RA patients who can not use etanercept may benefit from infliximab

Furst, Yocum, Weisman, Troum, Bray, wallace, Gaylis, Ritter, Yeilding, Gilmer

INFLIXIMAB PROVIDES ADDITIONAL CLINICAL AND RADIOGRAPHIC BENEFITS IN RA PATIENTS WHO HAVE AN INADEQUATE RESPONSE TO ETANERCEPT

Objectives: This multi-center, randomized, open-label, exploratory 30 week study was designed to evaluate whether switching from etanercept (ETA) plus MTX to infliximab (IFX) + MTX provides evidence of additional therapeutic and radiographic benefit in patients who have failed ETA. Clinical and radiographic data through week 16 are summarized below.

Methods: The study population consisted of subjects with RA who, despite receiving a stable dose of ETA (25 mg sq, biw) + MTX for at least 2 months before study entry, had an incomplete response to therapy as defined by a tender joint count (TJC) ≥ 9 and a swollen joint count (SJC) ≥ 6. Patients were randomized to either continue ETA (25mg biw) or discontinue ETA and immediately begin IFX therapy (3mg/kg at 0, 2, and 6 wks then q8 wks). 27 subjects were randomized and treated, 13 received IFX and 14 received ETA.

Results: 91% of patients at baseline were female and had a mean age of 49 years, had a mean disease duration of 11 years and a mean DAS28 score of 6.2 for the IFX group and 6.5 for ETA. At 16 weeks, IFX treated patients achieved an ACR20 response of 61% (8 of 13 patients) compared to an ACR20 response of 29% (4 of 14 patients) for ETA treated patients. The response was rapid with a difference noted as early as week 2 (31% ACR20 with IFX vs. 14% ACR20 with ETA). By week 16 there were notable additional improvements for the IFX group in the parameters described in the table. Radiographs taken at baseline and week 14 were evaluated in a blinded fashion by two trained readers using van der Heijde”s modification of the Sharp (vdH-S) score. At baseline, the patients had median vdH-S scores of 20.5 for the IFX group and 23.3 for the ETA group. At week 14 the median change in vdH-S scores were 0.0 (IQR: –0.5, 0.5) for IFX and 0.3 (IQR: –0.3, 0.8) for ETA. The annualized median rate of radiographic progression was 0.0 (IQR: -1.3, 1.3) for IFX and 0.9 (IQR:-0.9, 2.8) for ETA.

[ESR = Erythrocyte Sedimentation Rate; CRP = C-Reactive Protein; TJC = Tender Joint Count, SJC = Swollen Joint Count, PtGA = Patients Global Assessment, PhGA = Physicians Global Assessment, HAQ = Health Assessment Questionnaire, DAS=Disease Activity Score]

*Negative values denote improvement

Conclusion: This trial suggests that infliximab plus MTX provides clinical benefit for RA patients who failed to respond to the combination of etanercept and MTX. There appears to be an incremental radiographic benefit with infliximab use in patients who failed to respond to etanercept.

This multiceter study was carried out by:

1. Furst1, D. Yocum 2 , M. Weisman 3 , O. Troum 4 , V. Bray 5 , D. Wallace 6 , N. Gaylis 7 , J. Ritter 8 , N. Yeilding 9 , K. Gilmer 9

1Division of Rheumatology, University of California Los Angeles, Los Angeles, 2Arizona Arthritis Center, University of Arizona Health Sciences Center, Tucson, 3Division of Rheumatology, Cedars-Sinai Medical Center, Los Angeles, 4Keck School of Medicine, University of Southern California, Santa Monica, 5Denver Arthritis Clinic, University of Colorado Health Sciences Center, Denver, 6Rheumatology, Wallace Rheumatic Study Center, Los Angeles, 7Rheumatology, Arthritis and Rheumatic Disease Specialties, Aventura, 8Rheumatology, Center for Arthritis and Rheumatology, South Miami, 9Medical Affairs, Centocor, Inc., Horsham, United States