The dose ranging study, called G204, failed to find the optimal quantity of GrassMATAMPL required.
As a result it will use the process deployed during research on its Pollinex Quattro Birch product.
The next dose range study is planned to start next year with Allergy waiting until it hears the outcome of what’s called an End of Phase II meeting with the US Food & Drug Administration.
"Defining the optimal dose is part of late-stage product development and we will revisit dose evaluation as we recently successfully did with our PQ Birch product, using two separate and complimentary dose-ranging studies,” said chief executive Manuel Llobet.
“Additionally, the new findings of our Phase II EEC study will need to be discussed with FDA before deciding on the recommended dose for the following Phase III registration trial.
“While still being determined to become the first company to introduce SCIT to the US, a deferred entry time into the market is now anticipated.”
GrassMATAMPL is an ultra-short course injection given at the start of the grass pollen fever that is being developed for hay fever sufferers.
Separately, the company revealed its European sales of are currently growing at 19% as “penetration” of its allergy products continued to grow.