Efficacy, Safety, and Tolerability, of EN3835 vs Placebo in the Treatment of Plantar Fibromatosis

March 26, 2026 updated by: Endo Pharmaceuticals

Phase 2, Double-blind, Randomized, Placebo-Controlled Study to Assess the Efficacy, Safety, and Tolerability of EN3835 vs Placebo in the Treatment of Plantar Fibromatosis

This randomized, double-blind, placebo-controlled study will evaluate the efficacy and safety of up to 2 treatments of EN3835 vs placebo in participants with plantar fibromatosis.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
176

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Arizona
      • Mesa, Arizona, United States, 85206
        • Endo Clinical Trial Site #29
      • Tucson, Arizona, United States, 85712
        • Endo Clinical Trial Site #42
    • California
      • Bakersfield, California, United States, 93311
        • Endo Clinical Trial Site #15
      • Encinitas, California, United States, 92024
        • Endo Clinical Trial Site #41
      • Fresno, California, United States, 93710
        • Endo Clinical Trial Site #9
      • La Mesa, California, United States, 91942
        • Endo Clinical Trial Site #27
      • Los Angeles, California, United States, 90010
        • Endo Clinical Trial Site #30
      • Tarzana, California, United States, 91356
        • Endo Clinical Trial Site #12
      • Torrance, California, United States, 90502
        • Endo Clinical Trial Site #36
      • Vista, California, United States, 92083
        • Endo Clinical Trial Site #22
      • Whittier, California, United States, 90603
        • Endo Clinical Trial Site #13
    • Florida
      • Atlantis, Florida, United States, 33462
        • Endo Clinical Trial Site #16
      • Jacksonville, Florida, United States, 32209
        • Endo Clinical Trial Site #43
      • Miami, Florida, United States, 33176
        • Endo Clinical Trial Site #40
      • Pinellas Park, Florida, United States, 33782
        • Endo Clinical Trial Site #10
      • South Miami, Florida, United States, 33143
        • Endo Clinical Trial Site #3
      • Sweetwater, Florida, United States, 33172
        • Endo Clinical Trial Site #14
    • Georgia
      • Lawrenceville, Georgia, United States, 30043
        • Endo Clinical Trial Site #38
    • Idaho
      • Meridian, Idaho, United States, 83642
        • Endo Clinical Trial Site #31
    • Illinois
      • Decatur, Illinois, United States, 62521
        • Endo Clinical Trial Site #32
      • O'Fallon, Illinois, United States, 62269
        • Endo Clinical Trial Site #19
      • Springfield, Illinois, United States, 62704
        • Endo Clinical Trial Site #33
    • Maryland
      • Pasadena, Maryland, United States, 21122
        • Endo Clinical Trial Site #23
    • Missouri
      • Jefferson City, Missouri, United States, 65109
        • Endo Clinical Trial Site #28
    • Nevada
      • Las Vegas, Nevada, United States, 89119
        • Endo Clinical Trial Site #20
    • Oklahoma
      • Oklahoma City, Oklahoma, United States, 73109
        • Endo Clinical Trial Site #34
    • Pennsylvania
      • York, Pennsylvania, United States, 17402
        • Endo Clinical Trial Site #4
    • Texas
      • Arlington, Texas, United States, 76015
        • Endo Clinical Trial Site #35
      • Bedford, Texas, United States, 76021
        • Endo Clinical Trial Site #5
      • Cedar Park, Texas, United States, 78613
        • Endo Clinical Trial Site #24
      • Dallas, Texas, United States, 75208
        • Endo Clinical Trial Site #17
      • Dallas, Texas, United States, 75251
        • Endo Clinical Trial Site #2
      • Fort Worth, Texas, United States, 76104
        • Endo Clinical Trial Site #7
      • Georgetown, Texas, United States, 78628
        • Endo Clinical Trial Site #39
      • Houston, Texas, United States, 77027
        • Endo Clinical Trial Site #25
      • Houston, Texas, United States, 77095
        • Endo Clinical Trial Site #8
      • McAllen, Texas, United States, 78501
        • Endo Clinical Trial Site #1
      • San Antonio, Texas, United States, 78211
        • Endo Clinical Trial Site #21
      • San Antonio, Texas, United States, 78229
        • Endo Clinical Trial Site #6
    • Utah
      • Salt Lake City, Utah, United States, 84107
        • Endo Clinical Trial Site #18
    • Virginia
      • Lynchburg, Virginia, United States, 24501
        • Endo Clinical Trial Site #26
      • Midlothian, Virginia, United States, 23114
        • Endo Clinical Trial Site #37
      • Suffolk, Virginia, United States, 23434
        • Endo Clinical Trial Site #11

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Has a diagnosis of plantar fibromatosis AND have at least 1 measurable, hard or firm, palpable fibrous nodule on clinical examination.
  2. Has no significant medical history or examination findings related to the participant's plantar nodule(s), which in the investigator's opinion, would make the participant unsuitable for study intervention administration.
  3. Agree not to use opioids during the study period and has not used opioids 2 weeks before the Screening Visit.
  4. Agree to not initiate or change use of orthotics or inserts designed to relieve symptoms of plantar fibromatosis during the study period.
  5. If female, be of non-childbearing potential (history of hysterectomy, bilateral oophorectomy, bilateral tubal ligation, or postmenopausal with no history of menstrual flow in the 12 months prior to the Screening Visit); or, if of childbearing potential, be non-pregnant, non-lactating and agree to use effective contraception when with a male partner for the duration of the study and for 28 days after any active treatment period.
  6. Willing and able to comply with all protocol required visits and assessments.
  7. Be adequately informed and understand the nature and risks of the study and be able to provide consent.

Exclusion Criteria:

  1. Has the presence of non-plantar fibromatosis-related nodules on the foot/feet (eg, neurofibroma, rhabdomyosarcoma, liposarcoma, neurilemmomas, rheumatoid nodules, desmoid tumors, or malignant soft tissue lesions of the foot or ankle).
  2. Has any musculoskeletal, neuromuscular, neurosensory, other neurological or related disorder that affects the participant's use of his or her feet and/or would impair his/her completion of study assessments as determined by the investigator.
  3. Has a known allergy to collagenase or any other excipient of EN3835.
  4. Has a known coagulation disorder or is taking any medications that would increase the risk of bleeding (except <150mg of aspirin daily), 7 days prior to first injection and for the duration of the study.
  5. Has concurrent diseases that might interfere with the conduct of the study, confound the interpretation of the study results or endanger the participant's well-being. If there is a history of such disease and the condition has been stable for greater than one year and is judged by the investigator not to interfere, the participant may be included, with the documented approval of the Medical Monitor.
  6. Is from a vulnerable population, as defined by the US Code of Federal Regulations (CFR) Title 45, Part 46, Section 46.111(b) and other local and national regulations, including but not limited to, employees (temporary, part-time, full-time, etc) or a family member of the research staff conducting the study, or of the sponsor, or of the contract research organization, or of the IRB/IEC.
  7. Has any other condition(s) that, in the investigator's opinion, might indicate the participants to be unsuitable for the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: EN3835 Group
Participant will receive a maximum dose of up to 1.8mg of EN3835 injection
Biological: EN3835
Participant will receive a maximum dose of up to1.8mg of EN3835 injection
Placebo Comparator: Placebo Group
Participant will receive a matched Placebo injection
Other: Placebo
Participant will receive a matched Placebo injection

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change From Baseline to Day 57 in the Foot Function Index (FFI) Pain Subscale Score
Time Frame: Baseline (Day 1), Day 57
FFI pain subscale consisted of 9 items which were scored on a scale of 0 ("None") to 4 ("Extreme") with a total score ranging from 0 to 36. Lower scores indicated better foot function, while higher scores reflected greater impairment.
Baseline (Day 1), Day 57

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change From Baseline to Day 57 in the FFI Total Combined (Pain and Difficulty) Score
Time Frame: Baseline (Day 1), Day 57
The FFI pain subscale consisted of 9 items which were scored on a scale of 0 ("None") to 4 ("Extreme") with a total score ranging from 0 to 36. The FFI difficulty subscale consisted of 9 items which were scored on a scale of 0 ("No difficulty") to 4 ("A lot of difficulty") with a total score ranging from 0 to 36. The Total Combined score of pain and difficulty comprised scores of answered items in each subscale with a maximum total score range of 0 to 72. Lower scores indicated better foot function, while higher scores reflected greater impairment.
Baseline (Day 1), Day 57
Percentage of Participants With a Response of "Minimal Improvement", "Much Improvement" or "Very Much Improvement" (Responders) in the Clinician Global Impression of Change Scale
Time Frame: Day 57
The responder (by foot/feet) was defined as a participant with a response of "Minimal Improvement", "Much Improvement" or "Very Much Improvement" in the CGIC Scale. All participants who withdrew early from the study were considered as non-responders. If participant was treated for both feet, then the assessment could be combined at participant level using worst case approach, if one foot response was recorded as 'Minimal Improvement' and 'Very Much Improvement' in another foot, then response was considered as 'Minimal Improvement'.
Day 57
Change From Baseline to Day 57 in the Nodular Hardness of the Treated Nodules by Durometer Measurement
Time Frame: Baseline (Day 1), Day 57
A durometer was used to measure the hardness of treated nodules, on a scale ranging from 0 to 100. Higher scores indicated a greater hardness.
Baseline (Day 1), Day 57

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Endo Pharmaceuticals

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Luis Ortega, MD, Endo Pharmaceuticals

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 29, 2021

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 10, 2023

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 10, 2023

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 29, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 29, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 9, 2021

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 27, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 26, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • EN3835-222

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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