Merck, the German pharmaceuticals and chemicals group, is abandoning its diabetes research after a string of disappointments.

Merck said it would focus its pharmaceuticals division on cancer treatments after halting development of two experimental medicines - EML 16336, an insulin mimetic that stimulates glucose uptake, and the aldose reductase inhibitor IDD 676.

The decision to abandon its efforts in diabetes is a blow to confidence in a company which until recently sold the world's biggest-selling diabetes treatment. Shares in Merck have been under sustained pressure as sales of Glucophage, its key diabetes drug, plummeted after the loss of patent protection last year. They fell 5.3 per cent to €28.22 yesterday on analysts' downgrades.

Mr Bernhard Scheuble, chief executive, said: "Over the last months, we have seen a lot of good reasons for increasing optimism in oncology, together with disappointments in diabetes. As a consequence, we have to focus our development efforts even more strongly." - (Financial Times Service)