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A Clinical Study of Ifinatamab Deruxtecan Based Treatment Combinations or as Monotherapy to Treat Metastatic Castrate Resistant Prostate Cancer (mCRPC) (MK-2400-01A/IDeate-Prostate02)

Phase 1
Not yet recruiting
Conditions
Castration-Resistant Prostatic Cancer
Metastasis
Interventions
Registration Number
NCT06863272
Lead Sponsor
Merck Sharp & Dohme LLC
Brief Summary

The purpose of this substudy is to assess the efficacy and safety of ifinatamab deruxtecan (I-DXd), given alone or with other treatments in participants with metastatic castration-resistant prostate cancer (mCRPC). The goals of this study are to learn about:

* The safety of the study treatment and if people tolerate it.

* A safe dose level of I-DXd that can be used with other treatments.

* Participant levels of prostate specific antigen (PSA) during treatment.

Detailed Description

This sub study MK-2400-01A assesses treatments for metastatic castration-resistant prostate cancer (mCRPC).

The master screening protocol is MK-2400-U01.

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
All
Target Recruitment
360
Inclusion Criteria

The main inclusion criteria include but are not limited to the following:

  • Has histologically- or cytologically-confirmed adenocarcinoma of the prostate without small cell histology
  • Has prostate cancer progression while on androgen deprivation therapy (ADT) (or post bilateral orchiectomy) within 6 months before Screening
  • Has current evidence of metastatic disease
  • Has received prior treatment with 1 or 2 androgen receptor pathway inhibitors (ARPIs) and progressed during or after treatment
  • Participants receiving bone resorptive therapy (including, but not limited to bisphosphonate or denosumab) must have been on stable doses for ≥4 weeks before allocation/randomization
  • An Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1 assessed within 10 days before allocation/randomization
  • Has prior treatment with poly-ADP-ribose polymerase inhibitors (PARPi) if indicated by local approved regimen or were deemed ineligible to receive PARPi by the investigator
Exclusion Criteria

The main exclusion criteria include but are not limited to the following:

  • History of (non-infectious) interstitial lung disease (ILD)/pneumonitis that required steroids, or has current ILD/pneumonitis or suspected ILD/pneumonitis
  • Clinically severe pulmonary compromise resulting from intercurrent pulmonary illnesses
  • Uncontrolled or significant cardiovascular disease
  • History of pituitary dysfunction
  • Poorly controlled diabetes mellitus
  • History or current condition of adrenal insufficiency (eg, Addison's disease)
  • Has received prior treatment with taxane-based chemotherapy agent for metastatic castration-resistant prostate cancer (mCRPC).
  • Chronic steroid treatment (dose of >10 mg daily prednisone equivalent), except for low-dose inhaled steroids (for asthma/chronic obstructive pulmonary disease), topical steroids (for mild skin conditions), or intra-articular steroid injections
  • Received prior radiotherapy within 2 weeks of start of study intervention, or has radiation-related toxicities, requiring corticosteroids
  • Known additional malignancy that is progressing or has required active treatment within the past 3 years
  • Known active central nervous system (CNS) metastases and/or carcinomatous meningitis
  • Active autoimmune disease that has required systemic treatment in the past 2 years
  • History of allogeneic tissue/solid organ transplant

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
DocetaxelDocetaxelParticipants will receive docetaxel at a determined dose every 3 weeks (Q3W) for a maximum of 10 cycles. Each cycle is 21 days.
Ifinatamab Deruxtecan (I-DXd)Ifinatamab DeruxtecanParticipants will receive I-DXd at a determined dose Q3W until unacceptable toxicity, progressive disease (PD), death or withdrawal of consent.
I-DXd + MK-5684Ifinatamab DeruxtecanFollowing a dose escalation regimen with I-DXd, participants will receive I-DXd at a determined dose until unacceptable toxicity, PD, death or withdrawal of consent PLUS MK-5684 at a determined dose until any of the criterion for discontinuation of study intervention is met.
I-DXd + MK-5684MK-5684Following a dose escalation regimen with I-DXd, participants will receive I-DXd at a determined dose until unacceptable toxicity, PD, death or withdrawal of consent PLUS MK-5684 at a determined dose until any of the criterion for discontinuation of study intervention is met.
I-DXd +ARPI (Abiraterone or Enzalutamide)Ifinatamab DeruxtecanFollowing a dose escalation regimen with I-DXd, participants will receive I-DXd at a determined dose until unacceptable toxicity, PD, death or withdrawal of consent PLUS ARPI (Androgen Receptor Pathway Inhibitor) - Abiraterone acetate OR Enzalutamide at a determined dose until any of the criterion for discontinuation of study intervention is met.
I-DXd +ARPI (Abiraterone or Enzalutamide)AbirateroneFollowing a dose escalation regimen with I-DXd, participants will receive I-DXd at a determined dose until unacceptable toxicity, PD, death or withdrawal of consent PLUS ARPI (Androgen Receptor Pathway Inhibitor) - Abiraterone acetate OR Enzalutamide at a determined dose until any of the criterion for discontinuation of study intervention is met.
I-DXd +ARPI (Abiraterone or Enzalutamide)EnzalutamideFollowing a dose escalation regimen with I-DXd, participants will receive I-DXd at a determined dose until unacceptable toxicity, PD, death or withdrawal of consent PLUS ARPI (Androgen Receptor Pathway Inhibitor) - Abiraterone acetate OR Enzalutamide at a determined dose until any of the criterion for discontinuation of study intervention is met.
Primary Outcome Measures
NameTimeMethod
Efficacy Phase: Number of Participants Who Experience One or More Dose-Limiting Toxicities (DLTs) - Combination Arms OnlyUp to approximately 21 days

The following events if considered drug related by the Investigator, will be considered a DLT: Grade 4 nonhematologic toxicity (not based on laboratory value); Grade 4 hematologic toxicity lasting ≥7 days, except thrombocytopenia; Grade 4 thrombocytopenia of any duration; Grade 3 thrombocytopenia associated with clinically significant bleeding; Nonhematologic AEs ≥Grade 3 with exceptions; Grade 3 or Grade 4 non-hematologic laboratory values if requires medical intervention, leads to hospitalization, persists for \>1 week, or results in a Drug-induced Liver Injury with exceptions; Grade 3 or 4 febrile neutropenia; Study intervention - related toxicities that lead to discontinuation of study treatment during Cycle 1; Prolonged delay (\>2 weeks) in initiating Cycles 2 due to treatment-related toxicity; Missing \>25% of study intervention doses as a result of treatment-related AE during Cycle 1; Grade 5 toxicity.

Efficacy Phase: Number of Participants Who Experienced an Adverse Event (AE)Up to approximately 54 months

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention.

Efficacy Phase: Number of Participants Who Discontinued Study Intervention Due to an AEUp to approximately 24 months

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention.

Efficacy Phase: Prostate-Specific Antigen (PSA) response rateUp to approximately 54 months

PSA response is defined per prostate cancer working group (PCWG) criteria as a reduction in the PSA level of 50% or more from baseline measured at consecutive assessments at least 3 weeks apart.

Safety Lead-in Phase: Number of Participants Who Experience One or More Dose-Limiting Toxicities (DLTs) - Combination Arms OnlyUp to approximately 21 days

The following events if considered drug related by the Investigator, will be considered a DLT: Grade 4 nonhematologic toxicity (not based on laboratory value); Grade 4 hematologic toxicity lasting ≥7 days, except thrombocytopenia; Grade 4 thrombocytopenia of any duration; Grade 3 thrombocytopenia associated with clinically significant bleeding; Nonhematologic AEs ≥Grade 3 with exceptions; Grade 3 or Grade 4 non-hematologic laboratory values if requires medical intervention, leads to hospitalization, persists for \>1 week, or results in a Drug-induced Liver Injury with exceptions; Grade 3 or 4 febrile neutropenia; Study intervention - related toxicities that lead to discontinuation of study treatment during Cycle 1; Prolonged delay (\>2 weeks) in initiating Cycles 2 due to treatment-related toxicity; Missing \>25% of study intervention doses as a result of treatment-related AE during Cycle 1; Grade 5 toxicity.

Safety Lead-in Phase: Number of Participants Who Experienced an Adverse Event (AE) - Combination Arms OnlyUp to approximately 21 days

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention.

Safety Lead-in Phase: Number of Participants Who Discontinued Study Intervention Due to an AE - Combination Arms OnlyUp to approximately 21 days

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention.

Secondary Outcome Measures
NameTimeMethod
Objective Response Rate (ORR)Up to approximately 54 months

ORR is defined as the percentage of participants with Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: at least a 30% decrease in the sum of diameters of target lesions) per PCWG-Modified Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1). The percentage of participants who experience CR or PR as assessed by Blinded Independent Central Review (BICR) will be presented.

Radiographic Progression-Free Survival (rPFS)Up to approximately 54 months

rPFS is defined as the time from randomization to the first documented progressive disease (PD) per PCWG-modified RECIST 1.1 based on BICR or death due to any cause, whichever occurred first. Per PCWG-modified RECIST 1.1, PD is defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also have demonstrated an absolute increase of ≥5 mm. The appearance of one or more new lesions or ≥2 new bone lesions was also considered PD. PCWG-modified RECIST is similar to RECIST 1.1 with the exception that a confirmation assessment of PD (\>4 weeks after the initial PD) is required for participants who remain on treatment following a documented PD per RECIST 1.1 and PCWG rules include new bone lesions. The rPFS per PCWG-modified RECIST as assessed by BICR for all participants is presented. The nonparametric Kaplan-Meier method will be used to estimate the rPFS curve in each treatment arm

Overall Survival (OS)Up to approximately 54 months

Overall survival (OS) is defined as the time from randomization to death due to any cause. The nonparametric Kaplan-Meier method will be used to estimate the survival curves.

Duration of Response (DOR)Up to approximately 54 months

DOR is defined as the time from first documented evidence of CR or PR until progressive disease (PD) or death. Per PCWG-modified RECIST 1.1, PD is defined as at least a 20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. The appearance of ≥ 2 new bone lesions is also considered PD. DOR as assessed by BICR is presented. The nonparametric Kaplan-Meier method will be used to estimate the DOR in each treatment arm.

Time from allocation/randomization to initiation of the first subsequent anticancer therapy (TFST)Up to approximately 54 months

TFST is defined as the time from randomization to initiation of the first subsequent anticancer therapy or death, whichever occurs first. The nonparametric Kaplan-Meier method will be used to estimate the TFST in each treatment arm.

Time to Prostate-Specific Antigen (PSA) ProgressionUp to approximately 54 months

Time to PSA progression is defined as the time from randomization to PSA progression. Participants without PSA progression will be censored at the last PSA assessment date. The PSA progression date is defined as the date of:

1) ≥25% increase and ≥2 ng/mL above the nadir, confirmed by a second value ≥3 weeks later if there is PSA decline from baseline, OR 2) ≥25% increase and ≥2 ng/mL increase from baseline beyond 12 weeks if there is no PSA decline from baseline.

Time to pain progression (TTPP)Up to approximately 54 months

The time from allocation/randomization to pain progression based on the Brief Pain Inventory-Short Form (BPI-SF) Item 3 "worst pain in 24 hours" and by the Analgesic Quantification Algorithm (AQA) score.

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