Unexplained benefit in sham group sees GenSight trial miss endpoint

Announcing top-line results from the REVERSE Phase III trial, Paris-based GenSight Biologics (Euronext: SIGHT) says its Leber hereditary optic neuropathy (LHON) candidate GS010 showed a clinically meaningful improvement, but failed to meet its primary endpoint as the sham injection produced an almost equivalent response.

Investors reacted negatively to the announcement, causing the firm’s share price to drop by almost 50%.

The firm could not explain the reaction from the placebo injections, but chief executive Bernard Gilly suggested that the candidate could be benefiting both eyes “in a way that is still to be understood.”