Allergy Therapeutics has begun dosing in a mid-stage trial designed to assess the dose-response and safety of its ultra-short course PQ Grass immunotherapy, which targets the cause of symptoms of allergic rhinoconjunctivitis due to grass pollen.

The study is expected to run for one year and involve around 440 patients in more than 50 sites across Germany, Austria and Poland.

The Worthing, UK-based group has designed the trial to identify the optimal cumulative dose of the therapy using conjunctival provocation testing, a type of challenge testing recently used in studies for a similar subcutaneous birch pollen product that resulted in selection and approval of dose for use in a Phase III study.

Results of the trial are expected in the first half of next year, after which the group will meet with regulatory authorities in the US and Germany to discuss Phase III trial design.

“The start of treatment in this important Phase II trial marks an exciting and critical period of trials for the Group’s research and development pipeline,” said Manuel Llobet, Allergy’s chief executive. “This trial aims to strengthen the Group’s portfolio in Europe and the US and takes us another step closer to treating patients in the major US market.”

The firm estimates that the US allergy immunotherapy market, expected to be the main market for this product, is worth $2 billion with potential peak grass vaccine sales of $300-400 million per annum.

If approved, the product will be the first registered subcutaneous immunotherapy product in the US for allergy, it noted.