Abstract
Background: The significant treatment effect of the 300IR birch pollen (BP) allergen extract sublingual solution could be translated into a relevant improvement of allergic rhinoconjunctivitis (ARC) symptoms and/or the reduction of symptomatic medication use in patients with BP-induced ARC1 . Here we aimed at illustrating clinical trial results into a concrete treatment benefit for patients.Method: In a randomised, DBPC clinical trial (NCT01731249), adults with moderate-to-severe seasonal BP-induced ARC with or with- out mild asthma received the 300IR BP solution or placebo pre-co-seasonally over 2 consecutive pollen seasons. The efficacy of the BP solution was evaluated through a balanced Total Combined Score ranging from 0 to 38 (TCS 0-38 ) quasi-equally weighing symptom and medication scores. The TCS 0-38 was analysed post hoc by ANCOVA in a modified ITT set over the pollen period (PP) of each year, the primary endpoint being over PP2.Results: In the patients evaluable (n = 536 and 500 in PP1 and PP2, respectively), the treatment effect on the TCS 0-38 with the BP solution was found equal to an absolute difference vs placebo of -2.76 over PP1 and -3.81 over PP2 on average. As previously published1 , a minimum 2-point reduction reflects a benefit over the PP in terms of symptom severity decrease of 1 class in 2 symptoms or 2 classes in 1 symptom, or medication use reduction (about 1 month less medications per 3 months for a patient taking antihistamines daily). For example, assuming a placebo patient and a patient treated with the 300IR BP solution with an average TCS 0-38 of 10.27 and 6.46 over PP2, respectively, the reduction of -3.81 may apply on the blocked nose and itchy eye severity considering the other symptoms and use of medication stable. With such a reduction equally distributed between both symptoms, the actively treated patient may expect having no days with severe or moderate blocked nose and itchy eyes over PP2 as shown in the figure below. A patient case reflecting the treatment benefit on medication use is also displayed. Same analyses also showed a treatment benefit over PP1.Conclusion: Displayed calculated patient cases illustrating the effect of the 300IR birch pollen sublingual solution reflect the clinical meaningfulness of this treatment for patients with an average birch pollen ARC severity and presume a greater impact in more severe patients.