Objective:

To assess pain relief after multiple incobotulinumtoxinA (incoA) injections in a large sample of patients (pts) with limb spasticity-associated pain (SAP) using pooled data from six phase 2/3 studies (four placebo-controlled).

Background:

Repeated treatment with incoA has shown pain-relieving benefits in pts with limb spasticity in individual studies.

Design/Methods:

Adults with upper limb SAP received up to 4 incoA injections (total dose ≤400U) administered at 12- to 14-week intervals (injection cycles [ICs] 1–4; total observation period up to 56 weeks). Only IC 1 was placebo-controlled. Pain severity was assessed at control visits (CVs; 4 weeks after each injection) using the Disability Assessment Scale (DAS; pain scores ranging from 0 [no pain] to 3 [severe pain]). The proportions of pts with a response (defined as a reduction by ≥1 point in the DAS score from baseline to each CV) and with a complete response (DAS pain score=0) were assessed at every CV. Data were descriptively analyzed. As placebo-treated pts in IC 1 received incoA in subsequent cycles, they contributed data to the appropriate incoA CVs 1–4.

Results:

515 pts with SAP at baseline were included in this analysis (515, 297, 263, and 181 pts at CVs 1–4, respectively). Response rates increased over time, being 53.0%, 63.3%, 66.9%, and 72.4% at CVs 1–4, respectively. Likewise, the proportion of pts with complete response increased over time, being 27.6%, 38.4%, 39.5%, and 43.6% at CVs 1–4, respectively.

Conclusions:

In pts with upper limb SAP, treatment response rates were sustained and showed a cumulative effect over 56 weeks after multiple incoA injections, with a complete pain relief in >40.0% of pts. Results support the use of incoA in reducing upper limb SAP in affected adults.