Addex Pharmaceuticals has prematurely ended the trial of its lead drug candidate against migraine due to reports of liver problems.

Routine safety monitoring of blinded data in study 206 revealed an incidence of abnormalities of liver function tests that is higher than expected in this population, the company said.

The abnormalities do not appear until day 28 of dosing with ADX10059, but the severity increases progressively with any increased duration of participation in the study.