The FDA approval was supported by findings from phase 3 of the GO-FURTHER trial (Golimumab, an Anti-TNF-alpha Monoclonal Antibody, Administered Intravenously, in Subjects with Active Rheumatoid Arthritis Despite Methotrexate Therapy).

In separate news, the FDA is likely to expand the use of another existing biologic, certolizumab (Cimzia), to include axial spondyloarthritis (axSpA). The drug, a TNF inhibitor, is already approved to treat RA. An FDA advisory panel recently recommended its approval for these two other conditions. While the panel’s recommendation doesn’t guarantee approval of the new uses – also called indications – the FDA usually follows the advice of its advisory panels.

Axial SpA is a type of arthritis that mainly affects the spine and pelvic joints, causing low back pain due to inflammation of the sacroiliac joint, which connects the base of the spine and the top of the pelvis. Ankylosing Spondylitis (AS) is a subtype of axial SpA that causes swelling between the vertebrae in the spine. Over time, it can cause some of the vertebrae to fuse together.

Certolizumab would be the fifth TNF inhibitor on the market for these conditions. Just like with RA, if one isn’t working well for you, your doctor can turn to another. “There’s always a sense with any medication that some people respond better to one versus another in a way that’s not easily predictable,” says Dr. Pisetsky.

The same advisory panel recommended against expanding the use of another biologic drug, adalimumab (Humira). It’s currently used to treat RA and AS. The manufacturer sought approval for treating non-radiographic axial SpA (nr-axSpA) – cases of SpA in which no damage or swelling is visible on X-rays (damage may take years to show up in an X-ray, or may never appear).

The panel recommended against approval in part because in the study that the drug maker presented, some of the patients who were thought to have non-radiographic axSpA turned out, on further review of their X-rays, to actually have the AS form of the disease. This meant that the drug was tested on a very small group of patients that truly had non-radiographic axSpA.

Humira did a great job, they showed that it worked,” says Dr. Husni. “But the FDA is responsible for safety, and part of showing that a drug is safe is exposing it to a lot of people,” she explains.

Determining the presence of AS isn’t always easy, says Dr. Pisetsky. “For ankylosing spondylitis, trying to measure the changes on radiographs [X-rays] is still a developing field.”

Yet, waiting until damage is clearly visible on X-rays may be waiting too long. “There’s a movement to try to better define non-radiographic AS,” says Dr. Husni. “In AS, the X-ray changes can occur very late in the disease. The argument is that there’s a group of people who should be treated before there’s evidence of damage.”

Dr. Husni says it is likely the maker of adalimumab will test the drug in a larger group of people with non-radiographic axSpA and approach the FDA again.