Castration-resistant Prostate CancerPhase 2NCT05534646
Study of AR Suppression With Carotuximab in Metastatic, Castration-Resistant Prostate Canc
A Phase 2 study testing AR Blockade and Carotuximab in people with Castration-resistant Prostate Cancer, run by Edwin Posadas, MD at 3 sites in United States.
Trial summary
This is an open-label, multi-site study of AR Blockade with carotuximab in patients who have progressed on androgen receptor signaling inhibitor (ARSI) therapy. This study will begin with a safety assessment in the first 10 subjects (part 1: Safety Lead-in). Read more about this study
- Who is it for?
- Ages 18 years and older, men only
- Conditions the study is for
- Castration-resistant Prostate Cancer
- What is being tested?
- AR Blockade and Carotuximab
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 116 participants
- Where
- 3 sitesUnited States
- Study dates
- 27 Dec 2023to Jan 2028
- Phase
- Phase 2
- 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
- History of castration-resistant prostate cancer with rising PSA on a contemporary ARSI (e.g. abiraterone or, enzalutamide, darolutamide). Bicalutamide, nilutamide, and flutamide will not be considered as contemporary ARSIs.
- PSA rise will be defined as an increase in PSA of 0.2 ng/mL or higher on at least 2 separate occasions greater than 1 week apart while on an ARSI
- Patient must be surgically castrated or have serum testosterone concentrations much be consistent with castrate levels of testosterone (under 50 ng/dL) while on LHRH analog therapy
- Patient must have had 1 and can have up to 2 prior AR targeted agents (if patients have had previous enzalutamide, they will be considered only for arm C). therapy with the exception of apalutamide.
- Patients may not have had previous chemotherapy with the exception of docetaxel administered for castration-sensitive disease.
- Patients must decline or be ineligible for taxane therapy in the opinion of the treating physician.
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- Have Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0-1
- Resolution of adverse events results as described below:
- If the subject's patient's most recent line of therapy is treatment with abiraterone or enzalutamide, then all adverse events must be resolved to Grade 2 or less
- If the subject's patient's most recent line of therapy is any other treatment for mCRPC then all Adverse events must be resolved to grade 1 or less, with the exception of fatigue, alopecia and neuropathy (which must resolve to CTCAE grade 2)
- Adequate organ function
- All patients must agree to use an adequate method of contraception, in the opinion of the treating investigator, while on protocol treatment and for 3 months after the last dose of protocol treatment (apalutamide/enzalutamide and/or carotuximab)
- Written informed consent obtained from subject and ability for subject to comply with the requirements of the study
Who cannot join
- Non-PSA producing prostate cancers such as small cell prostate cancers or those prostate cancers which exhibit radiographic progression without PSA rise
- Other prior malignancy requiring active anticancer therapy
- Prior exposure to carotuximab or any CD105 targeted antibody
- Any major surgical procedure, in the opinion of the treating physician, within 2 weeks of starting therapy
- Uncontrolled chronic hypertension defined as sustained systolic pressure (SBP) >150 mmHg or diastolic pressure (DBP) >90 despite optimal therapy
- Active bleeding or pathologic medical conditions, including but not limited to factor deficiencies, hemophilia, etc., that carries a high bleeding risk
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- Use of thrombolytics within 10 days prior to the first day of carotuximab
- Known hypersensitivity to Chinese hamster ovary products or other recombinant human, chimeric, or humanized antibodies
- A known diagnosis of Osler-Weber-Rendu syndrome
- Ascites or pericardial or pleural effusion requiring external drainage procedures
- History of untreated brain involvement with cancer, spinal cord compression, or carcinomatous meningitis, or new evidence of brain or leptomeningeal disease. Patients with radiated or resected lesions are permitted, provided the lesions are fully treated and inactive, patients are asymptomatic, and no steroids have been administered for at least 28 days. Imaging for CNS disease will not be required for screening unless there is a history of a neurological finding such as new onset of weakness or numbness that cannot be explained by other medical history.
- Acute cardiovascular event within the past 6 months. An acute cardiovascular event will be defined as a myocardial infarction, NYHA Class II or worse congestive heart failure, cerebrovascular accident, transient ischemic attack, arterial embolism, pulmonary embolism, percutaneous transluminal coronary angioplasty (PTCA), or CABG.
- Deep venous thrombosis within the past 6 months, unless the patient is anti-coagulated without the use of warfarin for at least 2 weeks. In this situation, low molecular weight heparin is preferred but clearance should be given by the local PI.
Trial locations and contacts
3 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Edwin Posadas, MD FACP contact
United States3 sites, 3 recruiting
- Recruiting
City of Hope
Duarte, California, 91010
Tanya Dorff, MD, 626-256-4673, tdorff@coh.org
- Recruiting
Cedars-Sinai Medical Center
Los Angeles, California, 90048
Clinical Trial Recruitment Navigator, 310-423-5842, GroupCancerTrialInformation@cshs.org
Edwin Posadas, edwin.posadas@csmc.edu
- Recruiting
Huntsman Cancer Institute and Hospital
Salt Lake City, Utah, 84112
Umang Swami, MD, 801-587-4381, Umang.Swami@hci.utah.edu
About this study
Official title: Phase II Study of AR Suppression With Carotuximab in Metastatic, Castration-Resistant Prostate Canc
This is an open-label, multi-site study of AR Blockade with carotuximab in patients who have progressed on androgen receptor signaling inhibitor (ARSI) therapy. This study will begin with a safety assessment in the first 10 subjects (part 1: Safety Lead-in). If the combination is deemed safe, the trial will proceed to the Phase II stage. The purpose of this study is to compare progression free survival (PFS) between patients receiving AR Blockade and AR Blockade + carotuximab using Response Evaluation Criteria in Solid Tumors (RECIST 1.1) and Prostate Cancer Working Group 3. The secondary objectives are to describe adverse events related to the intervention, overall response rate (ORR), proportion of patients resistant to AR blockade that benefit from the addition of carotuximab, and to determine the ORR, radiographic PFS, and biochemical PFS in the overall population.
- Conditions
- Castration-resistant Prostate Cancer
- Being tested
- AR Blockade, Carotuximab
- Keywords
- Prostate cancer, Castration-resistant, CRPC
- Medical subject headings
- Prostatic Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AR BlockadeDrug
Also called Apalutamide, Enzalutamide
Standard of care Apalutamide 240 mg / Enzalutamide 160mg administered orally and daily on Days 1-28 of every 28 day cycle
CarotuximabDrug
Carotuximab administered intravenously at the following doses:
Cycle 1 Day 1: 3 mg/kg Cycle 1 Day 4: 7 mg/kg Cycle 1 Day 8: 10 mg/kg Cycle 1 Day 15: 10 mg/kg Cycle 1 Day 22: 10 mg/kg Cycle 2 Day 1: 15 mg/kg Cycle 2 Day 15: 15 mg/kg Cycle 3+ Day 1: 15 mg/kg After completion of cycle 2, dosing of carotuximab will continue at a q4 week schedule using the 15 mg/kg dose.
| Study group | Role | What they receive |
|---|---|---|
| Enzalutamide Naive - Monotherapy | Active comparator | After progression, subjects will crossover to combination therapy Receives: Drug: AR Blockade |
| Enzalutamide Naive - Combination therapy (Androgen Receptor Blockade + Carotuximab) | Experimental | Androgen Receptor is Apalutamide 240mg for Lead-In group \& Enzalutamide 160mg for all other groups Receives: Drug: AR Blockade; Drug: Carotuximab |
| Enzalutamide Exposed - Combination therapy (Androgen Receptor Blockade + Carotuximab) | Experimental | Androgen Receptor is Apalutamide 240mg for Lead-In group \& Enzalutamide 160mg for all other groups Receives: Drug: AR Blockade; Drug: Carotuximab |
What is being measured
The primary outcome is the main question the study is designed to answer.
Progression free survival (rPFS) between patients receiving AR blockade and AR blockade + carotuximab
From the start of study treatment until documented progression, per Response Evaluation Criteria in Solid Tumors (RECIST 1.1) and Prostate Cancer Working Group 3, or death due to any cause.
Measured: From the start of study treatment until documented progression, or death due to any cause, up to 30 days of follow-up after end of treatment.
Secondary outcomes (6)
Incidence of Adverse events (grade 3 or higher) related to carotuximab and AR blockade
Grade 3 or above treatment related adverse events as assessed per NCI Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.
Measured: From start of study treatment through 4 weeks on treatment
Overall radiographic response rate (ORR) of the combination of AR blockade + carotuximab
Participants of the combination of AR blockade + carotuximab, with confirmed complete response (CR) or partial response (PR) per RECIST v.1.1 and Prostate Cancer Working Group 3
Measured: From the start of combination study treatment until documented progression, or death due to any cause, up to 30 days of follow-up after end of treatment.
Proportion of patients resistant to AR blockade benefit from the addition of carotuximab
Participants of the monotherapy group that crossover to combination therapy at progression, with confirmed complete response (CR) or partial response (PR) per RECIST v.1.1 and Prostate Cancer Working Group 3
Measured: From the start of combination therapy study treatment until documented progression, or death due to any cause, up to 30 days of follow-up after end of treatment.
Overall radiographic response rate (ORR) in the overall population
Determined by confirmed complete response (CR) or partial response (PR) per Response Evaluation Criteria in Solid Tumors (RECIST 1.1) and Prostate Cancer Working Group 3
Measured: From the start of study treatment until documented progression, or death due to any cause, up to 30 days of follow-up after end of treatment.
To determine the radiographic progression free survival (rPFS) in the overall population
From the start of study treatment until documented progression, per Response Evaluation Criteria in Solid Tumors (RECIST 1.1) and Prostate Cancer Working Group 3, or death due to any cause.
Measured: From the start of study treatment until documented progression, or death due to any cause, up to 30 days of follow-up after end of treatment.
To determine the biochemical PFS (by PCWG3) in the overall population
From the start of study treatment until documented progression, per Prostate Cancer Working Group 3, or death due to any cause.
Measured: From the start of study treatment until documented progression, or death due to any cause, up to 30 days of follow-up after end of treatment.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Sep 2022
- Study start27 Dec 2023
- Primary completionJan 2028 (estimated)
- Study completionJan 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for 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 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 116 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Edwin Posadas, MD
- Sponsor type
- University, hospital or other
- Collaborators
- Kairos Pharma
- Responsible party
- Sponsor-investigator, Edwin Posadas, MD, Cedars-Sinai Medical Center
- Investigators
- Edwin Posadas, MD FACP, Principal investigator, Cedars-Sinai Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05534646
- Sponsor's protocol ID
- IIT2021-06-Posadas-AR105
- Status last verified
- Sep 2026
- First submitted
- 6 Sep 2022
- Last updated
- 5 Oct 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 5 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phase II Study of AR Suppression With Carotuximab in Metastatic, Castration-Resistant Prostate Canc
- ClinicalTrials.gov ID
- NCT05534646
- Acronym / sponsor ID
- IIT2021-06-Posadas-AR105
- Conditions
- Castration-resistant Prostate Cancer
- Keywords
- Prostate cancer, Castration-resistant, CRPC
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 116 participants (estimated)
- Lead sponsor
- Edwin Posadas, MDUniversity, hospital or other
- Collaborators
- Kairos Pharma
- Study start
- 27 Dec 2023 (actual)
- Primary completion
- Jan 2028 (estimated)
- Study completion
- Jan 2028 (estimated)
- First posted
- 9 Sep 2022 (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.
This is an open-label, multi-site study of AR Blockade with carotuximab in patients who have progressed on androgen receptor signaling inhibitor (ARSI) therapy. This study will begin with a safety assessment in the first 10 subjects (part 1: Safety Lead-in). If the combination is deemed safe, the trial will proceed to the Phase II stage. The purpose of this study is to compare progression free survival (PFS) between patients receiving AR Blockade and AR Blockade + carotuximab using Response Evaluation Criteria in Solid Tumors (RECIST 1.1) and Prostate Cancer Working Group 3. The secondary objectives are to describe adverse events related to the intervention, overall response rate (ORR), proportion of patients resistant to AR blockade that benefit from the addition of carotuximab, and to determine the ORR, radiographic PFS, and biochemical PFS in the overall population.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Enzalutamide Naive - Monotherapy | Active comparator | Drug: AR BlockadeAfter progression, subjects will crossover to combination therapy |
| Enzalutamide Naive - Combination therapy (Androgen Receptor Blockade + Carotuximab) | Experimental | Drug: AR Blockade, Drug: CarotuximabAndrogen Receptor is Apalutamide 240mg for Lead-In group \& Enzalutamide 160mg for all other groups |
| Enzalutamide Exposed - Combination therapy (Androgen Receptor Blockade + Carotuximab) | Experimental | Drug: AR Blockade, Drug: CarotuximabAndrogen Receptor is Apalutamide 240mg for Lead-In group \& Enzalutamide 160mg for all other groups |
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (13 listed)
- History of castration-resistant prostate cancer with rising PSA on a contemporary ARSI (e.g. abiraterone or, enzalutamide, darolutamide). Bicalutamide, nilutamide, and flutamide will not be considered as contemporary ARSIs.
- Patients must decline or be ineligible for taxane therapy in the opinion of the treating physician.
- Have Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0-1
- Resolution of adverse events results as described below:
- Adequate organ function
Key exclusion criteria (13 listed)
- Non-PSA producing prostate cancers such as small cell prostate cancers or those prostate cancers which exhibit radiographic progression without PSA rise
- Other prior malignancy requiring active anticancer therapy
- Prior exposure to carotuximab or any CD105 targeted antibody
- Any major surgical procedure, in the opinion of the treating physician, within 2 weeks of starting therapy
- Uncontrolled chronic hypertension defined as sustained systolic pressure (SBP) >150 mmHg or diastolic pressure (DBP) >90 despite optimal therapy
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 |
|---|---|---|
| AR BlockadeAlso: Apalutamide, EnzalutamideStandard of care Apalutamide 240 mg / Enzalutamide 160mg administered orally and daily on Days 1-28 of every 28 day cycle | Drug | Enzalutamide Exposed - Combination therapy (Androgen Receptor Blockade + Carotuximab), Enzalutamide Naive - Combination therapy (Androgen Receptor Blockade + Carotuximab), Enzalutamide Naive - Monotherapy |
| CarotuximabCarotuximab administered intravenously at the following doses: Cycle 1 Day 1: 3 mg/kg Cycle 1 Day 4: 7 mg/kg Cycle 1 Day 8: 10 mg/kg Cycle 1 Day 15: 10 mg/kg Cycle 1 Day 22: 10 mg/kg Cycle 2 Day 1: 15 mg/kg Cycle 2 Day 15: 15 mg/kg Cycle 3+ Day 1: 15 mg/kg After completion of cycle 2, dosing of carotuximab will continue at a q4 week schedule using the 15 mg/kg dose. | Drug | Enzalutamide Exposed - Combination therapy (Androgen Receptor Blockade + Carotuximab), Enzalutamide Naive - Combination therapy (Androgen Receptor Blockade + Carotuximab) |
Primary outcome
Progression free survival (rPFS) between patients receiving AR blockade and AR blockade + carotuximab
Time frame: From the start of study treatment until documented progression, or death due to any cause, up to 30 days of follow-up after end of treatment.
From the start of study treatment until documented progression, per Response Evaluation Criteria in Solid Tumors (RECIST 1.1) and Prostate Cancer Working Group 3, or death due to any cause.
6 secondary outcomes
Incidence of Adverse events (grade 3 or higher) related to carotuximab and AR blockade
Time frame: From start of study treatment through 4 weeks on treatment
Overall radiographic response rate (ORR) of the combination of AR blockade + carotuximab
Time frame: From the start of combination study treatment until documented progression, or death due to any cause, up to 30 days of follow-up after end of treatment.
Proportion of patients resistant to AR blockade benefit from the addition of carotuximab
Time frame: From the start of combination therapy study treatment until documented progression, or death due to any cause, up to 30 days of follow-up after end of treatment.
Overall radiographic response rate (ORR) in the overall population
Time frame: From the start of study treatment until documented progression, or death due to any cause, up to 30 days of follow-up after end of treatment.
To determine the radiographic progression free survival (rPFS) in the overall population
Time frame: From the start of study treatment until documented progression, or death due to any cause, up to 30 days of follow-up after end of treatment.
To determine the biochemical PFS (by PCWG3) in the overall population
Time frame: From the start of study treatment until documented progression, or death due to any cause, up to 30 days of follow-up after end of treatment.
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 5 Oct 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.
Edwin Posadas, MD FACP contact
Edwin Posadas, MD FACP principal investigator
Cedars-Sinai Medical Center
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing AR Blockade and Carotuximab in people with Castration-resistant Prostate Cancer, run by Edwin Posadas, MD at 3 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 13 inclusion and 13 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 5 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 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 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
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 Trial Recruitment Navigator (310-423-5842, GroupCancerTrialInformation@cshs.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Progression free survival (rPFS) between patients receiving AR blockade and AR blockade + carotuximab (time frame: From the start of study treatment until documented progression, or death due to any cause, up to 30 days of follow-up after end of treatment.). 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 5 Oct 2026.