Switching from weekly subcutaneous (SC) injections of abatacept (Orencia) to a single intravenous (IV) dose and back again after 4 weeks is safe and effective and may be used to bridge most vacations for patients with rheumatoid arthritis (RA) in low disease activity (LDA) or remission at the time of the switch, a prospective, open-label study has shown.
In a per-protocol population of 49 patients, 46 or 93.9% of patients (95% CI 83.5-97.9) were still in low disease activity as defined by a Disease Activity Score in 28 joints (DAS28) of 3.2 or less 28 days after replacing weekly subcutaneous injections with a single IV dose of abatacept, reported Ruediger B. Mueller, MD, Kantonsspital St. Gallen, Switzerland, and colleagues.
After 28 days, patients resumed their weekly subcutaneous schedule, and 93.6% of patients (95% CI 82.8-97.8) remained stable with low disease activity at study endpoint on day 168.
"Vacations may cause problem for patients with RA treated with SC biologics because transportation of the biologics may be complicated for various reasons such as customs regulations, maintenance of the cold chain, or fragility of vials/syringes in the luggage," Mueller and colleagues wrote in Arthritis Research & Therapy.
"IV abatacept has to be administered only once every 4 weeks, a time period covering most vacations," he added. "Administration of only one IV dose may help patients on abatacept to cover even longer periods of absence for vacations or other reasons (e.g., business trips)."
The abatacept study to omit weekly subcutaneous injections in RA patients during holiday break (A-BREAK) was a phase IV, 24-week, single-arm study in which patients were switched from SC injections at a dose of 125 mg/week to a weight-adjusted IV dose of 500 mg for patients who weighed less than 60 kg, 750 mg for those between 60 and 100 kg, and 1,000 mg for those who weighed more than 100 kg.
At day 28, all patients received the same subcutaneous dose of abatacept as they had prior to the switch.
Patients had to have effective disease control at baseline and had to remain under continuous synthetic DMARD therapy throughout the study. Fifty out of 52 patients completed the 24-week study, and 49 were included in the per-protocol analysis.
The average DAS28 values were 1.73 at baseline, 2.03 on day 28, and 1.96 at study endpoint.
"Two out of the three patients with a DAS28 of more than 3.2 on day 28 were back to LDA at the end of the study -- i.e., on day 168," Mueller noted. "And pre-exposition to IV abatacept or TNF [tumor necrosis factor] antagonists did not significantly influence the average DAS28 or the proportion of patients retaining LDA."
The investigators documented other measures of disease activity as well, including the Health Assessment Questionnaire Disability Index (HAQ-DI). The results showed that the HAQ-DI scores also remained stable throughout the study interval.
The safety profile of abatacept was similar to that seen in other studies, and the rate of adverse events did not increase following IV dosing.
"The study demonstrated the effectiveness and safety of switching from SC to IV abatacept before a vacation or business trip and then continuing with SC abatacept 4 weeks later," Mueller concluded. "In our view, it emphasizes the need for both ways of abatacept administration."
Eric Matteson, MD, a rheumatologist at Mayo Clinic in Rochester, Minn., told MedPage Today that the study does demonstrate that the strategy maintains disease control.
"It can also be useful for patients unable or unwilling to travel with their medications, recognizing how important it is to keep the medications cool," Matteson added.
In addition, drug syringes must be stored in a cool carrier set at a temperature of 36°F to 46°F and kept away from light.
Citing drawbacks to the IV bridging strategy on the other hand, "the infusion itself takes approximately 30 minutes, it can be time consuming to arrange for it, and to go for the infusion and the process may require prior authorization," Matteson noted.
The study was funded by Bristol-Myers Squibb.
The authors declared that they had no competing interest. Matteson has received a research grant from Bristol-Myers Squibb.
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