AbbVie rheumatoid arthritis drug succeeds in late stage trial

NEW YORK (Reuters) - AbbVie Inc on Tuesday said its experimental rheumatoid arthritis (RA) treatment showed significant improvement in physical function, pain and quality of life compared with the commonly prescribed generic drug methotrexate in a late stage clinical trial.

The U.S. drugmaker hopes the drug, upadacitinib, can help replace lost revenue from its top-selling RA treatment Humira when it starts to face biosimilar competition in the United States in 2023.

AbbVie said it will file applications this years seeking regulatory approval for the medicine. Top-line results from the Phase III study were previously announced in June.

Upadacitinib belongs to a class of drugs known as JAK inhibitors, which block inflammation-causing enzymes called Janus kinases. Pfizer Inc's Xeljanz belongs to the same class of drugs.

AbbVie said that after 14 weeks of treatment, 69 percent of patients receiving a 30 milligram dose of the drug and 65 percent of patients receiving a 15 mg dose reported improvements in physical function. That compared with improvements reported in 45 percent of patients receiving methotrexate, which is typically the first medicine prescribed for RA patients.

It said that 75 percent of patients receiving the 30 mg dose of the drug and 64 percent of patients receiving the lower dose said they had less pain. That compared with 46 percent of patients receiving methotrexate.

In addition, 73 percent of patients receiving the higher dose of upadacitinib and 65 percent of those who got the lower dose reported quality of life improvements versus 48 percent for methotrexate.

Humira, the world's biggest-selling prescription drug with sales expected to reach $20 billion this year, began facing competition from biosimilar versions in Europe last week.

(Reporting by Michael Erman; Editing by Bill Berkrot)