Trial Outcomes & Findings for A Four-Week Multicenter Study Evaluating the Safety and Efficacy of Gefapixant (AF-219/MK-7264) in Subjects With Osteoarthritis of the Knee (NCT NCT01554579)

NCT ID: NCT01554579

Last Updated: 2019-06-27

Results Overview

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.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

171 participants

Primary outcome timeframe

2 Weeks

Results posted on

2019-06-27

Participant Flow

Participant milestones

Participant milestones
Measure
Sugar Pill
Sugar Pill: Placebo Subjects in the trial received one tablet twice daily for 4 weeks.
Gefapixant
Gefapixant: BID Subjects received one tablet twice daily for 4 weeks.
Overall Study
STARTED
86
85
Overall Study
COMPLETED
76
58
Overall Study
NOT COMPLETED
10
27

Reasons for withdrawal

Reasons for withdrawal
Measure
Sugar Pill
Sugar Pill: Placebo Subjects in the trial received one tablet twice daily for 4 weeks.
Gefapixant
Gefapixant: BID Subjects received one tablet twice daily for 4 weeks.
Overall Study
Adverse Event
6
25
Overall Study
Lack of Efficacy
2
1
Overall Study
Withdrawal by Subject
2
1

Baseline Characteristics

A Four-Week Multicenter Study Evaluating the Safety and Efficacy of Gefapixant (AF-219/MK-7264) in Subjects With Osteoarthritis of the Knee

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Sugar Pill
n=86 Participants
Sugar Pill: Placebo
Gefapixant
n=85 Participants
Gefapixant: BID Subjects received one tablet twice daily for 4 weeks.
Total
n=171 Participants
Total of all reporting groups
Age, Categorical
<=18 years
0 Participants
n=93 Participants
0 Participants
n=4 Participants
0 Participants
n=27 Participants
Age, Categorical
Between 18 and 65 years
64 Participants
n=93 Participants
65 Participants
n=4 Participants
129 Participants
n=27 Participants
Age, Categorical
>=65 years
22 Participants
n=93 Participants
20 Participants
n=4 Participants
42 Participants
n=27 Participants
Sex: Female, Male
Female
52 Participants
n=93 Participants
57 Participants
n=4 Participants
109 Participants
n=27 Participants
Sex: Female, Male
Male
34 Participants
n=93 Participants
28 Participants
n=4 Participants
62 Participants
n=27 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=93 Participants
1 Participants
n=4 Participants
1 Participants
n=27 Participants
Race (NIH/OMB)
Asian
2 Participants
n=93 Participants
2 Participants
n=4 Participants
4 Participants
n=27 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=93 Participants
0 Participants
n=4 Participants
0 Participants
n=27 Participants
Race (NIH/OMB)
Black or African American
21 Participants
n=93 Participants
20 Participants
n=4 Participants
41 Participants
n=27 Participants
Race (NIH/OMB)
White
62 Participants
n=93 Participants
62 Participants
n=4 Participants
124 Participants
n=27 Participants
Race (NIH/OMB)
More than one race
0 Participants
n=93 Participants
0 Participants
n=4 Participants
0 Participants
n=27 Participants
Race (NIH/OMB)
Unknown or Not Reported
1 Participants
n=93 Participants
0 Participants
n=4 Participants
1 Participants
n=27 Participants
Region of Enrollment
United States
86 participants
n=93 Participants
85 participants
n=4 Participants
171 participants
n=27 Participants
Numeric Pain Rating Scale (NPRS)
6.7 units on a scale
n=93 Participants
6.8 units on a scale
n=4 Participants
6.75 units on a scale
n=27 Participants

PRIMARY outcome

Timeframe: 2 Weeks

Population: 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.

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.

Outcome measures

Outcome measures
Measure
Sugar Pill
n=82 Participants
Sugar Pill: Placebo Subjects in the trial received one tablet twice daily for 4 weeks.
Gefapixant
n=74 Participants
Gefapixant: BID Subjects received one tablet twice daily for 4 weeks.
The Primary Efficacy Endpoint of This Study is the Weekly Average Daily NPRS (Average Pain)
5.3 units on a scale
Interval 0.0 to 10.0
4.9 units on a scale
Interval 0.0 to 10.0

SECONDARY outcome

Timeframe: 4 Weeks

Population: 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.

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.

Outcome measures

Outcome measures
Measure
Sugar Pill
n=79 Participants
Sugar Pill: Placebo Subjects in the trial received one tablet twice daily for 4 weeks.
Gefapixant
n=71 Participants
Gefapixant: BID Subjects received one tablet twice daily for 4 weeks.
WOMAC Scores
40.7 units on a scale
Standard Deviation 23.12
41.0 units on a scale
Standard Deviation 25.26

SECONDARY outcome

Timeframe: 4 Weeks

Population: 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.

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.

Outcome measures

Outcome measures
Measure
Sugar Pill
n=80 Participants
Sugar Pill: Placebo Subjects in the trial received one tablet twice daily for 4 weeks.
Gefapixant
n=73 Participants
Gefapixant: BID Subjects received one tablet twice daily for 4 weeks.
SF-36
3.8 units on a scale
Standard Deviation 2.39
4.1 units on a scale
Standard Deviation 2.77

Adverse Events

Sugar Pill

Serious events: 1 serious events
Other events: 17 other events
Deaths: 0 deaths

Gefapixant

Serious events: 0 serious events
Other events: 75 other events
Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure
Sugar Pill
n=86 participants at risk
Sugar Pill: Placebo Subjects in the trial received one tablet twice daily for 4 weeks.
Gefapixant
n=85 participants at risk
Gefapixant: BID Subjects received one tablet twice daily for 4 weeks.
Infections and infestations
Bronchitis
1.2%
1/86 • Number of events 1
0.00%
0/85

Other adverse events

Other adverse events
Measure
Sugar Pill
n=86 participants at risk
Sugar Pill: Placebo Subjects in the trial received one tablet twice daily for 4 weeks.
Gefapixant
n=85 participants at risk
Gefapixant: BID Subjects received one tablet twice daily for 4 weeks.
Nervous system disorders
Dysgeusia
4.7%
4/86 • Number of events 4
75.3%
64/85 • Number of events 64
Nervous system disorders
Ageusia
0.00%
0/86
14.1%
12/85 • Number of events 12
Nervous system disorders
headache
11.6%
10/86 • Number of events 10
10.6%
9/85 • Number of events 9
Nervous system disorders
hypogeusia
0.00%
0/86
8.2%
7/85 • Number of events 7
Nervous system disorders
dizziness
3.5%
3/86 • Number of events 3
7.1%
6/85 • Number of events 6

Additional Information

Clinical Development

Afferent Pharmaceuticals

Phone: 650-286-1276

Results disclosure agreements

  • Principal investigator is a sponsor employee 60 days prior to the submission of any results, the PI shall submit to SPONSOR any proposed PUBLICATION, which period may be extended for an additional 30 days if requested by SPONSOR. If any Confidential Information should be redacted or patent applications relating to an Invention should be filed prior to PUBLICATION, then PUBLICATION will be delayed until patent application has been filed. Delay of a PUBLICATION shall not exceed 24 months from the date of such notice to the PI.
  • Publication restrictions are in place

Restriction type: OTHER