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Study of Gabapentin Extended Release (G-ER)in the Treatment of Vasomotor (Hot Flashes/Hot Flushes) Symptoms in Postmenopausal Women.

A Phase 3 Multicenter, Randomized, Double-Blind, Placebo-Controlled Study to Investigate the Safety and Efficacy of Gabapentin Extended Release (G-ER) Tablets in the Treatment of Vasomotor Symptoms in Postmenopausal Women

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00777023
Enrollment
565
Registered
2008-10-22
Start date
2008-10-31
Completion date
2009-10-31
Last updated
2012-02-22

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hot Flashes

Keywords

Hot Flashes, Hot Flushes, Postmenopausal symptoms, Vasomotor symptoms

Brief summary

Depomed's Gabapentin Extended Release is an investigational, extended release formulation of gabapentin that is being studied for the treatment of hot flashes in postmenopausal women

Detailed description

The primary study objective is to assess the efficacy of G-ER dosed in either of the following regimens: G-ER 1200mg daily (single evening dose) G-ER 1800mg daily (dosed asymmetrically; 600mg AM/1200mg PM) compared to placebo in reducing the average daily frequency and severity score of moderate to severe hot flashes in postmenopausal women after 4 weeks and 12 weeks of treatment with a stable dose, compared with the baseline week.

Interventions

G-ER 1200 mg daily dosage given as two 600-mg tablets.

G-ER 1800 mg daily dosage given as one 600-mg tablet in the morning and two 600-mg tablets in the evening.

DRUGPlacebo

Matching placebo dosages of 1200 mg daily (two 600-mg tablets) and 1800 mg daily (one 600-mg tablet in the morning and two 600-mg tablets in the evening).

Sponsors

Depomed
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
FACTORIAL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Investigator)

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 70 Years
Healthy volunteers
No

Inclusion criteria

1. Postmenopausal women aged 18 to 70 years experiencing ≥7 moderate to severe hot flashes per day (or ≥50 per week) accompanied by sweating during previous 30 days or longer. 2. Had amenorrhea for ≥12 months, amenorrhea for 6 to 12 months with serum follicle-stimulating hormone (FSH) levels \>40 mIU/mL, or was ≥6 weeks postsurgical bilateral oophorectomy with or without hysterectomy. 3. Willing to discontinue the following: vaginal hormonal products; transdermal or oral estrogen or estrogen/progestin combination; intrauterine progestin; progestin implants; injectable estrogen; topical progesterone cream. 4. Had to have daily average of ≥7 moderate to severe hot flashes and had to complete ≥4 days of diary entries during baseline week to be randomized. 5. If treated with antidepressants, could not have had any changes in drug doses during past month. Other Inclusions apply.

Exclusion criteria

1. Patient treated with a gonadotrophin releasing hormone agonist, anti-estrogens, or aromatase inhibitors within 2 months prior to study entry. 2. Patient treated with estrogen pellets or progestin injectable drugs within 6 months prior to study entry. 3. Patient experience only nighttime hot flashes or worked night shifts on a regular basis. 4. Patient was concurrently treated with gabapentin for other indications. If patient was using gabapentin for treatment of hot flashes, she could be screened after a 7-day washout period provided hot flashes returned. 5. Patient had previously experienced dose-limiting adverse effects that prevented titration of gabapentin to an effective dose. 6. Patient had a hypersensitivity to gabapentin. 7. Patient was in an immunocompromised state. 8. Patient had a malignancy other than basal cell carcinoma within 2 years prior to study entry. 9. Patient had gastric reduction surgery, severe chronic diarrhea, chronic constipation, uncontrolled irritable bowel syndrome, uncontrolled inflammatory bowel disease, or unexplained weight loss. 10. Patient had clinically significant abnormal chemistry or hematology results, or calculated glomerular filtration rate \<60 mL/min. 11. Patient had history of substance abuse within year prior to study entry. 12. Patient was concurrently taking morphine. 13. Patient had history of chronic hepatitis B or C, hepatitis within 3 months prior to study entry, or history of human immunodeficiency virus. Other Exclusions apply.

Design outcomes

Primary

MeasureTime frameDescription
Change From Baseline in Average Daily Frequency of Moderate or Severe Hot Flashes After 4 Weeks of TreatmentAt baseline and 4 weeks of treatmentMean change from baseline in average daily number of moderate or severe hot flashes at stable dose week (SDW) 4 of treatment relative to placebo; last observation carried forward (LOCF) analysis
Change From Baseline in Average Daily Frequency of Moderate or Severe Hot Flashes After 12 Weeks of TreatmentAt baseline and 12 weeks of treatmentMean change from baseline in average daily number of moderate or severe hot flashes at stable dose week (SDW) 12 of treatment relative to placebo; last observation carried forward (LOCF) analysis
Change From Baseline in Average Daily Severity Score of Moderate or Severe Hot Flashes After 4 Weeks of TreatmentAt baseline and 4 weeks of treatmentMean change from baseline in average daily severity score of moderate or severe hot flashes at stable dose week (SDW) 4 of treatment relative to placebo; last observation carried forward (LOCF) analysis. Severity of hot flashes is scored on a scale of 1 to 3 where 1=mild, 2=moderate, 3=severe.
Change From Baseline in Average Daily Severity Score of Moderate or Severe Hot Flashes After 12 Weeks of TreatmentAt baseline and 12 weeks of treatmentMean change from baseline in average daily severity score of moderate or severe hot flashes at stable dose week (SDW) 12 of treatment relative to placebo; last observation carried forward (LOCF) analysis. Severity of hot flashes is scored on a scale of 1 to 3 where 1=mild, 2=moderate, 3=severe.

Countries

United States

Participant flow

Pre-assignment details

A total of 565 patients were randomly assigned to treatment: 190 in G-ER 1800 mg group, 192 in G-ER 1200 mg group, and 183 in placebo group. Of these 565 patients, 559 patients (190 in G-ER 1800 mg group, 186 in 1200 mg group, and 183 in placebo group) received study treatment and were included in intent to treat (ITT) and safety populations.

Participants by arm

ArmCount
G-ER 1200 mg
Gabapentin extended-release (G-ER) 1200 mg
186
G-ER 1800 mg
Gabapentin extended-release (G-ER) 1800 mg
190
Sugar Pill
Placebo 1200 mg or 1800 mg
183
Total559

Withdrawals & dropouts

PeriodReasonFG000FG001FG002
Overall StudyAdverse Event15218
Overall StudyDeath010
Overall StudyLack of Efficacy1014
Overall StudyLast dose date unknown331
Overall StudyLost to Follow-up233
Overall StudyMissing data110
Overall StudyProtocol Violation211
Overall StudyReasons not specified442
Overall StudyWithdrawal by Subject778

Baseline characteristics

CharacteristicG-ER 1200 mgG-ER 1800 mgSugar PillTotal
Age Continuous53.1 years
STANDARD_DEVIATION 7
53.6 years
STANDARD_DEVIATION 6.1
52.9 years
STANDARD_DEVIATION 6
53.2 years
STANDARD_DEVIATION 6.4
Age, Customized
<65 years
175 participants181 participants177 participants533 participants
Age, Customized
>=65 years
11 participants9 participants6 participants26 participants
Frequency of hot flashes
Mild
1.1 Hot flashes
STANDARD_DEVIATION 2
1.0 Hot flashes
STANDARD_DEVIATION 2
1.7 Hot flashes
STANDARD_DEVIATION 2.9
1.2 Hot flashes
STANDARD_DEVIATION 2.3
Frequency of hot flashes
Moderate
6.1 Hot flashes
STANDARD_DEVIATION 5.8
5.4 Hot flashes
STANDARD_DEVIATION 4
6.2 Hot flashes
STANDARD_DEVIATION 5.1
5.9 Hot flashes
STANDARD_DEVIATION 5
Frequency of hot flashes
Severe
6.7 Hot flashes
STANDARD_DEVIATION 5.1
6.9 Hot flashes
STANDARD_DEVIATION 5.5
6.6 Hot flashes
STANDARD_DEVIATION 4.9
6.8 Hot flashes
STANDARD_DEVIATION 5.2
Sex: Female, Male
Female
186 Participants190 Participants183 Participants559 Participants
Sex: Female, Male
Male
0 Participants0 Participants0 Participants0 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
deaths
Total, all-cause mortality
— / —— / —— / —
other
Total, other adverse events
70 / 18683 / 19029 / 183
serious
Total, serious adverse events
2 / 1862 / 1902 / 183

Outcome results

Primary

Change From Baseline in Average Daily Frequency of Moderate or Severe Hot Flashes After 12 Weeks of Treatment

Mean change from baseline in average daily number of moderate or severe hot flashes at stable dose week (SDW) 12 of treatment relative to placebo; last observation carried forward (LOCF) analysis

Time frame: At baseline and 12 weeks of treatment

Population: Intent to treat population

ArmMeasureValue (LEAST_SQUARES_MEAN)
G-ER 1200 mgChange From Baseline in Average Daily Frequency of Moderate or Severe Hot Flashes After 12 Weeks of Treatment-7.7 Hot flashes
G-ER 1800 mgChange From Baseline in Average Daily Frequency of Moderate or Severe Hot Flashes After 12 Weeks of Treatment-7.3 Hot flashes
Sugar PillChange From Baseline in Average Daily Frequency of Moderate or Severe Hot Flashes After 12 Weeks of Treatment-6.2 Hot flashes
Comparison: Null hypothesis: no treatment differences relative to placebo in mean change from baseline in average daily number of moderate or severe hot flashes at SDW 12p-value: 0.002497.5% CI: [-2.72, -0.41]ANCOVA
Comparison: Null hypothesis: no treatment differences relative to placebo in mean change from baseline in average daily number of moderate or severe hot flashes at SDW 12p-value: 0.028197.5% CI: [-2.26, 0.02]ANCOVA
Primary

Change From Baseline in Average Daily Frequency of Moderate or Severe Hot Flashes After 4 Weeks of Treatment

Mean change from baseline in average daily number of moderate or severe hot flashes at stable dose week (SDW) 4 of treatment relative to placebo; last observation carried forward (LOCF) analysis

Time frame: At baseline and 4 weeks of treatment

Population: Intention to treat population

ArmMeasureValue (LEAST_SQUARES_MEAN)
G-ER 1200 mgChange From Baseline in Average Daily Frequency of Moderate or Severe Hot Flashes After 4 Weeks of Treatment-7.0 Hot flashes
G-ER 1800 mgChange From Baseline in Average Daily Frequency of Moderate or Severe Hot Flashes After 4 Weeks of Treatment-6.9 Hot flashes
Sugar PillChange From Baseline in Average Daily Frequency of Moderate or Severe Hot Flashes After 4 Weeks of Treatment-5.4 Hot flashes
Comparison: Null hypothesis: no treatment differences relative to placebo in mean change from baseline in average daily number of moderate or severe hot flashes at SDW 4p-value: 0.002497.5% CI: [-2.8, -0.42]ANCOVA
Comparison: Null hypothesis: no treatment differences relative to placebo in mean change from baseline in average daily number of moderate or severe hot flashes at SDW 4p-value: 0.00497.5% CI: [-2.69, -0.33]ANCOVA
Primary

Change From Baseline in Average Daily Severity Score of Moderate or Severe Hot Flashes After 12 Weeks of Treatment

Mean change from baseline in average daily severity score of moderate or severe hot flashes at stable dose week (SDW) 12 of treatment relative to placebo; last observation carried forward (LOCF) analysis. Severity of hot flashes is scored on a scale of 1 to 3 where 1=mild, 2=moderate, 3=severe.

Time frame: At baseline and 12 weeks of treatment

Population: Intent to treat population

ArmMeasureValue (LEAST_SQUARES_MEAN)
G-ER 1200 mgChange From Baseline in Average Daily Severity Score of Moderate or Severe Hot Flashes After 12 Weeks of Treatment-0.8 Units on a scale
G-ER 1800 mgChange From Baseline in Average Daily Severity Score of Moderate or Severe Hot Flashes After 12 Weeks of Treatment-0.8 Units on a scale
Sugar PillChange From Baseline in Average Daily Severity Score of Moderate or Severe Hot Flashes After 12 Weeks of Treatment-0.5 Units on a scale
Comparison: Null hypothesis: no treatment differences relative to placebo in mean change from baseline in average daily severity score of moderate or severe hot flashes at SDW 12p-value: 0.02897.5% CI: [-0.43, 0]ANCOVA
Comparison: Null hypothesis: no treatment differences relative to placebo in mean change from baseline in average daily severity score of moderate or severe hot flashes at SDW 12p-value: 0.002697.5% CI: [-0.51, -0.07]ANCOVA
Primary

Change From Baseline in Average Daily Severity Score of Moderate or Severe Hot Flashes After 4 Weeks of Treatment

Mean change from baseline in average daily severity score of moderate or severe hot flashes at stable dose week (SDW) 4 of treatment relative to placebo; last observation carried forward (LOCF) analysis. Severity of hot flashes is scored on a scale of 1 to 3 where 1=mild, 2=moderate, 3=severe.

Time frame: At baseline and 4 weeks of treatment

Population: Intent to treat population

ArmMeasureValue (LEAST_SQUARES_MEAN)
G-ER 1200 mgChange From Baseline in Average Daily Severity Score of Moderate or Severe Hot Flashes After 4 Weeks of Treatment-0.5 Units on a scale
G-ER 1800 mgChange From Baseline in Average Daily Severity Score of Moderate or Severe Hot Flashes After 4 Weeks of Treatment-0.6 Units on a scale
Sugar PillChange From Baseline in Average Daily Severity Score of Moderate or Severe Hot Flashes After 4 Weeks of Treatment-0.4 Units on a scale
Comparison: Null hypothesis: no treatment differences relative to placebo in mean change from baseline in average daily severity score of moderate or severe hot flashes at SDW 4p-value: 0.060897.5% CI: [-0.32, -0.03]ANCOVA
Comparison: Null hypothesis: no treatment differences relative to placebo in mean change from baseline in average daily severity score of moderate or severe hot flashes at SDW 4p-value: 0.000397.5% CI: [-0.45, -0.11]ANCOVA

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026