Sage Therapeutics (SAGE.US) shares fell 27% in pre-market trading after Biogen (BIIB.US) announced the termination of a collaboration to develop a medicine for a rare disease.

According to CEF News, Biogen(BIIB.US) and Sage Therapeutics(SAGE.US) announced on Wednesday that they would no longer pursue Sage-324, an oral experimental treatment for essential tremor, after failing in a mid-stage trial. The news sent Biogen's shares down 0.3% at the time of writing, while Sage Therapeutics shares were down about 27% in pre-market trading.

Biogen and Sage cited top-line data from their KINETIC2ii trial, saying Sage-324, also known as BIIB124, did not produce statistically significant results from baseline to the primary endpoint at day 91. The study did not show a statistically significant dose-response relationship or difference between Sage-324 and placebo in improving symptoms of essential tremor. Biogen and Sage will end ongoing safety studies and do not plan to further develop Sage-324 for ET. The companies are considering next steps for other potential uses. As for drug tolerability, the companies said there was a relationship between Sage-324 and treatment-emergent adverse events (TEAEs) related to the central nervous system and the frequency of TEAEs.

However, Biogen and Sage have not given up on research plans for Sage-324 in other indications. The two companies are considering next steps for other potential uses.