SAN DIEGO, June 15 /PRNewswire/ -- MediciNova, Inc., a specialty pharmaceutical company that is publicly traded on the Hercules Market of the Osaka Securities Exchange (Code number: 4875), today announced that the Board of Directors has authorized to extend the previously announced stock option repurchase plan through December 31, 2006. The repurchase authority, previously adopted in November 2005, covers up to 5 million shares of its outstanding common stock at an aggregate purchase price of up to 700 million Japanese yen. Since inception, the Company has repurchased 925,000 shares with an aggregate purchase price of approximately 120 million Japanese yen under the repurchase program.