 A novel biotechnological product, a recombinant hypoallergenic parvalbumin, called mCyp c 1, is used for the first time in a phase IIb clinical trial, to test the efficacy of subcutaneous immunotherapy for the treatment of fish allergy. The investigational medicinal product mCyp c1, is based on the recombinant wild type carp parvalbumin rCyp c 1 and is the result of site directed mutagenesis, by which the disruption of the two calcium binding sites of carp parvalbumin is performed. The modified parvalbumin mCyp c 1, is both hypoallergenic and immunogenic. That way it is a promising molecule for the safe and effective treatment of fish allergy. 