Baseline neutrophil-to-lymphocyte ratio predicts drug retention of IL-6 inhibitors and JAK inhibitors in rheumatoid arthritis: the ANSWER cohort study

Objective This study aimed to compare drug retention rates according to the baseline neutrophil-to-lymphocyte ratio (NLR) in patients with rheumatoid arthritis (RA) initiating biologic/targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs). Methods Data were obtained from 774 treatment courses with moderate to high disease activity at the initiation of b/tsDMARD therapy from the Kansai Multicentre ANSWER cohort. Patients were categorised into NLRlow group and NLRhigh group based on the median NLR value of 3.30. A multivariate Cox proportional hazards model, adjusted for potential confounders, was used to estimate hazard ratios (HRs) for drug retention over two years. Results Patients in the NLRhigh group exhibited significantly higher baseline Clinical Disease Activity Index (CDAI) scores (p = 0.004) and more frequent glucocorticoid use (p < 0.001) than those in the NLRlow group. In the NLRlow group, drug retention rates did not significantly differ among tumour necrosis factor inhibitors (TNFi), anti-IL-6 receptor antibodies (aIL-6R), cytotoxic T-lymphocyte antigen 4 immunoglobulin (CTLA4-Ig), and Janus kinase inhibitors (JAKi). In contrast, within the NLRhigh group, treatment with aIL-6R and JAKi was associated with significantly higher retention rates compared with TNFi (HR = 0.53, 95% CI: 0.32–0.88; HR = 0.36, 95% CI: 0.20–0.64, respectively). At 12 months, CDAI scores did not significantly differ among the four treatment groups in either NLR group. Conclusion In patients with elevated baseline NLR values, aIL-6R and JAKi may offer superior drug retention compared with TNFi when initiating b/tsDMARD therapy.