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RecruitingPhase 1 / Phase 2

A Trial to Find Out if REGN4336 is Safe and How Well it Works Alone and in Combination With REGN5678 for Adult Participants With Advanced Prostate Cancer

Phase 1/2 Study of REGN4336 (a PSMAxCD3 Bispecific Antibody) Administered Alone or in Combination With REGN5678 (a PSMAxCD28 Bispecific Antibody) in Patients With Metastatic Castration-Resistant Prostate Cancer

Who can join

As published by the study on ClinicalTrials.gov. "Not stated" means the study hasn't said — ask the study team.

Age
18 Years and older
Sex
Male only
Healthy volunteers
Not accepted
Compensation
Not stated

Other requirements are listed under Eligibility below. Only the study team can confirm whether you can join.

What to expect

No one can promise a trial will help you personally — that is what the research is trying to find out.

What participation involves

Not stated in the study description — ask the study team about visits and procedures.

Compensation
Not stated
  • Study-related exams and procedures are typically provided at no cost. This is how many trials work in general — confirm the details for this study with the study team.
  • Participants are monitored closely by the research team throughout the study.
  • Some participants may receive access to an investigational treatment, which is still being studied.
  • Your participation helps researchers learn whether this approach could help future patients.

About this study

In plain language

This study tests REGN4336 alone and with REGN5678 in adults with previously treated prostate cancer that has spread. It looks for safe doses, checks side effects, and tests how well the drugs together shrink tumors.

This study is researching an investigational drug called REGN4336 both alone or together with another investigational drug called REGN5678. The study is focused on participants with previously treated metastatic prostate cancer. The main purpose of the study is to look at the safety, tolerability (how the body reacts to the drug) and effectiveness (how well the drug works to shrink tumors) of REGN4336 when given in combination with REGN5678. The study has 2 parts. The purpose of Part 1 is to determine a safe dose(s) of REGN4336 to be given alone or in combination with REGN5678. Part 1 is known as the "dose escalation" phase. The purpose of Part 2, (known as the "dose expansion" phase), is to use the doses of REGN4336 and REGN5678 selected in Part 1 to further test how well the combination treatment with REGN4336 and REGN5678 works to shrink tumors. The study is looking at several other research questions, including: * What side effects may happen from taking REGN4336 alone or in combination with REGN5678 * How well does REGN4336 in combination with REGN5678 reduce tumor size * How much REGN4336 is in the blood at different times when it is given alone or in combination with REGN5678 * Does the body make antibodies against the study drugs (REGN4336 or REGN5678)

Compensation is read from the study's own description and may be missing — always confirm with the study team.

Eligibility

Who can join

  • Tests of tissue or cells must confirm prostate adenocarcinoma, a type of prostate cancer, not pure small cell cancer.
  • The cancer must have spread and keep growing despite treatment to lower male hormones.
  • Your PSA, a blood marker for prostate cancer, must be at least 4 ng/mL at screening.
  • The cancer must have worsened in the past 6 months. This can be shown by rising PSA confirmed by tests at least 1 week apart, growth on scans, or at least 2 new cancer spots on a bone scan.
  • At least 2 past drug treatments, besides hormone-lowering therapy, must have stopped working or caused side effects you could not tolerate.
  • Past treatments must include at least one newer hormone-blocking drug, such as abiraterone, enzalutamide, apalutamide, or darolutamide.

Who can't join

  • You received an approved biologic treatment, a medicine made from living sources that works throughout the body, within 3 weeks before study dosing, or have not recovered enough from its short-term side effects. Some lab changes are exceptions.
  • You received a biologic treatment or cancer immune treatment too recently. The required wait is 5 half-lives—the time it takes the amount of drug in the body to drop by half, repeated 5 times.
  • You had treatment targeting PSMA, a protein on prostate cancer cells. PSMA-targeted radiation drugs are allowed if the last dose was at least 12 weeks before the study drug.
  • You need ongoing steroid treatment above 10 mg of prednisone a day, or an equal dose of another steroid, within 1 week before the first study dose.
  • You have, or had within 5 years, a serious disease in which the immune system attacks the body that needed medicines to weaken the immune system.
  • In the past year, you had brain inflammation, inflammation around the brain and spinal cord, a disease that damages nerves over time, or uncontrolled seizures. Mild dementia that does not affect daily activities is allowed.
  • You have uncontrolled HIV, hepatitis B, or hepatitis C, or a diagnosed condition that weakens your immune system.

Simplified for readability. The official criteria below are what the study team uses.

Official eligibility criteria

Key Inclusion Criteria: 1. Histologically or cytologically confirmed adenocarcinoma of the prostate without pure small cell carcinoma 2. Metastatic, Castration-Resistant Prostate Cancer (mCRPC) with PSA value at screening ≥4 ng/mL and that has progressed within 6 months prior to screening, according to at least 1 of the following: 1. PSA progression as defined by a rising PSA level confirmed with an interval of ≥1 week between each assessment 2. Radiographic disease progression in soft tissue based on Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 criteria with or without PSA progression 3. Radiographic disease progression in bone defined as the appearance of 2 or more new bone lesions on bone scan with or without PSA progression NOTE: Measurable disease per RECIST version 1.1 per local reading at screening is not an eligibility criterion for enrollment 3. Has progressed upon or intolerant to ≥2 lines prior systemic therapy approved in the metastatic and/or castration-resistant setting (in addition to Androgen Deprivation Therapy \[ADT\]) including at least one second-generation anti-androgen therapy (e.g. abiraterone, enzalutamide, apalutamide, or darolutamide) Key Exclusion Criteria: 1. Has received treatment with an approved systemic biologic therapy within 3 weeks of dosing or has not yet recovered (ie, grade ≤1 or baseline) from any acute toxicities except for laboratory changes as described in inclusion criteria 2. Has received any previous systemic biologic or anti-cancer immunotherapy within 5 half-lives of first dose of study therapy, as described in the protocol 3. Has received prior Prostate-Specific Membrane Antigen (PSMA)-targeting therapy NOTE: Prior therapy with PSMA-targeting radioligand(s) (eg, 177Lu-PSMA-617) is permitted. However, a period of 12 weeks must elapse between the last dose of the PSMA- targeting radioligand and the first dose of study drug 4. Any condition that requires ongoing/continuous corticosteroid therapy (\>10 mg prednisone/day or anti-inflammatory equivalent) within 1 week prior to the first dose of study therapy 5. Ongoing or recent (within 5 years) evidence of significant autoimmune disease that required treatment with systemic immunosuppressive treatments 6. Encephalitis, meningitis, neurodegenerative disease (with the exception of mild dementia that does not interfere with Activities of Daily Living \[ADLs\]) or uncontrolled seizures in the year prior to first dose of study therapy 7. Uncontrolled infection with Human Immunodeficiency Virus (HIV), Hepatitis B Virus (HBV), or Hepatitis C Virus (HCV) infection; or diagnosis of immunodeficiency, as described in the protocol. NOTE: Other protocol defined Inclusion/Exclusion Criteria apply

Study sites (14)

CA

CT

KY

MD

NC

NJ

NY

OH

PA

TX

WI