Ablynx has entered into a collaboration with Merck & Co which could be worth over 450 million euros to the Belgian biotech firm.

The deal will see the US major gain exclusive global rights to nanobodies against a selected target, with an option for similar rights to a second target. Merck will pay Ablynx a 6.5 million euros upfront payment and a 2 million euros fee for research funding. The Ghent-based group will also be eligible to receive up to 448 million euros in research, regulatory and commercial milestone payments, plus tiered royalties.

Nanobodies are a novel class of therapeutic proteins based on single-domain antibody fragments being developed for a range of conditions, including inflammation, haematology, oncology and pulmonary disease. Ablynx' chief executive Edwin Moses, said: "We are delighted to initiate this collaboration with Merck in the area of ion channels where to date monoclonal antibodies have demonstrated little success".

He added that due to "the formatting flexibility of nanobodies, we are able to combine antibody-like selectivity and multi-specificity in one molecule, making them ideal candidates for ion channel modulators". Dr Moses concluded that the agreement reflects "the considerable success we have had to date with seven nanobody programmes at the clinical development stage".

Ablynx also has partnerships in place with firms including Boehringer Ingelheim, Merck Serono and Novartis.