Israel’s Teva Pharmaceutical Industries has presented disappointing data from a late-stage trial which showed an increased dose of its multiple sclerosis blockbuster Copaxone was not more efficient than the currently-approved lower-dose version.

The firm has announced top-line results from a Phase III study designed to assess the efficacy, safety and tolerability of Copaxone (glatiramer acetate) 40mg as compared to the approved 20mg version in the treatment of relapsing-remitting MS. The 40mg dose did not demonstrate increased efficacy in reducing the relapse rate but did maintain the favourable safety and tolerability profile of Copaxone 20mg.

78% of Copaxone 20mg-treated patients remained relapse-free throughout the study, Teva added and the firm said that “this robust effect was also reflected in a remarkable reduction of inflammatory activity as measured by MRI”. Moshe Manor, vice president of the firm’s global innovative resources unit, was still upbeat and noted that while the trial did not demonstrate an enhanced efficacy at the higher dose level, it reaffirms that Copaxone 20mg “remains the optimal treatment dose with unmatched long term efficacy confirmed over 10 years".

Teva said it is also evaluating the use of Copaxone for additional indications. In March, however, the blockbuster has failed to prove effective as a treatment for amyotrophic lateral sclerosis, also known as Lou Gehrig's disease.