The new guideline issued by the European Medicines Agency (EMA) creates the first harmonised European framework for the development and authorisation of allergen products – especially in cases where classic study designs cannot be implemented due to small study populations. It marks an important step towards more innovation and better access to care in allergy diagnostics and therapy. The guideline was developed in a European network led by the Paul-Ehrlich-Institut, Federal Institute for Vaccines and Biomedicines, was adopted by the Committee for Medicinal Products for Human Use (CHMP) on 10 June 2025, and comes into force on 1 January 2026.
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The new EMA guideline, "Guideline on Allergen Products Development for Immunotherapy and Allergy Diagnosis in Moderate to Low-Sized Study Populations", paves the way for significant progress in the development and authorisation of allergen products for type I and type IV allergies. These new conditions are particularly relevant for allergen sources that have been difficult to research in clinical studies due to limited patient populations. "Rare" allergies, as defined in the guideline, refer not only to the low frequency (prevalence) of the allergy, but also to the limited availability of suitable patient populations due to the difficulty of recruiting patients for therapies and/or clinical trials. In addition, patients are often sensitised to several allergen sources, which makes inclusion in a clinical trial difficult or impossible.
Under the leadership of the Paul-Ehrlich-Institut, the guideline was developed in the Rheumatology and Immunology Working Party (RIWP) of the EMA in cooperation with experts from several European countries. The aim of the guideline is to noticeably improve the availability of diagnostic and therapeutic allergen preparations, including epicutaneous test substances. Numerous stakeholders submitted their suggestions during the public consultation phase, and those suggestions were incorporated into the final version. Professional societies and representatives from the industry and patient groups actively participated.
The new guideline contains concrete facilitations for the development of diagnostic and therapeutic allergen products when limited numbers of patients are available for clinical trials. It proposes alternative study designs – such as dose-finding studies – and thus makes the development of new medicinal products much easier, even under difficult study conditions.
The guideline is the result of intensive efforts to reconcile regulatory requirements with clinical practice and the needs of allergy patients. It was important to take into account the necessary requirements for the proof of quality, safety, and efficacy on the one hand, and the limited feasibility of studies due to the special nature of allergen products on the other. The guideline applies to both diagnostic and therapeutic allergen products and, for the first time, creates a Europe-wide framework for products with a small study population.
Many of the new regulatory approaches have been used in Germany for years by the Paul-Ehrlich-Institut in the national evaluation of allergen products. The EMA guideline now provides a harmonised European framework that should facilitate development and sustainably improve access to care for patients with previously poorly considered allergies.
Updated: 07.07.2025
