Efficacy and Safety of Botulinum Toxin in Adults with Raynaud's Phenomenon Secondary to Systemic Sclerosis: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Study.

[OBJECTIVE] To determine whether a single session of botulinum toxin type A (BTA) injections into both hands more effectively decreases the frequency of systemic sclerosis-associated Raynaud's phenomenon (SSc-RP) episodes than placebo.

[METHODS] This multicenter, randomized, double-blind, placebo-controlled, parallel-group phase III trial in patients with SSc-RP assessed the effect of 50-unit BTA or placebo injections into the palms of both hands around each neurovascular bundle during 1 session in winter. The primary end point was the between-group difference in the median change in the number of RP episodes from baseline (day 0) to 4 weeks postinjection. Values between the groups were compared with the Wilcoxon rank-sum test.

[RESULTS] The intent-to-treat analysis included 46 BTA-treated patients and 44 placebo recipients. At 4 weeks after assigned treatment injections, the median number of daily RP episodes decreased comparably in the BTA and placebo groups (median change -1 episode/day [interquartile range (IQR) -1.5, 0 episodes/day] and -1 episode/day [IQR -2.5, 0 episodes/day], respectively) (P = 0.77 versus placebo). Moreover, change in Raynaud's Condition Score, quality of life assessed by Health Assessment Questionnaire disability index, and hand function assessed by shortened Disabilities of the Arm, Shoulder, and Hand (QuickDASH) and Cochin Hand Function Scale from baseline to follow-up weeks 4, 12, and 24 did not differ significantly between groups. The BTA group experienced transient hand muscle weakness significantly more frequently (P = 0.003).

[CONCLUSION] Neither the primary nor secondary end points were reached, and our results do not support any beneficial effect of palmar BTA injections to treat SSc-RP.