The company, which has developed short course inoculations against hay fever, said turnover was £40.4mln in the six months ended December 31.
That represents an increase of 18% at constant currencies or 39% when the translational currency effect of the weak pound is brought into play.
“We are excited by the prospects of the company as we continue expanding our operations in Europe, progressing our development pipeline and moving forward with a world-class portfolio of allergy vaccines,” said chief executive Manuel Llobet.
“We are confident about the full year and look forward to updating shareholders on further progress throughout 2017."
The drug development programme in the US and Europe is proceeding to plan, Allergy said.