Researchers prove that it is not compulsory for anti-drug antibody detection test to be performed at a particular time. A study conducted by the University of Manchester claims to have developed a test that could identify which patients of rheumatoid arthritis (RA) would fail to respond to the biological drugs prescribed for their treatment. The research findings could help to significantly improve healthcare management of patients.

The study was funded by the Medical Research Council, Arthritis Research UK and the NIHR Manchester Musculoskeletal Biomedical Research Unit.

Treating Rheumatoid Arthritis With Biologic Drugs

Rheumatoid arthritis is a chronic autoimmune illness characterized by pain in the joints, reduced physical activity, and even premature death if not diagnosed and effectively treated on time. RA affects almost 1.5 percent of the population.

Treating RA using biologic drugs is a fairly new concept. Administered via injection, these drugs work by halting certain chemicals in the blood, which activate the immune system and attack joints. Biologics are frequently given along with an anti-rheumatic, such as methotrexate, once the latter alone becomes ineffective.

Not Effective For Everyone

The use of biologics has significantly improved the overall health of people suffering from severe RA. Symptoms such as joint damage and loss of mobility have drastically decreased. Despite this prognosis, one in every five patients stops exhibiting improvements after a few months of treatment. This is sometimes because of the formation of anti-drug antibodies within the patient’s body. Instances such as these greatly limit the effectiveness of biologic treatment.

It was previously thought that tests which detect the presence and amounts of anti-drug antibodies would be useful only when conducted immediately before the next dose of drugs was to be taken; in other words, when the level of the drug in the patient’s system would be at the lowest level. This approach was difficult in a clinical setting, since every patient took the drug according to their own routines and schedules – at different times and on different days.

Researchers have now proved that it is not compulsory for the anti-drug antibody detection test to be performed at a particular time – random testing is also possible for conclusive results.

Results Of Present Study

A total of 311 RA patients were enrolled in the study. Blood samples for conducting tests were drawn after three, six and 12 months of starting treatment with two different kinds of biologic drugs, adalimumab and etanercept. Results of the test showed that 25 percent of the patients who were using adalimumab developed anti-drug antibodies, but none of the patients using etanercept developed any of the latter.

“Our study demonstrates that detecting low drug levels in rheumatoid arthritis patients on adalimumab, one of the most commonly prescribed biologics, was the strongest factor associated with non-response to treatment over 12 months,” said Dr Meghna Jani from the University’s Centre for Musculoskeletal Research and the study’s lead author.

Dr Jani added that the test was easy to perform in clinical settings and could uncover useful information about patient management, especially those whose symptoms were not improving via adalimumab treatment.

Further Aspects

Researchers also found that administering higher doses of methotrexate along with biologic drugs resulted in lower levels of anti-drug antibodies in a patient’s system. These findings suggest that patients should be encouraged to use methotrexate at the highest dosage tolerable to them, so that the risk of developed antibodies can be minimized.

“The next step will be to explore whether it is cost-effective to use these tests routinely in clinical practice, so that we can adjust treatments in those patients with low drug levels and anti-drug antibodies,” said Professor Anne Barton, a consultant rheumatologist at Central Manchester University Hospitals NHS Foundation Trust and Director of the Centre for Musculoskeletal Research at The University of Manchester.