Mosges R, et al. - Researchers assessed the safety, efficacy and immune mechanisms of short-course treatment with adjuvant-free Lolium perenne peptides (LPP) following a 6-week dose-escalation protocol. Findings suggested safety of subcutaneous LPP when administered in increasing doses. Moreover, substantially diminished reactivity to conjunctival provocation test (CPT) and the presence of blocking antibodies as early as 4 weeks after treatment initiation were noted as a result of treatment with increasing doses of subcutaneous LPP.

• A prospective, dose-escalation study was performed including 61 grass pollen–allergic patients who were administered 2 subcutaneous injections of LPP once weekly for 6 weeks.
• Local reactions, systemic reactions and adverse events were assessed to determine safety.
• Reactivity to the conjunctival provocation test (CPT) was assessed to determine the clinical effect of LPP.
• At baseline (V1), during (V6) and after treatment (V8), specific IgE, IgG₄ and blocking antibodies were measured.

• As per data, no fatality, serious adverse event or epinephrine use was reported.
• Independent of dose, the observed mean wheal diameters after injections were <0.6 cm and mean redness diameters <2.5 cm.
• Thirty-three patients suffered transient and mostly mild adverse events.
• A grade I and a grade II reaction (AWMF classification) was experienced by 2 patients and 4 patients, respectively.
• Nonreactivity to CPT was noted at V8 in 69.8% of patients.
• Compared at V1, sIgG₄ levels were found to be higher at V6 (8.1-fold, P < .001) and V8 (12.2-fold, P < .001).
• Researchers found that the sIgE:sIgG₄ ratio decreased at V6 (-54.6%, P < .001) and V8 (-71.6%, P < .001) compared to V1.
• They also noted that the absolute decrease in IgE-facilitated allergen binding was 18% (P < .001) at V6 and 25% (P < .001) at V8.