Objectives: To determine whether the tumour necrosis factor-alpha (TNF-alpha) antagonist adalimumab (Humira) can be efficacious after secondary loss of efficacy (i.e. loss of clinical response in patients who had initially demonstrated clinical response) to infliximab (Remicade) or etanercept (Enbrel).
Patients and methods: We studied 36 patients from the Stockholm TNF-alpha follow-up registry (STURE) who received adalimumab after secondary loss of efficacy to infliximab (group A, n = 27) or etanercept (group B, n = 9), and 26 patients who were started on adalimumab as the first TNF-alpha antagonist (group C).
Results: In group A, the baseline disease activity score 28 (DAS28) at infliximab institution was 5.5+/-0.2. During infliximab treatment, the mean best DAS28 was 3.7+/-0.2 (p<0.001), but increased to 5.2+/-0.3 when infliximab was stopped. After 3 months on adalimumab, the mean DAS28 decreased to 4.5+/-0.3 (p<0.003), and then to 4.2+/-0.2 at 6 months (p<0.001). In group B, the baseline DAS28 at etanercept institution was 6.6+/-0.5. During etanercept treatment, the mean best DAS28 was 4.6+/-0.5 (p<0.01), but increased to 5.7+/-0.4 by the time etanercept was stopped. After 3 months on adalimumab, the mean DAS28 decreased to 4.8+/-0.3 (p<0.005), and to 4.1+/-0.2 at 6 months (p<0.001). In group C, the mean baseline DAS28 was 5.6+/-0.3. After 6 months of adalimumab therapy, the DAS28 decreased to 3.5+/-0.4 (p<0.001). ACR20 responses with adalimumab in groups A, B, and C were similar (70-78%).
Conclusions: For patients with secondary loss of efficacy from infliximab or etanercept, switching to adalimumab can restore a good clinical response.