A Study Evaluating Pain Relief and Safety of Orally Administered CR845 in Patients With Osteoarthritis of Hip or Knee

A Randomized, Double-Blind, Placebo-Controlled, Titration-to-Effect Study of Orally Administered CR845 in Patients With Osteoarthritis of the Hip or Knee

The study schedule consists of a Screening Period (up to 14 days), a blinded 4- week Titration-to-Effect Period with weekly visits, a blinded 4-week Maintenance Treatment Period at the optimal dose level determined for each patient, and a 1-week Follow-up Period.

Eligible patients will be randomized to receive either CR845 or placebo in a 2:1 ratio. Every patient will be started on a 1-mg dose of CR845 or matching placebo. During the post-randomization Titration-to-Effect period, the dose of study drug may be increased to 2.5 mg or 5 mg in a double-blind fashion. Patients may know their dose is being changed but will not know whether they were randomization to active study drug or placebo. Approximately 330 patients will be enrolled in this study.

Study Overview

• Status: Completed
• Conditions: Arthritis; Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Osteoarthritis, Knee; Osteoarthritis, Hip
• Intervention / Treatment: Drug: CR845 tablet 1 mg; Drug: CR845 tablet 2.5 mg; Drug: CR845 tablet 5 mg; Drug: Placebo tablet

Detailed Description

This is a multicenter, randomized, double-blind, placebo-controlled, titration-to-effect study of orally administered CR845 in patients with osteoarthritis of the hip or knee.

The study schedule consists of a Screening Period (up to 14 days), a blinded 4- week Titration-to-Effect Period with weekly visits, a blinded 4-week Maintenance Treatment Period at the optimal dose level determined for each patient, and a 1-week Follow-up Period.

Eligible patients will be randomized to receive either CR845 or placebo in a 2:1 ratio. Randomization will be stratified based on a patient's primary OA joint (knee vs. hip). Every patient will be started on a 1-mg dose of CR845 or matching placebo. During the post-randomization Titration-to-Effect period, the dose of study drug may be increased to 2.5 mg or 5 mg in a double-blind fashion.

Patients may know their dose is being changed but will not know whether they were randomized to active study drug or placebo. Approximately 330 patients will be enrolled in this study.

During the Screening, Titration-to-Effect and Follow-up Period, pain intensity scores will be obtained at specified time points. Blood sampling and safety assessments will be conducted during this period as well.

The use of rescue medication for the treatment of any pain (including but not limited to headache, menstrual cramps, or non-target joint pain) during the study will be discussed with the patients at the Screening Visit. Acetaminophen is the only allowable rescue medication for pain beginning from Day -5 until the end of the Maintenance Treatment Period. Starting at the Screening Visit Acetaminophen will be provided as 325-mg tablets and its use (number of tablets taken in the previous 24 hours) will be reported each evening in the patient diary.

• Study Type: Interventional
• Enrollment (Actual): 761
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Alabama
    • Birmingham, Alabama, United States, 35216
      • Cara Therapeutics Study Site
  • Arizona
    • Peoria, Arizona, United States, 85351
      • Cara Therapeutics Study Site
    • Phoenix, Arizona, United States, 85023
      • Cara Therapeutics Study Site
  • California
    • Carmichael, California, United States, 95608
      • Cara Therapeutics Study Site
    • San Diego, California, United States, 92123
      • Cara Therapeutics Study Site
    • Tustin, California, United States, 92780
      • Cara Therapeutics Study Site
  • Florida
    • Homestead, Florida, United States, 33030
      • Cara Therapeutics Study Site
    • Jupiter, Florida, United States, 33458
      • Cara Therapeutics Study Site
    • Lake Worth, Florida, United States, 33462
      • Cara Therapeutics Study Site
    • Miami, Florida, United States, 33183
      • Cara Therapeutics Study Site
    • Oldsmar, Florida, United States, 34677
      • Cara Therapeutics Study Site
    • Orlando, Florida, United States, 32806
      • Cara Therapeutics Study Site
    • Plantation, Florida, United States, 33317
      • Cara Therapeutics Study Site
    • South Miami, Florida, United States, 33143
      • Cara Therapeutics Study Site
    • Tampa, Florida, United States, 33634
      • Cara Therapeutics Study Site
  • Georgia
    • Savannah, Georgia, United States, 31406
      • Cara Therapeutics Study Site
  • Missouri
    • Hazelwood, Missouri, United States, 63042
      • Cara Therapeutics Study Site
  • Nebraska
    • Omaha, Nebraska, United States, 68134
      • Cara Therapeutics Study Site
  • Nevada
    • Las Vegas, Nevada, United States, 89144
      • Cara Therapeutics Study Site
  • New Jersey
    • Berlin, New Jersey, United States, 08009
      • Cara Therapeutics Study Site
  • New York
    • Binghamton, New York, United States, 13901
      • Cara Therapeutics Study Site
    • Rochester, New York, United States, 14609
      • Cara Therapeutics Study Site
  • Ohio
    • Cincinnati, Ohio, United States, 45242
      • Cara Therapeutics Study Site
    • Cincinnati, Ohio, United States, 45246
      • Cara Therapeutics Study Site
  • Oklahoma
    • Oklahoma City, Oklahoma, United States, 73119
      • Cara Therapeutics Study Site
  • Pennsylvania
    • Duncansville, Pennsylvania, United States, 16635
      • Cara Therapeutics Study Site
  • South Carolina
    • Charleston, South Carolina, United States, 29407
      • Cara Therapeutics Study Site
    • Charleston, South Carolina, United States, 29406
      • Cara Therapeutics Study Site
    • Greenville, South Carolina, United States, 29601
      • Cara Therapeutics Study Site
  • Texas
    • Austin, Texas, United States, 78731
      • Cara Therapeutics Study Site
    • Dallas, Texas, United States, 75234
      • Cara Therapeutics Study Site
    • Plano, Texas, United States, 75024
      • Cara Therapeutics Study Site
    • Plano, Texas, United States, 75075
      • Cara Therapeutics Study Site
    • San Antonio, Texas, United States, 78209
      • Cara Therapeutics Study Site
  • Virginia
    • Charlottesville, Virginia, United States, 22911
      • Cara Therapeutics Study Site

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 25 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Voluntarily provides written informed consent to participate in the study prior to any study procedures.
2. Is able to speak, read, and communicate clearly in English or Spanish; is able to understand the study procedures.
3. Male or female ≥ 25 years of age.
4. Body mass index (BMI) ≤ 40 kg/m2.
5. Has OA of the hip or knee according to American College of Rheumatology (ACR) criteria.
6. Reports an average pain intensity level ≥ 5 in the index joint at Screening on a 0-10 NRS scale.
7. Is either opioid-naïve (defined as taking < 10 mg a day of morphine equivalent 14 days prior to screening) or opioid-experienced. If receiving opioid analgesic medication for OA, patients must be on a stable dose ≤ 40 mg of morphine equivalents for 14 days prior to screening.
8. Willing to discontinue currently used pain medications beginning 5 days prior to the Baseline Visit and throughout the study. Acetaminophen use is allowed. (Section 8.8)

9. If female:

   1. Of childbearing potential - the patient must be willing to practice an acceptable form of birth control (defined as the use of an intrauterine device, a barrier method with spermicide, condoms, any form of hormonal contraceptives, or abstinence from sexual intercourse) for the duration of treatment and for at least 3 days following the last dose of study drug.
   2. Of non-childbearing potential - the patient must be surgically or biologically sterile (hysterectomy, bilateral oophorectomy, bilateral tubal ligation, or postmenopausal for at least 1 year).
10. If male, the patient must be surgically or biologically sterile. If not sterile, the patient must agree to use an acceptable form of birth control with a heterosexual partner (as described in inclusion criterion #9) or abstain from sexual relations during the treatment period and for 3 days following the last dose of study drug.
11. Is free of other physical, mental, or medical conditions that, in the opinion of the Investigator, would make study participation inadvisable.
12. Reports a daily pain intensity score in the index joint ≥ 5 (on a 0-10 NRS scale) during 4 or more of the last 7 days prior to randomization, with 2 consecutive days ≥ 5 occurring just prior to randomization

Exclusion Criteria:

Inclusion Criteria:

A patient will be eligible for enrollment if the following criteria are met:

1. Voluntarily provides written informed consent to participate in the study prior to any study procedures.
2. Is able to speak, read, and communicate clearly in English or Spanish; is able to understand the study procedures.
3. Male or female ≥ 25 years of age.
4. Body mass index (BMI) ≤ 40 kg/m2.
5. Has OA of the hip or knee according to American College of Rheumatology (ACR) criteria.
6. Reports an average pain intensity level ≥ 5 in the index joint at Screening on a 0-10 NRS scale.
7. Is either opioid-naïve (defined as taking < 10 mg a day of morphine equivalent 14 days prior to screening) or opioid-experienced. If receiving opioid analgesic medication for OA, patients must be on a stable dose ≤ 40 mg of morphine equivalents for 14 days prior to screening.
8. Willing to discontinue currently used pain medications beginning 5 days prior to the Baseline Visit and throughout the study. Acetaminophen use is allowed. (Section 8.8)

9. If female:

   1. Of childbearing potential - the patient must be willing to practice an acceptable form of birth control (defined as the use of an intrauterine device, a barrier method with spermicide, condoms, any form of hormonal contraceptives, or abstinence from sexual intercourse) for the duration of treatment and for at least 3 days following the last dose of study drug.
   2. Of non-childbearing potential - the patient must be surgically or biologically sterile (hysterectomy, bilateral oophorectomy, bilateral tubal ligation, or postmenopausal for at least 1 year).
10. If male, the patient must be surgically or biologically sterile. If not sterile, the patient must agree to use an acceptable form of birth control with a heterosexual partner (as described in inclusion criterion #9) or abstain from sexual relations during the treatment period and for 3 days following the last dose of study drug.
11. Is free of other physical, mental, or medical conditions that, in the opinion of the Investigator, would make study participation inadvisable.
12. Reports a daily pain intensity score in the index joint ≥ 5 (on a 0-10 NRS scale) during 4 or more of the last 7 days prior to randomization, with 2 consecutive days ≥ 5 occurring just prior to randomization

Exclusion Criteria:

1. Has had a joint replacement in the index joint.
2. Has received an intra-articular injection of corticosteroids or hyaluronic acid in the index joint within 3 months prior to the Screening Visit.
3. Has started a new medication for chronic illness within 30 days prior to the Screening Visit.
4. Is receiving opioid analgesic treatment for OA of the hip or knee at a dose > 40 mg of morphine equivalent.
5. Uses antipsychotics, antiepileptics, sedatives, hypnotics, or antianxiety agents, selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants with a dose change <30 days prior to day 1 of the study.
6. Has a history or current diagnosis of substance dependence (except caffeine or nicotine) or alcohol abuse, according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5).
7. Has a positive urine drug screen for drugs of abuse at Screening.
8. Has been diagnosed with a condition of hyperhidrosis (excessive sweating) or primary hypodipsia (a reduced sense of thirst).
9. Has a history (within 6 months) of clinically meaningful orthostatic changes in vital signs OR, at Screening, has a decrease in systolic blood pressure by > 20 mm Hg or a decrease in diastolic blood pressure by 10 mm Hg together with an increase in heart rate of > 30 beats per minute when transitioning from supine to standing measurements.
10. Has a medical condition (e.g., a cardiovascular, pulmonary, hepatic, renal, hematologic, gastrointestinal, endocrine [adrenal hyperplasia], immunologic, dermatologic, neurologic, oncologic, or psychiatric) or a significant laboratory abnormality that, in the Investigator's opinion, would jeopardize the safety of the patient or is likely to confound the study measurements.
11. Has had any gastric bypass surgery (for weight loss).
12. Has a corrected QT interval of >450 msec in males, >470 msec in females, or clinically significant abnormality on screening ECG.
13. Has a serum sodium level > 143 mmol/L at Screening.
14. Has impaired renal function indicated by serum creatinine > 2 × the reference upper limit of normal (ULN).
15. Has a serum alanine aminotransferase (ALT) or aspartate aminotransferase (AST) > 2.5 × the reference ULN, or total bilirubin > 2 × the ULN at Screening.
16. Has, in the opinion of the Investigator, any clinical signs of dehydration or hypovolemia (e.g., symptomatic hypotension) or associated laboratory abnormalities (e.g., elevated hematocrit or elevated blood urea nitrogen [BUN] > 1.5 × the reference ULN) at Screening.
17. Has taken opioid or non-opioid pain medication (e.g., nonsteroidal anti-inflammatory drugs [NSAIDs] such as naproxen or cyclooxygenase-2 inhibitors) within 5 days prior to study drug administration. Acetaminophen use is allowed. (Section 8.8)
18. Has received another investigational drug within 30 days prior to Baseline or has planned to participate in another clinical trial while enrolled in this study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: CR845 tablet 1 mg; Dosing twice a day (BID) for a total of 8 weeks, with each dose administered at least 2 hours prior to or after a meal.	Drug: CR845 tablet 1 mg; CR845 tablets will be provided as 1 mg enteric-coated tablets. All tablets are white in color with no markings and are identical in appearance, regardless of dose and treatment.
Active Comparator: CR845 tablet 2.5 mg; Dosing twice a day (BID) for a total of 8 weeks, with each dose administered at least 2 hours prior to or after a meal.	Drug: CR845 tablet 2.5 mg; CR845 tablets will be provided as 2.5 mg enteric-coated tablets. All tablets are white in color with no markings and are identical in appearance, regardless of dose and treatment.
Active Comparator: CR845 tablet 5 mg; Dosing twice a day (BID) for a total of 8 weeks, with each dose administered at least 2 hours prior to or after a meal.	Drug: CR845 tablet 5 mg; CR845 tablets will be provided as 5 mg enteric-coated tablets. All tablets are white in color with no markings and are identical in appearance, regardless of dose and treatment.
Placebo Comparator: Placebo tablet; Dosing twice a day (BID) for a total of 8 weeks, with each dose administered at least 2 hours prior to or after a meal.	Drug: Placebo tablet; Placebo tablets will be provided as enteric-coated tablets. All tablets are white in color with no markings and are identical in appearance, regardless of dose and treatment.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change From Baseline at Week 8 With Respect to the Weekly Mean of the Daily 24-hour Pain Intensity for the Index Joint as Measured by the Numeric Rating Scale (NRS).	11-point NRS scale where 0 = no pain, and 10= pain as bad as you can imagine	Baseline, Week 8

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change From Baseline in the Western Ontario & McMaster Osteoarthritis (WOMAC) Index Total Score at Week 8	The WOMAC Index is a self-administered assessment used to measure pain, stiffness, and physical function in patients with osteoarthritis. The WOMAC Index contains 24 questions across 3 different sub-scales (pain, stiffness, and function) all with scoring 0-10 (0 = No Pain/Stiffness/Difficulty, 10 = Extreme Pain/Stiffness/Difficulty). Each WOMAC Index Subscale score (Pain/Stiffness/Function) is calculated as the sum of all scores within that subscale. The pain subscale consists of five scores from 0-10, 0 is no pain 10 is extreme pain possible for a range of 0 - 50 points. The stiffness subscale consists of two scores from 0-10, 0 is no stiffness 10 is extreme stiffness possible for a range of 0 - 20 points. The function subscale consists of 17 scores from 0-10, 0 is no difficulty and 10 is extreme difficulty, for a range of 0 - 170 points. The WOMAC Index Total Score is calculated as the sum of all 24 scores (range of 0-240).	Baseline, Week 8
Change From Baseline in the WOMAC Pain Intensity Sub-scale Score at Week 8	The pain subscale consists of five scores from 0-10, 0 is no pain 10 is extreme pain possible for a range of 0 - 50 points.	Baseline, Week 8
Change From Baseline in the WOMAC Stiffness Sub-scale Score at Week 8	The stiffness subscale consists of two scores from 0-10, 0 is no stiffness 10 is extreme stiffness possible for a range of 0 - 20 points.	Baseline, Week 8
Change From Baseline in the WOMAC Function Sub-scale Score at Week 8	The function subscale consists of 17 scores from 0-10, 0 is no difficulty and 10 is extreme difficulty, for a range of 0 - 170 points.	Baseline, Week 8
Proportion of Patients With at Least 30% Improvement From Baseline in the Weekly Mean Pain Intensity at Week 8	A patient's pain response to treatment is defined as the percent improvement from baseline with respect to the weekly mean of "average pain in the last 24 hours" pain score during the last week of the Maintenance Treatment Period (Week 8) . If a patient's mean weekly pain score during the last week of the Maintenance Treatment Period is greater than the baseline score (i.e., the patient has an increase in pain compared to baseline), his/her response to treatment will be assigned a value of 0 (i.e. the patient will be considered a non-responder). Patients who discontinue study drug early will be considered non-responders to treatment and will be assigned a pain response of 0. The percentage of subjects achieving levels of treatment response 10% to 100% by 10% increments as defined above will be calculated with 30% of key interest as it has been shown to represent a clinically important improvement in pain.	Week 8
Proportion of Patients With at Least 50% Improvement From Baseline in the Weekly Mean Pain Intensity at Week 8	A patient's pain response to treatment is defined as the percent improvement from baseline with respect to the weekly mean of "average pain in the last 24 hours" pain score during the last week of the Maintenance Treatment Period (Week 8) . If a patient's mean weekly pain score during the last week of the Maintenance Treatment Period is greater than the baseline score (i.e., the patient has an increase in pain compared to baseline), his/her response to treatment will be assigned a value of 0 (i.e. the patient will be considered a non-responder). Patients who discontinue study drug early will be considered non-responders to treatment and will be assigned a pain response of 0. The percentage of subjects achieving levels of treatment response 10% to 100% by 10% increments as defined above will be calculated with 30% of key interest as it has been shown to represent a clinically important improvement in pain.	Week 8
Proportion of Patients Whose OA Pain Was "Very Much Improved" or "Much Improved" as Indicated by Patient Global Impression of Change (PGIC) Score at Week 8	The PGIC is a self-administered instrument that measures the patient's overall impression of his/her OA on a 7-point scale where 1 = "Very much improved" and 7 = "Very much worse".	Week 8
Average Daily Number of Acetaminophen Tablets Used During Entire Study	The average daily number of acetaminophen tablets used during the study will be calculated using data recorded in the patient diary as the sum of the total number of tablets used divided by the length of exposure (in days). The supplemental pain medication for OA will be grouped categorically into the following classes: (1) no supplemental acetaminophen tablets, (2) 0 to ≤ 0.5 tablets, (3) > 0.5 to ≤ 1.0 tablets, (4) > 1.0 to ≤ 2.0 tablets, and (5) > 2.0 tablets.	Week 8
Proportion of Patients Withdrawing From Treatment Due to Lack of Analgesic Efficacy		Week 8

Collaborators and Investigators

• Sponsor: Cara Therapeutics, Inc.
• Investigators: Study Director: Joseph Stauffer, DO, MBA, Cara Therapeutics

Study record dates

Study Major Dates

• Study Start: September 1, 2016
• Primary Completion (Actual): May 1, 2017
• Study Completion (Actual): June 1, 2017

Study Registration Dates

• First Submitted: October 4, 2016
• First Submitted That Met QC Criteria: October 24, 2016
• First Posted (Estimate): October 25, 2016

Study Record Updates

• Last Update Posted (Actual): October 20, 2020
• Last Update Submitted That Met QC Criteria: October 19, 2020
• Last Verified: October 1, 2020

More Information

Terms related to this study

• Keywords: Osteoarthritis; Knee; Hip; Analgesic; CR845; difelikefalin; Kappa opioid
• Additional Relevant MeSH Terms: Connective Tissue Diseases; Arthritis; Osteoarthritis; Osteoarthritis, Knee; Joint Diseases; Rheumatic Diseases; Collagen Diseases; Osteoarthritis, Hip; Musculoskeletal Diseases
• Other Study ID Numbers: CR845-CLIN2002-PO

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED