The FAST project aims at the development of safe and effective treatment of food allergies. It targets persistent and severe allergy to fish and fruit. Besides persistence and severity, this choice is based on prevalence and the importance of these foods for a healthy diet. Classical allergen-specific immunotherapy (SIT) for treatment of food allergy using subcutaneous injections with food extracts has proven to be effective but too dangerous due to anaphylactic side-effects. FAST will therefore develop a safe alternative by replacing food extracts with hypo-allergenic recombinant major allergens, the active ingredients of SIT. Both severe fish and fruit allergy are caused by a single major allergen, parvalbumin for fish and lipid transfer protein for fruit. This makes development of a novel biotechnological product feasible. Two approaches will be evaluated for achieving hypoallergenicity, i.e. site-directed mutagenesis and chemical modification. The most promising hypo-allergenic versions of parvalbumin and lipid transfer protein will be produced under GMP conditions. After pre-clinical testing (toxicology testing and efficacy in mouse models), Phase I and II randomized double-blind placebo-controlled multi-center clinical trials will be performed. Two routes of administration will be evaluated, subcutaneous in case of fish and sublingual in case of fruit. The primary read-out will be the double-blind placebo-controlled food challenge. To understand the underlying immune mechanisms of subcutaneous and sublingual immunotherapy, these trials will be accompanied by in depth serological and cellular immune analyses, allowing identification of novel biomarkers for monitoring treatment efficacy. FAST will improve the quality of life of food allergic patients by providing a safe and effective curative treatment that will end their dependence on avoidance and rescue medication.