Trial · NCT01554579
A Four-Week Multicenter Study Evaluating the Safety and Efficacy of Gefapixant (AF-219/MK-7264) in Subjects With Osteoarthritis of the Knee
NCT01554579, Phase 2, Completed, Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA); results first posted 2017-03-01
3 sourcestrials-2026-11-12-0.5.0
Cite this record
ConductScience Library. A Four-Week Multicenter Study Evaluating the Safety and Efficacy of Gefapixant (AF-219/MK-7264) in Subjects With Osteoarthritis of the Knee. Trials, record NCT01554579. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT01554579
On this page
Trial
As registered on ClinicalTrials.gov, in the graph's capture of the registry.
- Title
- A Four-Week Multicenter Study Evaluating the Safety and Efficacy of Gefapixant (AF-219/MK-7264) in Subjects With Osteoarthritis of the Knee
- NCT number
- NCT01554579
- Status
- Completed
- Phases
- Phase 2
- Enrollment
- 171 participants, actual
- Lead sponsor
- Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA)
- Conditions
- Osteoarthritis of the Knee
- Interventions
- Gefapixant, Sugar Pill
- First posted
- 2012-03-15
- Last updated
- 2019-06-27
- Results first posted
- 2017-03-01
Source ClinicalTrials.gov
Registered outcomes3
Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.
| List | Outcome | Time frame | Description |
|---|---|---|---|
| Primary | The Primary Efficacy Endpoint of This Study is the Weekly Average Daily NPRS (Average Pain) | 2 Weeks | Subjects were instructed to select a number on a scale that best described their knee arthritis pain during the past 24 hours. The scale was between 0 and 10 where 0 was no pain and 10 was the worst possible pain. The scale was completed by telephone (an interactive voice response system \[IVRS\]) every evening before bedtime. |
| Secondary | WOMAC Scores | 4 Weeks | This is the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). This is a questionnaire that asks subjects to evaluate their pain, stiffness, and physical activities affecting their knee over the past 48 hours. Subjects evaluate their pain, stiffness and physical activities by selecting a number between 0 and 10 where 0 is no pain/no stiffness/no difficulty doing physical activities and 10 is extreme pain/extreme stiffness/extreme difficulty doing physical activities. The questionnaire was administered at Screening, Baseline and at the end of Week 4 by telephone (an interactive voice response system \[IVRS\]) before bedtime. The scores for each category are totaled (range is 0-100). A lower total score means less pain and a higher total score means greater pain. |
| Secondary | SF-36 | 4 Weeks | The SF-36 (acute version 2) was a 36 question survey administered at Baseline and at the end of study or early termination (Week 4). The questionnaire contained numerous domain scores to evaluate physical function, mental function, general health, bodily pain, social functioning and vitality. The question of interest for the analysis was question #1 regarding walking pain. Scores range from 0 - 100. A lower score means decreased pain while walking and a higher score means increased pain while walking. |
Source ClinicalTrials.gov
Outcomes3
Each outcome the trial posted results for, in ClinicalTrials.gov's words.
| Type | Outcome | Time frame | Population | Units | Measured as |
|---|---|---|---|---|---|
| PRIMARY | The Primary Efficacy Endpoint of This Study is the Weekly Average Daily NPRS (Average Pain) | 2 Weeks | Per protocol population defined as subjects who received at least 1 dose of drug, had at least 1 post-baseline efficacy measure, complied with protocol and did not have major protocol deviations. Compliance with the protocol defined as having (in the last week of the study) a weekly average NPRS score w/ at least 50% non-missing dairy NPRS scores. | units on a scale | MEAN |
| SECONDARY | WOMAC Scores | 4 Weeks | Per protocol population defined as subjects who received at least 1 dose of drug, had at least 1 post-baseline efficacy measure, complied with protocol and did not have major protocol deviations. Compliance with the protocol defined as having (in the last week of the study) a weekly average NPRS score w/ at least 50% non-missing dairy NPRS scores. | units on a scale | MEAN |
| SECONDARY | SF-36 | 4 Weeks | Per protocol population defined as subjects who received at least 1 dose of drug, had at least 1 post-baseline efficacy measure, complied with protocol and did not have major protocol deviations. Compliance with the protocol defined as having (in the last week of the study) a weekly average NPRS score w/ at least 50% non-missing dairy NPRS scores. | units on a scale | MEAN |
Source ClinicalTrials.gov
Results by group6
Each measurement the trial posted, group by group, in the words and numbers it posted.
| Outcome | Group | Category | Value | Spread | Units |
|---|---|---|---|---|---|
| The Primary Efficacy Endpoint of This Study is the Weekly Average Daily NPRS (Average Pain) | Sugar Pill | 5.3 | Full Range 0 to 10 | units on a scale | |
| The Primary Efficacy Endpoint of This Study is the Weekly Average Daily NPRS (Average Pain) | Gefapixant | 4.9 | Full Range 0 to 10 | units on a scale | |
| WOMAC Scores | Sugar Pill | 40.7 | Standard Deviation 23.12 | units on a scale | |
| WOMAC Scores | Gefapixant | 41.0 | Standard Deviation 25.26 | units on a scale | |
| SF-36 | Sugar Pill | 3.8 | Standard Deviation 2.39 | units on a scale | |
| SF-36 | Gefapixant | 4.1 | Standard Deviation 2.77 | units on a scale |
Source ClinicalTrials.gov
Participant flow6
How many started, completed or left each group, period by period.
| Period | Milestone | Group | Participants | Units counted |
|---|---|---|---|---|
| Overall Study | STARTED | Sugar Pill | 86 | |
| Overall Study | STARTED | Gefapixant | 85 | |
| Overall Study | COMPLETED | Sugar Pill | 76 | |
| Overall Study | COMPLETED | Gefapixant | 58 | |
| Overall Study | NOT COMPLETED | Sugar Pill | 10 | |
| Overall Study | NOT COMPLETED | Gefapixant | 27 |
Source ClinicalTrials.gov
Adverse events12
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 | Events |
|---|---|---|---|---|---|---|
| other | Dysgeusia | Nervous system disorders | Sugar Pill | 4 | 86 | 4 |
| other | Dysgeusia | Nervous system disorders | Gefapixant | 64 | 85 | 64 |
| other | Ageusia | Nervous system disorders | Sugar Pill | 0 | 86 | 0 |
| other | Ageusia | Nervous system disorders | Gefapixant | 12 | 85 | 12 |
| other | headache | Nervous system disorders | Sugar Pill | 10 | 86 | 10 |
| other | headache | Nervous system disorders | Gefapixant | 9 | 85 | 9 |
| other | hypogeusia | Nervous system disorders | Sugar Pill | 0 | 86 | 0 |
| other | hypogeusia | Nervous system disorders | Gefapixant | 7 | 85 | 7 |
| other | dizziness | Nervous system disorders | Sugar Pill | 3 | 86 | 3 |
| other | dizziness | Nervous system disorders | Gefapixant | 6 | 85 | 6 |
1 to 10 of 12Source ClinicalTrials.gov
See all 12 adverse eventsAdverse event totals6
The totals the trial posted for each group.
| Total | Group | Affected | At risk |
|---|---|---|---|
| Total, all-cause mortality | Sugar Pill | ||
| Total, all-cause mortality | Gefapixant | ||
| Total, other adverse events | Sugar Pill | 17 | 86 |
| Total, other adverse events | Gefapixant | 75 | 85 |
| Total, serious adverse events | Sugar Pill | 1 | 86 |
| Total, serious adverse events | Gefapixant | 0 | 85 |
Source ClinicalTrials.gov
Papers0
The papers the trial lists on ClinicalTrials.gov.
None in this release.
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 comparisons1
Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.
| Comparison |
|---|
| Sugar Pill vs Gefapixant: serious adverse events |
Source 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.
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/NCT01554579
GET https://conductscience.org/api/trials/v1/NCT01554579/registered