Budget impact analysis of botulinum toxin A therapy for upper limb spasticity in the United Kingdom

Background: Botulinum toxin A (BoNT-A) is an effective treatment for patients with upper limb spasticity (ULS), which is a debilitating feature of upper motor neuron lesions. BoNT-A preparations available in the UK are associated with different costs. Methods: We developed a budget impact model to assess the effect of changing market shares of different BoNT-A formulations - abobotulinumtoxinA, onabotulinumtoxinA, and incobotulinumtoxinA - and best supportive care, from the UK payer perspective, over a 5-year time horizon. Epidemiological and resource use data were derived from published literature and clinical expert opinion. One-way sensitivity analyses were performed to determine parameters most influential on budget impact. Results: Base-case assumptions showed that an increased uptake of abobotulinumtoxinA resulted in a 5-year savings of 6,283,829 pound. Treatment with BoNT-A costs less than best supportive care per patient per year, although treating a patient with onabotulinumtoxinA (20,861) pound and incobotulinumtoxinA (20,717) pound cost more per patient annually than with abobotulinumtoxinA (19,800) pound. Sensitivity analyses showed that the most influential parameters on budget were percentage of cerebral palsy and stroke patients developing ULS, and the prevalence of stroke. Conclusion: Study findings suggest that increased use of abobotulinumtoxinA for ULS in the UK could potentially reduce total ULS cost for the health system and society.