Flexible HammertoePhase 3NCT07846280
Study to Assess the Long-term Safety of KN3835 in the Treatment and Retreatment of Flexible/Semi-Flexible Hammertoe (HMT)
A Phase 3 study testing KN3835 in people with Flexible Hammertoe and Semi-flexible Hammertoe, run by Endo USA Inc., a Keenova Therapeutics Company.
Trial summary
The primary purpose of this study is to assess the long-term safety of treatment and retreatment with KN3835 for flexible/semi-flexible HMT. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Flexible Hammertoe, Semi-flexible Hammertoe
- What is being tested?
- KN3835
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 470 participants
- Where
- No sites listed yet
- Study dates
- 11 Oct 2026to Dec 2028
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Were enrolled in and completed Study KN3835-313 (participants who completed the study are those that completed the Day 57/End of Study Visit, were assessed for safety, and received at least 1 dose of study intervention).
- Has no significant medical history or examination findings related to the foot to be treated, which in the investigator's opinion, would make the participant unsuitable for study intervention administration or study required evaluations.
- If female, be of non-childbearing potential 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 treatment.
- Be willing and able to comply with all protocol required visits and assessments.
Who cannot join
- Has any significant medical condition, or a serious or severe event in the parent study or any ongoing event from the parent study, which in the investigator's opinion, would make the participant unsuitable for enrollment in the study.
- Has received or plans to receive surgical or nonsurgical treatments on the foot or toe that was treated for the duration of study participation.
- Note: Other inclusion/exclusion criteria may apply.
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: A Phase 3, Multi-center Extension Study to Evaluate the Long-term Safety, Efficacy, and Maintenance of Response of KN3835 in the Treatment and Retreatment of Flexible/Semi-flexible Hammertoe
The primary purpose of this study is to assess the long-term safety of treatment and retreatment with KN3835 for flexible/semi-flexible HMT.
Read the detailed description
This extension study is for eligible participants who completed parent study KN3835-313 HMT. The study comprises 2 parts:
- Part I: a double-blind Observation Period from Observational Day 1 to Observational Day 360, and
- Part 2: an optional open-label Treatment/Retreatment Period from Observational Day 180 (Treatment/Retreatment Day 1) to Treatment/Retreatment Day 360 (End of Study).
- Conditions
- Flexible Hammertoe, Semi-flexible Hammertoe
- Being tested
- KN3835
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
KN3835Biological
Also called EN3835
Participants will receive KN3835 in Part 2 of the Study
| Study group | Role | What they receive |
|---|---|---|
| Observation then KN3835 | Experimental | After observation during Part 1 of the study, participants will have the option to receive treatment or retreatment with KN3835 in Part 2. Receives: Biological: KN3835 |
| Observation Only | No intervention | Participants will be observed through Part 1. After completion of Part 1, participants will have the option to be observed only during Part 2 of the study. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants with Adverse Events
Measured: Observational Day 1 up to Treatment/Retreatment Period Day 360
Secondary outcomes (19)
Change from Baseline In Foot Function Index (FFI) Total Score In Part 1 Observational Period
Measured: Baseline and up to Observational Day 360
Change from Baseline In FFI Subscales (Difficulty, Pain and Activity Limitation) Scores In Part 1 Observational Period
Measured: Baseline and up to Observational Day 360
Change from Baseline In Pain Intensity Numeric Rating Scale (NRS) Score In Part 1 Observational Period
Measured: Baseline and up to Observational Day 360
Percentage of Participants That Meet Retreatment/Treatment Criteria In Part 1 Observational Period
Measured: Observational Day 180
Percentage of Participants Reporting To Be "Quite Satisfied" and "Very Satisfied" On The Subject Satisfaction With Treatment Scale In Part 1 Observational Period
Measured: Up to Observational Day 360
Percentage Participants with Investigator Reported "Minimal Improvement", "Much Improvement", or "Very Much Improvement" on the Clinician Global Impression of Change Scale (CGIC) Scale Score in Part 1 Observational Period
Measured: Up to Observational Day 360
Change from Baseline In Flexion Contracture As Measured By Goniometer in Part 1 Observational Period
Measured: Baseline and up to Observational Day 360
Percent Change from Baseline In Flexion Contracture As Measured By Goniometer in Part 1 Observational Period
Measured: Baseline and up to Observational Day 360
Change from Baseline In The Patient Global Impression of Severity (PGIS) HMT Overall Scale Score in Part 1 Observational Period
Measured: Baseline and up to Observational Day 360
Percentage Of Participants reporting "Minimal Improvement", "Much Improvement", or "Very Much Improvement" on the Patient Global Impression of Change Scale (PGIC) HMT Overall Scale Score in Part 1 Observational Period
Measured: Up to Observational Day 360
Change from Baseline In FFI Total Score In Part 2 Treatment/Retreatment Period
Measured: Baseline and up to Treatment/Retreatment Period Day 360
Change from Baseline In FFI Subscales (Difficulty, Pain and Activity Limitation) Scores In Part 2 Treatment/Retreatment Period
Measured: Baseline and up to Treatment/Retreatment Period Day 360
Change from Baseline In Pain Intensity NRS Score In Part 2 Treatment/Retreatment Period
Measured: Baseline and up to Treatment/Retreatment Period Day 360
Percentage of Participants Reporting To Be "Satisfied" and "Very Satisfied" On The Subject Satisfaction With Treatment Scale In Part 2 Treatment/Retreatment Period
Measured: Up to Treatment/Retreatment Period Day 360
Percentage Of Participants with Investigator Reported "Minimal Improvement", "Much Improvement", or "Very Much Improvement" on the CGIC HMT Overall Scale Score in Part 2 Treatment/Retreatment Period
Measured: Up to Treatment/Retreatment Period Day 360
Change from Baseline In Flexion Contracture As Measured By Goniometer in Part 2 Treatment/Retreatment Period
Measured: Baseline and up to Treatment/Retreatment Period Day 360
Percent Change from Baseline In Flexion Contracture As Measured By Goniometer in Part 2 Treatment/Retreatment Period
Measured: Baseline and up to Treatment/Retreatment Period Day 360
Change from Baseline In The PGIS HMT Overall Scale Score in Part 2 Treatment/Retreatment Period
Measured: Baseline and up to Treatment/Retreatment Period Day 360
Percentage Of Participants reporting "Minimal Improvement", "Much Improvement", or "Very Much Improvement" on the PGIC HMT Overall Scale Score in Part 2 Treatment/Retreatment Period
Measured: Up to Treatment/Retreatment Period Day 360
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Sep 2026
- Study start11 Oct 2026 (estimated)
- Primary completionDec 2028 (estimated)
- Study completionDec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Flexible HammertoeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 470 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Endo USA Inc., a Keenova Therapeutics Company
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, MD, Study director, Endo USA Inc., a Keenova Therapeutics Company
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07846280
- Sponsor's protocol ID
- KN3835-314 HMT
- Status last verified
- Sep 2026
- First submitted
- 23 Sep 2026
- Last updated
- 29 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 3, Multi-center Extension Study to Evaluate the Long-term Safety, Efficacy, and Maintenance of Response of KN3835 in the Treatment and Retreatment of Flexible/Semi-flexible Hammertoe
- ClinicalTrials.gov ID
- NCT07846280
- Acronym / sponsor ID
- KN3835-314 HMT
- Conditions
- Flexible Hammertoe, Semi-flexible Hammertoe
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 470 participants (estimated)
- Lead sponsor
- Endo USA Inc., a Keenova Therapeutics CompanyIndustry (pharma, biotech, devices)
- Study start
- 11 Oct 2026 (estimated)
- Primary completion
- Dec 2028 (estimated)
- Study completion
- Dec 2028 (estimated)
- First posted
- 29 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The primary purpose of this study is to assess the long-term safety of treatment and retreatment with KN3835 for flexible/semi-flexible HMT.
Detailed description
This extension study is for eligible participants who completed parent study KN3835-313 HMT. The study comprises 2 parts:
- Part I: a double-blind Observation Period from Observational Day 1 to Observational Day 360, and
- Part 2: an optional open-label Treatment/Retreatment Period from Observational Day 180 (Treatment/Retreatment Day 1) to Treatment/Retreatment Day 360 (End of Study).
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Observation then KN3835 | Experimental | Biological: KN3835After observation during Part 1 of the study, participants will have the option to receive treatment or retreatment with KN3835 in Part 2. |
| Observation Only | No intervention | –Participants will be observed through Part 1. After completion of Part 1, participants will have the option to be observed only during Part 2 of the study. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Were enrolled in and completed Study KN3835-313 (participants who completed the study are those that completed the Day 57/End of Study Visit, were assessed for safety, and received at least 1 dose of study intervention).
- Has no significant medical history or examination findings related to the foot to be treated, which in the investigator's opinion, would make the participant unsuitable for study intervention administration or study required evaluations.
- If female, be of non-childbearing potential 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 treatment.
- Be willing and able to comply with all protocol required visits and assessments.
Key exclusion criteria (3 listed)
- Has any significant medical condition, or a serious or severe event in the parent study or any ongoing event from the parent study, which in the investigator's opinion, would make the participant unsuitable for enrollment in the study.
- Has received or plans to receive surgical or nonsurgical treatments on the foot or toe that was treated for the duration of study participation.
- Note: Other inclusion/exclusion criteria may apply.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| KN3835Also: EN3835Participants will receive KN3835 in Part 2 of the Study | Biological | Observation then KN3835 |
Primary outcome
Number of Participants with Adverse Events
Time frame: Observational Day 1 up to Treatment/Retreatment Period Day 360
19 secondary outcomes
Change from Baseline In Foot Function Index (FFI) Total Score In Part 1 Observational Period
Time frame: Baseline and up to Observational Day 360
Change from Baseline In FFI Subscales (Difficulty, Pain and Activity Limitation) Scores In Part 1 Observational Period
Time frame: Baseline and up to Observational Day 360
Change from Baseline In Pain Intensity Numeric Rating Scale (NRS) Score In Part 1 Observational Period
Time frame: Baseline and up to Observational Day 360
Percentage of Participants That Meet Retreatment/Treatment Criteria In Part 1 Observational Period
Time frame: Observational Day 180
Percentage of Participants Reporting To Be "Quite Satisfied" and "Very Satisfied" On The Subject Satisfaction With Treatment Scale In Part 1 Observational Period
Time frame: Up to Observational Day 360
Percentage Participants with Investigator Reported "Minimal Improvement", "Much Improvement", or "Very Much Improvement" on the Clinician Global Impression of Change Scale (CGIC) Scale Score in Part 1 Observational Period
Time frame: Up to Observational Day 360
Change from Baseline In Flexion Contracture As Measured By Goniometer in Part 1 Observational Period
Time frame: Baseline and up to Observational Day 360
Percent Change from Baseline In Flexion Contracture As Measured By Goniometer in Part 1 Observational Period
Time frame: Baseline and up to Observational Day 360
Change from Baseline In The Patient Global Impression of Severity (PGIS) HMT Overall Scale Score in Part 1 Observational Period
Time frame: Baseline and up to Observational Day 360
Percentage Of Participants reporting "Minimal Improvement", "Much Improvement", or "Very Much Improvement" on the Patient Global Impression of Change Scale (PGIC) HMT Overall Scale Score in Part 1 Observational Period
Time frame: Up to Observational Day 360
Change from Baseline In FFI Total Score In Part 2 Treatment/Retreatment Period
Time frame: Baseline and up to Treatment/Retreatment Period Day 360
Change from Baseline In FFI Subscales (Difficulty, Pain and Activity Limitation) Scores In Part 2 Treatment/Retreatment Period
Time frame: Baseline and up to Treatment/Retreatment Period Day 360
Change from Baseline In Pain Intensity NRS Score In Part 2 Treatment/Retreatment Period
Time frame: Baseline and up to Treatment/Retreatment Period Day 360
Percentage of Participants Reporting To Be "Satisfied" and "Very Satisfied" On The Subject Satisfaction With Treatment Scale In Part 2 Treatment/Retreatment Period
Time frame: Up to Treatment/Retreatment Period Day 360
Percentage Of Participants with Investigator Reported "Minimal Improvement", "Much Improvement", or "Very Much Improvement" on the CGIC HMT Overall Scale Score in Part 2 Treatment/Retreatment Period
Time frame: Up to Treatment/Retreatment Period Day 360
Change from Baseline In Flexion Contracture As Measured By Goniometer in Part 2 Treatment/Retreatment Period
Time frame: Baseline and up to Treatment/Retreatment Period Day 360
Percent Change from Baseline In Flexion Contracture As Measured By Goniometer in Part 2 Treatment/Retreatment Period
Time frame: Baseline and up to Treatment/Retreatment Period Day 360
Change from Baseline In The PGIS HMT Overall Scale Score in Part 2 Treatment/Retreatment Period
Time frame: Baseline and up to Treatment/Retreatment Period Day 360
Percentage Of Participants reporting "Minimal Improvement", "Much Improvement", or "Very Much Improvement" on the PGIC HMT Overall Scale Score in Part 2 Treatment/Retreatment Period
Time frame: Up to Treatment/Retreatment Period Day 360
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Sep 2026.
- Individual participant dataSharing planned: No
Related trials for Flexible Hammertoe
RecruitingPhase 3
Study to Assess KN3835 in the Treatment of Flexible/Semi-Flexible Hammertoe (HMT)
Flexible Hammertoe, Semi-flexible Hammertoe
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Medical Director, MD study director
Endo USA Inc., a Keenova Therapeutics Company
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing KN3835 in people with Flexible Hammertoe and Semi-flexible Hammertoe, run by Endo USA Inc., a Keenova Therapeutics Company.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 29 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Clinical Operations (800-462-3636, clinicaltrials@endo.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants with Adverse Events (time frame: Observational Day 1 up to Treatment/Retreatment Period Day 360). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Sep 2026.