AbbVie Inc. said patients treated with its investigational rheumatoid arthritis drug upadacitinib showed additional improvements, based on new data from three phase 3 trials.

The three studies, called Select-Next, Select-Beyond and Select-Monotherapy, evaluated the drug in adults with moderate to severe rheumatoid arthritis.

Patients in Select-Next reported improvements in physical function, joint pain and morning stiffness as early as one week after first receiving upadacitinib, compared to placebo.

In Select-Beyond, which also used placebo as a comparison, the upadacitinib group said physical function and joint pain improved after two weeks, while morning stiffness improved after one week.

Upadacitinib, in as early as two weeks, delivered clinically meaningful quality of life improvements to patients in Select-Monotherapy. Patients treated with anti-rheumatic drug methotrexate improved, in terms of physical function, only after eight weeks, and in terms of pain and morning stiffness, only after four weeks. AbbVie said additional data from Select-Monotherapy will be presented at a future medical meeting.

North Chicago, Ill.-based AbbVie is evaluating upadacitinib, which has yet to secure regulatory approval, across six studies in its Select clinical trial program.

Rhematoid arthritis is a disease that affects about 1.5 million people in the U.S. and happens when the body's immune system mistakenly attacks the joints, causing inflammation, swelling and pain.