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CompletedNCT03731364Updated Feb 15, 2022Results posted

Study of CA-008 (Vocacapsaicin) in Total Knee Arthroplasty

A Phase 2 interventional study of CA-008 and Placebo in Postsurgical Pain, sponsored by Concentric Analgesics. Completed at 1 site in United States. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2022-02-15.

Sponsored by Concentric Analgesics · Phase 2, Interventional, and Treatment

Phase
Phase 2
Study type
Interventional
Enrollment
55
Allocation
Randomized
Ages
18 Years to 80 Years
Sex
All
01

Study summary

This is a two-part, Phase 2, multi-center, randomized, double-blind, placebo-controlled, parallel design study of CA-008 (vocacapsaicin) vs. placebo injected/instilled during an elective TKA.

Read the detailed description

This is a Phase 2, multi-center, randomized, double-blind, placebo-controlled, parallel design study evaluating, in a pilot stage of the study, up to 3 ascending dose level cohorts each evaluating a single dose of CA-008 vs. placebo injected/instilled during an elective TKA. Up to 54 subjects will be randomized in the pilot stage. During the optional second stage of the study, subjects will be randomized to one of either 2 or 3 CA-008 dose levels (to be determined) or placebo. The Sponsor made the decision not to proceed with the second stage.

02

Conditions studied

  • Postsurgical Pain

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03

In context

Pain, Postoperative

5,640 studies on the registry are indexed under Pain, Postoperative; 1,230 are open to participants now.

This study's enrollment of 55 is below the median of 75 across 4,821 interventional studies indexed under Pain, Postoperative.

Browse Pain, Postoperative studies →

Lead sponsor

Concentric Analgesics is the lead sponsor of 7 studies on the registry; none are open to participants now.

Of its 7 completed or terminated interventional studies of FDA-regulated products, 7 (100%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 80 Years
Sexes eligible
All
Accepts healthy volunteers
No

Eligibility criteria

Key Inclusion Criteria:

  1. Plan to undergo an elective primary unilateral total knee arthroplasty (TKA or knee replacement), without collateral procedure or additional surgeries.
  2. Be a reasonably healthy adult aged 18 - 80 years old, inclusive, with a ≤ 36 kg/m2 and American Society of Anesthesiology (ASA) physical Class 1, 2 or 3 at the time of randomization.
  3. Males and females must abstain from intercourse, use acceptable methods or be sterile or otherwise incapable of having children.
  4. Be willing and able to sign the form (ICF)
  5. Be willing and able to complete study procedures and pain scales and to communicate meaningfully in English. Be able and willing to return for outpatient follow up visits as required.

Key Exclusion Criteria:

  1. In the opinion of the Investigator,

    1. have a concurrent painful condition, other than pain in the knee to be replaced, that may require pain treatment during the study period.
    2. have active skin disease or other abnormality at the anticipated site of surgery that could interfere with the planned surgery.
  2. Have a known allergy to chili peppers, capsaicin or the components of CA-008, ropivacaine, ketorolac, acetaminophen, fentanyl, hydromorphone, morphine or oxycodone.
  3. Have significant medical, neuropsychiatric or other condition.

  4. The following are considered disallowed medications:

    1. tolerant to opioids as defined
    2. capsaicin-containing products or foods.
    3. central nervous system active agent as an analgesic adjunct medication
    4. antiarrhythmics except beta-blockers, digoxin, warfarin, lithium, or aminoglycosides or other antibiotics for an infection
    5. parenteral or oral .
    6. antianginal, antihypertensive agent or diabetic regimen at a dose that has not been stable for at least 30 days or which is not expected to remain stable while participating in the study.
  5. Have positive results on the alcohol breath/saliva test indicative of alcohol abuse or urine drug screen indicative of illicit drug use at screening, and/or prior to surgery.
Terms in these criteria, in plain language(5)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
55 participants (actual)

Study arms

  • Active comparator
    CA-008 5 mg (0.05 mg/mL) Cohort 1

    Cohort 1 (5 mg), was prepared at 0.05 mg/mL CA-008 (vocacapsaicin)

    Drug: CA-008

  • Placebo comparator
    Placebo - Cohort 1

    Placebo for Cohort 1 Placebo comparator identical in appearance to the investigational product, containing the same excipients as the active

    Drug: Placebo

  • Active comparator
    CA-008 10 mg (0.1 mg/mL) Cohort 2

    Cohort 2 (10 mg), was prepared at 0.1 mg/mL CA-008 (vocacapsaicin)

    Drug: CA-008

  • Active comparator
    CA-008 15 mg (0.15 mg/mL) Cohort 3

    Cohort 3 (15 mg), was prepared at 0.15 mg/mL CA-008 (vocacapsaicin)

    Drug: CA-008

  • Placebo comparator
    Placebo - Cohorts 2 and 3

    Placebo - Cohorts 2 and 3 Placebo comparator identical in appearance to the investigational product, containing the same excipients as the active

    Drug: Placebo

Interventions

  • DrugCA-008

    5 mg CA-008 (0.05 mg/mL), 10 mg CA-008 (0.1 mg/mL) and 15 mg CA-008 (0.15 mg/mL)

    Also known as: vocacapsaicin

  • DrugPlacebo

    Placebo

06

What researchers measure

Primary outcomes

  1. Time-specific Mean Pain Intensity Scores (NRS) at Time 96 Hours for CA-008 vs. Placebo

    Primary Efficacy Endpoint for the Pilot Stage. Time-specific mean pain intensity scores at Time 96 hours for CA-008 vs. placebo based on a 10-point numerical rating scale (NRS) from 0-10 where 0 is no pain and 10 is the worst pain imaginable).

    Time frame: At 96 hours

  2. CA-008 Dose vs. Placebo Comparison: Area Under the Curve (AUC) 0 to 96 Hours

    Primary Efficacy Endpoint for Stage 2. Area Under the Curve (AUC) of the NRS current pain intensity scores from Time 0 hours to 96 hours at rest (AUC0 to 96h) where 0 is no pain and 10 is the worst pain imaginable for CA-008 compared to placebo. • During the inpatient stay, NRS at rest beginning with the PACU admission may be assessed once the subject is awake. The maximum is an NRS score of 10 x all 96 hours = 960 NRS units\*hrs; the minimum is 0 x 96h = 0 NRS units\*hrs

    Time frame: From 0 hours to 96 hours

Secondary outcomes

  1. Percentage of Subjects Who do Not Require Opioids

    Key Secondary Efficacy Endpoints for Stage 2. For each CA-008 dose vs. placebo comparison, percentage of subjects who do not require opioids.

    Time frame: Time 0 hours to Time 96 hours: Opioid Free 0 hours to 96 hours

  2. Total Opioid Consumption (in Daily Oral Morphine Equivalents)

    Key Secondary Efficacy Endpoints for Stage 2. Mean total postoperative opioid consumption (in daily oral morphine equivalents) for CA-008 compared to placebo

    Time frame: OC from Time 0 hours to Time 96 hours: OC 0 hours to 96 hours

07

Results

Posted Feb 15, 2022

Participant flow

One subject in Cohort 3, CA-008 15 mg had an adverse event before receiving treatment and was discontinued from the study without receiving study drug. This subject is not included in the results section

Participant flow — Overall Study
MilestoneCA-008 5 mg (0.05 mg/mL) Cohort 1Placebo - Cohort 1CA-008 10 mg (0.1 mg/mL) Cohort 2CA-008 15 mg (0.15 mg/mL) Cohort 3Placebo - Cohorts 2 and 3
Started99131311
Completed99121110
Not completed00121
Withdrew: Adverse event00121

Outcome measures

PrimaryTime-specific Mean Pain Intensity Scores (NRS) at Time 96 Hours for CA-008 vs. Placebo

Primary Efficacy Endpoint for the Pilot Stage. Time-specific mean pain intensity scores at Time 96 hours for CA-008 vs. placebo based on a 10-point numerical rating scale (NRS) from 0-10 where 0 is no pain and 10 is the worst pain imaginable).

Time frame:
At 96 hours
Reported as:
Mean · scores on a scale
Time-specific Mean Pain Intensity Scores (NRS) at Time 96 Hours for CA-008 vs. Placebo
scores on a scaleCA-008 5 mg (0.05 mg/mL) Cohort 1Placebo - Cohort 1CA-008 10 mg (0.1 mg/mL) Cohort 2CA-008 15 mg (0.15 mg/mL) Cohort 3Placebo - Cohorts 2 and 3
Time-specific Mean Pain Intensity Scores (NRS) at Time 96 Hours for CA-008 vs. Placebo3.8 ± 2.115.1 ± 2.854.9 ± 2.024.8 ± 3.475.5 ± 2.91
Statistical analysis
  • CA-008 5 mg (0.05 mg/mL) Cohort 1 vs Placebo - Cohort 1 · ANOVA · p = 0.276
  • CA-008 10 mg (0.1 mg/mL) Cohort 2 vs Placebo - Cohorts 2 and 3 · ANOVA · p = 0.651
  • CA-008 15 mg (0.15 mg/mL) Cohort 3 vs Placebo - Cohorts 2 and 3 · ANOVA · p = 0.556
PrimaryCA-008 Dose vs. Placebo Comparison: Area Under the Curve (AUC) 0 to 96 Hours

Primary Efficacy Endpoint for Stage 2. Area Under the Curve (AUC) of the NRS current pain intensity scores from Time 0 hours to 96 hours at rest (AUC0 to 96h) where 0 is no pain and 10 is the worst pain imaginable for CA-008 compared to placebo. • During the inpatient stay, NRS at rest beginning with the PACU admission may be assessed once the subject is awake. The maximum is an NRS score of 10 x all 96 hours = 960 NRS units\*hrs; the minimum is 0 x 96h = 0 NRS units\*hrs

Time frame:
From 0 hours to 96 hours
Reported as:
Mean · NRS units*hours
CA-008 Dose vs. Placebo Comparison: Area Under the Curve (AUC) 0 to 96 Hours
NRS units*hoursCA-008 5 mg (0.05 mg/mL) Cohort 1Placebo - Cohort 1CA-008 10 mg (0.1 mg/mL) Cohort 2CA-008 15 mg (0.15 mg/mL) Cohort 3Placebo - Cohorts 2 and 3
CA-008 Dose vs. Placebo Comparison: Area Under the Curve (AUC) 0 to 96 Hours476.13 ± 182.315593.93 ± 178.958529.51 ± 147.247532.14 ± 188.144539.43 ± 217.047
Statistical analysis
  • CA-008 5 mg (0.05 mg/mL) Cohort 1 vs Placebo - Cohort 1 · Wilcoxon (Mann-Whitney) · p = 0.136
  • CA-008 10 mg (0.1 mg/mL) Cohort 2 vs Placebo - Cohorts 2 and 3 · Wilcoxon (Mann-Whitney) · p = 0.649
  • CA-008 15 mg (0.15 mg/mL) Cohort 3 vs Placebo - Cohorts 2 and 3 · Wilcoxon (Mann-Whitney) · p = 0.608
SecondaryPercentage of Subjects Who do Not Require Opioids

Key Secondary Efficacy Endpoints for Stage 2. For each CA-008 dose vs. placebo comparison, percentage of subjects who do not require opioids.

Time frame:
Time 0 hours to Time 96 hours: Opioid Free 0 hours to 96 hours
Reported as:
Count of participants · Participants
Percentage of Subjects Who do Not Require Opioids
ParticipantsCA-008 5 mg (0.05 mg/mL) Cohort 1Placebo - Cohort 1CA-008 10 mg (0.1 mg/mL) Cohort 2CA-008 15 mg (0.15 mg/mL) Cohort 3Placebo - Cohorts 2 and 3
Percentage of Subjects Who do Not Require Opioids00000
Statistical analysis
  • CA-008 5 mg (0.05 mg/mL) Cohort 1 vs Placebo - Cohort 1 · Regression, Logistic · p = 0 (Not estimable) · Odds ratio (or): 0Not estimable
  • CA-008 10 mg (0.1 mg/mL) Cohort 2 vs Placebo - Cohorts 2 and 3 · Regression, Logistic · p = 0 (Not estimable) · Odds ratio (or): 0Not estimable
  • CA-008 15 mg (0.15 mg/mL) Cohort 3 vs Placebo - Cohorts 2 and 3 · Regression, Logistic · p = 0 (Not estimable) · Odds ratio (or): 0Not estimable
SecondaryTotal Opioid Consumption (in Daily Oral Morphine Equivalents)

Key Secondary Efficacy Endpoints for Stage 2. Mean total postoperative opioid consumption (in daily oral morphine equivalents) for CA-008 compared to placebo

Time frame:
OC from Time 0 hours to Time 96 hours: OC 0 hours to 96 hours
Reported as:
Mean · mg morphine equivalents
Total Opioid Consumption (in Daily Oral Morphine Equivalents)
mg morphine equivalentsCA-008 5 mg (0.05 mg/mL) Cohort 1Placebo - Cohort 1CA-008 10 mg (0.1 mg/mL) Cohort 2CA-008 15 mg (0.15 mg/mL) Cohort 3Placebo - Cohorts 2 and 3
Total Opioid Consumption (in Daily Oral Morphine Equivalents)244.17 ± 170.578321.33 ± 137.462242.77 ± 133.667365.25 ± 201.161280.36 ± 174.278
Statistical analysis
  • CA-008 5 mg (0.05 mg/mL) Cohort 1 vs Placebo - Cohort 1 · ANOVA · p = 0.306
  • CA-008 10 mg (0.1 mg/mL) Cohort 2 vs Placebo - Cohorts 2 and 3 · ANOVA · p = 0.595
  • CA-008 15 mg (0.15 mg/mL) Cohort 3 vs Placebo - Cohorts 2 and 3 · ANOVA · p = 0.242

Adverse events

Collected over Adverse event data were collected up to 76 days for participants in the study. This was comprised of a screening period that could be up to 45 days and subsequent clinic visits through Day 29.. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
CA-008 5 mg (0.05 mg/mL) Cohort 10/9 (0%)1/9 (11.1%)7/9 (77.8%)
Placebo - Cohort 10/9 (0%)0/9 (0%)7/9 (77.8%)
CA-008 10 mg (0.1 mg/mL) Cohort 20/13 (0%)0/13 (0%)12/13 (92.3%)
CA-008 15 mg (0.15 mg/mL) Cohort 30/12 (0%)1/12 (8.3%)10/12 (83.3%)
Placebo - Cohorts 2 and 30/11 (0%)1/11 (9.1%)9/11 (81.8%)
Most frequent serious events
Most frequent serious events
EventCA-008 5 mg (0.05 mg/mL) Cohort 1Placebo - Cohort 1CA-008 10 mg (0.1 mg/mL) Cohort 2CA-008 15 mg (0.15 mg/mL) Cohort 3Placebo - Cohorts 2 and 3
Deep vein thrombosisVascular disorders1/90/90/130/120/11
Perforated ulcerGeneral disorders0/90/90/130/121/11
Cerebrovascular accidentNervous system disorders0/90/90/131/120/11
SeizureNervous system disorders0/90/90/131/120/11
Most frequent other events
Showing 10 of 54
Most frequent other events
EventCA-008 5 mg (0.05 mg/mL) Cohort 1Placebo - Cohort 1CA-008 10 mg (0.1 mg/mL) Cohort 2CA-008 15 mg (0.15 mg/mL) Cohort 3Placebo - Cohorts 2 and 3
NauseaGastrointestinal disorders5/95/98/135/124/11
Sinus tachycardiaCardiac disorders5/90/92/133/126/11
VomitingGastrointestinal disorders1/90/94/135/122/11
ConstipationGastrointestinal disorders2/93/90/133/120/11
PyrexiaGeneral disorders3/92/94/132/121/11
HypertensionVascular disorders0/90/92/134/122/11
Application site painGeneral disorders0/92/90/130/120/11
Post procedural haematomaInjury, poisoning and procedural complications1/92/90/130/121/11
ContusionInjury, poisoning and procedural complications1/90/90/132/120/11
DizzinessNervous system disorders1/90/91/132/120/11

Baseline characteristics

The reason for the difference in the analysis population versus the number of participants in Participant Flow is due to the participant in CA-008 15 mg Cohort 3 who was randomized but not treated with study drug. This participant discontinued early from the study (on the same day of randomization) due to an adverse event.

Age, Continuous
Age, Continuous(years)CA-008 5 mg (0.05 mg/mL) Cohort 1Placebo - Cohort 1CA-008 10 mg (0.1 mg/mL) Cohort 2CA-008 15 mg (0.15 mg/mL) Cohort 3Placebo - Cohorts 2 and 3Total
Mean64.9 ± 9.6261.4 ± 7.6766.8 ± 7.3067.0 ± 8.5764.8 ± 7.2665.2 ± 8.00
Sex: Female, Male
Sex: Female, Male(Participants)CA-008 5 mg (0.05 mg/mL) Cohort 1Placebo - Cohort 1CA-008 10 mg (0.1 mg/mL) Cohort 2CA-008 15 mg (0.15 mg/mL) Cohort 3Placebo - Cohorts 2 and 3Total
Female7486429
Male2556725
Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)CA-008 5 mg (0.05 mg/mL) Cohort 1Placebo - Cohort 1CA-008 10 mg (0.1 mg/mL) Cohort 2CA-008 15 mg (0.15 mg/mL) Cohort 3Placebo - Cohorts 2 and 3Total
Hispanic or Latino121217
Not Hispanic or Latino8712101047
Unknown or Not Reported000000
Race (NIH/OMB)
Race (NIH/OMB)(Participants)CA-008 5 mg (0.05 mg/mL) Cohort 1Placebo - Cohort 1CA-008 10 mg (0.1 mg/mL) Cohort 2CA-008 15 mg (0.15 mg/mL) Cohort 3Placebo - Cohorts 2 and 3Total
American Indian or Alaska Native000000
Asian100102
Native Hawaiian or Other Pacific Islander000000
Black or African American004127
White89910945
More than one race000000
Unknown or Not Reported000000
Region of Enrollment
Region of Enrollment(participants)CA-008 5 mg (0.05 mg/mL) Cohort 1Placebo - Cohort 1CA-008 10 mg (0.1 mg/mL) Cohort 2CA-008 15 mg (0.15 mg/mL) Cohort 3Placebo - Cohorts 2 and 3Total
United States9913121154
08

Study locations

1 site
  • HD Research
    Houston, Texas 77402, United States
09

References and documents

Study documents

PDFs hosted by the registry, ClinicalTrials.gov.

Individual participant data

Plan to share: No

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Feb 15, 2022, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT03731364
Lead sponsor
Concentric Analgesics
Responsible party
Sponsor
First posted
Nov 6, 2018
Start date
Oct 29, 2018
Primary completion
Apr 30, 2019
Completion
May 31, 2019
Results posted
Feb 15, 2022
Last update
Feb 15, 2022

Study contacts

Daneshvari Solanki, MD
principal investigator · First Surgical Hospital

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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