In the study, 326 patients were randomized (1:1) to receive ACTEMRA 8 mg/kg intravenously (IV) every four weeks (plus placebo adalimumab) or adalimumab 40 mg subcutaneously (SC) every two weeks (plus placebo ACTEMRA) for 24 weeks.
The study met its primary endpoint of a significantly greater reduction in the mean change from baseline in the DAS28 score in patients receiving ACTEMRA as a single-agent therapy compared to those receiving adalimumab as a single-agent therapy at 24 weeks. Specifically:
- Patients achieved a significantly greater DAS28 score reduction of 3.3 with ACTEMRA compared to 1.8 with adalimumab and also had a significantly greater proportion of patients achieving DAS28 low disease activity with a rate (DAS28 < 2.6) of 40 percent versus 11 percent, at 24 weeks respectively.
- Patients also achieved significant responses in favor of ACTEMRA with ACR20, 50 and 70 responses of 65 percent, 47 percent and 33 percent with ACTEMRA versus 49 percent, 28 percent and 18 percent with adalimumab at 24 weeks.
In the United States, the recommended dose for ACTEMRA in RA is 4 mg/kg (IV) every four weeks followed by an increase to 8 mg/kg (IV) every four weeks based on clinical response. The recommended dose for adalimumab in RA is 40 mg administered subcutaneously every other week. Some patients not taking concomitant methotrexate may derive additional benefit from increasing the dosing frequency of adalimumab to 40 mg every week.
Adverse event (AE) profiles in the two treatment groups were comparable and the safety profile of ACTEMRA in ADACTA was consistent with previous ACTEMRA RA clinical trials.
About the Long-Term Follow-Up of AMBITION Study Participants (Abstract #454)
A post hoc analysis of patients from the Phase III AMBITION study who enrolled into the ongoing long-term extension GROWTH96 study confirmed that single-agent therapy with ACTEMRA provided durable efficacy up to 240 weeks, as demonstrated by the increasing number of patients who achieved significant reduction in signs and symptoms of RA and/or DAS28 <2.6 or low disease activity over time. The post hoc analysis was designed to evaluate the long-term efficacy of intravenous (IV) ACTEMRA 8 mg/kg in patients with moderately to severely active RA who remained on single-agent therapy.