Thresholds in disease activity for switching biologics in rheumatoid arthritis patients: Experience from a large US cohort

Authors

  • Jie Zhang,

    1. University of Alabama at Birmingham
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  • Ying Shan,

    1. University of Massachusetts Medical School, Worcester
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  • George Reed,

    1. University of Massachusetts Medical School, Worcester
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    • Dr. Reed has a research contract with the Consortium of Rheumatology Researchers of North America (CORRONA).

  • Joel Kremer,

    1. Albany Medical College, Albany, New York
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    • Dr. Kremer has received research support from Amgen, Abbott, Centocor, BMS, Genentech, HGS, Pfizer, Roche, and UCB, and honoraria (less than $10,000 each) from Abbott, Centocor, BMS, Roche, and Genentech.

  • Jeffrey D. Greenberg,

    1. Langone Medical Center, New York University, New York
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    • Dr. Greenberg has received fees as Chief Scientific Officer and owns restricted stock shares in CORRONA, and has received consultant fees (less than $10,000 each) from Genentech, Pfizer, AstraZeneca, and Novartis, and (more than $10,000) from CORRONA.

  • Scott Baumgartner,

    1. Amgen, Thousand Oaks, California
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    • Dr. Baumgartner owns stock and/or holds stock options in Amgen.

  • Jeffrey R. Curtis

    Corresponding author
    1. University of Alabama at Birmingham
    • Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, FOT 805D, 510 20th Street South, Birmingham, AL 35294
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    • Dr. Curtis is a consultant for and has received research support (less than $10,000 each) from Pfizer, BMS, Crescendo, and Abbott, and (more than $10,000 each) from Amgen, Centocor, CORRONA, Roche/Genentech, and UCB.


Abstract

Objective

To examine the threshold in disease activity associated with switching biologic treatment regimens in rheumatoid arthritis (RA) patients in real-world clinical practice.

Methods

Using data from a prospective observational North American cohort of RA patients through December 30, 2009, patients who initiated a new anti–tumor necrosis factor α (anti-TNFα) agent with ≥6 months of followup were identified. Patients were classified as switchers or maintainers depending on whether they continued their anti-TNF treatment or switched (including discontinuation) within 12 months. Level of disease activity measured by the Clinical Disease Activity Index (CDAI) and Disease Activity Score in 28 joints (DAS28) at the time of the switch (corresponding followup visit for maintainers) was examined and random-effect multivariable logistic regression was used to adjust for covariates.

Results

Mean age and RA duration among 1,549 eligible patients were 56.1 and 9.6 years, respectively, 80% were women, 62% were initiating their first biologic, and 30% were initiating their second biologic. At the time of the switch, the median DAS28 and CDAI score were 3.1 and 8.4 among maintainers and 4.0 and 15.2 among switchers, respectively. Maintainers also experienced a greater amount of reduction in disease activity compared with switchers (CDAI: −7.7 versus −2.3, DAS28: −1.1 versus −0.3). The threshold to switch decreased over calendar time, with the greatest amount of reduction observed among patients with moderate disease activity.

Conclusion

On average, physicians and patients were willing to continue biologic treatment for patients who were at or near low disease activity. The threshold to switch decreased over time, especially among partial responders.

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