Study Identifies Barriers to Therapeutic Drug Monitoring of TNF in RA

Sean Gavan, PhD, MSc

Credit: University of Manchester

Recent data show barriers to adopting therapeutic drug monitoring of tumor necrosis factor-α (TNF-α) inhibitors hinder a patient’s ability to benefit from effective management strategies, according to a study published in Advances in Practice.¹ To overcome these barriers, investigators believe a coordinated response from stakeholders across health care systems must be enacted.

“Barriers to adopting new testing or monitoring strategies are a phenomenon faced by care providers across many clinical areas,” wrote a team of investigators led by Sean Gavan, PhD, MSc, a research fellow in health economics at the Manchester Centre for Health Economics, School of Health Sciences, Faculty of Biology, Medicine and Health.

“Complementary testing strategies, such as TNF therapeutic drug monitoring, are not mandatory when making prescribing decisions within current regulatory or reimbursement frameworks. The proposed benefits of TNF therapeutic drug monitoring can only be realized if care providers choose to integrate and follow tests measuring TNF anti-drug antibodies and/or drug levels within their routine care settings.”

According to the European Alliance of Associations for Rheumatology (EULAR), monitoring these drug levels and/or anti-drug antibodies has been proven to improve the health outcomes of patients and the value of care among patients with rheumatic diseases. However, rheumatologists may perceive barriers to adopting therapeutic drug monitoring within their practice, which can limit the benefits for both patients and health care systems alike.

In 2023, the EULAR taskforce on therapeutic drug monitoring noted that although the clinical evidence is maturing, there is still limited understanding regarding the barriers these rheumatologists face when considering monitoring TNF and anti-drug antibodies.²

To further examine these perceived barriers, investigators conducted semi-structured, one-to-one telephone interviews with senior rheumatologists residing in the United Kingdom with experience treating patients with rheumatoid arthritis (RA). These interviews analyzed the understanding of therapeutic drug monitoring and how they can be included into routine practice. During the interview process, rheumatologists were encouraged to discuss their current knowledge of TNF therapeutic drug monitoring in RA. These sessions were transcribed and anonymized and barriers to therapeutic drug monitoring of TNF were identified using a thematic framework analysis.

A total of 45 recruitment emails were sent out, of which 11 rheumatologists agreed to participate in these interviews. Their residence was equally distributed across the country (north: 36%; midlands: 36%; south: 27%).

Five barriers to adopting TNF therapeutic drug monitoring emerged: 1) not seeing the need for drug monitoring within their practice; 2) not understanding how this testing can improve practice; 3) insufficient clinical evidence of the benefits; 4) insufficient resources to pay for this testing using their hospital’s budget; and 5) an insufficient capability to deliver testing to these patients.

Rheumatologists interviewed stated concerns including an uncertainty about how resources to pay for testing could be acquired and how this could in turn lead to a lack of incentive to integrate drug monitoring into practice. They also mentioned the practical barrier to adopting this practice if there is variation between the facilities to perform testing among providers.

Investigators noted the data were not collected to achieve saturation, which was considered a limitation. Additionally, as information was collected in 2015, it may not be relevant to current practice. Lastly, the interview schedule did not differentiate between proactive therapeutic drug monitoring and reactive therapeutic drug monitoring. Currently, EULAR recommends against proactive monitoring as optimal blood concentration rages for biologic treatment has not been defined for the majority of indications.

“If effective TNF therapeutic drug monitoring strategies are being considered for adoption, early and active engagement with stakeholders across health care systems, including rheumatologists responsible for front-line care, will be vital to pre-empt and mitigate barriers to ensure that patients can benefit,” investigators concluded.

References

1. ^{Gavan SP, Payne K, Barton A. Overcoming provider barriers to therapeutic drug monitoring of tumour necrosis factor inhibitors for rheumatoid arthritis: a qualitative analysis. Rheumatol Adv Pract. 2024;8(2):rkae030. Published 2024 Mar 4. doi:10.1093/rap/rkae030}
2. ^{Krieckaert C, van Tubergen A, Gehin J et al.EULAR points to consider for therapeutic drug monitoring of biopharmaceuticals in inflammatory rheumatic and musculoskeletal diseases. Ann Rheum Dis 2023;82:65–73.}