Trial Outcomes & Findings for Efficacy and Safety Study of BOTOX® Compared to Topiramate for the Prevention of Chronic Migraine in Adults (NCT NCT02191579)
NCT ID: NCT02191579
Last Updated: 2018-06-07
Results Overview
Participants recorded their headaches in a daily e-diary. A headache day was defined as a calendar day (00:00 to 23:59) with 4 or more hours of headache and/or headache of any duration with the use of migraine-specific acute headache medication(s). The number of headache days over the 28-day period was counted. The percentage of participants with a ≥ 50% decrease in headache days in the 28-day period prior to Week 32 relative to Baseline (28-day period prior to Day 1) is reported.
COMPLETED
PHASE4
282 participants
Baseline (First 28 days from Screening) to the last 28-day period ending with Week 32
2018-06-07
Participant Flow
Participant milestones
| Measure |
BOTOX®
155U onabotulinumtoxinA (BOTOX®) total dose per treatment by intramuscular injection every 12 weeks for up to 3 treatments.
|
Topiramate/BOTOX®
Topiramate starting at a daily oral dose of 25 mg/day titrated up to a maximum dose of 100 mg/day for 36 weeks. Participants who discontinue topiramate are eligible to receive treatment with BOTOX®.
|
|---|---|---|
|
Treatment 1
STARTED
|
140
|
142
|
|
Treatment 1
COMPLETED
|
113
|
84
|
|
Treatment 1
NOT COMPLETED
|
27
|
58
|
|
Treatment 2
STARTED
|
0
|
80
|
|
Treatment 2
COMPLETED
|
0
|
55
|
|
Treatment 2
NOT COMPLETED
|
0
|
25
|
Reasons for withdrawal
| Measure |
BOTOX®
155U onabotulinumtoxinA (BOTOX®) total dose per treatment by intramuscular injection every 12 weeks for up to 3 treatments.
|
Topiramate/BOTOX®
Topiramate starting at a daily oral dose of 25 mg/day titrated up to a maximum dose of 100 mg/day for 36 weeks. Participants who discontinue topiramate are eligible to receive treatment with BOTOX®.
|
|---|---|---|
|
Treatment 1
Multiple Reasons Specified
|
27
|
58
|
|
Treatment 2
Multiple Reasons Specified
|
0
|
25
|
Baseline Characteristics
Efficacy and Safety Study of BOTOX® Compared to Topiramate for the Prevention of Chronic Migraine in Adults
Baseline characteristics by cohort
| Measure |
BOTOX®
n=140 Participants
155U onabotulinumtoxinA (BOTOX®) total dose per treatment by intramuscular injection every 12 weeks for up to 3 treatments.
|
Topiramate
n=142 Participants
Topiramate starting at a daily oral dose of 25 mg/day titrated up to a maximum dose of 100 mg/day for 36 weeks. Participants who discontinue topiramate are eligible to receive treatment with BOTOX®.
|
Total
n=282 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
40.2 years
STANDARD_DEVIATION 11.7 • n=5 Participants
|
39.4 years
STANDARD_DEVIATION 12.6 • n=7 Participants
|
39.8 years
STANDARD_DEVIATION 12.1 • n=5 Participants
|
|
Age, Customized
18 to <25
|
16 Participants
n=5 Participants
|
21 Participants
n=7 Participants
|
37 Participants
n=5 Participants
|
|
Age, Customized
25 to <35
|
30 Participants
n=5 Participants
|
40 Participants
n=7 Participants
|
70 Participants
n=5 Participants
|
|
Age, Customized
35 to <45
|
43 Participants
n=5 Participants
|
29 Participants
n=7 Participants
|
72 Participants
n=5 Participants
|
|
Age, Customized
45 to <55
|
33 Participants
n=5 Participants
|
34 Participants
n=7 Participants
|
67 Participants
n=5 Participants
|
|
Age, Customized
≥55
|
18 Participants
n=5 Participants
|
18 Participants
n=7 Participants
|
36 Participants
n=5 Participants
|
|
Sex: Female, Male
Female
|
117 Participants
n=5 Participants
|
122 Participants
n=7 Participants
|
239 Participants
n=5 Participants
|
|
Sex: Female, Male
Male
|
23 Participants
n=5 Participants
|
20 Participants
n=7 Participants
|
43 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
White
|
111 Participants
n=5 Participants
|
118 Participants
n=7 Participants
|
229 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Black
|
13 Participants
n=5 Participants
|
8 Participants
n=7 Participants
|
21 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Asian
|
4 Participants
n=5 Participants
|
2 Participants
n=7 Participants
|
6 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Hispanic
|
11 Participants
n=5 Participants
|
12 Participants
n=7 Participants
|
23 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Other
|
1 Participants
n=5 Participants
|
2 Participants
n=7 Participants
|
3 Participants
n=5 Participants
|
|
Height
|
167.4 centimeter (cm)
STANDARD_DEVIATION 8.5 • n=5 Participants
|
167.0 centimeter (cm)
STANDARD_DEVIATION 8.7 • n=7 Participants
|
167.2 centimeter (cm)
STANDARD_DEVIATION 8.5 • n=5 Participants
|
|
Weight
|
81.0 kilogram (kg)
STANDARD_DEVIATION 21.8 • n=5 Participants
|
80.5 kilogram (kg)
STANDARD_DEVIATION 20.6 • n=7 Participants
|
80.8 kilogram (kg)
STANDARD_DEVIATION 21.1 • n=5 Participants
|
|
Body Mass Index (BMI
|
28.9 kg/m^2
STANDARD_DEVIATION 7.1 • n=5 Participants
|
28.8 kg/m^2
STANDARD_DEVIATION 6.5 • n=7 Participants
|
28.8 kg/m^2
STANDARD_DEVIATION 6.8 • n=5 Participants
|
|
Use of Headache Prophylactic Treatment(s)
|
26 Participants
n=5 Participants
|
25 Participants
n=7 Participants
|
51 Participants
n=5 Participants
|
PRIMARY outcome
Timeframe: Baseline (First 28 days from Screening) to the last 28-day period ending with Week 32Population: ITT Set included all randomized participants.
Participants recorded their headaches in a daily e-diary. A headache day was defined as a calendar day (00:00 to 23:59) with 4 or more hours of headache and/or headache of any duration with the use of migraine-specific acute headache medication(s). The number of headache days over the 28-day period was counted. The percentage of participants with a ≥ 50% decrease in headache days in the 28-day period prior to Week 32 relative to Baseline (28-day period prior to Day 1) is reported.
Outcome measures
| Measure |
BOTOX®
n=140 Participants
155U onabotulinumtoxinA (BOTOX®) total dose per treatment by intramuscular injection every 12 weeks for up to 3 treatments.
|
Topiramate
n=142 Participants
Topiramate starting at a daily oral dose of 25 mg/day titrated up to a maximum dose of 100 mg/day for 36 weeks. Participants who discontinue topiramate are eligible to receive treatment with BOTOX®.
|
|---|---|---|
|
Percentage of Participants With a ≥ 50% Decrease From Baseline in the Frequency of Headache Days
|
40.0 percentage of participants
|
12.0 percentage of participants
|
SECONDARY outcome
Timeframe: Baseline (First 28 days from Screening) to the last 28-day period ending with Week 32Population: ITT Set included all randomized participants.
Participants recorded their headaches in a daily e-diary. A headache day was defined as a calendar day (00:00 to 23:59) with 4 or more hours of headache and/or headache of any duration with the use of migraine-specific acute headache medication(s). The number of headache days over the 28-day period was counted. A negative change from Baseline (less headache days) indicates improvement.
Outcome measures
| Measure |
BOTOX®
n=140 Participants
155U onabotulinumtoxinA (BOTOX®) total dose per treatment by intramuscular injection every 12 weeks for up to 3 treatments.
|
Topiramate
n=142 Participants
Topiramate starting at a daily oral dose of 25 mg/day titrated up to a maximum dose of 100 mg/day for 36 weeks. Participants who discontinue topiramate are eligible to receive treatment with BOTOX®.
|
|---|---|---|
|
Change From Baseline in the Frequency of Headache Days Per 28-day Period
|
-8.3 days
Standard Deviation 8.9
|
-2.1 days
Standard Deviation 5.6
|
SECONDARY outcome
Timeframe: Baseline (Day 1) to the last 28-day period ending with Week 30Population: Participants from the ITT Set, all randomized participants, with data available for analysis.
The HIT-6 is a valid disease-targeted measure used to assess the impact of headaches, comprised of 6 items that assess pain, role functioning, social functioning, cognitive functioning, vitality, and psychological distress. A total score is created by summingacross all items, and ranges from 36 (no impact) to 78 (severe impact) reflecting a "best to worst" scoring. A negative change from Baseline (a lower score) indicates improvement.
Outcome measures
| Measure |
BOTOX®
n=110 Participants
155U onabotulinumtoxinA (BOTOX®) total dose per treatment by intramuscular injection every 12 weeks for up to 3 treatments.
|
Topiramate
n=115 Participants
Topiramate starting at a daily oral dose of 25 mg/day titrated up to a maximum dose of 100 mg/day for 36 weeks. Participants who discontinue topiramate are eligible to receive treatment with BOTOX®.
|
|---|---|---|
|
Change From Baseline in Headache Impact Test (HIT-6) Total Score
|
-5.6 score on a scale
Standard Deviation 7.2
|
-1.3 score on a scale
Standard Deviation 3.9
|
SECONDARY outcome
Timeframe: Baseline (First 28 days from Screening) to the last 28-day period ending with Week 32Population: ITT Set included all randomized participants.
Participants recorded their headaches in a daily e-diary. A headache day was defined as a calendar day (00:00 to 23:59) with 4 or more hours of headache and/or headache of any duration with the use of migraine-specific acute headache medication(s). The number of headache days over the 28-day period was counted. The percentage of participants with a ≥ 70% decrease in headache days in the 28-day period prior to Week 32 relative to Baseline (28-day period prior to Day 1) is reported.
Outcome measures
| Measure |
BOTOX®
n=140 Participants
155U onabotulinumtoxinA (BOTOX®) total dose per treatment by intramuscular injection every 12 weeks for up to 3 treatments.
|
Topiramate
n=142 Participants
Topiramate starting at a daily oral dose of 25 mg/day titrated up to a maximum dose of 100 mg/day for 36 weeks. Participants who discontinue topiramate are eligible to receive treatment with BOTOX®.
|
|---|---|---|
|
Percentage of Participants With a ≥ 70% Decrease From Baseline in the Frequency of Headache Days
|
27.1 percentage of participants
|
8.5 percentage of participants
|
Adverse Events
BOTOX®
Topiramate
Serious adverse events
| Measure |
BOTOX®
n=220 participants at risk
155U onabotulinumtoxinA (BOTOX®) total dose per treatment by intramuscular injection every 12 weeks for up to 3 treatments.
The 80 participants originally treated with topiramate who then received BOTOX® are included in this arm.
|
Topiramate
n=142 participants at risk
Topiramate starting at a daily oral dose of 25 mg/day titrated up to a maximum dose of 100 mg/day for 36 weeks.
|
|---|---|---|
|
Cardiac disorders
Atrial tachycardia
|
0.45%
1/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
0.00%
0/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Injury, poisoning and procedural complications
Concussion
|
0.45%
1/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
0.70%
1/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Respiratory, thoracic and mediastinal disorders
Chronic obstructive pulmonary disease
|
0.45%
1/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
0.70%
1/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Vascular disorders
Deep vein thrombosis
|
0.00%
0/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
0.70%
1/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Metabolism and nutrition disorders
Dehydration
|
0.00%
0/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
0.70%
1/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
Invasive lobular breast carcinoma
|
0.45%
1/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
0.00%
0/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Renal and urinary disorders
Nephrolithiasis
|
0.00%
0/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
0.70%
1/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Vascular disorders
Peripheral arterial occlusive disease
|
0.00%
0/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
0.70%
1/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Infections and infestations
Pneumonia
|
0.45%
1/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
0.70%
1/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Injury, poisoning and procedural complications
Road traffic accident
|
0.45%
1/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
0.70%
1/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Nervous system disorders
Syncope
|
0.45%
1/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
0.00%
0/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
Other adverse events
| Measure |
BOTOX®
n=220 participants at risk
155U onabotulinumtoxinA (BOTOX®) total dose per treatment by intramuscular injection every 12 weeks for up to 3 treatments.
The 80 participants originally treated with topiramate who then received BOTOX® are included in this arm.
|
Topiramate
n=142 participants at risk
Topiramate starting at a daily oral dose of 25 mg/day titrated up to a maximum dose of 100 mg/day for 36 weeks.
|
|---|---|---|
|
Nervous system disorders
Cognitive Disorder
|
0.45%
1/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
12.7%
18/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Nervous system disorders
Distubance in attention
|
0.00%
0/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
8.5%
12/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Eye disorders
Vision blurred
|
2.7%
6/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
7.7%
11/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Metabolism and nutrition disorders
Decreased appetite
|
0.00%
0/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
10.6%
15/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Nervous system disorders
Paraesthesia
|
0.45%
1/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
31.0%
44/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Nervous system disorders
Dizziness
|
2.7%
6/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
12.7%
18/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Infections and infestations
Sinusitis
|
5.9%
13/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
7.0%
10/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Gastrointestinal disorders
Nausea
|
0.45%
1/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
13.4%
19/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
General disorders
Fatigue
|
0.45%
1/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
13.4%
19/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
|
Psychiatric disorders
Depression
|
1.8%
4/220 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
5.6%
8/142 • First dose of study drug to the final visit (Up to 48 Weeks)
Adverse Events (AEs) were counted in the treatment group based on investigator's determination. If investigators determined AE was related to both treatments or relatedness was unknown, it was counted in both treatment groups, but only once for the total population.
|
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee A disclosure restriction on the PI is that the sponsor can review results communications prior to public release and can embargo communications regarding trial results for a period that is less than or equal to 90 days from the time submitted to the sponsor for review. The sponsor cannot require changes to the communication and cannot extend the embargo.
- Publication restrictions are in place
Restriction type: OTHER