Emminger W, Kapp A, et al. Longterm clinical efficacy in grass pollen-induced rhinoconjunctivitis after treatment with SQ-standardized grass allergy immunotherapy tablet. J Allergy Clin Immunol. 2010;125:131-138.
- Skoner D, Gentile D, Bush R, et al. Sublingual immunotherapy in patients with allergic rhinoconjunctivitis caused by ragweed pollen. J Allergy Clin Immunol. 2010;125:660-666.
- Senti G, Graf N, Haug S, et al. Epicutaneous allergen administration as a novel method of all ergenspecific immunotherapy. J Allergy Clin Immunol. 2009;124:997-1002.
- Agostinis F, Forti S, Di Berardino F. Grass transcutaneous immunotherapy in children with seasonal rhinoconjunctivitis. Allergy. 2010;65:410-411.
- Massanari M, Nelson H, Casale T, et al. Effect of pretreatment with omalizumab on the tolerability of specific immunotherapy in allergic asthma. J Allergy Clin Immunol. 2010;125:383-389