Shares of San Diego-based biotech MediciNova Inc. have shot up 31 percent following the announcement that early trials of its drug for treating methamphetamine addiction showed positive results.

Shares rose from $2.57 to $3.37 in the course of the day following the announcement. MediciNova, founded in 2000, has a market capitalization of $66.27 million.

The company is working with scientists at UCLA, studying a compound called MN-166’s role in possibly treating methamphetamine abuse.

MediciNova licensed the drug technology from Japanese drugmaker Kyorin Pharmaceutical Co. Ltd. in 2000. The compound has been marketed there since 1989 for asthma treatment — but never in America.

— Meghana Keshavan