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The following is a summary of “Six Injections of Modified Adjuvanted PQ Grass Is Effective and Well-Tolerated in a Pivotal Phase III Trial,” published in the February 2025 issue of European Journal of Allergy and Clinical Immunology by Zielen et al. 

PQ Grass 27600 SU (PQ Grass) is a 6-injection, aluminium-free subcutaneous immunotherapy developed for allergic rhinitis (AR). A phase III trial assessed its efficacy and safety in patients with seasonal AR. 

Researchers conducted a phase III trial to evaluate the efficacy and safety of PQ Grass for seasonal AR.  

They designed an adaptive group sequential trial, PQGrass306 (G306), with 1 pre-defined interim analysis. About 2 parallel groups with a 1:1 randomization of patients aged 18–65 was used, and the primary efficacy endpoint was the European Academy of Allergy and Clinical Immunology (EAACI) Combined Symptom and Medication Score (EAACI-CSMS _0–6 ) averaged over the peak grass pollen season (GPS). 

The results showed that 858 subjects were screened, and 555 were randomized. After the interim analysis, the trial stopped for success, showing PQ Grass superiority. The primary endpoint EAACI-CSMS _0–6  (peak GPS) showed a −0.27-point difference (95% CI: −0.42 to −0.12) vs placebo, a −20.3% relative difference (P = 0.0005). All key secondary endpoints showed consistent benefits. Significant induction of blocking IgG4 and IgA occurred. PQ Grass was well tolerated, and there were no unexpected safety signals. 

Investigators demonstrated a significant effect on the primary endpoint, consistent secondary results, and a supportive safety profile. 

Source: onlinelibrary.wiley.com/doi/10.1111/all.16491