Study of Apalutamide With Carotuximab in Metastatic, Castration-Resistant Prostate Cancer

January 29, 2026 updated by: Edwin Posadas, MD

Phase II Study of Apalutamide With Carotuximab in Metastatic, Castration-Resistant Prostate Cancer

This is an open-label, multi-site study of apalutamide 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 apalutamide and apalutamide + 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 apalutamide that benefit from the addition of carotuximab, and to determine the ORR, radiographic PFS, and biochemical PFS in the overall population.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

100

Phase

  • 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 Contact

Study Locations

  • United States
    • California
      • Duarte, California, United States, 91010
        • Recruiting
        • City of Hope
        • Contact:
      • Los Angeles, California, United States, 90048
        • Recruiting
        • Cedars-Sinai Medical Center
        • Sub-Investigator:
          • David Hoffman, MD
        • Contact:
        • Sub-Investigator:
          • Robert Figlin, MD FACP
        • Sub-Investigator:
          • Kevin Scher, MD MBA
        • Sub-Investigator:
          • Leland Green, MD
        • Sub-Investigator:
          • Kristopher Wentzel, MD
        • Sub-Investigator:
          • Jun Gong, MD
    • Utah
      • Salt Lake City, Utah, United States, 84112
        • Recruiting
        • Huntsman Cancer Institute and Hospital
        • Contact:

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

Ages Eligible for Study

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • History of castration-resistant prostate cancer with rising PSA (prostate-specific antigen) on a contemporary ARSI (Androgen receptor (AR) signaling inhibitor: abiraterone, enzalutamide, darolutamide). Bicalutamide, nilutamide, and flutamide will not be considered as contemporary ARSIs
  • Patient must have had 1 and can have up to 2 prior AR targeted therapy with the exception of apalutamide.
  • Patients must decline or be ineligible for taxane therapy in the opinion of the treating physician.
  • 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 and/or carotuximab)

Exclusion Criteria:

  • Non-PSA producing prostate cancers such as small cell prostate cancers or those prostate cancers which exhibit radiographic progression without PSA rise
  • Prior use of apalutamide
  • Other prior malignancy requiring active anticancer therapy
  • Prior exposure to carotuximab or any CD105 targeted antibody
  • Active bleeding or pathologic medical conditions that carries a high bleeding risk
  • A known diagnosis of Osler-Weber-Rendu syndrome

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: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Apalutamide monotherapy
After progression, subjects will crossover to combination therapy
Drug: Apalutamide
Standard of care Apalutamide 240 mg administered orally and daily on Days 1-28 of every 28 day cycle
Experimental: Combination therapy (Apalutamide + Carotuximab)
Drug: Apalutamide
Standard of care Apalutamide 240 mg administered orally and daily on Days 1-28 of every 28 day cycle
Drug: Carotuximab

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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Progression free survival (rPFS) between patients receiving apalutamide and apalutamide + 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.
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 Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of Adverse events (grade 3 or higher) related to carotuximab and apalutamide
Time Frame: From start of study treatment through 4 weeks on treatment
Grade 3 or above treatment related adverse events as assessed per NCI Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.
From start of study treatment through 4 weeks on treatment
Overall radiographic response rate (ORR) of the combination of apalutamide + 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.
Participants of the combination of apalutamide + carotuximab, with confirmed complete response (CR) or partial response (PR) per RECIST v.1.1 and Prostate Cancer Working Group 3
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 apalutamide 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.
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
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.
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
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.
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.
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.
From the start of study treatment until documented progression, per Prostate Cancer Working Group 3, or death due to any cause.
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.

Collaborators and Investigators

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

Sponsor

Edwin Posadas, MD

Collaborators

Enviro Therapeutics, Inc.

Investigators

  • Principal Investigator: Edwin Posadas, MD FACP, Cedars-Sinai Medical Center

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)

December 27, 2023

Primary Completion (Estimated)

January 1, 2027

Study Completion (Estimated)

January 1, 2027

Study Registration Dates

First Submitted

September 6, 2022

First Submitted That Met QC Criteria

September 6, 2022

First Posted (Actual)

September 9, 2022

Study Record Updates

Last Update Posted (Actual)

February 2, 2026

Last Update Submitted That Met QC Criteria

January 29, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IIT2021-06-Posadas-APA105

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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