Switzerland-based Roche Pharmaceuticals has signed a definitive merger agreement with Nasdaq-listed Memory Pharmaceuticals to acquire all the outstanding shares of latter, in an all-cash transaction for an aggregate price of approximately USD 50 million.

Under the terms of agreement, Roche will commence a tender offer to acquire all of the outstanding shares of Memory common stock at a price of $0.61 per share in cash, which represents a 319% premium to the closing price on 24 November 2008.

Following completion of the tender offer, Roche will acquire all remaining shares through a second step merger.

Headquartered in Montvale, New Jersey Memory Pharmaceuticals is a biopharmaceutical company, which is focused on the discovery and development of drug candidates for the treatment of central nervous system conditions.

On other hand, Roche is one of the world's leading research-focused healthcare groups in the fields of pharmaceuticals and diagnostics. The group employs about 80,000 people worldwide.

The shares of Memory Pharmaceutical were presently trading at $ 0.57 on Nasdaq, up 291% compared to previous close of $ 0.15. The scrip during early trading session has touched an intraday high and low of $0.58 and $0.56 respectively.