Efficacy Remaining at Time of Requested Retreatment Following Botulinum Toxin Treatment for Cervical dystonia: Potential for a New Treatment Paradigm with DaxibotulinumtoxinA
Aaron Ellenbogen1, Robert Hauser2, Atul Patel3, Peter McAllister4, Domenico Vitarella5, Todd Gross5, Rashid Kazerooni5, Conor Gallagher5, David Hollander5
1Michigan Institute for Neurological Disorders, 2Movement Disorders Center, 3Kansas City Bone & Joint Clinic, 4New England Inst for Neurology and Headache, 5Revance Therapeutics Inc
Objective:
To assess the residual therapeutic efficacy of prior botulinum toxin (BoNT) injection at the patient-desired retreatment interval in cervical dystonia (CD).
Background:
BoNT injections are standard of care for the symptomatic treatment of CD. Therapeutic efficacy often wanes after 8-10 weeks leading to symptom re-emergence between injections, as current FDA product labeling restricts treatments to every 12 weeks. The amount of therapeutic efficacy remaining when patients would like to be retreated for their CD symptoms is not well understood.
Design/Methods:
A post-hoc analysis of the Phase III ASPEN-1 and ASPEN-OLS trials for daxibotulinumtoxinA (Daxxify®) in CD was conducted. These trials allowed patients to request retreatment rather than wait until returning to pretreatment symptom levels. The median percent efficacy remaining, as determined by changes in peak TWSTRS total score, was determined in subjects who requested reinjection prior to loss of 80% of peak efficacy. This estimate of percentage of efficacy remaining at preferred reinjection was then mapped across the full study population.
Results:
A total of 72 (28.2%), 118 (33.1%), and 113 (34.9%) patients requested reinjection prior to loss of 80% of peak efficacy in ASPEN-1, ASPEN-OLS cycles 1-2. The median percent efficacy remaining was 45.3%, 41.6%, and 49.2% at the time of requested reinjection in each of the treatment cycles. The time to loss of 50% efficacy in the overall population was 16.7, 16.6, and 16.3 weeks, respectively.
Conclusions:
These findings demonstrate, for the first time, a significant proportion of efficacy remained in patients who requested BoNT reinjection for their CD symptoms. With the long duration of benefit of daxibotulinumtoxinA, there is opportunity for a new approach whereby physicians can tailor treatments to individual patient needs and treat patients as their symptoms re-emerge at 12 weeks or beyond.