Jan 9 (Reuters) - Portola Pharmaceuticals Inc said its experimental drug met the main goal of reversing the effect of Johnson & Johnson's blood thinner, Xarelto, in a late-stage study.

Data showed that an intravenous shot of the drug, andexanet alfa, immediately reversed the anticoagulation activity of Xarelto in healthy volunteers aged 50-75 years.

Further data on the study is expected in mid-2015, Portola said on Friday.

Portola said in October that the drug was effective in reversing the effect of Eliquis, an anti-clotting drug by Bristol-Myers Squibb Co and Pfizer Inc.

(Reporting by Natalie Grover in Bengaluru; Editing by Kirti Pandey)