Rheumatoid Arthritis Biosimilar as Effective as Adalimumab

Biosimilar may offer patients with RA drug cost relief in the near future.

Patients with moderate to severe rheumatoid arthritis, despite getting methotrexate treatment, responded as well to a biologic agent called SB5 as they did to adalimumab.

Reporting at the American College of Rheumatology meeting in San Francisco, CA, Michael Weinblatt of Brigham and Women's Hospital in Boston, MA and colleagues in other nations described a phase 3 study involving 544 patients.

All had severe RA and had been taking methotrexate for at least 52 weeks. Patients were randomized to receive either SB5 or adalimumab subcutaneously every other week for 24 weeks.

The primary endpoint of the study was the ACR20 response rate at the 24th week of the study. Both groups had a similar response rate, 72.5% for those getting SB5 and 72% for those getting adalimumab.

The ACR20 response rate at week 24 was shown to be equivalent in the full analysis set as well when non-responder analysis was applied. SB5 also had a generally similar safety profile.

The overall incidence of anti-drug antibody up to week 24 was 32.8% in patients getting SB5 vs. 31.7% in those getting adalimumab.

"SB5 was shown to be equivalent in terms of clinical efficacy, when compared with adalimumab," the researchers concluded.

The study was presented in an abstract.