UCL researchers have developed a test to predict which patients will benefit from an expensive drug commonly used to treat rheumatoid arthritis.
The test could benefit thousands of patients by speeding up the process of getting them onto a treatment that works for them and could save the NHS millions every year.
Adalimumab (often sold under the trade name Humira) is routinely given to patients with the disease, but only 2 in 3 respond to it.
The drug works by boosting the number of regulatory T cells (known as Tregs), a type of blood cell – this mechanism was discovered in 2016. This boost in Treg count suppresses the protein tumour necrosis factor (TNF), which can cause inflammation in arthritis patients.
But for a third of patients, this anti-TNF treatment does not work.
In a study, funded by Arthritis Research UK and supported by the NIHR biomedical research centre at University College London Hospitals, and published in the Journal of Allergy and Clinical Immunology, 19 patients with rheumatoid arthritis underwent blood tests.
For the test, blood samples were taken from each patient, and researchers added adalimumab to these samples in the lab to see whether Treg levels went up indicating the drug would be effective.
For 12 patients, adalimumab boosted Treg counts by more than 40% in the blood samples, suggesting the drug would work if these patients took it.
For 7 patients, Treg counts did not go up by 40% or more, suggesting the drug would not work in these patients.
The blood test was accurate in nearly all cases. All 12 patients predicted to respond to the drug responded when they took the drug. For the 7 patients predicted not to respond, the drug was not effective in 5 of those patients.
Working with the blood samples, researchers also found 2 other ways of predicting whether a patient would respond to the drug.
The presence of TNF on the surface of a certain type of cell which can interact with Tregs, and the extent to which adalimumab was binding to surface TNF, were linked to whether a person would respond to the drug.
Researchers said these blood tests would be easy to roll out, because they can be done using flow cytometers, equipment used routinely in clinical practice.
Lead author of the study at UCL, Professor Mike Ehrenstein, said:
‘A lot of effort has been invested in predicting which patients with rheumatoid arthritis will respond to anti-TNF therapy without much success. Our findings bring us closer to more personalised healthcare in this area, where the treatment you are given is based on what you as an individual will respond to. This is great for patients who will be able to receive more effective treatment earlier – and good for the health service, which will save money as we stop paying for ineffective interventions.’
Professor Ehrenstein added that it will be important to repeat this study in another group of patients to confirm these findings.
The full research paper can be read on the Journal of Allergy and Clinical Immunology’s website.
