Elan Corporation plc has agreed to sell the rights to Prialt (ziconotide, non-opioid severe chronic pain agent) in Europe to Eisai Co. Ltd, while retaining the product rights in the United States.

Under the terms of the agreement, Elan may receive up to $100 million in cash; $50 million on the closing of the transaction, a further $10 million on the earlier of two years from closing or launches of Prialt in key European markets, and an additional $40 million contingent on Prialt achieving revenue related milestones in Europe. The closing of the transaction, which is expected to occur in the first quarter of 2006, is subject to the receipt of relevant regulatory authority approvals and other customary closing conditions. Elan expects to record a gain on closing in excess of $40 million, claims the company release.

Kelly Martin, Elan's president and CEO said, "Prialt is a highly innovative, approved, intrathecal analgesic for patients suffering from severe chronic pain. Patient need in this area remains significant given that there have not been any meaningful therapeutic advances in this area for more than two decades. We are delighted that this transaction will enable Eisai to offer this new therapy to patients throughout Europe."

Martin concluded, "Elan will continue to market Prialt in the US and we look forward to working closely with Eisai on providing patients with a unique and effective choice in the treatment of severe chronic pain."

In February 2005, the European Commission (EC) granted marketing approval for Prialt (ziconotide) for the treatment of severe, chronic pain in patients who require intrathecal (IT) analgesia. Prialt has been awarded orphan drug status in the European Union, which designates it as a product used for the diagnosis, prevention or treatment of life-threatening or very serious rare disorders or conditions.

Prialt is in a class of non-opioid analgesics known as N-type calcium channel blockers. Prialt is the synthetic equivalent of a naturally occurring conopeptide found in a marine snail known as Conus magus.

Prialt is currently marketed by Elan in the US where it was launched in the first quarter of 2005. Prialt revenue for full-year 2005 was $6.3 million.

Severe chronic pain is defined as pain lasting longer than six months and has multiple causes, such as failed back surgery, injury, accident, cancer, AIDS, and other nervous system disorders.