Trial shows apple allergen as effective treatment option for birch pollen-related apple allergy

The food allergy, which is related to birch pollen, is a very common attendant phenomenon associated with birch pollen allergy - indeed around 70% of those with a birch pollen allergy are also allergic to apples. That amounts to around 280,000 people in Austria. In those affected, eating apples leads to swelling and rashes or itching in the mouth and gullet, as well as in the ear area, and even to blistering.  Working in close collaboration with Tamar Kinaciyan at MedUni Vienna's Department of Dermatology, a research group led by Barbara Bohle at the Institute of Pathophysiology and Allergy Research has now proven in a Phase II trial that the apple allergen "Mal d 1" significantly reduces the symptoms of apple allergy and is therefore an effective and safe treatment option.

Of the 60 volunteers with birch pollen-related apple allergy, 20 were treated with placebo, 20 with a birch pollen allergen and with the recombinant apple allergen Mal d 1, that is to say genetically manufactured, reproducible, very stable and therefore easily stored.

The volunteers were administered Mal d 1 once a day in the form of sublingual drops. The results are very promising: "In 6 out of 20 volunteers, the allergy or symptoms did not manifest at all. Following the treatment, they were able to eat two apples a day without any symptoms. In all the others, the symptoms were significantly reduced, so that even they no longer needed to avoid eating healthy, native apples," says lead investigator Bohle.

The results of the Phase II trial now have to be verified in a (multi-center) clinical Phase III trial - as soon as this trial has been successfully completed and a partner has been found from the pharmaceutical industry, this immunotherapy could be available in a few years for treating apple allergy.

Around 400,000 Austrians suffer from a birch pollen allergy. The symptoms triggered by pollen are easily treated by immunotherapy but the vaccines that have hitherto been available are not effective against the birch pollen allergen or against various cross-sensitivities. The results of the trial lead us to hope that Mal d 1 can be used to reduce the symptoms of cross-sensitivities with apples and might even be effective for other fruit allergies.