Treatment frequency for long-term efficacy of abobotulinumtoxinA injections: A phase 3 study in patients with upper limb spasticity following stroke or traumatic brain injury

Abstract

Long-term safety and efficacy of repeated abobotulinumtoxinA (aboBoNT-A) injections in patients with upper limb spasticity (ULS) after stroke or traumatic brain injury have been described in an open-label study (Gracies et al. Muscle Nerve , 2018). Continuous improvements in active movements, and perceived and active function were reported, with no unexpected safety signals identified. Here, we describe the frequency of repeated aboBoNT-A injections over the open-label study. A phase 3, international, double-blind, single-treatment study ( NCT01313299 ) of aboBoNT-A in the hemiparetic upper limb, followed by a 12-month open-label extension study ( NCT01313312 ) with up to four additional treatment cycles, at least 12 weeks apart. Re-treatment was per investigator's clinical judgement, based on muscle tone, spasticity measures and other findings. Patients not requiring re-treatment completed the study. A total of 254 patients entered in open-label cycle 1 ( Table 1 ). In cycle 1, 14/254 patients withdrew and 240 completed the cycle. After cycle 1, 10 patients completed the study without subsequent aboBoNT-A injections. In cycle 2, 219/229 patients completed the cycle (10 withdrew) and 44 did not require subsequent injections. Of 175 patients entered cycle 3, six withdrew and 169 completed the cycle, 88 of whom did not require subsequent injections. Overall, 55.9% ( n = 142) of patients required three or fewer injections of aboBoNT-A over the course of the 12-month study, 21.6% required two or fewer injections, and 3.9% required one injection. Over half of the patients (55.9%) enrolled in this phase 3 study required three or fewer injections of aboBoNT-A over the course of a year, based on physician clinical assessment. This decreased injection frequency, with respect to usual practice, may reduce the burden associated with treatment for patients and their caregivers/families.