PRT120 Mechanism of Action


Principle: The acquisition of tolerance is achieved through immunomodulation of the body’s response to the allergen. Prota’s proprietary oral immunotherapy has been shown to have immunomodulatory effects that are expected to support acquisition of oral tolerance.



Mechanism: In allergic individuals, an inappropriate T helper 2 (Th2) response has developed to the food allergen(s) leading to production of peanut-specific IgE antibodies and differentiation of mast cells. Upon re-exposure to peanut, peanut allergens bind to peanut specific IgE antibodies on the surface of the mast cells, and crosslinking of adjacent IgE antibodies results in activation of mast cells, triggering the release of mast cell mediators which in turn lead to the symptoms of an allergic reaction.

The immune modulating actions of PRT120 direct the immune system to respond differently to peanut allergen, supporting a tolerance-type response in place of an allergic response. Over time there is redirection of the peanut specific immune response away from allergy towards tolerance. Prota’s clinical studies have shown that children who achieve sustained unresponsiveness / remission after treatment have significant reduction in blood levels of peanut sIgE as well as Ara h 2 sIgE, indicating redirection of the underlying peanut allergy.


Prota Therapeutics is developing an innovative novel treatment for peanut allergy, based on over a decade of research by the company’s scientific founder, Prof Mimi Tang.

In a randomized controlled clinical study, administration of PRT120 has been shown to:

  • reduce peanut skin prick test wheal size,
  • reduce peanut specific IgE levels in the blood,
  • increase peanut specific IgG4 levels in the blood

Further investigation of the mode of action of PRT120 is underway.