Objective:

To compare real-world clinical utilization of onabotulinumtoxinA (onabotA) and abobotulinumtoxinA (abobotA) in the treatment of adult upper limb spasticity (ULS).

Background:

3 botulinum toxin type A (BoNT/A) products are approved by the US Food and Drug Administration (FDA) to treat ULS. Each BoNT/A product is manufactured and tested via proprietary processes, resulting in unique clinical profiles. FDA-mandated boxed warnings state that potency units of one product are not interchangeable and cannot be converted into units of another BoNT/A product. We compared real-world clinical utilization of onabotA and abobotA in the treatment of adult ULS.

Design/Methods:

De-identified medical records were obtained via survey of 101 unique healthcare professionals on patients diagnosed with ULS per International Classification of Diseases, 10th revision, (ICD-10) and treated via botulinum toxin using current procedural terminology (CPT) in the US. 215 patient charts were reviewed: 107 treated with onabotA and 108 with abobotA. Patients received at least 3 treatments of onabotA or abobotA in 1 spastic upper limb prior to March 2020. Number and type of muscles injected were compared between BoNT/A products.

Results:

75% of patients were classified as having moderate-to-severe ULS by the injector. On average, patients were diagnosed with ULS for >3 years: onabotA 44.2 months (10-200) or abobotA 40.0 months (11-212). A significantly greater average number of muscles were injected with onabotA (4.3; range, 1 to 16), compared with abobotA (3.1; range, 1 to 8), P=0.0001. Significantly more patients received onabotA injections in forearm muscles (87/107, 81.3%) compared with abobotA (70/108, 64.8%), P=0.0064. Similarly, a significant difference was observed in the utilization of onabotA in hand muscles (23/107, 21.5%) compared with abobotA (4/108, 3.7%), P=0.0001.

Conclusions:

These results are consistent with published evidence across other indications, further supporting that each BoNT/A product is unique and not interchangeable as indicated by the FDA.