Strong dose response after immunotherapy with PQ grass using conjunctival provocation testing

Zielen S, Kuna P, Aberer W, Lassmann S, Pfaar O, Klimek L, Wade A, Kluehr K, Raab J, Wessiepe D, Lee D, Kramer MF, Gunawardena K, Higenbottam T, Heath MD, Skinner MA, de Kam PJ.

World Allergy Organ J. 2019 Oct 25;12(11):100075. doi: 10.1016/j.waojou.2019.100075. eCollection 2019 Nov.
PMID: 31709029

Abstract

Background:

Pollinex Quattro Grass (PQ Grass) is an effective, well-tolerated, short pre-seasonal subcutaneous immunotherapy to treat seasonal allergic rhinoconjunctivitis (SAR) due to grass pollen. In this Phase II study, 4 cumulative doses of PQ Grass and placebo were evaluated to determine its optimal cumulative dose.

Methods:

Patients with grass pollen-induced SAR were randomised to either a cumulative dose of PQ Grass (5100, 14400, 27600 and 35600 SU) or placebo, administered as 6 weekly subcutaneous injections over 31-41 days (EudraCT number 2017-000333-31). Standardized conjunctival provocation tests (CPT) using grass pollen allergen extract were performed at screening, baseline and post-treatment to determine the total symptom score (TSS) assessed approximately 4 weeks after dosing. Three models were pre-defined (Emax, logistic, and linear in log-dose model) to evaluate a dose response relationship.

Results:

In total, 95.5% of the 447 randomized patients received all 6 injections. A highly statistically significant (p < 0.0001), monotonic dose response was observed for all three pre-specified models. All treatment groups showed a statistically significant decrease from baseline in TSS compared to placebo, with the largest decrease observed after 27600 SU (p < 0.0001). The full course of 6 injections was completed by 95.5% of patients. Treatment-emergent adverse events were similar across PQ Grass groups, and mostly mild and transient in nature.

Conclutions:

PQ Grass demonstrated a strong curvilinear dose response in TSS following CPT without compromising its safety profile.