Table 2. Comparison of Study Primary Efficacy and Safety Outcome Measures.
| Outcome | Unique participants (longitudinal samples used), No. (No.) | Baseline mean (SD)a | End of follow up mean (SD)b | Statistical model or test P value (2-sided 95% CI) |
|---|---|---|---|---|
| Efficacy | ||||
| TTSTAND velocity, rises/s | ||||
| Higher-dose vamorolone LTEc | 23 (66) | 0.25 (0.10) | 0.20 (0.13) | vs DNHS (MMRM) |
| GC in DNHS | 75 (313) | 0.25 (0.10) | 0.25 (0.13) | Quadratic comparisond: >.99 (−0.30 to 0.30); linear comparison: .10 (−0.66 to 0.05) |
| With ≥1.5 y follow-up)e | 30 (153) | 0.24 (0.09) | 0.24 (0.12) | |
| TTCLIMB velocity, tasks/s | ||||
| Higher-dose vamorolone LTEc | 23 (63) | 0.31 (0.13) | 0.32 (0.19) | vs DNHS (MMRM) |
| GC in DNHS | 75 (311) | 0.32 (0.14) | 0.33 (0.18) | Quadratic comparison: >.99 (–0.36 to 0.36) linear comparison: .93 (−0.41 to 0.44) |
| With ≥1.5 y follow-up) | 30 (153) | 0.31 (0.13) | 0.32 (0.16) | |
| TTRW velocity, meters/s | ||||
| Higher-dose vamorolone LTEc | 23 (63) | 1.90 (0.34) | 1.87 (0.63) | vs DNHS (MMRM) |
| GC in DNHS | 75 (317) | 1.91 (0.52) | 1.89 (0.71) | Quadratic comparison: .90 (−1.24 to 1.41) Linear comparison: .94 (−1.57 to 1.46) |
| With ≥1.5 years follow-up) | 30 (153) | 1.85 (0.37) | 1.85 (0.64) | |
| 6MWT, m walked | ||||
| Higher-dose vamorolone LTEc | 20 (37) | 377.9 (64.77) | 369.9 (77.81) | Paired sample (within group) t test: .20 (−18.95 to 82.95) |
| NSAA scoref | ||||
| Higher-dose vamorolone LTEc | 23 (41) | 22.3 (4.72) | 21.78 (7.86) | vs NorthStar UK cohort (independent t test on change over 2 y)f |
| GC in NSUK Network | 110 (159) | 26.63 (5.65)g | 26.24 (7.2) | .92 (−4.48 to 4.04) |
| Height percentile | ||||
| Higher-dose vamorolone LTEc | 23 (65) | 32.26 (26.87) | 37.03 (31.14) | vs DNHS (MMRM) |
| GC in DNHS | 75 (312) | 19.88 (21.70) | 13.42 (18.62) | 8.94 × 10−7 (0.23 to 0.52) |
| BMI z score | ||||
| Higher-dose vamorolone LTEc | 23 (65) | 1.28 (0.51) | 1.52 (0.66) | vs DNHS (MMRM) |
| GC in DNHS | 75 (309) | 0.65 (1.03) | 0.79 (1.11) | .58 (−0.01 to 0.01) |
Abbreviations: DNHS, Duchenne Natural History Study; GC, glucocorticoid; LTE, long-term extension; MMRM, mixed-effect model with repeated measures; NSAA, NorthStar Ambulatory Assessment; NSUK, NorthStar United Kingdom; TTCLIMB, time to climb 4 stairs; TTRW, time to run or walk 10 m; TTSTAND, time to stand from supine position; 6MWT, 6-minute walk test distance.
Baseline values after approximately 6 months of continual treatment with vamorolone or GC.
Last visit of participants is used. One participant in vamorolone LTE had 1 measurement and was included in baseline comparator and end of follow-up summaries.
Participants assigned to higher-dose vamorolone (ie, 2.0 and 6.0 mg/kg/d) at start of study and maintained at 2.0 mg/kg/d or more at follow up.
The multivariable model included a quadratic term in addition to model trajectories (ie, Duchenne muscular dystrophy natural history during the age range of interest includes periods of improvement followed by stability and deterioration); P values are provided for comparisons between comparator cohorts.
DNHS is a natural history study with different participants followed up for different durations in the age range of comparison. Summary characteristics are also provided for participants in DNHS with 1.5 years or more of follow-up in the age range of interest.
Owing to NorthStar UK Network participant-level data sharing restrictions, NSAA data was analyzed separately by UK Network researchers and summaries were shared for comparison with the vamorolone LTE cohort. NSAA data had a possible range from 0 to 34.
Owing to the use of independent t test for change in NSAA over 2 years, the baseline mean is provided for 49 participants with 2 years of follow-up.