Positive outcome of the pivotal Phase III study with PQ Grass 27600 SU, a modified grass allergen subcutaneous immunotherapy (SCIT) product using MicroCrystalline Tyrosine (MCT) and Monophosphoryl Lipid A (MPL) as adjuvant system

Rationale: PQ Grass 27600SU is a modified broad spectrum grass allergen SCIT product using an MCT- MPL adjuvant system. The optimal cumulative dose of PQ Grass of 27600SU was established in Phase II dose finding based on a highly statistically dose-response relationship with plateau formation. We report here the results of the RESONATE study conducted to support a marketing authorisation application.

Methods: Patients (pts, 18 to 65 years) with seasonal allergic rhinitis ascribed to grass pollen were included in this Phase III randomised double-blind, placebo-controlled clinical study in US & EU to evaluate efficacy & safety of PQ Grass 27600SU. Primary endpoint was the EAACI recommended combined symptom & medication score (CSMS) during peak grass pollen season (P-GPS). Key secondary endpoints were symptom & medication score, CSMS during the entire grass pollen season, Rhinitis quality of Life Questionnaire (RQLQ), IgG4 & safety.

Results: 555 pts with allergic conjunctivitis and/or rhinitis were randomized to PQ Grass 27600SU; (278 pts) or placebo (277 pts) & 507 (91.4%) completed all 6 injections. CSMS over P-GPS demonstrated a statistically significant improvement of 20.3% (p=0.0002) compared to placebo. Consistently, the secondary endpoints demonstrated significant superiority of PQ Grass 27600SU. A statistically significant improvement in RQLQ (p=0.0003) was observed, indicative of a clinically meaning improvement in quality of life. Immunogenicity of PQ Grass 27600SU was shown by a ~6-fold increase in IgG4 compared to placebo (p<0.0001). PQ Grass 27600SU was generally safe & well tolerated with no unexpected safety signals.

Conclusions: PQ Grass 27600SU is an innovative short-course allergen-specific SCIT product with 6 injections per treatment year. RESONATE is the first state-of-the-art Phase III SCIT trial to reach both a clinically relevant & statistically significant primary outcome & beneficial secondary efficacy results for an AIT product under the TAO.

Publication History

Article published online:
18 March 2025