Grass pollen allergy immunotherapy(Stallergenes Greer Ltd.)

Whereas specific immunotherapy (SIT) has already been shown to be cost-effective in the treatment of allergic rhinitis compared with symptomatic treatment, only a small number of investigations have compared sublingual (SLIT) and subcutaneous (SCIT) immunotherapeutic approaches. This analysis discusses the cost-effectiveness of SCIT compared with SLIT and a symptomatic treatment modality. At the same time, particular attention is paid to preparation-specific characteristics.

The investigation is based on a previously published health economic model calculation. A Markov model, with predefined disease stages and a time period of 9 years, formed the basis of the analysis. The data on specific SCIT (Allergovit®) and SLIT (Oralair®) preparations required for the calculation were adjusted for the present analysis. Quality-adjusted life years (QALYs) based on symptom scores were calculated as the endpoint for effectiveness. Furthermore, the total costs and cost effectiveness of SCIT were determined. Model uncertainties were estimated by means of additional sensitivity analyses.

With regard to effectiveness, both the SCIT and SLIT preparations proved superior compared to symptomatic treatment. Although more expensive, SIT seem to be cost-effective. A direct comparison of SCIT (Allergovit®) and SLIT (Oralair®) showed lower total costs for SCIT treatment over the study period (SCIT 1159 € versus SLIT 1322 €) and improved effectiveness (SCIT 7.112 QALYs versus SLIT 7.060 QALYs).

SIT represents a cost-effective treatment option for patients with allergic rhinitis compared with symptomatic treatment. The comparison of SCIT (Allergovit®) and SLIT (Oralair®) showed SCIT to be predominant and cost-effective, due in particular to somewhat greater patient compliance and lower drug costs. It also became evident that, as far as possible, product-specific model variables are required for an economic evaluation of SIT treatment.

In Europe, allergen extracts are standardized based on skin prick wheal size in 20–30 allergic subjects. To understand the biological activity of clinically effective Sublingual immunotherapy, we used this method to determine the biological activity of solution and tablet Timothy grass pollen (TIM) extracts, compared to an FDA‐approved extract (Reference) of 10 000 BAU/ml. Blinded, quadruplicate skin prick tests with concentrate and three serial half‐log dilutions allowed the construction of a semilogarithmic regression line per extract. Bioequivalent allergy units (BAU) values were obtained from the comparison with reference. Extracts and dilutions showed a neat linear dose response (all: R2 > 0.98) in 33 rhinitis patients. Relative potencies: Staloral® 12 000 BAU/ml, Soluprick® 10 300 BAU/ml, Oralair® 8200 BAU, and Grazax® 6200 BAU. Even though all extract concentrates differed in wheal size (P = 0.01–0.001), Grazax® producing a 25% smaller wheal size than Oralair®, and the biological activity of these clinically effective TIM tablets led in the same range (6200–8200 BAU; 0.92–1.23 cm2). SLIT dose‐finding studies for other pollens might start with allergen extracts producing 1.1 cm2 wheal surface.