(RxWiki News) Anti-TNFs are a class of medications often used to treat inflammatory conditions like rheumatoid arthritis (RA). But when an anti-TNF fails, what's the next step?
In two new studies, a team of researchers from France found that RA patients who don’t respond to initial anti-TNF treatment may achieve better outcomes if they are next prescribed biologic therapy instead of another anti-TNF drug. These researchers also found that studying anti-drug antibodies in these patients may also help guide doctors toward the best next step in treatment.
"This study demonstrated a better effectiveness of [biologic therapy] than a second anti-TNF for patients who did not respond to their first anti-TNF," said lead study author Jacques-Eric Gottenberg, MD, PhD, of the Department of Rheumatology at Strasbourg University Hospital in France, in a press release. "However, at least 40 percent of patients failed to respond to their second-line biologic, which emphasizes the unmet need to continue to increase the number of treatment options and develop personalized medicine for people with RA."
RA is a chronic inflammatory disorder that often affects the small joints in the hands and feet. Unlike normal joint damage that occurs with age, RA affects the lining of the joints, causing painful swelling that can result in bone erosion and joint deformity. RA is what's known as an autoimmune disorder, where the body's immune system mistakenly attacks its own tissues.
Anti-TNFs (anti-tumor necrosis factors) are often prescribed to reduce inflammation and stop RA progression. However, according to these researchers, about one-third of patients don't have success with anti-TNFs. When this happens, rheumatologists often consider one of two strategies: trying a second anti-TNF drug or switching to biologic therapy.
Biologic therapy is designed to stimulate or restore the immune system's ability to fight off disease. This treatment often involves the use of substances naturally produced in the body for the treatment of cancer and other diseases like RA.
For the first study, Dr. Gottenberg and team looked at 292 RA patients who were randomly assigned to begin either biologic therapy or a second anti-TNF — after it was first established that their initial anti-TNF wasn't working. Follow-ups were then conducted after three, six and 12 months.
After three months, about 64 percent of the patients on biologic therapy and about 48 percent on a second anti-TNF achieved a good or moderate response. After six months, these rates increased to about 70 and 52 percent, respectively. After 12 months, these rates dropped to about 60 and 43 percent, respectively.
Among the patients on biologic therapy, about 41 percent achieved low disease activity. About 27 percent achieved remission. By comparison, about 24 percent achieved low disease activity and about 14 percent achieved remission on a second anti-TNF.
For the second study, Dr. Gottenberg and team looked at 278 patients from the first study to see if the presence of anti-drug antibodies could be helpful in selecting a second biologic therapy.
"Sometimes a person’s immune system can fight against a drug being used to treat a disease," Dr. Gottenberg said. "This causes the body to create anti-drug antibodies, which may render the drug useless and may even cause side effects. We wanted to see if these antibodies were present in people who weren’t having success with anti-TNF drugs because we believe this knowledge could help a rheumatologist make a better choice for the second treatment strategy."
These researchers found that anti-drug antibodies could not be detected in 227 of these patients. While there were detectable anti-drug antibodies in 32 of these patients, blood levels of the first anti-TNF were very low.
According to Dr. Gottenberg and team, the absence of anti-drug antibodies may indicate that RA is not TNF-driven in a given patient. Therefore, the best choice might be to change the treatment plan and use biologic therapy instead.
These studies were presented Nov. 7 at the American College of Rheumatology's Annual Meeting in San Francisco. Research presented at conferences may not have been peer-reviewed.
Information on funding sources and conflicts of interest was not available at the time of publication.
