Changes in the anticitrullinated peptide antibody response in relation to therapeutic outcome in early rheumatoid arthritis: results from the SWEFOT trial.

OBJECTIVE: To determine the relationship between changes in antibody levels towards citrullinated peptides derived from different candidate autoantigens and therapeutic outcome in early rheumatoid arthritis (RA). METHODS: Baseline and 3-month serum samples from 316 patients with early RA enrolled in the Swedish Farmacotherapy (SWEFOT) trial were analysed for antibodies against cyclic citrullinated peptides (CCP) and citrullinated peptides derived from vimentin (cVim), fibrinogen (cFib) and α-enolase (CEP-1). At 3-month follow-up, methotrexate monotherapy-inadequate responders were randomised to add-on therapy with sulfasalazine and hydroxychloroquine or infliximab. In these patients, anticitrullinated peptide antibodies (ACPA) were also assessed at 12 and 24 months. The proportion of antibody-positive patients and relative changes in antibody levels were compared across ACPA specificities and related to therapeutic response and radiographic progression. RESULTS: During the 2-year follow-up, the proportion of patients testing positive declined significantly regarding antibodies to cVim, cFib and CEP-1, while anti-CCP antibody occurrence remained stable over time. Turning anti-cVim antibody negative was most common, and anti-cVim antibody seroreversion during the first three months associated with significantly less 2-year radiographic progression compared with patients who remained positive. Median antibody levels of all tested ACPAs declined uniformly during initial methotrexate therapy and following response to add-on therapy, with no significant relation to treatment regimen or radiographic progression. CONCLUSIONS: The influence of early antirheumatic therapy on ACPA seroreversions was markedly different across specificities, and early disappearance of anti-cVim antibodies associated with better radiological outcome. Thus, these data suggest that the disappearance of particular ACPA reactivities may be beneficial in early RA. TRIAL REGISTRATION NUMBER: WHO database at the Karolinska institute: CT20080004; and clinicaltrials.gov: NCT00764725.

Cost-effectiveness of infliximab versus conventional combination treatment in methotrexate-refractory early rheumatoid arthritis: 2-year results of the register-enriched randomised controlled SWEFOT trial.

OBJECTIVE: To estimate the incremental cost-effectiveness of infliximab versus conventional combination treatment over 21 months in patients with methotrexate-refractory early rheumatoid arthritis. METHODS: In this multicentre, two-arm, parallel, randomised, active-controlled, open-label trial, rheumatoid arthritis patients with <1 year symptom duration were recruited from 15 rheumatology clinics in Sweden between October 2002 and December 2005. After 3-4 months of methotrexate monotherapy, patients not achieving low disease activity were randomised to addition of infliximab or sulfasalazine+hydroxychloroquine (conventional treatment group). Costs of drugs, healthcare use, and productivity losses were retrieved from nationwide registers, while EuroQol 5-Dimensions utility was collected quarterly. RESULTS: Of 487 patients initially enrolled, 128 and 130 were randomised to infliximab and conventional treatment, respectively. The infliximab group accumulated higher drug and healthcare costs (€27,487 vs €10,364; adjusted mean difference €16,956 (95% CI 14,647 to 19,162)), while productivity losses did not differ (€33,804 vs €29,220; €3961 (95% CI -3986 to 11,850)), resulting in higher societal cost compared to the conventional group (€61,291 vs €39,584; €20,916 (95% CI 12,800 to 28,660)). Mean accumulated quality-adjusted life-years (QALYs) did not differ (1.10 vs 1.12; adjusted mean difference favouring infliximab treatment 0.01 (95% CI -0.07 to 0.08)). The incremental cost-effectiveness ratios for the infliximab versus conventional treatment strategy were €2,404,197/QALY from the societal perspective and €1,948,919/QALY from the healthcare perspective. CONCLUSIONS: In early, methotrexate-refractory rheumatoid arthritis, a treatment strategy commencing with addition of infliximab, as compared to sulfasalazine+hydroxychloroquine, was not cost-effective over 21 months at willingness to pay levels generally considered acceptable. TRIAL REGISTRATION NUMBER: NCT00764725.

Is swollen to tender joint count ratio a new and useful clinical marker for biologic drug response in rheumatoid arthritis? Results from a Swedish cohort.

OBJECTIVE: To study the impact of swollen to tender joint count ratio (STR) and other baseline characteristics on treatment response to a first course of anti-tumor necrosis factor (anti-TNF) therapy in rheumatoid arthritis (RA) patients. METHODS: Patients with RA initiating their first course of anti-TNF treatment were included in a structured clinical followup protocol. Based on pragmatic thresholds and plausibility, patients were categorized as having low (STR <0.5), moderate (0.5 ≤ STR ≤ 1.0), or high (STR >1.0) joint count ratios. The data were collected and followed during the period of March 1999 through December 2010. RESULTS: A total of 2,507 patients were included in the study (median age 56 years, 78% women). Of these patients, 344 (14%) had a low STR, 1,180 (47%) had a moderate STR, and 983 (39%) had a high STR. According to these STR thresholds, 23% of patients (95% confidence interval [95% CI] 18-29%) with low, 39% (95% CI 35-43%) with moderate, and 40% (95% CI 36-44%) with high STR achieved the American College of Rheumatology criteria for 50% improvement (ACR50) response at 6 months after initiation. Correlation tests showed that STR was associated with ACR50 response independent of both swollen and tender joint counts. Logistic regression analysis consistently showed that moderate STR, high STR, not using prednisolone, high baseline Disease Activity Score in 28 joints, and low baseline Health Assessment Questionnaire scores were significantly associated with favorable ACR50 response with odds ratios of 1.93 (P < 0.01), 2.82 (P < 0.01), 0.65 (P < 0.01), 1.49 (P < 0.01), and 0.47 (P < 0.01), respectively. CONCLUSION: STR is a new and feasible predictor of treatment response in RA. RA patients with a moderate to high STR have a 2- to 3-fold increased likelihood of responding according to ACR50 criteria.

Addition of infliximab compared with addition of sulfasalazine and hydroxychloroquine to methotrexate in early rheumatoid arthritis: 2-year quality-of-life results of the randomised, controlled, SWEFOT trial.

OBJECTIVE: To compare EuroQol 5-Dimensions (EQ-5D) utility and quality-adjusted life-years (QALYs) in patients with early, methotrexate (MTX) refractory rheumatoid arthritis (RA), randomised to addition of infliximab (IFX) or sulfasalazine and hydroxychloroquine (SSZ+HCQ). METHODS: RA-patients with symptoms <1 year were enrolled between 2002 and 2005 at 15 Swedish centres. After 3-4 months of MTX monotherapy, patients with a remaining DAS28>3.2 were randomised to addition of IFX or SSZ+HCQ and followed for 21 months. EQ-5D profiles were collected every 3 months. Between-group comparisons of utility change and accumulated QALYs were performed, using last observation carried forward (LOCF) following protocol breach. Missing data were imputed by linear interpolation or LOCF. Sensitivity analyses applying baseline observation carried forward (BOCF) or restricted to completers were conducted. RESULTS: Of 487 patients initially enrolled, 128 and 130 were randomised to IFX or SSZ+HCQ, respectively. Mean utility in the IFX and SSZ+HCQ groups increased from 0.52 (SD 0.27) and 0.55 (SD 0.27) at randomisation to 0.66 (SD 0.25) and 0.63 (SD 0.27) at 21 months (adjusted mean difference favouring IFX 0.04; 95% CI -0.01, 0.09; p=0.15). Average accumulated QALYs were 1.10 (SD 0.37) and 1.07 (SD 0.42) in the IFX and SSZ+HCQ groups, respectively (adjusted mean difference favouring IFX 0.07; 95%CI -0.01, 0.14; p=0.07). BOCF analysis showed similar results, while differences were reversed, though remained statistically non-significant among completers. Dropout rates in the IFX/SSZ+HCQ groups were 30%/43% (p=0.01). CONCLUSIONS: Comparing addition of IFX or SSZ+HCQ to MTX in active early RA, no statistically significant differences in utility or QALY gain could be detected over 21 months. TRIAL REGISTRATION: Registered in WHO database at the Karolinska University Hospital, number CT20080004.

National EQ-5D tariffs and quality-adjusted life-year estimation: comparison of UK, US and Danish utilities in south Swedish rheumatoid arthritis patients.

OBJECTIVE: To study how the choice of national EQ-5D tariff may affect utility and incremental quality-adjusted life-year (QALY) estimates. METHODS: South Swedish rheumatoid arthritis patients in an observational study, starting and continuing anti-tumour necrosis factor (TNF) monotherapy (n=54) or anti-TNF plus methotrexate (n=215) for 1 year during May 2002 to April 2009, were included. EQ-5D questionnaires were completed at baseline, 3, 6 and 12 months. Utilities and accumulated QALY were compared using the UK, US and Danish EQ-5D tariffs. Utilities for all 243 possible EQ-5D health states were also compared. RESULTS: US utilities were generally higher than UK, with Danish falling in between. A substantial 1-year mean utility improvement was seen in both study groups using all tariffs (UK 0.28 vs 0.29; US 0.18 vs 0.19; Danish 0.20 vs 0.22). Adjusting for baseline differences between groups, the incremental QALY gain of combined treatment was 0.09 using the UK tariff, while 0.06 according to both US and Danish tariffs. Inter-tariff disagreement in utility and accumulated QALY varied irregularly across the range of utilities. CONCLUSIONS: Applying different national EQ-5D tariffs to the same data may result in substantially different incremental QALY estimates, crucial knowledge when interpreting cost-utility analyses. Studies using different tariffs cannot be directly compared.