NEW YORK, Dec 31 - Anesiva Inc (ANSV.O), a developer of pharmaceutical products for chronic pain, said on Thursday it will file for bankruptcy after it was unable to complete a proposed merger with Arcion Therapeutics Inc.

Anesiva said it had failed to satisfy closing conditions of the deal.

It said in a statement on Thursday that it plans to cease operations immediately and file for bankruptcy protection.

The company had announced the deal earlier this month, saying the merger was contingent on it working with creditors and resolving certain ongoing litigation.

Anesiva's shares closed at 17 cents on the Nasdaq on Thursday. (Reporting by Emily Chasan; editing by Andre Grenon)