Efficacy and safety of abobotulinumtoxinA for upper limb spasticity in children with cerebral palsy: a randomized repeat-treatment study.

AIM: To assess the efficacy and safety of repeat abobotulinumtoxinA injections in reducing upper limb spasticity in children with cerebral palsy (CP). METHOD: This was a double-blind, repeat-cycle study (NCT02106351) in children with CP (2-17y). Children were randomized to receive 2U/kg (control), 8U/kg, or 16U/kg abobotulinumtoxinA injections into the target muscle group (wrist or elbow flexors) and additional muscles alongside occupational therapy via a home-exercise therapy program (HETP; minimum five 15min sessions/wk). Children received 8U/kg or 16U/kg plus HETP in cycles 2 to 4. RESULTS: During cycle 1, 210 children (126 males, 84 females; mean age [SD] 9y [4y 5mo], range 2-17y; n=70/group) had at least one upper limb abobotulinumtoxinA injection and 209 complied with the HETP. At week 6 of cycle 1, children in the 8U/kg or 16U/kg groups had significantly lower Modified Ashworth scale scores versus the 2U/kg group (primary outcome: treatment differences of -0.4 [p=0.012] and -0.7 [p<0.001] respectively). All groups improved on Physician Global Assessment and children in all groups achieved their treatment goals at least as expected. Therapeutic benefits were sustained during cycles 2 to 4; muscular weakness was the only treatment-related adverse event reported in at least one child/group (4.3% and 5.7% vs 1.4% respectively). INTERPRETATION: Treatment with 8U/kg or 16U/kg abobotulinumtoxinA significantly reduced upper limb spasticity versus the 2U/kg control dose. Therapeutic benefits of abobotulinumtoxinA plus HETP were sustained with repeat treatment cycles. WHAT THIS PAPER ADDS: AbobotulinumtoxinA injections significantly reduced upper limb spasticity in children with cerebral palsy. Children treated with abobotulinumtoxinA and targeted home exercises showed global improvement and goal attainment. Benefits were sustained over 1 year with repeat cycles of abobotulinumtoxinA and home exercises. AbobotulinumtoxinA injections into the upper limb were well tolerated over 1 year.

Goal Attainment after Treatment with Abobotulinumtoxina and a Tailored Home Therapy Programme in Children with Upper Limb Spasticity: Descriptive, Exploratory Analysis of a Large Randomized, Controlled Study

OBJECTIVE: This exploratory analysis of a large, randomized, double-blind study (NCT02106351) describes the effect of treatment with abobotulinumtoxinA followed by a tailored home exercises therapy programme in enabling children with upper limb spasticity due to cerebral palsy to achieve their functional goals using goal attainment scaling (GAS). METHODS: Children with cerebral palsy and spasticity in ≥ 1 upper limb received up to 4 injection cycles of abobotulinumtoxinA (2 U/kg (cycle 1 only), 8U/kg and 16U/kg) into the elbow and wrist flexors and other upper limb muscles selected to support individual treatment goals. Children followed a home exercises therapy programme, which included stretches and exercises specifically chosen to facilitate goal achievement and engagement in activities. RESULTS: For cycle 1, most children had active function goals set as their primary goal (69.7% vs 19.2% passive function goals). GAS T- scores and goal responder rates at week 16 indicated that most types of primary goal were achieved at least as expected during cycle 1 (all groups). Primary goal GAS T-scores were generally maintained for the first 3 abobotulinumtoxinA treatment cycles. CONCLUSION: Most children with upper limb spasticity treated with repeat cycles of abobotulinumtoxinA supported by an individualized home exercises therapy programme achieved their functional goals.

Muscle Selection and Dosing in a Phase 3, Pivotal Study of AbobotulinumtoxinA Injection in Upper Limb Muscles in Children With Cerebral Palsy.

Background: Guidelines recommend botulinum toxin-A in pediatric upper limb spasticity as part of routine practice. Appropriate dosing is a prerequisite for treatment success and it is important that injectors have an understanding on how to tailor dosing within a safe and effective range. We report upper limb dosing data from a phase 3 study of abobotulinumtoxinA injections in children with cerebral palsy. Methods: This was a double-blind, repeat-treatment study (NCT02106351). In Cycle 1, children were randomized to abobotulinumtoxinA at 2 U/kg control dose or clinically relevant 8 U/kg or 16 U/kg doses. Doses were divided between the primary target muscle group (PTMG, wrist or elbow flexors) and additional muscles tailored to clinical presentation. During Cycles 2-4, children received doses of 8 U/kg or 16 U/kg and investigators could change the PTMG and other muscles to be injected. Injection of muscles in the other upper limb and lower limbs was also permitted in cycles 2-4, with the total body dose not to exceed 30 U/kg or 1,000 U (whichever was lower) in the case of upper and lower limb treatment. Results: 212 children were randomized, of which 210 received ≥1 abobotulinumtoxinA injection. Per protocol, the elbow and wrist flexors were the most commonly injected upper limb muscles. Across all 4 cycles, the brachialis was injected in 89.5% of children (dose range 0.8-6 U/kg), the brachioradialis in 83.8% (0.4-3 U/kg), the flexor carpi ulnaris in 82.4% (0.5-3 U/kg) and the flexor carpi radialis in 79.5% (0.5-4 U/kg). Other frequently injected upper limb muscles were the pronator teres(70.0%, 0.3-3 U/kg). adductor pollicis (54.3%, 0.3-1 U/kg), pronator quadratus (44.8%, 0.1-2 U/kg), flexor digitorum superficialis (39.0%, 0.5-4 U/kg), flexor digitorum profundus (28.6%, 0.5-2 U), flexor pollicis brevis/opponens pollicis (27.6%, 0.3-1 U/kg) and biceps (27.1%, 0.5-6 U/kg). AbobotulinumtoxinA was well-tolerated at these doses; muscular weakness was reported in 4.3% of children in the 8 U/kg group and 5.7% in the 16 U/kg group. Conclusions: These data provide information on the pattern of injected muscles and dose ranges used in this study, which were well-tolerated. Per protocol, most children received injections into the elbow and wrist flexors. However, there was a wide variety of other upper limb muscles injected as physicians tailored injection patterns to clinical need.

Use of trihexyphenidyl in children with cerebral palsy.

A paucity of information exists regarding medications to treat dystonia in children with cerebral palsy. This study sought to review the benefits and tolerability of trihexyphenidyl in children with cerebral palsy, treated for dystonia or sialorrhea or both in a pediatric tertiary care hospital, through a retrospective chart review. In total, 101 patients (61 boys and 40 girls) were evaluated. The mean age at drug initiation was 7 years and 10 months (range, 1-18 years). The mean initial dose was 0.095 mg/kg/day. The dose was increased by 10-20% no sooner than every 2 weeks. The mean maximum dose reached was 0.55 mg/kg/day. Ninety-three patients (91%) tolerated the medication well, with a mean duration of treatment of 3 years and 7 months. Side effects occurred in 69% of subjects, the majority in patients aged ≥7 years, and soon after treatment initiation. Sixty-four percent continued the treatment at study end. Ninety-seven patients reported benefits, including reduction of dystonia in upper (59.4%) and lower (37.6%) extremities, sialorrhea (60.4%), and speech issues (24.7%). The majority of patients tolerated trihexyphenidyl well on a schedule of gradual dose increases, and almost all demonstrated improvements in dystonia or sialorrhea or both.