-The primary efficacy analyses were reworded to specify that if a pairwise comparison in MAS-B was not statistically significant, the corresponding pairwise comparison in CGI by Physician would not be considered statistically significant regardless of the actual p-value. -Addition of Section 7.7 Additional Analysis/Inference for US FDA to clarify when dose effectiveness would be concluded. This change addressed US FDA (United States Food and Drug Administration) comments during Special Protocol Assessment review. -Revised approximate volume of blood collection for hematology and chemistry laboratory assessments from 5 to 7 mL (milliliters) (participants weighing < 15 kg) and from 12 to 14 mL (participants weighing ≥ 15 kg) to meet revised central laboratory requirements. -Revised participant-reported onset of spasticity symptom relief question from “have you noticed any treatment effect…” to “have you noticed any effect…” to minimize potential bias based on central IRB requirement.

-Amended primarily to add assessment of suicidal ideation/behavior using the C-SSRS as a standard safety measure required by the US FDA’s Division of Neurology Products. -Added distinction between US FDA and non-US FDA clinical hypotheses and analyses. -Added participant-reported benefit of injection as an efficacy measure. -Specified that C-SSRS was to be performed as a safety measure for participants ≥ 6 years of age at Day 1, and provided description of scale, data handling, and reference information. Request from US FDA. -Revised Inclusion Criterion and screening procedure to remove requirement of true equinus foot deformity referenced in Rodda and Graham. Clarified gait pattern analysis not required to confirm equinus foot deformity. -Revised Exclusion Criterion to remove definition of significant knee spasticity. -Modified Exclusion Criterion regarding seizure frequency for exclusion. -Added Exclusion Criterion to exclude participants with significant suicidality from treatment so as to avoid data confounding. -Clarified that participants could stay in the study even if prohibited medication was administered -Clarified MTS scale description by adding “with knee extended and knee flexed”. -Changed multiple testing procedure to gatekeeping procedure to control type I error rate -Removed pairwise comparison for higher dose versus lower dose to incorporate US FDA recommendation. -Removed overall test for among group comparison. Gatekeeping procedure sufficient to control type I error rate -Removed subgroup efficacy analyses by type of anesthesia. -Revised sample size calculation to base the calculation on 2 sample t test as the overall test for among group comparison was removed. -Removed requirement that urine pregnancy test must be performed prior to study treatment. -Updated serious adverse event reporting procedures -Revised MAS-B description so the assessment could be performed by other qualified site personnel.

-Protocol amended primarily to modify the statistical methods (introduction of the Hochberg procedure, change in imputation methods, and sensitivity analyses) to reflect the simultaneous changes being made to Protocol 191622-101. -The ITT population was replaced with the mITT population (defined as all randomized participants with a valid MAS-B at baseline of the principal muscle group and ≥ 1 postbaseline measurement at Weeks 2, 4, or 6 for the MAS-B of the principal muscle group and CGI by Physician). Revised based on US FDA recommendation. -Added a responder status based on +1 score of CGI by Physician. -Changed sensitivity analyses of MAS-B and CGI by Physician to use the MI method for missing values instead of observed cases and deleted sensitivity analyses using LOCF. Revised to address US FDA feedback. -Changed primary MAS-B analysis and coprimary MAS-B and CGI by Physician (for US FDA) analyses to use MMRM with observed data; ANCOVA with MI and observed data was used as sensitivity analyses. Revised to address US FDA feedback. -Deleted subgroup analyses of adverse events because deemed unnecessary. -Changed multiple testing procedure (gatekeeping procedure) to Hochberg procedure for the coprimary analysis (for US FDA) to control type I error rate.