The BIORA-PAIN study was a feasibility randomised clinical trial in people with RA requiring treatment with biologic therapies. We tested the pain outcome profile in people with RA on treatment with abatacept or adalimumab respectively in participants attending the Rheumatology clinic at St George’s University Hospitals NHS Foundation Trust at the time of initiation of biologic therapy and for 12 months thereafter.
Participants
The participants in our database who were receiving care for their rheumatoid arthritis with biologic treatments were screened for enrolment. Participants were identified from rheumatology clinics in Southwest London based at St Georges University Hospitals NHS Trust. Inclusion criteria were participants with active RA with a DAS28 > 5.1. Participants needed to have already received conventional DMARD therapy for a period of four weeks prior to study drug initiation and not have achieved remission with previous treatment of conventional cDMARD therapy as per UK NICE guidelines. The age range for inclusion was 18–75 years. Exclusion criteria included pregnancy or planned pregnancy in the next 12 months, current or previous unsuccessful use of the biologics adalimumab or abatacept, co-existing other autoimmune conditions, for example systemic lupus erythematosus, primary/secondary Sjogren’s syndrome, connective tissue disease, fibromyalgia, primary osteoarthritis and gout. Full exclusion criteria were followed as per study protocol (clinicaltrials.gov reference number was NCT04255134).
The study started in September 2020 and the last patient visit occurred on 25th October 2022. Ethical approval was given by East of England Cambridgeshire and Hertfordshire Research Ethics Committee, approval number 9/EE/0382.
Procedures
We compared the differences in pain measures in the 2 groups and evaluated the modalities of pain outcomes in our cross-sectional population using neuropathic pain assessed by painDETECT (10), nociplastic pain sensitisation evaluated by quantitative sensory testing (QST) (11), and inflammatory pain measured by the visual analogue scale (VAS) (12) questionnaires. Objective pain score comparisons using quantitative sensory testing (QST) were also performed in the abatacept and TNF inhibitor group. QST assessments were performed as previously described with a Somedic hand held algometer (11).
At baseline, pain assessment scores inclusive of VAS, painDETECT scores and DAS-28 were taken. Body Mass Index (BMI) was recorded, with screening blood tests before starting biologics taken inclusive of liver function tests, renal function tests, TB, hepatitis B/C testing and inflammatory markers including ESR and CRP. As part of the biologic screening, each participant required a chest radiograph to exclude infection. After baseline measures were obtained, participants were seen a further four times at 3-month intervals. Information collected at each visit included pain and function questionnaires, patient-related outcome measures (PROMs) (see outcomes section), QST, CCP (anti-Cyclic Citrullinated Protein antibody) status, blood and urine for inflammatory markers and biomarker testing, and concomitant medications.
Randomisation and masking
The web-based randomisation programme developed by King’s Clinical Trials Unit was used to assign participants randomly in a 1:1 ratio. The study was not blinded; this was to allow participants to receive their usual treatment more easily, and to identify those who would need further treatment swiftly switched back to usual care at the end of the study. It also allowed for easier monitoring of possible adverse effects.
Outcomes
The primary aim was to assess the feasibility of undertaking a statistically powered, randomised, controlled trial. The primary outcomes to determine feasibility were recruitment, randomisation rates and retention. We identified suitable pain measures and ascertained if they could be collected during the study. Clinical pain measures included patient reported scores, painDETECT and Visual Analogue Scale (VAS), and objective measures of pain using PPT after 12 months of treatment. The VAS outcome measure is a validated measure for inflammatory pain and forms part of the IMMPACT guidelines in clinical studies (12). The painDETECT questionnaire has been increasingly adopted to assess participants for inflammatory and neuropathic pain elements in RA (10), with a measure of 0–12 suggestive of inflammatory pain, 13–18 suggesting possible neuropathic elements and 19–38 suggesting a likely neuropathic component. Participants were also assessed for nociplastic pain components using quantitative sensory testing (QST), as described above. Subjects were also stratified by CCP (Anti-Cyclic Citrullinated Peptide antibody) status. Additional clinical characteristics were obtained, including the inflammatory markers C-reactive protein (CRP) and ESR (Erythrocyte Sedimentation Rate (ESR), plus the Hospital Anxiety and Depression Scale (HADS) (13), Health Assessment Questionnaire Disability Index (HAQ DI) (14), SF36 (36-item short form survey) (15) and PROMIS-29 (which measures physical function, fatigue, pain interference, depressive symptoms, anxiety, ability to participate in social roles and activities, and sleep disturbance) (16).
A brief description of the questionnaires and their rationale for use is discussed as follows: the Health Assessment Questionnaire-Disability Index (HAQ-DI) is the most widely used measure of function in inflammatory arthritis (14). Worse HAQ scores are associated with an increased risk of all-cause mortality. The SF36 (Short Form 36 survey) is a patient reported outcome for quality of life measures, including limitations in physical activities due to health issues, bodily pain, mental health and fatigue (15). The PROMIS-29 is a 4-item form for physical function, fatigue, depression, anxiety, sleep disturbance and satisfaction with participation in social roles (16).
Quantitative Sensory Testing (QST): Sites were selected to assess peripheral and central sensitisation, including the sternum, hand (30 joints including both hands and wrists), knees and malleoli. The pain pressure threshold (PPT), which was the value recorded when the pressure stimulus was perceived as pain, was measured (in kPa) at each site 3 times and a mean of all 3 values reported.
HAQ-DI (Health Assessment Questionnaire – Disability Index): It is measured via 20 items, which are divided into 8 categories: dressing, rising, walking, reach, grip, hygiene and usual activities. Those with a high HAQ score at baseline or one year, are associated with worse function outcomes in the long term.
PROMIS-29 outcome measure (Patient Reported Outcomes Information System): Each item is ranked from 1–5, therefore the score can range from 4–20. The scores are converted to T scores, where the mean for the normal population is 50 and the standard deviation is 10. A larger number, above 50, represents a positive score and an increase in the item being measured. If the score is 60 for physical function, the participant has greater than normal physical function.
All adverse events were recorded and reported according to MHRA guidelines. An independent Data Monitoring Committee was chaired by an independent clinician (Dr Andrew Hitchings) and reviewed by the Trial Management Group and Trial Steering Committee.
Sample size
As this was a feasibility trial, no formal sample size calculation was used and the study was not powered to test the relative efficacy of adalimumab versus abatacept. We initially estimated that 60 participants would need to be recruited, which would allow us to observe the variability of the efficacy of the outcomes to power a full trial. A proportionately reduced sample size, which required implementation due to recruitment challenges during the Covid pandemic, was still felt to be sufficient to test the primary feasibility outcomes, which was agreed with the Clinical trials unit and trial steering committee based on previous feasibility study sample sizes (17–22). Following the revised sample size, 25 participants were recruited to the study.
Statistical analysis
The analysis and presentation of results adhered to the CONSORT guidelines (17). All analyses followed the intention-to-treat principle: all randomly allocated participants were analysed according to the group they were allocated to, irrespective of the intervention they received. Demographic and clinical data were presented as frequencies and percentages for categorical variables and mean and standard deviation for normally distributed continuous variables. Statistical hypothesis testing was not performed since this was a feasibility study.
The study planned to investigate the pain responses in subjects with RA receiving biologic therapies. The trial was not powered to test or demonstrate efficacy of one biologic over another. Outcome analyses were conducted according to the statistical analysis plan described in the protocol. Clinical primary outcomes for pain and QST were calculated as proportions with corresponding binomial exact 95% CIs. Missing data were imputed by scoring guidelines and pre-defined rules as specified for the corresponding questionnaire. Data were analysed using IBM SPSS Statistics 29 for analysis and trends in outcomes in each treatment group. Graphpad Prism 9 was used for graphical illustration.
Role of the funding source
The funder of the study had no role in the study design, data analysis, data interpretation, writing of the report, or the decision to submit the manuscript for publication.