Trial Outcomes & Findings for A Study to Evaluate the Efficacy and Safety of Gefapixant (MK-7264) in Women With Endometriosis-Related Pain (MK-7264-034) (NCT NCT03654326)

Last Updated: 2024-11-04

Results Overview

Pelvic pain (cyclic pain associated with menses, and non-cyclic pain not associated with menses) severity score was measured using a 0-10 numeric rating scale (NRS), with 0 representing no pain and 10 representing extremely severe pain. The averages of the daily pelvic pain scores (cyclic and non-cyclic, combined) entered in participants' electronic diaries (eDiaries) were calculated for Baseline and Treatment Cycle 2 (approximately Week 4 to Week 8). A negative change indicates a decrease in pain severity from baseline.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

187 participants

Primary outcome timeframe

Baseline and Treatment Cycle 2 (Week 4 to Week 8; each cycle is approximately 28 days)

Results posted on

2024-11-04

Participant Flow

This study included a baseline menstrual cycle (approximately 4 weeks) prior to randomization to either gefapixant or placebo.

Participant milestones

Participant milestones
Measure	Gefapixant Participants received a gefapixant 45 mg tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.	Placebo Participants received a placebo matching gefapixant tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.
Overall Study STARTED	94	93
Overall Study COMPLETED	88	87
Overall Study NOT COMPLETED	6	6

Reasons for withdrawal

Reasons for withdrawal
Measure	Gefapixant Participants received a gefapixant 45 mg tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.	Placebo Participants received a placebo matching gefapixant tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.
Overall Study Withdrawal by Subject	5	3
Overall Study Physician Decision	0	1
Overall Study Unable to adhere to study schedule	0	1
Overall Study Lost to Follow-up	1	1

Baseline Characteristics

A Study to Evaluate the Efficacy and Safety of Gefapixant (MK-7264) in Women With Endometriosis-Related Pain (MK-7264-034)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Gefapixant n=94 Participants Participants received a gefapixant 45 mg tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.	Placebo n=93 Participants Participants received a placebo matching gefapixant tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.	Total n=187 Participants Total of all reporting groups
Age, Continuous	34.5 Years STANDARD_DEVIATION 6.6 • n=5 Participants	34.8 Years STANDARD_DEVIATION 7.3 • n=7 Participants	34.6 Years STANDARD_DEVIATION 6.9 • n=5 Participants
Sex: Female, Male Female	94 Participants n=5 Participants	93 Participants n=7 Participants	187 Participants n=5 Participants
Sex: Female, Male Male	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	35 Participants n=5 Participants	31 Participants n=7 Participants	66 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	59 Participants n=5 Participants	62 Participants n=7 Participants	121 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	4 Participants n=5 Participants	3 Participants n=7 Participants	7 Participants n=5 Participants
Race (NIH/OMB) White	88 Participants n=5 Participants	86 Participants n=7 Participants	174 Participants n=5 Participants
Race (NIH/OMB) More than one race	1 Participants n=5 Participants	4 Participants n=7 Participants	5 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Average Daily Pelvic Pain Score	6.5 Scores on a scale STANDARD_DEVIATION 1.0 • n=5 Participants	6.5 Scores on a scale STANDARD_DEVIATION 1.0 • n=7 Participants	6.5 Scores on a scale STANDARD_DEVIATION 1.0 • n=5 Participants

PRIMARY outcome

Timeframe: Baseline and Treatment Cycle 2 (Week 4 to Week 8; each cycle is approximately 28 days)

Population: All randomized participants who received at least one dose of double-blind study intervention and had at least one day of eDiary entries during the post-randomization treatment cycle.

Outcome measures

Outcome measures
Measure	Gefapixant n=94 Participants Participants received a gefapixant 45 mg tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.	Placebo n=93 Participants Participants received a placebo matching gefapixant tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.
Change From Baseline in Average Daily Pelvic Pain Score During Treatment Cycle 2	-2.2 Scores on a Scale Interval -2.79 to -1.62	-1.7 Scores on a Scale Interval -2.3 to -1.13

PRIMARY outcome

Timeframe: Up to approximately 10 weeks

Population: All randomized participants who received at least one dose of study intervention.

An adverse event (AE) is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. Per protocol, this analysis included AEs reported up to 14 days after end of study intervention.

Outcome measures

Outcome measures
Measure	Gefapixant n=94 Participants Participants received a gefapixant 45 mg tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.	Placebo n=93 Participants Participants received a placebo matching gefapixant tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.
Percentage of Participants Who Experienced an Adverse Event	53.2 Percentage of Participants	35.5 Percentage of Participants

PRIMARY outcome

Timeframe: Up to approximately 8 weeks

Population: All randomized participants who received at least one dose of study intervention.

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention.

Outcome measures

Outcome measures
Measure	Gefapixant n=94 Participants Participants received a gefapixant 45 mg tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.	Placebo n=93 Participants Participants received a placebo matching gefapixant tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.
Percentage of Participants Who Discontinued Study Drug Due to an Adverse Event	3.2 Percentage of Participants	0.0 Percentage of Participants

SECONDARY outcome

Timeframe: Baseline and Treatment Cycle 2 (Week 4 to Week 8; each cycle is approximately 28 days)

Population: All randomized participants who received at least one dose of double-blind study intervention, had at least one day of eDiary entry during the post-randomization treatment cycle, and had available cyclic pelvic pain score data.

Cyclic pelvic pain (associated with menses) severity score was measured using a 0-10 NRS, with 0 representing no pain and 10 representing extremely severe pain. The average of the daily cyclic pelvic pain scores entered in participants' eDiaries was calculated for Baseline and Treatment Cycle 2 (Week 4 to Week 8). A negative change indicates a decrease in pain severity from baseline.

Outcome measures

Outcome measures
Measure	Gefapixant n=89 Participants Participants received a gefapixant 45 mg tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.	Placebo n=90 Participants Participants received a placebo matching gefapixant tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.
Change From Baseline in Average Daily Cyclic Pelvic Pain Score During Treatment Cycle 2	-2.0 Scores on a Scale Interval -2.55 to -1.35	-1.3 Scores on a Scale Interval -1.94 to -0.73

SECONDARY outcome

Timeframe: Baseline and Treatment Cycle 2 (Week 4 to Week 8; each cycle is approximately 28 days)

Non-cyclic pelvic pain (not associated with menses) severity score was measured using a 0-10 NRS, with 0 representing no pain and 10 representing extremely severe pain. The average of the non-cyclic daily pelvic pain scores entered in participants' eDiaries was calculated for the Baseline and Treatment Cycle 2 (Week 4 to Week 8). A negative change indicates decrease in pain severity from baseline.

Outcome measures

Outcome measures
Measure	Gefapixant n=91 Participants Participants received a gefapixant 45 mg tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.	Placebo n=90 Participants Participants received a placebo matching gefapixant tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.
Change From Baseline in Average Daily Non-Cyclic Pelvic Pain Score During Treatment Cycle 2	-2.3 Scores on a Scale Interval -2.9 to -1.69	-1.8 Scores on a Scale Interval -2.4 to -1.18

Adverse Events

Gefapixant

Serious events: 0 serious events

Other events: 36 other events

Deaths: 0 deaths

Placebo

Serious events: 0 serious events

Other events: 12 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Gefapixant n=94 participants at risk Participants received a gefapixant 45 mg tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.	Placebo n=93 participants at risk Participants received a placebo matching gefapixant tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets were also provided to participants, as needed, for endometriosis-related pain.
Gastrointestinal disorders Diarrhoea	6.4% 6/94 • Number of events 6 • All-cause mortality: Up to approximately 24 weeks Serious adverse events and other adverse events: Up to approximately 12 weeks All randomized participants who received at least one dose of study intervention	0.00% 0/93 • All-cause mortality: Up to approximately 24 weeks Serious adverse events and other adverse events: Up to approximately 12 weeks All randomized participants who received at least one dose of study intervention
Gastrointestinal disorders Dry mouth	6.4% 6/94 • Number of events 6 • All-cause mortality: Up to approximately 24 weeks Serious adverse events and other adverse events: Up to approximately 12 weeks All randomized participants who received at least one dose of study intervention	2.2% 2/93 • Number of events 2 • All-cause mortality: Up to approximately 24 weeks Serious adverse events and other adverse events: Up to approximately 12 weeks All randomized participants who received at least one dose of study intervention
Nervous system disorders Ageusia	9.6% 9/94 • Number of events 9 • All-cause mortality: Up to approximately 24 weeks Serious adverse events and other adverse events: Up to approximately 12 weeks All randomized participants who received at least one dose of study intervention	1.1% 1/93 • Number of events 1 • All-cause mortality: Up to approximately 24 weeks Serious adverse events and other adverse events: Up to approximately 12 weeks All randomized participants who received at least one dose of study intervention
Nervous system disorders Dysgeusia	16.0% 15/94 • Number of events 16 • All-cause mortality: Up to approximately 24 weeks Serious adverse events and other adverse events: Up to approximately 12 weeks All randomized participants who received at least one dose of study intervention	2.2% 2/93 • Number of events 2 • All-cause mortality: Up to approximately 24 weeks Serious adverse events and other adverse events: Up to approximately 12 weeks All randomized participants who received at least one dose of study intervention
Nervous system disorders Headache	4.3% 4/94 • Number of events 4 • All-cause mortality: Up to approximately 24 weeks Serious adverse events and other adverse events: Up to approximately 12 weeks All randomized participants who received at least one dose of study intervention	7.5% 7/93 • Number of events 7 • All-cause mortality: Up to approximately 24 weeks Serious adverse events and other adverse events: Up to approximately 12 weeks All randomized participants who received at least one dose of study intervention
Nervous system disorders Hypogeusia	5.3% 5/94 • Number of events 5 • All-cause mortality: Up to approximately 24 weeks Serious adverse events and other adverse events: Up to approximately 12 weeks All randomized participants who received at least one dose of study intervention	0.00% 0/93 • All-cause mortality: Up to approximately 24 weeks Serious adverse events and other adverse events: Up to approximately 12 weeks All randomized participants who received at least one dose of study intervention

Additional Information

Senior Vice President, Global Clinical Development

Merck Sharp & Dohme Corp.

Phone: 1-800-672-6372

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee If publication activity is not directed by the Sponsor, the investigator agrees to submit all manuscripts or abstracts to the Sponsor before submission.
Publication restrictions are in place

Restriction type: OTHER