Trial · NCT01569438

The Safety and Efficacy of Gefapixant (AF-219/MK-7264) in Female Participants With Interstitial Cystitis /Bladder Pain Syndrome (MK-7264-005)

NCT01569438, Phase 2, Terminated, Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA); results first posted 2017-01-12

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ConductScience Library. The Safety and Efficacy of Gefapixant (AF-219/MK-7264) in Female Participants With Interstitial Cystitis /Bladder Pain Syndrome (MK-7264-005). Trials, record NCT01569438. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT01569438

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Trial

As registered on ClinicalTrials.gov, in the graph's capture of the registry.

Title: The Safety and Efficacy of Gefapixant (AF-219/MK-7264) in Female Participants With Interstitial Cystitis /Bladder Pain Syndrome (MK-7264-005)
NCT number: NCT01569438
Status: Terminated
Phases: Phase 2
Enrollment: 107 participants, actual
Lead sponsor: Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA)
Conditions: Bladder Pain Syndrome
Interventions: Gefapixant, Placebo
First posted: 2012-04-03
Last updated: 2020-08-17
Results first posted: 2017-01-12

Source ClinicalTrials.gov

Registered outcomes4

Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.

List	Outcome	Time frame	Description
Primary	Change From Baseline in the Average Mean Numeric Pain Rating Scale (NPRS) Score at Week 4	Baseline and Week 4	The bladder pain severity was measured using 0-10 NPRS, with 0 representing 'no pain' and 10 representing 'the worst pain possible'. Participants were asked to select a number on the scale that best described the severity of bladder pain during past 24 hours over telephone using an interactive voice response system (IVRS) every evening at bedtime during the baseline assessment phase and treatment phase (up to 4 weeks). The primary analysis was conducted using a Mixed Model with Repeated Measures (MMRM) approach to calculate the Least Squares (LS) mean change from baseline in NPRS score and associated Standard Error (SE) at Week 4 for each treatment arm. Negative values indicate decrease in bladder pain severity.
Secondary	Change From Baseline in Painful Bladder/Interstitial Cystitis Symptom Diary (PBIC-SD) Score at Week 4	Baseline and Week 4	To assess the severity of bladder pain syndrome (BPS), an 8-item participant self-report PBIC-SD measure was used. Participants were asked to select a number on the scale that best described the severity of bladder pain over telephone using an IVRS each evening on the three consecutive days (during the Baseline Assessment Phase and during each Treatment Week up to 4 weeks). Each item was graded on a scale from 0 (good condition) to 4 (poor condition) with a total score range 0-32. Higher scores indicate more severe BPS. The analysis was conducted using a MMRM approach to calculate the LS mean change from baseline PBIC-SD total score and associated SE at Week 4 for each treatment arm. Negative values indicate decrease in severity of BPS.
Secondary	Change From Baseline in O'Leary-Sant Interstitial Cystitis Symptom Index (ICSI) Score at Week 4	Baseline and Week 4	To measure the severity of BPS (urgency and frequency of urination, nighttime urination, and pain or burning) over past month, a 4-item self-report ICSI measure was used. Participants were asked to select a number on the scale that best described the severity of symptoms over telephone using an IVRS every evening at bedtime during the baseline assessment phase and treatment phase (up to 4 weeks). The ICSI score range from 0 (Not at all) to 5 (Almost always) for the first 3 items and a score of 0 (Not at all) to 4 (Almost always) for the last item, with an index score range of 0-19. Higher scores indicate more severe BPS. The analysis was conducted using one-way ANCOVA model to calculate the LS mean change from baseline ICSI total score and associated SE at Week 4 for each treatment arm. Negative values indicate decrease in severity of BPS.
Secondary	Change From Baseline in Genitourinary Pain Index (GUPI) Score at Week 4	Baseline and Week 4	To measure the degree of genitourinary pain symptoms, an 8-item self-report GUPI measure was used. Participants were asked to select a number on the scale that best described the severity of symptoms over telephone using an IVRS every evening at bedtime during the baseline assessment phase and treatment phase (up to 4 weeks). The GUPI instrument yields a total score of 0-45 and 3 subscales: pain (score = 0-23), urinary (score = 0-10), and quality of life (score = 0-12). Higher scores indicate more severe symptoms. The analysis was conducted using one-way ANCOVA model to calculate the LS mean change from baseline GUPI total score and associated SE at Week 4 for each treatment arm. Negative values indicate decrease in degree of genitourinary pain symptoms.

Source ClinicalTrials.gov

Outcomes4

Each outcome the trial posted results for, in ClinicalTrials.gov's words.

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Change From Baseline in the Average Mean Numeric Pain Rating Scale (NPRS) Score at Week 4	Baseline and Week 4	Titration Completers Population - defined as participants who received at least 1 dose of drug, had at least 1 post-baseline NPRS Score, who titrated the dose in Week 1 of the treatment phase, and who completed the 4-week treatment phase	Score on a scale	LEAST_SQUARES_MEAN
SECONDARY	Change From Baseline in Painful Bladder/Interstitial Cystitis Symptom Diary (PBIC-SD) Score at Week 4	Baseline and Week 4	Titration Completers Population - defined as participants who received at least 1 dose of drug, had at least 1 post-baseline PBIC-SD Score, who titrated the dose in Week 1 of the treatment phase, and who completed the 4-week treatment phase.	Score on a scale	LEAST_SQUARES_MEAN
SECONDARY	Change From Baseline in O'Leary-Sant Interstitial Cystitis Symptom Index (ICSI) Score at Week 4	Baseline and Week 4	Titration Completers Population - defined as participants who received at least 1 dose of drug, had at least 1 post-baseline ICSI Score, who titrated the dose in Week 1 of the treatment phase, and who completed the 4-week treatment phase.	Score on a scale	LEAST_SQUARES_MEAN
SECONDARY	Change From Baseline in Genitourinary Pain Index (GUPI) Score at Week 4	Baseline and Week 4	Titration Completers Population - defined as participants who received at least 1 dose of drug, had at least 1 post-baseline GUPI Score, who titrated the dose in Week 1 of the treatment phase, and who completed the 4-week treatment phase.	Score on a scale	LEAST_SQUARES_MEAN

Source ClinicalTrials.gov

Results by group8

Each measurement the trial posted, group by group, in the words and numbers it posted.

Outcome	Group	Value	Spread	Units
Change From Baseline in the Average Mean Numeric Pain Rating Scale (NPRS) Score at Week 4	Gefapixant	-2.6	Standard Error 0.34	Score on a scale
Change From Baseline in the Average Mean Numeric Pain Rating Scale (NPRS) Score at Week 4	Placebo	-1.9	Standard Error 0.31	Score on a scale
Change From Baseline in Painful Bladder/Interstitial Cystitis Symptom Diary (PBIC-SD) Score at Week 4	Gefapixant	-7.8	Standard Error 1.29	Score on a scale
Change From Baseline in Painful Bladder/Interstitial Cystitis Symptom Diary (PBIC-SD) Score at Week 4	Placebo	-6.7	Standard Error 1.15	Score on a scale
Change From Baseline in O'Leary-Sant Interstitial Cystitis Symptom Index (ICSI) Score at Week 4	Gefapixant	-3.8	Standard Error 0.62	Score on a scale
Change From Baseline in O'Leary-Sant Interstitial Cystitis Symptom Index (ICSI) Score at Week 4	Placebo	-3.4	Standard Error 0.60	Score on a scale
Change From Baseline in Genitourinary Pain Index (GUPI) Score at Week 4	Gefapixant	-5.1	Standard Error 0.88	Score on a scale
Change From Baseline in Genitourinary Pain Index (GUPI) Score at Week 4	Placebo	-3.7	Standard Error 0.86	Score on a scale

Source ClinicalTrials.gov

Participant flow10

How many started, completed or left each group, period by period.

Period	Milestone	Group	Participants
Overall Study	STARTED	Placebo	52
Overall Study	STARTED	Gefapixant	55
Overall Study	Treated	Placebo	51
Overall Study	Treated	Gefapixant	54
Overall Study	Titration Set	Placebo	38
Overall Study	Titration Set	Gefapixant	36
Overall Study	COMPLETED	Placebo	45
Overall Study	COMPLETED	Gefapixant	33
Overall Study	NOT COMPLETED	Placebo	7
Overall Study	NOT COMPLETED	Gefapixant	22

Source ClinicalTrials.gov

Adverse events46

Each adverse event the trial posted, group by group: the participants affected out of those at risk.

Type	Event	Organ system	Group	Affected	At risk
other	Dysgeusia	Nervous system disorders	Placebo	9	51
other	Dysgeusia	Nervous system disorders	Gefapixant	38	54
other	Headache	Nervous system disorders	Placebo	6	51
other	Headache	Nervous system disorders	Gefapixant	5	54
other	Ageusia	Nervous system disorders	Placebo	0	51
other	Ageusia	Nervous system disorders	Gefapixant	7	54
other	Hypogeusia	Nervous system disorders	Placebo	0	51
other	Hypogeusia	Nervous system disorders	Gefapixant	3	54
other	Nausea	Gastrointestinal disorders	Placebo	10	51
other	Nausea	Gastrointestinal disorders	Gefapixant	10	54

1 to 10 of 46Source ClinicalTrials.gov

See all 46 adverse events

Adverse event totals6

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	Placebo	0	52
Total, all-cause mortality	Gefapixant	0	55
Total, other adverse events	Placebo	36	51
Total, other adverse events	Gefapixant	53	54
Total, serious adverse events	Placebo	0	51
Total, serious adverse events	Gefapixant	0	54

Source ClinicalTrials.gov

Papers1

The papers the trial lists on ClinicalTrials.gov.

PMID	Listed as
32734597	DERIVED

Source PubMed

Grants0

The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.

None in this release.

Trial comparisons2

Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.

Comparison	Source
Gefapixant vs Placebo: deaths from any cause	Trial comparisons
Gefapixant vs Placebo: serious adverse events	Trial comparisons

Tests0

The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.

None in this release.

Data dates

The day each source was copied for this release.

ClinicalTrials.gov: 2026-11-12; ClinicalTrials.gov
Results, from AACT: 2026-03-23; AACT
NIH grant links: 2026-11-13; NIH RePORTER

Sources 3

ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
ClinicalTrials.govNo license stated
NIH RePORTER's clinical studies and project filesPublic domain

Each source's terms

ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
ClinicalTrials.govnone stated
NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)

ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.

For software

Read this trial from software.

The record and each of its lists are JSON, twenty rows a page. No key.

GET https://conductscience.org/api/trials/v1/NCT01569438

GET https://conductscience.org/api/trials/v1/NCT01569438/events?page=2

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