** Shares of drug developer Portage Biotech Inc PRTG.O rise 187% at $9.09 premarket
** PRTG says that it has signed a letter of intent with Immunova for an option agreement to acquire its wholly owned subsidiary, iOx Therapeutics
** iOx Therapeutics focuses on developing immunotherapies - PRTG
** As of last close, stock has fallen ~91% YTD
(Reporting by Kamal Choudhury in Bengaluru)
((Kamal.Choudhury@thomsonreuters.com;))