Metastatic Castration Resistant Prostate CancerPhase 1NCT07719361
A Study in Patients With Metastatic Castration-Resistant Prostate Cancer
A Phase 1 study testing FX-111 in people with Metastatic Castration Resistant Prostate Cancer and mCRPC, run by Flare Therapeutics Inc. at 10 sites in United States.
Trial summary
The goal of this clinical trial is to find out if FX-111 is safe enough to permit further studies in adult male participants with metastatic castration-resistant prostate cancer (mCRPC). It will also study the drug's pharmacokinetics (how the body breaks down FX-111) and how well FX-111 treats mCRPC. Read more about this study
- Who is it for?
- Ages 18 years and older, men only
- Conditions the study is for
- Metastatic Castration Resistant Prostate Cancer, mCRPC, mCRPC (Metastatic Castration-resistant Prostate Cancer)
- What is being tested?
- FX-111
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 10 sitesUnited States
- Study dates
- 1 Jul 2026to 15 Feb 2029
- Phase
- Phase 1
- 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 years and older
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Confirmed adenocarcinoma of the prostate.
- PSA levels ≥ 2 ng/mL at screening visit.
- Progressing PSA, defined as two consecutive increases in the most recent PSA measurements taken at least 1 week apart.
- Progressed on Androgen Deprivation Therapy (ADT) and at least one prior potent Androgen Receptor (AR) pathway inhibitor given in castration-sensitive prostate cancer setting or approved for castration-resistant prostate cancer (eg, apalutamide, darolutamide, abiraterone, enzalutamide).
- Ongoing primary ADT with gonadotropin-releasing hormone agonist or antagonist in the absence of bilateral orchiectomy.
- Acceptable physical functioning and laboratory measurements, per the study protocol.
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- Discontinued prior therapies within protocol-specified timeframes.
- Commit to use of highly-effective contraception while on study and for 90 days after.
- Willing and able to adhere to the study visit schedule and other protocol defined requirements.
Who cannot join
- Predominance of small cell carcinoma of the prostate/neuroendocrine prostate cancer in most recent tumor biopsy.
- Participants with brain metastases that require ongoing treatment with radiation or high-dose steroids.
- Not recovered from side effects of prior surgery or cancer treatments.
- Evidence of active viral, bacterial, or fungal infection requiring treatment with antivirals, antibiotics, or anti-fungal medications.
- Prior treatment with AR degraders and molecules with an AR ligand such as AR Regulated Induced Proximity Targeting Chimera (RIPTAC).
- Blood clots ≤ 4 weeks prior to start of treatment.
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- Concurrent malignancy requiring treatment or history of prior malignancy active within 2 years prior to the first dose of study drug. Patients may be eligible if the malignancy is clinically stable or has been treated with curative intent.
- Any evidence of severe or uncontrolled systemic diseases.
- Any condition that, in the opinion of the Investigator, would interfere with evaluation of the investigational product or interpretation of the patient's safety or study results.
Trial locations and contacts
10 sites in 1 country. Contact the study team or a site near you to ask about taking part.
10 sites in 1 country
United States10 sites, 10 recruiting
- Not yet recruiting
Massachusetts General Hospital
Boston, Massachusetts, 02114
Xin Gao, MD
- Not yet recruiting
Dana Farber Cancer Institute
Boston, Massachusetts, 02215
Mary-Ellen Taplin, MD
- Recruiting
START New Jersey
East Brunswick, New Jersey, 08816
Nurse Navigator, 732-426-4750, dana.sapia@startresearch.com
Bruno Fang, MD
- Recruiting
START Dallas-Fort Worth
Fort Worth, Texas, 76104
Hope Team Distribution List, 682-350-3010, hopeteam@startresearch.com
Salwan Al Mutar, MD, M.Sc.
- Recruiting
START Midwest
Grand Rapids, Michigan, 49546
Hope Team Distribution List, 616-389-1810, hopeteam@startresearch.com
Emerson Lim, MD
- Recruiting
NEXT Houston
Houston, Texas, 77054
Emma Morales, emorales@nextoncology.com
Jennifer Segar, MD
- Recruiting
START Los Angeles
Los Angeles, California, 90025
Hope Team Distribution List, 424-465-1820, hopeteam@startresearch.com
Navid Hafez, MD, MPH
- Recruiting
START Carolinas
Myrtle Beach, South Carolina, 29572
Kate Valipour, Clinical Research Coordinator, 843-449-1010 ext. 5268, kate.valipour@startresearch.com
Paige Wilson, 843-449-1010 ext. 5147, paige.wilson@startresearch.com
- Not yet recruiting
Tennessee Oncology
Nashville, Tennessee, 37203
Katy Beckermann, MD, Ph.D.
- Recruiting
NEXT Oncology
San Antonio, Texas, 78229
Jordan Georg, jgeorg@nextoncology.com
Ildefonso Ismael Rodriguez Rivera, MD
About this study
Official title: A Phase 1, First-in-Human, Dose-Finding Study to Evaluate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of FX-111 in Patients With Metastatic Castration-Resistant Prostate Cancer
The goal of this clinical trial is to find out if FX-111 is safe enough to permit further studies in adult male participants with metastatic castration-resistant prostate cancer (mCRPC). It will also study the drug's pharmacokinetics (how the body breaks down FX-111) and how well FX-111 treats mCRPC. The main questions it aims to answer are:
What are the side effects of FX-111?
Does FX-111 work to reduce or prevent progression of mCRPC?
The study doctor will oversee participants' treatment with FX-111 and ask about any side effects. Participants will take FX-111 every day by mouth and will have regular physical and laboratory examinations to check health and tumor status.
- Conditions
- Metastatic Castration Resistant Prostate Cancer, mCRPC, mCRPC (Metastatic Castration-resistant Prostate Cancer), Prostatic Neoplasms, Prostatic Neoplasms, Castration-Resistant, mCRPC or Advanced/Metastatic Solid Tumors
- Being tested
- FX-111
- Medical subject headings
- Prostatic Neoplasms, Prostatic Neoplasms, Castration-Resistant
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
FX-111Drug
FX-111 will be administered orally once daily in continuous 28-day cycles.
| Study group | Role | What they receive |
|---|---|---|
| FX-111 Dose Level 1 | Experimental | Not described Receives: Drug: FX-111 |
| FX-111 Dose Level 2 | Experimental | Not described Receives: Drug: FX-111 |
| FX-111 Dose Level 3 | Experimental | Not described Receives: Drug: FX-111 |
| FX-111 Dose Level 4 | Experimental | Not described Receives: Drug: FX-111 |
| FX-111 Dose Level 5 | Experimental | Not described Receives: Drug: FX-111 |
What is being measured
The primary outcome is the main question the study is designed to answer.
The number of adverse events (AEs), serious adverse events (SAEs), and drug withdrawal due to AE in participants receiving FX-111
Measured: Study day 1 throughout the study, estimated to be 6 months.
Secondary outcomes (6)
Area Under the Concentration Time Curve
Total body exposure of FX-111
Measured: Study day 1 throughout the study for 6 months.
Maximum concentration (Cmax) of FX-111 in the bloodstream.
Measured: Study day 1 throughout the study for 6 months.
Time required (Tmax) to reach Cmax of FX-111 in the bloodstream.
Measured: Study day 1 throughout the study for 6 months.
Rate of confirmed prostate-specific antigen (PSA) decline of ≥ 50% from baseline (PSA50).
Measured: Baseline and every 4 weeks throughout the study, estimated to be 6 months.
Objective Response Rate (ORR)
The number of patients who achieve either a Complete Response (CR) or Partial Response (PR) to FX-111.
CR: disappearance of all lesions and pathologic lymph nodes. PR: ≥30% decrease in sum of lesions, no new lesions, no progression of non-target lesions.
Measured: Tumor assessments at baseline and every 8 weeks throughout the study, estimated to be 6 months.
Duration of Response (DoR)
DoR is the time from initial CR or PR until disease progression.
Measured: Tumor assessments at baseline and every 8 weeks throughout the study, estimated to be 6 months.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Jul 2026
- Study start1 Jul 2026
- Primary completion15 Feb 2028 (estimated)
- Study completion15 Feb 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Metastatic Castration Resistant Prostate CancerStudies 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 1
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Flare Therapeutics Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07719361
- Sponsor's protocol ID
- FX-111-CLINPRO-1
- Status last verified
- Jul 2026
- First submitted
- 17 Jul 2026
- Last updated
- 24 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- 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 24 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 1, First-in-Human, Dose-Finding Study to Evaluate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of FX-111 in Patients With Metastatic Castration-Resistant Prostate Cancer
- ClinicalTrials.gov ID
- NCT07719361
- Acronym / sponsor ID
- FX-111-CLINPRO-1
- Conditions
- Metastatic Castration Resistant Prostate Cancer, mCRPC, mCRPC (Metastatic Castration-resistant Prostate Cancer), Prostatic Neoplasms, Prostatic Neoplasms, Castration-Resistant, mCRPC or Advanced/Metastatic Solid Tumors
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Flare Therapeutics Inc.Industry (pharma, biotech, devices)
- Study start
- 1 Jul 2026 (actual)
- Primary completion
- 15 Feb 2028 (estimated)
- Study completion
- 15 Feb 2029 (estimated)
- First posted
- 22 Jul 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 goal of this clinical trial is to find out if FX-111 is safe enough to permit further studies in adult male participants with metastatic castration-resistant prostate cancer (mCRPC). It will also study the drug's pharmacokinetics (how the body breaks down FX-111) and how well FX-111 treats mCRPC. The main questions it aims to answer are:
What are the side effects of FX-111?
Does FX-111 work to reduce or prevent progression of mCRPC?
The study doctor will oversee participants' treatment with FX-111 and ask about any side effects. Participants will take FX-111 every day by mouth and will have regular physical and laboratory examinations to check health and tumor status.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 5
| Arm | Type | Receives |
|---|---|---|
| FX-111 Dose Level 1 | Experimental | Drug: FX-111 |
| FX-111 Dose Level 2 | Experimental | Drug: FX-111 |
| FX-111 Dose Level 3 | Experimental | Drug: FX-111 |
| FX-111 Dose Level 4 | Experimental | Drug: FX-111 |
| FX-111 Dose Level 5 | Experimental | Drug: FX-111 |
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- Confirmed adenocarcinoma of the prostate.
- PSA levels ≥ 2 ng/mL at screening visit.
- Progressing PSA, defined as two consecutive increases in the most recent PSA measurements taken at least 1 week apart.
- Progressed on Androgen Deprivation Therapy (ADT) and at least one prior potent Androgen Receptor (AR) pathway inhibitor given in castration-sensitive prostate cancer setting or approved for castration-resistant prostate cancer (eg, apalutamide, darolutamide, abiraterone, enzalutamide).
- Ongoing primary ADT with gonadotropin-releasing hormone agonist or antagonist in the absence of bilateral orchiectomy.
Key exclusion criteria (9 listed)
- Predominance of small cell carcinoma of the prostate/neuroendocrine prostate cancer in most recent tumor biopsy.
- Participants with brain metastases that require ongoing treatment with radiation or high-dose steroids.
- Not recovered from side effects of prior surgery or cancer treatments.
- Evidence of active viral, bacterial, or fungal infection requiring treatment with antivirals, antibiotics, or anti-fungal medications.
- Prior treatment with AR degraders and molecules with an AR ligand such as AR Regulated Induced Proximity Targeting Chimera (RIPTAC).
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 |
|---|---|---|
| FX-111FX-111 will be administered orally once daily in continuous 28-day cycles. | Drug | FX-111 Dose Level 1, FX-111 Dose Level 2, FX-111 Dose Level 3, FX-111 Dose Level 4, FX-111 Dose Level 5 |
Primary outcome
The number of adverse events (AEs), serious adverse events (SAEs), and drug withdrawal due to AE in participants receiving FX-111
Time frame: Study day 1 throughout the study, estimated to be 6 months.
6 secondary outcomes
Area Under the Concentration Time Curve
Time frame: Study day 1 throughout the study for 6 months.
Maximum concentration (Cmax) of FX-111 in the bloodstream.
Time frame: Study day 1 throughout the study for 6 months.
Time required (Tmax) to reach Cmax of FX-111 in the bloodstream.
Time frame: Study day 1 throughout the study for 6 months.
Rate of confirmed prostate-specific antigen (PSA) decline of ≥ 50% from baseline (PSA50).
Time frame: Baseline and every 4 weeks throughout the study, estimated to be 6 months.
Objective Response Rate (ORR)
Time frame: Tumor assessments at baseline and every 8 weeks throughout the study, estimated to be 6 months.
Duration of Response (DoR)
Time frame: Tumor assessments at baseline and every 8 weeks throughout the study, estimated to be 6 months.
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 24 Sep 2026.
- Individual participant dataSharing planned: No
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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.
10 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing FX-111 in people with Metastatic Castration Resistant Prostate Cancer and mCRPC, run by Flare Therapeutics Inc. at 10 sites in United States.
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 9 inclusion and 9 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: looking for participants now, as of the sponsor's last update on 24 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 10 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
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 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
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 Janine Koucheki, Associate Director, Clinical Operations (857-706-4400, clinops@flaretx.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The number of adverse events (AEs), serious adverse events (SAEs), and drug withdrawal due to AE in participants receiving FX-111 (time frame: Study day 1 throughout the study, estimated to be 6 months.). 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 24 Sep 2026.