Allergy immunotherapy demonstrates long-term effectiveness in allergic rhinitis

Key takeaways:

• Allergy immunotherapy for grass and house dust mite had greater decreases in prescriptions than tree allergy treatment.
• Patients on standard-quality sublingual immunotherapy reported no anaphylaxis events.

Allergy immunotherapy is effective in achieving long-term results for allergic rhinitis in real-world treatment, according to a study published in The Journal of Allergy Clinical Immunology.

Standardized-quality (SQ) sublingual immunotherapy (SLIT) tablets for grass allergies are particularly effective, Marco Contoli, PhD, assistant professor, respiratory section, department of translational medicine, University of Ferrara, and colleagues wrote.

The retrospective cohort REACT study examined the insurance claims data of 46,024 patients with allergic rhinitis and a prescription for allergen immunotherapy (AIT) between 1, 2007, and 31, 2017. These patients were matched 1:1 with control subjects with allergic rhinitis who did not have a prescription for AIT.

The treatment cohort included 36,927 with subcutaneous immunotherapy (SCIT) and 3,754 with a SLIT tablet, with 1,664 specifically on SQ SLIT tablets for grass allergy.

Treated allergens included grass (n = 11,713) as well as tree (n = 11,897) and house dust mite (n = 7,774). Also, 11,951 patients demonstrated persistence to AIT, and 34,073 were nonpersistent.

The patients in the AIT and control groups both saw reduced numbers of allergic rhinitis prescriptions during the follow-up period, although the patients in the AIT group had consistently greater reductions across all the follow-up years.

Mean numbers of allergic rhinitis prescriptions during the pre-index year included 1.06 for the SCIT group, 1.16 for the SLIT-tablet group and 1.03 for the control group, which the researchers called similar. The reductions in allergic rhinitis prescriptions per group during 8 years of follow-up also were similar, the researchers said.

The SLIT-tablet group had a numerically greater reduction in prescriptions than the SCIT group during years 1 through 3, but these changes were similar during years 4 through 8.

Also, the patients on AIT for grass and house dust mite had comparable greater reductions in allergic rhinitis prescriptions than the control group during years 2 through 9, but the patients on AIT for tree and those in the control group did not have any difference in reductions in allergic rhinitis prescriptions.

The patients on AIT for tree additionally had statistically significantly lower reductions in allergic prescriptions compared those on AIT for grass (P < .0001) and those on AIT for house dust mite (P < .0001)

Patients on AIT who were persistent and nonpersistent with their treatment both had greater reductions in allergic rhinitis prescriptions than the control groups, although the patients who were persistent had even greater reductions tha those who were not during 9 years of follow-up.

Specifically, the persistent group had a numerically greater reduction in allergic rhinitis prescriptions than the nonpersistent group at year 3, and this difference became statistically significantly greater in year 5 (P = .0006).

the reductions in allergic rhinitis prescriptions were numerically greater in the SLIT-tablet group compared controls, the SQ grass SLIT-tablet group had numerically greater reductions than the overall SLIT-tablet group during years 27.

The SQ SLIT-tablet group also had statistically significant reductions in allergic rhinitis prescriptions at year 3 (P = .002) and year 5 (P = .03) compared the SLIT-tablet controls, and these reductions were sustained across 7 years of follow-up.

Overall, the researchers classified rates of anaphylactic shock with 2 days of the first AIT prescription as low, with numerically lower incidence of anaphylactic shock among the SLIT-tablet group (0.027%) the SCIT group (0.081%).

The grass allergen group had a 0.051% rate of anaphylactic shock, and the tree allergen group had a 0.092% rate. Additionally, the grass and house dust mite patients in the SQ SLIT-tablet group did not experience any cases of anaphylactic shock.

Based on these findings, the researchers said the evidence for the disease-modifying effects of the SQ grass SLIT tablet is generalizable to real-life clinical practice. Also, they said that the SLIT tablets had faster onset of effectiveness than SCIT, based on initial rates of reductions in allergic rhinitis prescriptions.

These findings additionally emphasize the importance of persistence, the researchers continued. But many factors can affect persistence and adherence, they , so there is a need to improve persistence and adherence in the real world to ensure optimal long-term outcomes.

Despite the unmet need for evidence-based treatments for allergic rhinitis triggered by tree pollen, the researchers said, these findings overall demonstrate the consistent effectiveness of AIT in the real world.