Demographics and baseline characteristics
Overall, 166 patients were enrolled and completed the study; 135 patients (81.3%) completed the study per protocol from baseline to Month 6, and 31 patients (18.7%) completed the study protocol partially. Of the 166 patients, a majority (n=124, 74.7%) were female (Table 1). Seventy-one (42.8%) patients had CM and 95 (57.2%) had EM.
The demographic and baseline characteristics by CM and EM are presented in Table 1. The overall mean (SD) age of patients was 37.8 (8.99) years (Table 1). The difference in mean age between patients with CM and EM was not statistically significant; however, for age categories, the difference was statistically significant (p=0.0498). Most patients were aged ≥35 years to <50 years (53.6%) and a similar proportion of those with CM and EM were in this category. A higher proportion of patients with EM tended to be in the ≥18 to <35-year category and a lower proportion in the ≥50-year category compared with those with CM (EM: 43.2% and 3.2%; CM: 33.8% and 12.7%, respectively). A family history of migraine was reported for 30.7% of patients (Table 1). The mean (SD) age at onset of migraine for the overall study population was 29.0 (7.93) years, 29.4 (8.35) years for CM and 28.7 (7.63) years for EM (Table 1).
Table 1
Patient demographics and baseline characteristics
|
Overall N=166
|
Chronic migraine N=71
|
Episodic migraine N=95
|
p-value
|
Age, years, mean (SD)
|
37.8 (8.99)
|
38.8 (9.51)
|
37.1 (8.57)
|
0.2502
|
Age categories, years, n (%)
|
|
|
|
|
≥18 to <35
|
65 (39.2)
|
24 (33.8)
|
41 (43.2)
|
0.0498
|
≥35 to <50
|
89 (53.6)
|
38 (53.5)
|
51 (53.7)
|
|
≥ 50
|
12 (7.2)
|
9 (12.7)
|
3 (3.2)
|
|
Sex, female, n (%)
|
124 (74.7)
|
49 (69.0)
|
75 (78.9)
|
|
Ethnicity, n (%)
|
|
|
|
|
Local
|
123 (74.1)
|
53 (74.6)
|
70 (73.7)
|
0.8885
|
Non local
|
43 (25.9)
|
18 (25.4)
|
25 (26.3)
|
|
Arab
|
27 (16.3)
|
12 (16.9)
|
15 (15.8)
|
|
Asian
|
4 (2.4)
|
1 (1.4)
|
3 (3.2)
|
|
Western
|
4 (2.4)
|
2 (2.8)
|
2 (2.1)
|
|
European
|
7 (4.2)
|
3 (4.2)
|
4 (4.2)
|
|
Other
|
1 (0.6)
|
0
|
1 (1.1)
|
|
BMI, kg/m2, mean (SD)
|
28.2 (4.76)
|
28.4 (4.97)
|
28.1 (4.66)
|
0.8322
|
BMI category, kg/m2, n (%)
|
|
|
|
|
≥18.5 to <25
|
20 (26.0)
|
8 (25.8)
|
12 (26.1)
|
0.9985
|
≥25 to <30
|
32 (41.6)
|
13 (41.9)
|
19 (41.3)
|
|
>30
|
25 (32.5)
|
10 (32.3)
|
15 (32.6)
|
|
Family history of migraine, n (%)
|
|
|
|
|
Yes
|
51 (30.7)
|
21 (29.6)
|
30 (31.6)
|
0.8952
|
No
|
76 (45.8)
|
34 (47.9)
|
42 (44.2)
|
|
Unknown
|
39 (23.5)
|
16 (22.5)
|
23 (24.2)
|
|
Duration of migraine, years, mean (SD)
|
5.0 (9.75)
|
6.0 (7.82)
|
4.4 (10.92)
|
0.0223
|
Age at migraine onset, years, mean (SD)
|
29.0 (7.93)
|
29.4 (8.35)
|
28.7 (7.63)
|
0.5352
|
MHD over the past 1 month, days, mean (SD)
|
15.6 (8.54)
|
22.9 (6.35)
|
9.0 (3.05)
|
<0.0001
|
MHD at baseline, days, mean (SD)
|
15.7 (8.45)
|
22.9 (6.57)
|
9.2 (2.93)
|
NA
|
MSMD at baseline, days, mean (SD)
|
12.8 (10.00)
|
18.6 (8.55)
|
7.4 (8.11)
|
|
Number of PPTFs, n (%)
|
|
|
|
|
0
|
72 (43.4)
|
31 (43.7)
|
41 (43.2)
|
0.4886
|
1
|
28 (16.9)
|
14 (19.7)
|
14 (14.7)
|
|
2
|
34 (20.5)
|
10 (14.1)
|
24 (25.3)
|
|
3
|
5 (3.0)
|
2 (2.8)
|
3 (3.2)
|
|
4
|
17 (10.2)
|
8 (11.3)
|
9 (9.5)
|
|
≥5
|
10 (6.0)
|
6 (8.5)
|
4 (4.2)
|
|
Number of classes of preventive therapy used previously, n (%)
|
|
|
|
|
1
|
34 (20.5)
|
9 (12.7)
|
25 (26.3)
|
|
2
|
10 (6.0)
|
2 (2.8)
|
8 (8.4)
|
|
3
|
5 (3.0)
|
4 (5.6)
|
1 (1.1)
|
|
>3
|
4 (2.4)
|
2 (2.8)
|
2 (2.1)
|
|
BMI, body mass index; MHD, monthly headache/migraine days; MSMD, monthly acute migraine-specific medication days; n, number of patients; N, total number of patients; NA, not available; PPTF, previous preventive treatment failure; SD, standard deviation
Percentages are based on the total number of subjects in the full analysis set. P-value is derived from a Chi-square test or exact test for categorical variables and from t-test or Wilcoxon test for continuous variables. BMI is calculated as follows: (body weight in kg)/ (height in m)2; percentages for BMI categories are based on the total number of patients who had BMI data in the full analysis set.
|
The mean (SD) number of MHD over one month prior to enrolment in the overall population was 15.6 (8.54) days and, as expected, was significantly higher with CM (22.9 [6.35] days) than with EM (9.0 [3.05] days; p<0.0001). The mean (SD) number of MSMD at baseline was 12.8 (10.0) days, and this difference was statistically significant (p<0.0001) between the CM (18.6 [8.55] days) and EM subgroups (7.4 [8.11] days).
Baseline demographics and characteristics of all subgroups are presented in Table S1. All patients started erenumab at the 70-mg dose. The number of patients on erenumab 70 mg throughout the study was 98 (59.0%) and the dose was escalated to 140 mg in 68 (41.0%) patients. Overall, 72 (43.4%) patients had no PPTFs prior to receiving erenumab, whereas 94 (56.6%) had ≥1 PPTF.
No statistically significant differences were observed in the proportion of patients with CM and EM who had comorbidities (Fig. 1a). Comorbidities by subgroup are presented in Fig. S1. In total, 53 patients (31.9%) received at least one previous preventive treatment (Fig. 1b). Antiepileptics (15.7%), tricyclic antidepressants (10.2%), β-blockers (8.4%) and calcium channel blockers (7.8%) were the most frequently received previous preventive treatments (>5% of patients). In this study, 100 (60.2%) patients received erenumab as monotherapy, whereas 66 (39.8%) received erenumab as an add-on to a current preventive therapy (Fig. 1b). Tricyclic antidepressants (15.7%), antiepileptics (13.3%), β-blockers (8.4%) and calcium channel blockers (7.2%) were the most frequently received current preventive treatments (>5% of patients). There was a statistically significant difference between the proportions of patients receiving erenumab as monotherapy or add-on therapy (p=0.0466), with higher rates of PPTFs in the add-on subgroup.
Monthly headache/migraine days
In the overall population, the mean (SD) number of MHD decreased from 15.7 (8.45) at baseline to 7.3 (7.54) at Month 1. A further decrease was noted at Month 3 (4.6 [4.83]) and Month 6 (4.1 [4.28]). The corresponding mean changes from baseline were −8.2 (8.83) at Month 1, −11.0 (9.15) at Month 3 and −11.3 (8.90) at Month 6 (Fig. 2). A reduction in MHD was observed from baseline to Months 1, 3 and 6 in both CM and EM groups (Fig. 2).
At all time points, most patients in the overall population achieved at least a 50% reduction from baseline in MHD (80%–91%), and the proportion achieving the 75 to <100% or 100% reduction categories was 39.1% and 5.7% at Month 1; 46.5% and 14.1% at Month 3; and 52.6% and 9.5% at Month 6, respectively (Fig. 3). The mean (SD) number of MHD at baseline was 16.9 (8.83) in the erenumab monotherapy subgroup and 13.9 (7.57) in the erenumab add-on therapy subgroup. A greater reduction in the number of MHD was observed with erenumab monotherapy compared with erenumab as add-on therapy at all assessed time points, but the differences were not statistically significant (p>0.05 for all time points; Fig. S2). A similar trend in the reduction of mean MHD was observed in the subgroups of patients who were prescribed and remained on erenumab 70 mg and with dose escalation to 140 mg, as well as those in the treatment naïve and PPTF subgroups (Fig. S2). At all time points, most patients in the subgroup categories of with/without dose escalation, monotherapy/add-on therapy and treatment naïve/PPTF achieved at least a 50% reduction from baseline in MHD. As anticipated, at Month 1, a higher proportion of patients in the PPTF subgroup had a reduction from baseline in MHD by <50% versus those who were treatment naïve; however, this proportion improved over time with erenumab treatment (Fig. S3).
Monthly acute migraine-specific medication days
The mean (SD) MSMD at baseline in the overall population was 12.8 (10.00) and decreased to 4.1 (5.57) at Month 1, 2.9 (4.23) at Month 3 and 1.8 (3.02) at Month 6. The mean monthly change from baseline in MSMD was −9.0 (8.07) at Month 1 and was reduced further to −9.7 (8.73) at Month 3 and −10.7 (8.95) at Month 6 (Fig. 4). Similar to that in the overall population, there was a decrease in mean (SD) MSMD from baseline to Month 1, Month 3 and Month 6 in both CM and EM groups (Fig. 4).
Similar to the reduction in MHD, most patients in the overall population and CM and EM groups achieved at least a 50% reduction from baseline in MSMD at all time points, and more than half of the patients in the EM group achieved a 100% reduction in MSMD at all time points (Fig. 5). In the subgroups of patients with and without dose escalation, the mean monthly change from baseline in MSMD at Month 1 was –10.8 (9.61) and –8.1 (6.98), respectively; for patients who were treatment naïve and who had PPTF, the means changes were –8.9 (7.74) and –9.1 (8.32), respectively; and for those receiving erenumab as monotherapy or add-on therapy, the mean changes were –10.3 (8.25) and –7.7 (7.77), respectively (Fig. S4). In the subgroup of patients escalated to the 140-mg dose, a majority achieved at least a 50% reduction from baseline at all time points, and the proportion of patients achieving either a 75% to <100% or 100% reduction in MSMD increased from 76.5% at Month 3 (before dose escalation) to 84.2% at Month 6. The corresponding results in patients who remained on the 70-mg dose were 54.9% at Month 1, 65.5% at Month 3 and 82.7% at Month 6 (Fig. S5). A majority of patients achieved at least a 50% reduction at all time points in the monotherapy and add-on therapy subgroups and in the treatment naïve and PPTF subgroups. More than 35% of patients in the treatment naïve and PPTF subgroups had a 100% reduction in MSMD at all time points. Among those in the add-on therapy subgroup, 64% had a 100% reduction in MSMD by Month 6, increasing from 47.6% at Month 1 and 45% at Month 3.
Medication overuse
There was a decrease in the number of patients in the overall population with overuse of at least one medication for ≥15 days per month from 49 (29.5%) at baseline to 12 (7.2%), 6 (3.6%) and 0 at Months 1, 3 and 6, respectively. Non-steroidal anti-inflammatory drugs were the most frequently used medications in the overall population at baseline (29 [17.5%]), which declined to 4 (2.4%) and 1 (0.6%) at Months 1 and 3, respectively.
Exposure and safety
A total of 167 patients were included in the safety set (one patient who met the exclusion criteria was on medication and was excluded from the FAS but was included in the safety set). The mean (SD) treatment duration and on-treatment exposure were 5.6 (1.54) and 6.6 (1.54) months, respectively. Of the 167 patients, 34 (20.4%) experienced at least one AE. The most commonly reported AEs (>1%) were constipation (3%), insomnia (2.4%) and influenza (1.8%) followed by falls, dizziness, arthralgia, stress and headache (1.2% each; Table 2). A majority (76.5%) of AEs were mild to moderate in severity. Two patients (1.2%) had severe AEs: atypical pneumonia and spontaneous abortion in one (0.6%) patient each. In the remaining 4.8% of patients, the AE severity was unknown. Five patients (3.0%) experienced at least one AE that was related to study treatment. All five patients experienced constipation (3 [1.8%] experienced mild AEs and the severity was unknown in 2 [1.2%]). Approximately 41% of patients (68 of 167) had a dose change (all of these were dose escalation from 70 mg to 140 mg upon the treating physician’s decision) during the study, but only three patients (1.8%) experienced AEs leading to dose adjustments/interruptions. No deaths were reported.
Table 2
Treatment-emergent AEs (>1% of patients) by preferred term and maximum severity (safety set)
Preferred term
|
Mild
|
Moderate
|
Severe
|
Missing
|
Overall
N=167
|
Number of patients with at least 1 AE, n (%)
|
20 (12.0)
|
6 (3.6)
|
2 (1.2)
|
8 (4.8)
|
34 (20.4)
|
Constipation
|
3 (1.8)
|
0
|
0
|
2 (1.2)
|
5 (3.0)
|
Insomnia
|
4 (2.4)
|
0
|
0
|
0
|
4 (2.4)
|
Influenza
|
2 (1.2)
|
0
|
0
|
1 (0.6)
|
3 (1.8)
|
Fall
|
1 (0.6)
|
1 (0.6)
|
0
|
0
|
2 (1.2)
|
Arthralgia
|
0
|
1 (0.6)
|
0
|
1 (0.6)
|
2 (1.2)
|
Headache
|
2 (1.2)
|
0
|
0
|
0
|
2 (1.2)
|
Stress
|
2 (1.2)
|
0
|
0
|
0
|
2 (1.2)
|
Dizziness
|
1 (0.6)
|
0
|
0
|
1 (0.6)
|
2 (1.2)
|
AE, adverse event; n, number of patients; N, total number of patients Percentages are based on the total number of patients in the safety set. A patient with multiple AEs within a primary system organ class is counted only once in the total row. A patient with multiple occurrences of an AE under one treatment is counted only once in this AE category.
|