Safety Implications of Different Administration Routes for Specific Immunotherapy

Safety and tolerability of an intra-seasonal initiation of the SQ-standardised grass allergy immunotherapy tablet: a non-interventional observational study investigating the feasibility during routine administration

Background and Objective

For specific immunotherapy to pollen allergy, a pre-seasonal start of treatment is recommended by international guidelines. In a placebo-controlled clinical trial with adults, an intra-seasonal start of therapy with the SQ-standardised grass allergy immunotherapy tablet (AIT) was well-tolerated. The objective of our study was to investigate the feasibility of an intra-seasonal start of grass AIT administered during routine treatment by practising allergists.

Methods

In a multicentre, prospective, open-label, uncontrolled, non-interventional observational study, data on routine treatment with grass AIT were recorded in patients who started administration of tablets within the 2010 grass pollen season in Germany. Adverse events (AEs) were recorded by the physician at visits for the first administration in the clinic and at the end of the 1- to 3-month observation period. AEs and daily administration of the tablet were recorded by the patients in diaries for the first 14 days. Treatment satisfaction, global tolerability and perceived effect of treatment were assessed by the patient and physician at the end of the study.

Results

A total of 662 patients were treated with 1 tablet daily by 286 physicians. Grass AIT was started intra-seasonally in 620 patients and post-season in 42. The average treatment period was 51.6 days. AEs were recorded in 52.1 % of all patients and in 35.6 % at first administration, with throat irritation (21.3 %), paraesthesia oral (19.9 %), oral pruritus (14.0 %) and ear pruritus (10.3 %) being the most frequent AEs related to grass AIT. The intensity of the AEs was assessed as mild or moderate in 42.1 % of patients and severe in 8.0 %; AEs related to grass AIT were classified as serious in two patients. Grass AIT was discontinued due to AEs in 7.7 % of patients. Diaries were evaluable for 77.0 % of patients; the average rate of patients with AEs decreased continuously from 44.7 % (day 1) to 26.9 % (day 14) and the average daily rate of patients who forgot to take their tablet was about 5 %. Overall tolerability was assessed by 87.2 % of patients and 91.4 % physicians as “very good” or “good” and effectiveness of treatment was assessed as “very good” or “good” in 81.4 % of patients and 85.8 % of physicians. More than 90 % of patients and physicians were satisfied with the treatment.

Conclusion

The tolerability data for an intra-seasonal start of grass AIT during routine treatment confirm the safety profile from the previous controlled trial. Tolerability was assessed as good in combination with high satisfaction with the treatment and compliance.

Immunologic effects and tolerability profile of in-season initiation of a standardized-quality grass allergy immunotherapy tablet: a phase III, multicenter, randomized, double-blind, placebo-controlled trial in adults with grass pollen-induced rhinoconjunctivitis

BACKGROUND

The summary of product characteristics of the grass allergy immunotherapy tablet (AIT) (Phleum pratense grass pollen allergen extract) states that clinical effect may be observed in the first pollen season of treatment, if treatment is initiated ≥2 months (8 weeks) before the start of the grass pollen season. However, because patients with grass allergy may first present to physicians during the season, immediate treatment initiation (ie, in-season initiation) may increase treatment compliance and reduce the risk for disease progression compared with asking patients to return before the next pollen season to initiate treatment. This "in-season approach" may offer more patients the potentially beneficial treatment option of specific immunotherapy. However, to date, the immunomodulatory effects and tolerability of in-season treatment initiation is unknown.

OBJECTIVE

The aim of this study was to assess the immunologic effects and tolerability of in-season initiation of treatment with the grass AIT.

METHODS

This multicenter, randomized, double-blind, placebo-controlled trial was carried out in Germany and Austria. Adults with grass pollen allergy (positive skin-prick test and specific grass-pollen immunoglobulin [Ig] E) and grass pollen-induced moderate to severe persistent rhinoconjunctivitis were enrolled. Patients were randomly assigned to receive once-daily grass AIT or placebo, starting during the 2008 grass pollen season and continuing for 8 to 10 weeks. The primary end point was change from baseline in IgE-blocking factor (serum components competing with IgE for allergen binding). Secondary end points included changes from baseline in specific IgE and IgG(4) and measures of tolerability (assessed mainly by adverse events [AEs]). Blood samples for immunologic assessment were obtained by the investigators at baseline and after treatment. All AEs observed by the investigator and/or reported by the patient were recorded throughout the trial and follow-up.

RESULTS

A total of 276 patients were enrolled and formed the full analysis set (mean age, 35 years; 55% men, 45% women; 99% white; mean weight, 76 kg; history of asthma, 41%; mean duration of grass allergy, 15.1 years). No major differences in medical history were found between the grass AIT group (n = 219) and the placebo group (n = 57). The change from baseline in mean concentration of IgE-blocking factor was significantly greater with grass AIT compared with placebo (+0.14 vs +0.05; P < 0.0001). The changes from baseline in specific IgE and specific IgG(4) concentrations were significantly greater with AIT compared with placebo (IgE, +0.59 vs +0.21 log kU/L; IgG(4), +0.18 vs +0.04 log relative units; both, P < 0.0001). At least 1 AE was reported in 58% of patients in the AIT group and in 40% of patients in the placebo group. Most AEs considered related to AIT were mild or moderate events in the mouth, throat, and/or ears (eg, oral pruritus). Four serious AEs were reported in the AIT group (sinusitis, road traffic accident, salmonellosis, meniscus lesion), but all were considered unlikely to be related to treatment. Three percent of the grass AIT group and 2% of the placebo group were withdrawn from the trial due to an AE.

CONCLUSIONS

In-season initiation of grass AIT was associated with an immunomodulatory response in terms of induction of IgE-blocking factor, specific IgE, and specific IgG(4). In-season initiation of grass AIT was generally well tolerated in this group of adults with moderate to severe grass pollen-induced rhinoconjunctivitis. These findings are consistent with those related to the preseasonal initiation of AIT therapy.