D3.196 - Safety of subcutaneous immunotherapy with purified native protein Cup a 1, a major allergen of Cupressus arizonica: 6-year real-world data

In patients with seasonal respiratory allergy, the use of whole extracts in immunotherapy may involve the administration of complex allergenic mixtures including clinically irrelevant proteins with potential impact on treatment safety. Component-resolved diagnosis optimizes allergen selection. Sensitization to Cupressus arizonica constitutes a growing problem in areas with high environmental exposure. Cup a 1 is the major allergen and a specific marker of primary sensitization to the Cupressaceae family. The use of purified native protein Cup a 1 in molecular immunotherapy enables standardized, reproducible dosing, reducing exposure to non-relevant components present in conventional extracts and potentially optimizing treatment safety within a precision immunotherapy strategy.

The Pharmacovigilance Department of Diater Laboratorio de Diagnóstico y Aplicaciones, S.A. performs ongoing global safety in compliance with applicable regulatory standards. Safety data of subcutaneous immunotherapy with purified native protein Cup a 1 extract (maintenance dose 0.24 µg per injection) were evaluated based on spontaneously reported local (LRs) and systemic reactions (SRs) from routine clinical practice over a six-year period. SRs were classified according to the WAO 2010 grading system.

Within this period, over 44,000 injections were administered. The mean incidence for subcutaneous purified native protein Cup a 1 extract was 0.0340 LRs per 100 injections, 0.0068 Grade 1 and 0.0022 Grade 2 SRs per 100 injections. No Grade 3, 4 or 5 SRs were reported. In addition, all reported LRs were mild reactions commonly observed and expected with subcutaneous administration.

Over six years of real-world pharmacovigilance surveillance, subcutaneous immunotherapy with purified native protein Cup a 1 extract showed a low incidence of adverse reactions. SRs were infrequent and limited to Grades 1-2, with no SRs Grade ≥3 reported. All LRs were mild and consistent with the expected profile of subcutaneous administration. These findings provide supportive real-world evidence of the favourable safety profile of purified native protein Cup a 1–based immunotherapy. The use of a single, well-defined major allergen selected through component-resolved diagnosis may represent a rational approach to reducing unnecessary allergenic exposure and optimizing treatment safety in patients with Cupressus arizonica allergy.