July 17 (Reuters) - Cassava Sciences ( SAVA ) said CEO

Remi Barbier has resigned and the biotech firm named Richard

Barry as interim chief executive, weeks after a medical

professor linked to the company was charged with fraud.

The biotech firm's shares fell 31% to $9.30 in premarket

trading on Wednesday.

Earlier this month, Cassava said it would form an internal

committee to evaluate new probes by U.S. regulators into two

senior employees.

That came days after federal prosecutors charged Hoau-Yan

Wang, a doctor who collaborated with Cassava, with fraud for

allegedly submitting fabricated data to the National Institutes

of Health related to an experimental treatment for Alzheimer's

disease.