UCB has forged an alliance with Sanofi-Aventis to co-promote its antihistamine Xyzal, a follow-up to top allergy brand Zyrtec, in the USA.

Zyrtec (cetirizine) remains UCB’s top-selling product and is sold in the USA by Pfizer. It had been expected that the latter would also take on Xyzal (levocetirizine), which is already available in Europe and is under review by the US Food and Drug Administration for a number of indications, including seasonal and year-round allergies and a skin disorder called chronic idiopathic urticaria. But in March UCB said that Pfizer’s interest in the allergy sector ‘lay elsewhere’, and started the search for a new US partner for Xyzal.

Xyzal has got off to a good start in Europe, gaining pole position in eight marketplaces with sales of 88 million euros in the first six months of the year, up 13%, according to UCB.

In the USA, Sanofi-Aventis will book sales of the drug, make upfront and milestone payments to UCB and share profits.