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Checkpoint Inhibitor

Pembrolizumab for Prostate Cancer (CHOMP Trial)

Phase 2
Recruiting
Led By Matthew B. Rettig, MD
Research Sponsored by VA Office of Research and Development
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Adequate organ function: Hemoglobin (hgb) > 9.0 g/dL, Absolute neutrophil count (ANC) > 1500/ uL, Platelets > 100,000/ uL, Total bilirubin 1.5 x ULN OR direct bilirubin ULN for participants with total bilirubin levels >1.5 x ULN ALT and AST 2.5 x ULN ( 5 x ULN for participants with liver metastases) (Child-Pugh class A and B allowed; Child-Pugh class C is excluded). Creatinine < (2.0 mg/dL) during screening evaluation (>2.0 is allowed if EGFR >30 mL/min/1.73 m2). Subject must agree to use contraception during the treatment period plus an additional 120 days after the last dose of study treatment and must refrain from donating sperm during this period.
Progressive castration resistant prostate cancer as defined by serum testosterone < 50 ng/mL and one of the following: PSA progression confirmed per Prostate Cancer Clinical Trials Working Group (PCWG3), Radiographic progression of soft tissues according to Response Evaluation Criteria in Solid Tumors, version 1.1 (iRECIST 1.1) modified based on PCWG3, or radiographic progression of bone according to PCWG3. Prior use of a novel AR signaling inhibitor for 4 weeks, including abiraterone acetate plus prednisone/prednisolone, enzalutamide, apalutamide, and/or darolutamide. NOTE: These AR signaling inhibitors may have been used for mCSPC, M0CRPC, and/or mCRPC.
Timeline
Screening 3 weeks
Treatment Varies
Follow Up first day of pembrolizumab administration to 6 months after
Awards & highlights

CHOMP Trial Summary

This trial is testing the efficacy of pembrolizumab, a checkpoint inhibitor, in Veterans with metastatic castration-resistant prostate cancer. The study will also compare the pre-treatment and at-progression metastatic tumor biopsies to investigate the molecular correlates of resistance and sensitivity to pembrolizumab.

Who is the study for?
Men with advanced prostate cancer that's resistant to hormone therapy and has specific genetic changes (mismatch repair deficiency or CDK12 inactivation) can join. They must be adults, have a good performance status, agree to use contraception, and not have brain metastases or active infections. Prior treatments for cancer should be completed before joining.Check my eligibility
What is being tested?
The trial is testing pembrolizumab, an immune checkpoint inhibitor, on its effectiveness against certain types of advanced prostate cancer. It will also compare tumor samples before and after treatment to understand resistance or sensitivity to the drug.See study design
What are the potential side effects?
Pembrolizumab may cause immune-related side effects like inflammation in various organs including lungs (pneumonitis), liver issues, skin reactions, hormonal gland problems (like thyroid dysfunction), fatigue, infusion reactions and possibly other autoimmune-like conditions.

CHOMP Trial Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
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My prostate cancer is worsening despite low testosterone, and I've used specific prostate cancer medications for at least 4 weeks.
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My prostate cancer is worsening despite low testosterone levels.
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My liver function tests are within the required range.
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My prostate cancer is identified as adenocarcinoma or small cell type.
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My cancer has spread, confirmed by specific scans within the last 2 months.
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I am 18 years old or older.
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I am undergoing treatment to lower my testosterone levels below 50 ng/dL.
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I have a metastatic lesion that can be biopsied and was or will be biopsied within the last 6 months.
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My cancer has specific genetic changes, either in MMR genes or CDK12.
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I can carry out all my daily activities without help.
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I am 18 years old or older.
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My prostate cancer is diagnosed as adenocarcinoma or small cell.
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I have been treated with specific prostate cancer medications for at least 4 weeks.
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My cancer has grown or spread according to recent scans.
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My cancer has specific genetic changes (dMMR or CDK12-/-).
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I can do all my usual activities without help.
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My genetic test shows changes in the CDK12 gene.

CHOMP Trial Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~first day of pembrolizumab administration to 6 months after
This trial's timeline: 3 weeks for screening, Varies for treatment, and first day of pembrolizumab administration to 6 months after for reporting.

Treatment Details

Study Objectives

Outcome measures can provide a clearer picture of what you can expect from a treatment.
Primary outcome measures
Objective Response Rate
PSA Decline
Secondary outcome measures
Incidence of Treatment-Emergent Adverse Events [Safety and Tolerability]
Maximum PSA Response
Overall Survival
+1 more
Other outcome measures
Identification of Molecular Correlates and Biomarkers of Resistance and Sensitivity to Pembrolizumab

Side effects data

From 2024 Phase 2 trial • 57 Patients • NCT03004183
21%
Fatigue
13%
Nausea
11%
Back pain
9%
Shortness of Breath
9%
Anemia
9%
Abdominal pain
9%
Diarrhea
7%
Kidney Injury and/or Infection
7%
Pneumonia
7%
Dyspnea
7%
Weight Loss
5%
Malnutrition, Hypercalcemia and Weakness
5%
Pneumothorax
5%
Activated partial thromboplastin time prolonged
5%
Intractable pain, back pain, hip pain
4%
Pleural effusion
4%
Atrial fibrillation with rapid ventricular response
2%
Skin rash
2%
Thrombocytopenia
2%
Respiratory failure
2%
colitis
100%
80%
60%
40%
20%
0%
Study treatment Arm
Single Arm

CHOMP Trial Design

1Treatment groups
Experimental Treatment
Group I: Single ArmExperimental Treatment1 Intervention
This is a single-arm, open-label study of the checkpoint inhibitor, pembrolizumab, in Veterans with mCRPC who have progressed on at least 1 prior novel androgen receptor (AR) signaling inhibitor, inclusive of abiraterone acetate, enzalutamide, apalutamide, and darolutamide. In addition to progressive mCRPC, a patient must have a somatic tumor mutation characterized by dMMR or CDK12-/- detected by next generation sequencing (NGS). Patients enrolled in this study will be treated with pembrolizumab at the FDA approved dosage of 200 mg intravenously every 3 weeks (21 days) until disease progression or unacceptable toxicity. During study, patients will maintain a castrate level of testosterone, = 50 ng/dL by ongoing treatment with a GnRH analogue or prior bilateral orchiectomy. Prior to initiating treatment with pembrolizumab, patients will undergo a baseline biopsy of a metastatic lesion. An additional biopsy of a metastatic lesion at the time of progression will be encouraged as well.
Treatment
First Studied
Drug Approval Stage
How many patients have taken this drug
Pembrolizumab
FDA approved

Find a Location

Who is running the clinical trial?

Merck Sharp & Dohme LLCIndustry Sponsor
3,868 Previous Clinical Trials
5,051,969 Total Patients Enrolled
27 Trials studying Prostate Cancer
16,997 Patients Enrolled for Prostate Cancer
VA Office of Research and DevelopmentLead Sponsor
1,606 Previous Clinical Trials
3,305,975 Total Patients Enrolled
15 Trials studying Prostate Cancer
8,785 Patients Enrolled for Prostate Cancer
Matthew B. Rettig, MDPrincipal InvestigatorVA Greater Los Angeles Healthcare System, West Los Angeles, CA
2 Previous Clinical Trials
100 Total Patients Enrolled

Media Library

Pembrolizumab (Checkpoint Inhibitor) Clinical Trial Eligibility Overview. Trial Name: NCT04104893 — Phase 2
Prostate Cancer Research Study Groups: Single Arm
Prostate Cancer Clinical Trial 2023: Pembrolizumab Highlights & Side Effects. Trial Name: NCT04104893 — Phase 2
Pembrolizumab (Checkpoint Inhibitor) 2023 Treatment Timeline for Medical Study. Trial Name: NCT04104893 — Phase 2

Frequently Asked Questions

These questions and answers are submitted by anonymous patients, and have not been verified by our internal team.

Are additional participants being welcomed into this experiment?

"Affirmative. Clinicaltrials.gov hosts data indicating that, having been initially posted on February 20th 2020, this clinical trial is in pursuit of 30 participants from 12 different medical sites."

Answered by AI

How many subjects can be enrolled in this research program?

"Affirmative. Clinicaltrials.gov reveals that this medical trial is currently recruiting patients, which began back on February 20th 2020 and was recently updated on October 19th 2022. The research team requires 30 participants to be enrolled across 12 sites nationwide."

Answered by AI

How many health care centers in North America are hosting this research project?

"This clinical trial is open at Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA in Pennsylvania; the VA Central Office located Washington DC; Hunter Holmes McGuire VA Medical Center situated in Richmond, Virginia and an additional 12 sites across America."

Answered by AI

Has Pembrolizumab been explored in any other research projects?

"Since it was first studied in 2010 at City of Hope, pembrolizumab has featured in 251 completed trials and 961 active ones. A significant concentration of these tests are taking place within Philadelphia, Pennsylvania."

Answered by AI

Is Pembrolizumab efficacious enough to be relied upon with confidence?

"Due to the limited efficacy data and existing safety evidence, our team at Power assigned Pembrolizumab a score of 2."

Answered by AI

What is the primary purpose of this investigation?

"The primary end-point of this clinical trial, measured from the first day of pembrolizumab administration to 6 months later, is PSA Decline. Secondary outcomes include Overall Survival (time from enrolment until death), Time to Progression of Disease (Time to PSA progression and initiation of alternative anti-neoplastic therapy or radiographic progression) as well as Incidence of Treatment-Emergent Adverse Events [Safety and Tolerability] which gauges the safety profile of pembrolizumab in these patients with prostate cancer by evaluating adverse events experienced."

Answered by AI

What are the principal indications for Pembrolizumab?

"Pembrolizumab is a viable form of treatment for malignant neoplasms, those with unresectable melanoma, and those whose cancer has high microsatellite instability."

Answered by AI
~6 spots leftby Mar 2025