D3.202 - Characterising relevant major allergens beyond modification: from allergen to allergoid

PQ Grass 27600 SU is a mixed grass allergoid product with an associated adjuvant-depot system for time-dependant subcutaneous dose release, designed for the treatment of a broad spectrum of grass allergies. As part of the manufacturing process, the initial native allergen extraction is tested by monoclonal ELISA to confirm and quantify the presence of clinically relevant grass allergens, prior to modification and onward processing to final formulation.

Monoclonal ELISA methods utilise antibody binding to target specific epitopes on the analyte of interest, allowing accurate quantification of the analyte (allergen) in its native conformational state. The process of modification disrupts this native state to promote the antigenic properties of the allergen, potentially limiting the availability of previously targeted epitopes and adding complexity for the use of the monoclonal ELISA to accurately assess the modified allergoid. This provides an opportunity for developing additional analytical tools for the characterisation of the retention of relevant major allergen characteristics beyond modification.

Quantification of relevant major allergen content was performed by both monoclonal and polyclonal ELISA methods for the characterisation of group 1 grass allergen homologues present in native mixed grass extracts and modified allergoids respectively.

The group 1 grass allergen specific monoclonal ELISA accurately quantified group 1 allergen homologue content in native, unmodified extracts of mixed grass allergens. The subsequent modification of these extracts adds analytical complexity to the characterisation of the resultant allergoid. A Lol p 1 specific polyclonal ELISA method was therefore developed to address the complex nature of a modified adjuvant-enhanced allergoid system and generated a quantifiable dose-dependent response for the allergoid product in relation to a natural Lol p 1 reference.

The development and use of a group 1 grass allergen specific polyclonal ELISA provides increased ability to characterise relevant allergen qualities beyond modification of the native extract. This additional characterisation creates opportunities for deepening understanding of the mechanism by which immunological relevance is retained from initial allergen extraction to the final modified allergoid product.