Subjects’ characteristics and disposition
A total of 65 subjects with TS were screened from 11 hospitals. Of them, 58 were enrolled and randomly assigned to the treatment group (DA-3002, n = 28) or the comparator group (Genotropin®, n = 30). The distribution of subjects is shown in Fig. 1. Karyotypes and clinical characteristics of study subjects with TS are summarized in Table 1. Only four subjects had a 45,X karyotype. More than half (n = 43 [74.1%]) of subjects were revealed to have mosaicism. Structural abnormalities of the X chromosome without mosaicism were found in 11 (19.0%) girls with TS. The proportion of particular karyotypes was comparable between treatment and comparator groups. The mean (± SD) age of subjects was 6.84 ± 2.62 years for the treatment group and 7.06 ± 2.96 years for the comparator group. Other baseline characteristics were well balanced between the two groups.
Table 1
Karyotypes, demographics and baseline characteristics
|
Treatment group
(N = 28)
|
Comparator
(N = 30)
|
p-value
|
Karyotype
|
N (%)
|
|
Simple X monosomy (45, X)
|
3 (10.71)
|
1 (3.33)
|
0.345 ‡
|
Structural abnormalities of the X chromosome (e.g. 46, X, i[Xq], 46, X, Xq or Xp [short or long arm deletions])
|
6 (21.43)
|
5 (16.67)
|
0.644 †
|
Mosaic Karyotypes
|
19 (67.86)
|
24 (80.00)
|
0.291 †
|
a. 45, X/46, XX
|
3 (10.71)
|
7 (23.33)
|
0.301 ‡
|
b. 45, X/46, XY or 46, XY Yvar/Ydel
|
2 (7.14)
|
2 (6.67)
|
1.000 ‡
|
c. 45, X/46, X, i(Xq) or other structural chromosome abnormality
|
14 (50.00)
|
15 (50.00)
|
1.000 †
|
Baseline characteristic
|
Mean ± SD
|
|
Chronological age (year)
|
6.84 ± 2.62
|
7.06 ± 2.96
|
0.883 **
|
Bone Age (year)
|
6.03 ± 2.93
|
5.96 ± 2.63
|
0.919 **
|
Height (cm)
|
106.72 ± 13.49
|
106.93 ± 14.91
|
0.955 *
|
Height SDS
|
-2.36 ± 0.64
|
-2.44 ± 0.58
|
0.450 **
|
Body Weight (kg)
|
20.64 ± 8.56
|
20.88 ± 7.31
|
0.686 **
|
BMI (kg/m2)
|
17.35 ± 3.16
|
17.64 ± 2.46
|
0.339 **
|
TSH (uIU/ml)
|
3.20 ± 1.64
|
3.01 ± 1.52
|
0.619 **
|
fT4 (ng/dl)
|
1.40 ± 0.26
|
1.37 ± 0.20
|
0.889 **
|
IGF-1 (ng/ml)
|
146.57 ± 52.20
|
143.15 ± 62.96
|
0.981 **
|
IGFBP-3 (ug/ml)
|
3.95 ± 0.98
|
3.56 ± 0.68
|
0.083 *
|
SD: Standard Deviation; SDS: Standard Deviation Score; BMI: Body Mass Index; TSH: Thyroid Stimulating Hormone; fT4: Free Thyroxine; IGF-1: Insulin-like Growth Factor-1; IGFBP-3: Insulin-like Growth Factor Binding Protein-3 |
†: Chi-square test between treatment groups; ‡: Fisher’s exact test between treatment groups. |
*: Two sample t-test between treatment groups; **: Wilcoxon rank sum test between treatment groups. |
Table 2
Incidence rate of Treatment-Emergent Adverse Events, Serious Adverse Events and Adverse Drug Reactions
|
Treatment group
(N = 27)
|
Comparator
(N = 31)
|
p-value
|
TEAEs [N, %]
|
[21, 77.78]
|
[24, 77.42]
|
0.974†
|
SAEs [N, %]
|
[3, 11.11]
|
[3, 9.68]
|
1.000‡
|
ADRs [N, %]
|
[1, 3.70]
|
[0, 0.00]
|
0.466‡
|
TEAE: adverse event; SAE: Serious Adverse Event; ADR: Adverse Drug Reactions; |
†: Chi-square test between treatment groups; ‡: Fisher’s exact test between treatment groups. |
Full analysis (FA) set was defined as all subjects who received at least one dose of the study drug with at least one measurement of the primary efficacy endpoint after randomization. It consisted of a total of 58 subjects (28 in the treatment group and 30 in the comparator group). Per-protocol (PP) set was defined as all subjects who completed all 52 weeks of this study without any major protocol violation. It consisted of 53 subjects (26 in the treatment group and 27 in the comparator group). Safety set included all subjects who received at least one dose of the study drug with at least one measurement of safety-related data after dosing by telephone or visit. It had 58 subjects (27 in the treatment group and 31 in the comparator group).
Efficacy Results Based On The Pp Set
The primary efficacy endpoint, change from baseline in HV at 52 weeks, was 4.15 ± 0.30 cm/year in the treatment group and 4.34 ± 0.29 cm/year in the comparator group. The difference in HV change from baseline between the two groups (treatment group - comparator group) was − 0.19 ± 0.41 cm/year [95 % CI: -1.02 to 0.64 cm/year]. The lower limit of the 95 % confidence interval (i.e., 97.5 % one-sided confidence interval) was − 1.02 cm/year, which was greater than the non-inferiority limit of -1.5, proving that the treatment group was not inferior to the comparator group. In the case of changes from baseline in HV at 13, 26, and 39 weeks, both treatment and comparator groups showed statistically significant increases of HV from baseline at all time points after treatment (at 13, 26, and 39 weeks for both treatment group and comparator group, p < 0.001).(Fig. 2)
The change from baseline in htSDS was 0.43 ± 0.22 in the treatment group and 0.42 ± 0.24 in the comparator group at 26 weeks. It was 0.70 ± 0.23 in the treatment group and 0.66 ± 0.39 in the comparator group at 52 weeks.(Fig. 3) Both treatment and comparator groups showed statistically significant increases from baseline in height standard deviation score at all time points after treatment (all p < 0.001). There was no statistically significant difference between the treatment group and comparator group in the change of height standard deviation score at any time point (at 26 weeks and 52 weeks: p = 0.949 and p = 0.685, respectively).
The skeletal maturity defined as change in bone age/change in the chronological age was 0.84 ± 0.16 in the treatment group and 0.83 ± 0.14 in the comparator group at baseline. It was 1.44 ± 0.90 in the treatment group and 1.48 ± 0.90 in the comparator group at 26 weeks and 1.25 ± 0.58 in the treatment group and 1.47 ± 0.45 in the comparator group at 52 weeks. Both treatment and comparator groups showed statistically significant increases from baseline in skeletal maturity at all time points after treatment (treatment group: p = 0.004, comparator group: p = 0.002 at 26 weeks; treatment group: p = 0.004, comparator group: p < 0.001 at 52 weeks). There was no statistically significant difference in the skeletal maturity between two groups at any time point (at 26 weeks and 52 weeks, p = 0.864 and p = 0.134, respectively). (Fig. 4)
In the case of changes from baseline for IGF-1 and IGFBP-3 levels, IGF-1 level change was 208.33 ± 98.22 ng/ml in the treatment group and 226.65 ± 138.93 ng/ml in the comparator group at 26 weeks. It was 206.59 ± 105.76 ng/ml in the treatment group and 222.60 ± 95.15 ng/ml in the comparator group at 52 weeks. (Fig. 4) Both treatment and comparator groups showed statistically significant increases from baseline in IGF-1 levels at all time points after treatment (all p < 0.001). There was no statistically significant difference in IGF-1 level change between two groups at any time point (at 26 weeks and 52 weeks, p = 0.824 and p = 0.565, respectively). In the case of change in IGFBP-3 level from baseline, IGFBP-3 change was 1.18 ± 0.82 µg/ml in the treatment group and 1.22 ± 1.06 µg/ml in the comparator group at 26 weeks. It was 1.30 ± 0.93 µg/ml in the treatment group, and 1.42 ± 1.31 µg/ml in the comparator group at 52 weeks. Both treatment and comparator groups showed statistically significant increases from baseline in IGFBP-3 levels at all time points after treatment (all p < 0.001). There was no statistically significant difference in IGFBP-3 level change between two groups at any time point (at 26 weeks and 52 weeks, p = 0.838 and p = 0.388, respectively). (Fig. 4)
All analysis results of efficacy evaluation variables in the FA set were similar to those in the PP set.
Safety Results Based On The Safety Set
Adverse events (TEAEs) were found in 45 subjects (77.59 %): 21 subjects in the treatment group (77.78 %) and 24 subjects in the comparator group (77.42 %). The difference between the treatment group and the comparator group was not statistically significant (p = 0.974). (Table. 2) The number of subjects with adverse drug reactions related to the investigational product was one (1.72 %), which was one subject (3.70 %) in the treatment group. No ADRs occurred in the comparator group. The incidence of ADRs showed no statistically significant difference between two groups (p = 0.466). Preferred term of one adverse drug reaction that occurred in the treatment group was an injection site erythema. The severity was mild. The relevance with the investigational product was not assessable.
Serious adverse events occurred in 6 subjects (10.34 %) in this clinical study: 3 subjects (11.11 %) in the treatment group and 3 subjects (9.68 %) in the comparator group. There was no statistically significant difference between the treatment group and the comparator group (p = 1.000). There were no serious adverse drug reactions, adverse events that resulted in permanent discontinuation of the investigational product, or adverse events that resulted in death during this clinical study.
Among items of clinical laboratory tests (hematology, blood chemistry, urinalysis, and thyroid function, etc.), most of the parameters, except total cholesterol and urine red blood cell (RBC), did not show statistically significant changes after treatment. (Table 3.) There was significant difference in total cholesterol of treatment group, which was due to change from abnormal to normal (p = 0.025). In the urinalysis, there was a significant difference in urine RBC after 52 weeks of treatment within the treatment group and the comparator group (treatment group: p = 0.008; comparator group: p = 0.034), that was the change from normal status to clinically significant hematuria in two cases of the treatment group All of them were reported as adverse events and judged to be unrelated to the investigational product. In the comparator group, one subject showed increased levels aspartate aminotransferase (AST) and alanine aminotransferase (ALT). They were reported as adverse reactions (AST increased, ALT increased) and judged to be unrelated to the investigational product. These levels were normalized after the study was completed. Some subjects had normal thyroid-stimulating hormone (TSH) levels at baseline, but showed clinically significant abnormal levels after treatment with the investigational product. However, all of them were normal after the study was completed without treatment. All elevations were due to hypothyroidism history and reported as adverse events (blood TSH increased). All were considered to be unrelated to the investigational product. No subject showed a clinically significant abnormality in the free thyroxine (fT4) test at baseline or after treatment with the investigational product. In the antibody test, statistically significant difference from baseline was not found in both the treatment group and the comparator group at 26 weeks and 52 weeks (treatment group at 26 weeks and 52 weeks, p = 0.563 and p = 0.137, respectively; comparator group at 26 weeks and 52 weeks, p = 0.709 and p = 0.329, respectively). There was no difference in antibody test results between two groups at any time point (at 26 weeks and 52 weeks, p = 0.779 and p = 0.742, respectively).
Table 3
Laboratory results at baseline and week 52 in the treatment and comparative groups
|
|
Treatment group (N = 27)
|
Comparator (N = 31)
|
|
|
N
|
Mean ± SD
|
N
|
Mean ± SD
|
ALT (IU/L)
|
Baseline
|
27
|
18.9 ± 14.4
|
31
|
20.4 ± 14.1
|
Week 52
|
26
|
18.3 ± 19.9
|
29
|
19.3 ± 16.9
|
AST (IU/L)
|
Baseline
|
27
|
30.4 ± 7.5
|
31
|
32.3 ± 7.2
|
Week 52
|
26
|
28.2 ± 10.5
|
29
|
30.3 ± 13.0
|
ALP (IU/L)
|
Baseline
|
27
|
244.6 ± 164.2
|
31
|
274.0 ± 178.0
|
Week 52
|
26
|
298.0 ± 197.3
|
29
|
291.1 ± 162.6
|
Cholesterol
(mg/dl)
|
Baseline
|
27
|
173.9 ± 26.8
|
31
|
170.7 ± 31.7
|
Week 52
|
26
|
166.9 ± 21.2
|
29
|
160.6 ± 22.5
|
Triglyceride
(mg/dl)
|
Baseline
|
27
|
89.5 ± 61.6
|
31
|
119.9 ± 70.3
|
Week 52
|
26
|
99.5 ± 48.8
|
29
|
116.3 ± 89.0
|
Hemoglobin A1c
(%)
|
Baseline
|
27
|
5.01 ± 0.44
|
31
|
5.17 ± 0.35
|
Week 52
|
26
|
5.17 ± 0.45
|
29
|
5.32 ± 0.27
|
TSH (uIU/ml)
|
Baseline
|
27
|
3.06 ± 1.51
|
31
|
3.13 ± 1.65
|
Week 52
|
26
|
2.81 ± 1.62
|
29
|
3.14 ± 2.16
|
Free T4 (ng/dl)
|
Baseline
|
27
|
1.39 ± 0.27
|
31
|
1.37 ± 0.20
|
Week 52
|
26
|
1.36 ± 0.24
|
29
|
1.35 ± 0.18
|
Among results of vital signs, there were statistically significant changes in systolic blood pressure within the comparator group and differences between the two groups at 13 weeks. However, these changes were temporary and had no clinical significance. There was no statistically significant difference at other time points. In diastolic blood pressure and pulse, there was also no statistically significant differences between the two groups and among different time points within each group.