Objectives To compare the effect of tocilizumab(TCZ) plus methotrexate (MTX), with the effect of abatacept(ABT) plus MTX on bone mineral density(BMD) in TNF blockers resistant active rheumatoid arthritis(RA; without osteoporosis) patients, in a prospective open label randomized study design.
Methods RA patients were eligible if they had active disease despite treatment with MTX plus TNF blockers. All patients have no previous history of lumbar and hip fractures. Patients receiving or having received bisphosphonates or hormone replacement therapy, steroids, or any biologics were excluded. 28 patients with moderate to severe active RA patients (DAS28 >3.2) were randomly assigned to receive TCZ plus MTX (n=14) or ABT plus MTX (n=14). All patients with worsening disease activity at week 12, the patients were allowed to escape to another group (by clinician’s judgment). The primary outcomes were changes in lumbar and femoral BMD by dual-energy X-ray absorptiometry, secondary outcome were changes in biomarkers of bone turnover (procollagen type I amino-terminal propeptide(P1NP) from baseline to 52 weeks. Clinical data were collected at regular visit. All patients were taking calcium (1 g/day) and vitamin D (800 IU/day).
Results The characteristics of each group at baseline were not significantly different. 11 each in the TCZ and ABT groups completed 24 weeks.
Lumbar and femoral BMD were attenuated significantly by TCZ (weeks 52-baseline: lumbar BMD: 0.05±0.009 g/cm2, p <0.001; femoral BMD: 0.03±0.004 g/cm2, p <0.001).On the other hand, lumbar and femoral BMD were not attenuated significantly by ABT (weeks 52-baseline: lumbar BMD: 0.01±0.052 g/cm2, p =0.66; femoral BMD: -0.002±0.009 g/cm2, p =0.87. The change (weeks 52-baseline) lumbar and femoral BMD of the TCZ group were significantly improvement than those of the ABT group (TCZ vs. ABT, lumbar BMD: p <0.05; femoral BMD: p <0.05).
P1NP was significant increase by TCZ (weeks 52-baseline: 4.0±0.13μg/L, p<0.05), but was no significant change by ABT (weeks 52-baseline: 1.2. ±0.73μg/L, p=0.55).
DAS28 and CRP improved significantly in both groups (weeks 52-baseline; DAS28, TCZ: -2.31±0.65, ABT: -2.55±0.52) (CRP, TCZ: -19.6±5.2 mg/l, ABT: -16.7±3.3mg/l) (p<0.05). They were no significant difference between groups.
Conclusions TCZ plus MTX improves bone mineral density compared with ABT plus MTX in TNF blockers resistant RA. If RA patients were resist TNF blocker, we might think the patients were treated by TCZ than ABT.
Disclosure of Interest None Declared