Subcutaneous, Intravenous Abatacept as Potential Therapy for Polyarticular-Course JIA

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ATLANTA — Both intravenous and subcutaneous abatacept therapy is well-tolerated and effective in pediatric patients with polyarticular-course juvenile idiopathic arthritis (JIA) and prior methotrexate intolerance, according to research results presented at the 2019 American College of Rheumatology/The Association of Rheumatology Professionals (ACR/ARP) Annual Meeting, held November 8 to 13, 2019, in Atlanta, Georgia.

Researchers reported the safety and efficacy results of 2 phase 3 clinical trials examining abatacept use in patients with polyarticular-course JIA. The first trial (ClinicalTrials.gov Identifier: NCT01844518) focused on subcutaneous abatacept therapy; the second trial (ClinicialTrials.gov Identifier: NCT00095173) evaluated intravenous abatacept use in patients without concomitant methotrexate use but with prior biologic use.

In the first study, patients with polyarticular-course JIA were stratified by age (2-5 and 7-17 years) to receive doses of weight-tiered subcutaneous abatacept weekly for 4 months. At month 4, JIA-ACR30 criteria responders were eligible to receive subcutaneous abatacept for another 20 months.

In the second study, patients with polyarticular-course JA received open-label intravenous abatacept for 4 months (period A). At 4 months, JIA-ACR30 criteria responders were randomly assigned to receive 1:1 intravenous abatacept or placebo every 4 weeks for 6 months or until a flare (period B). Finally, patients were eligible to receive open-label abatacept over a 5-year follow-up period (period C).

Baseline characteristics were balanced between the treatment arms in both studies. Neither study’s results indicated any additional numerical benefit in JIA-ACR responses between the abatacept plus methotrexate vs abatacept monotherapy groups at month 4 (subcutaneous abatacept, 34.7% vs 34.8%; intravenous abatacept, 12.3% vs 13.5%). Flare rates were comparable between the abatacept plus methotrexate and the abatacept monotherapy groups from period B of the intravenous study (18.8% vs 25.0%; 95% CI, 7.7-29.8 and 0.5-49.5, respectively).

Efficacy responses in patients with prior methotrexate intolerance were also similar at month 4 in both studies. Researchers noted that patients who were biologic-naive and treated with abatacept had “a numerically greater clinical response than those with prior biologic use” at 4 months in both trials. This effect was independent of concomitant methotrexate use.

Reported adverse event rates were similar across all patient groups. In the subcutaneous abatacept study, no antidrug antibodies were reported with abatacept monotherapy, whereas only a few patients receiving intravenous abatacept monotherapy developed antidrug antibodies, but this did not affect the efficacy of abatacept therapy.

“Abatacept monotherapy was effective and well tolerated in patients with [polyarticular-course] JIA intolerant to [methotrexate] or when prior [methotrexate] was not effective,” the researchers concluded. “In addition, abatacept monotherapy can be considered for use in those with prior biologic therapy if [methotrexate] use is inappropriate.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

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Reference

Ruperto N, Lovell DJ, Bohnsack J, et al. Subcutaneous or intravenous abatacept monotherapy in pediatric patients with polyarticular-course JIA: results from two phase III trials. Presented at: 2019 ACR/ARP Annual Meeting; November 8-13, 2019; Atlanta, GA. Abstract 1815.