The first two-year direct comparison of the biologics abatacept (Orencia) and adalimumab (Humira) shows that the two medications are equally effective and have similar risks – though they combat the pain and inflammation of rheumatoid arthritis (RA) in different ways.

“Patients want to know not just if they are safe for weeks or months but long term,” explains the study’s lead author Michael H. Schiff, MD, a clinical professor of medicine in the division of rheumatology at the University of Colorado School of Medicine in Denver. “For a patient who has had an incomplete response or lack of response to methotrexate, rheumatologists now have clinical data over a two year period of time to tell them they have equivalent shots between abatacept added to methotrexate or adalimumab added to methotrexate.”

The phase IIIb randomized study compared two of the nine biologics currently approved to treat RA. It built on data, released last year, about this same study group after one year of analysis.

This new, two-year data presented this month at the European League Against Rheumatism (EULAR) 2013 Annual Congress in Madrid, Spain analyzed 646 RA patients who weren’t responding to methotrexate, a traditional disease-modifying antirheumatic drug. Participants were either given 125 milligrams (mg) a week of abatacept, which reduces the stimulation of T lymphocytes, or T cells, or 40 mg every two weeks of adalimumab, which targets inflammation by blocking tumor necrosis factor alpha, or TNF-alpha. The study was funded by Bristol-Myers Squibb, which makes Orencia. It was also investigator-blinded.

After two years, researchers say participants taking either abatacept or adalimumab had comparable results when it came to clinical success in reducing pain and stiffness and minimizing the progression of joint damage as visible on X-rays. More than 60 percent of both groups reached ACR 20 status, meaning they showed 20 percent improvement in their pain, functional abilities and swollen and tender joints. Adverse events, serious adverse events and malignancies were similar in both groups and retention rates for both groups were in the 75 to 80 percent range. But more people on adalimumab discontinued medication compared to abatacept for adverse events (9.5 percent compared to 3.8 percent), serious adverse events (4.9 percent compared to 1.6 percent) and serious infections, respectively.

Jasvinder A. Singh, MD, the principal investigator of updated 2012 recommendations by the American College of Rheumatology (ACR) on biologic medications, says he believes this data shows the two biologics to be pretty evenly matched. “I think what this is telling me is the side effects are in a similar ballpark,” explains Dr. Singh, an associate professor of medicine at the University of Alabama at Birmingham School of Medicine.

He says he hopes future research looks at more patients with varying RA symptoms for longer periods of time. But he says already this kind of research gives doctors and patients more information to work with. As an example, he cites the fact that two cases of tuberculosis (TB) developed among the group in this study taking adalimumab, which he says is the kind of information that means a lot to a rheumatologist who has a patient with a history or risk of TB.

“It adds a lot more information, more clarity, allays fears and helps us explain what medications are doing for and to patients,” Dr. Singh says. “I think patients can have more knowledge and are better informed and can make better decisions with their providers.”

Dr. Schiff notes that it’s crucial to treat patients with RA “actively and aggressively. This study speaks to the fact that we can do this over a two-year period of time with two very good agents.”