Advanced Solid Tumors
Conditions
Brief summary
The study will evaluate the safety, tolerability, and pharmacokinetics (PK) of MK-1088 in monotherapy and in combination with pembrolizumab in participants with advanced solid tumors who have not responded to conventional therapy. The effect of MK-1088 on tumor size will also be examined.
Interventions
DRUGMK-1088
Oral Tablet
BIOLOGICALPembrolizumab
IV Infusion
Sponsors
Merck Sharp & Dohme LLC
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
The main inclusion and
Exclusion criteria
include but are not limited to the following: Inclusion Criteria: * Has a histologically- or cytologically-confirmed diagnosis of advanced/metastatic solid tumor by pathology report and have received, have been intolerant to, or have been ineligible for treatment known to confer clinical benefit * For metastatic castrate-resistant prostate cancer (mCRPC) only: (1) Must have previously received docetaxel, prior treatment with one other chemotherapy is allowed as well as up to 2 second-generation hormonal manipulations and (2) have prostate cancer progression within 6 months before screening, as determined by the investigator * If human immunodeficiency virus (HIV) positive, has well-controlled HIV on anti-retroviral therapy (ART)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Percentage of Participants Experiencing a Dose-limiting Toxicity (DLT) | Up to 21 days | A DLT is defined as an event with toxicity including the type, severity, time of onset, time of resolution, and the probable association with study treatment that are not due to pre-existing conditions as defined by the Common Terminology Criteria for Adverse Events Version 5.0 (CTCAE 5.0). Per protocol participants who switched over from MK-1088 monotherapy into MK-1088 100 mg + Pembrolizumab combination therapy completed the DLT evaluation period in the monotherapy arm assigned. Percentage of participants who experienced a DLT are presented. |
| Percentage of Participants Experiencing an Adverse Event (AE) | Up to ~13 months | An AE is any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product or protocol-specified procedure, whether or not considered related to the medicinal product or protocol-specified procedure. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product, is also an AE. Safety data from participants who experienced disease progression in the monotherapy arm and crossed over into the combination arm are summarized in their initial monotherapy dose group until the time of cross over and are summarized separately thereafter. The percentage of participants who experienced an AE are presented. |
| Percentage of Participants Discontinuing Study Treatment Due to an AE | Up to ~10 months | An AE is any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product or protocol-specified procedure, whether or not considered related to the medicinal product or protocol-specified procedure. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product, is also an AE. Safety data from participants who experienced disease progression in the monotherapy arm and crossed over into the combination arm are summarized in their initial monotherapy dose group until the time of cross over and are summarized separately thereafter. The percentage of participants who discontinued study treatment due to an AE is presented. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Area Under the Plasma Concentration-time Curve (AUC) of MK-1088 | Pre-dose and 1, 2, 4, and 8 hours post-dose on Cycle 1 Day 1 and Cycle 2 Day 1; Pre-dose on Cycle 1 Day 2 and Cycle 2 Day 2; Pre-dose on Cycle 3, Cycle 4 and every 4 cycles up to ~3.5 months. Each cycle = 21 days | AUC of MK-1088 determined by blood samples collected pre-dose and at designated timepoints post-dose are presented. |
| Maximum Plasma Concentration (Cmax) of MK-1088 | Pre-dose and 1, 2, 4, and 8 hours post-dose on Cycle 1 Day 1 and Cycle 2 Day 1; Pre-dose on Cycle 1 Day 2 and Cycle 2 Day 2; Pre-dose on Cycle 3, Cycle 4 and every 4 cycles up to ~3.5 months. Each cycle = 21 days | Cmax of MK-1088 determined by blood samples collected pre-dose and at designated timepoints post-dose are presented. |
| Objective Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1) or Prostate Cancer Working Group (PCWG)-Modified RECIST 1.1 as Assessed by Investigator | Up to ~13 months | ORR is defined as the percentage of participants who have a Complete Response (CR: Disappearance of all target lesions) or a Partial Response (PR: At least a 30% decrease in the sum of diameters of target lesions) per RECIST 1.1 or Prostate Cancer Working Group (PCWG)-modified RECIST 1.1 as assessed by investigator. Efficacy data from participants who experienced disease progression in the monotherapy arm and crossed over into the combination arm will be summarized in their initial monotherapy dose group until the time of cross over and will be summarized separately thereafter. The percentage of participants who experience a CR or PR as assessed by the investigator based on RECIST 1.1 is presented. |
Countries
Canada, Denmark, Israel, Switzerland, United States
Participant flow
Recruitment details
The study was closed to enrollment on 04-MAY-2023 for all participants, and no participants remain on treatment with MK-1088. Part 2 of the study was not initiated.
Pre-assignment details
Per protocol two participants who progressed by radiographic evaluation on monotherapy with MK-1088 at the investigator's discretion and after consultation with the Sponsor, switched over to combination treatment arm of MK-1088 and pembrolizumab.
Participants by arm
| Arm | Count |
|---|---|
| MK-1088 100 mg Participants received MK-1088 daily (QD) orally at 100 mg on days 1-21 of each 21-day cycle for up to 35 cycles (up to \
24 months) | 3 |
| MK-1088 200 mg Participants received MK-1088 (QD) orally at 200 mg on days 1-21 of each 21-day cycle for up to 35 cycles (up to \
24 months) | 3 |
| MK-1088 400 mg Participants received MK-1088 (QD) orally at 400 mg on days 1-21 of each 21-day cycle for up to 35 cycles (up to \
24 months) | 11 |
| MK-1088 600 mg Participants received MK-1088 (QD) orally at 600 mg on days 1-21 of each 21-day cycle for up to 35 cycles (up to \
24 months) | 3 |
| MK-1088 100 mg + Pembrolizumab Participants received MK-1088 daily (QD) orally at 100 mg on days 1-21 of each 21-day cycle plus pembrolizumab at 200 mg intravenous (IV) infusion every 3 weeks (Q3W), on Day 1 of each 21-day cycle for up to 35 cycles (up to \
24 months) | 3 |
| MK-1088 200 mg + Pembrolizumab Participants received MK-1088 daily (QD) orally at 200 mg on days 1-21 of each 21-day cycle plus pembrolizumab at 200 mg intravenous (IV) infusion every 3 weeks (Q3W), on Day 1 of each 21-day cycle for up to 35 cycles (up to \
24 months) | 4 |
| Total | 27 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 | FG003 | FG004 | FG005 |
|---|---|---|---|---|---|---|---|
| Overall Study | Death | 2 | 2 | 4 | 0 | 1 | 0 |
| Overall Study | Study terminated by sponsor | 1 | 1 | 7 | 3 | 2 | 4 |
Baseline characteristics
| Characteristic | MK-1088 100 mg | MK-1088 200 mg | MK-1088 400 mg | MK-1088 600 mg | MK-1088 100 mg + Pembrolizumab | MK-1088 200 mg + Pembrolizumab | Total |
|---|---|---|---|---|---|---|---|
| Age, Continuous | 66.7 Years STANDARD_DEVIATION 13.6 | 58.7 Years STANDARD_DEVIATION 24.8 | 59.5 Years STANDARD_DEVIATION 13.5 | 62.7 Years STANDARD_DEVIATION 4.9 | 61.0 Years STANDARD_DEVIATION 10.1 | 55.8 Years STANDARD_DEVIATION 11.6 | 60.1 Years STANDARD_DEVIATION 12.9 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 1 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 1 Participants | 3 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 2 Participants | 3 Participants | 10 Participants | 3 Participants | 3 Participants | 3 Participants | 24 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 2 Participants | 0 Participants | 2 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 3 Participants | 3 Participants | 11 Participants | 2 Participants | 1 Participants | 4 Participants | 24 Participants |
| Sex: Female, Male Female | 1 Participants | 0 Participants | 5 Participants | 2 Participants | 1 Participants | 1 Participants | 10 Participants |
| Sex: Female, Male Male | 2 Participants | 3 Participants | 6 Participants | 1 Participants | 2 Participants | 3 Participants | 17 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk | EG004 affected / at risk | EG005 affected / at risk | EG006 affected / at risk |
|---|---|---|---|---|---|---|---|
| deaths Total, all-cause mortality | 2 / 3 | 2 / 3 | 4 / 11 | 0 / 3 | 1 / 3 | 0 / 4 | 0 / 2 |
| other Total, other adverse events | 3 / 3 | 3 / 3 | 11 / 11 | 3 / 3 | 3 / 3 | 4 / 4 | 2 / 2 |
| serious Total, serious adverse events | 2 / 3 | 2 / 3 | 6 / 11 | 1 / 3 | 2 / 3 | 2 / 4 | 0 / 2 |
Outcome results
Primary
Percentage of Participants Discontinuing Study Treatment Due to an AE
An AE is any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product or protocol-specified procedure, whether or not considered related to the medicinal product or protocol-specified procedure. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product, is also an AE. Safety data from participants who experienced disease progression in the monotherapy arm and crossed over into the combination arm are summarized in their initial monotherapy dose group until the time of cross over and are summarized separately thereafter. The percentage of participants who discontinued study treatment due to an AE is presented.
Time frame: Up to ~10 months
Population: All participants who received at least one dose of study intervention
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| MK-1088 100 mg | Percentage of Participants Discontinuing Study Treatment Due to an AE | 0.0 Percentage of participants |
| MK-1088 200 mg | Percentage of Participants Discontinuing Study Treatment Due to an AE | 0.0 Percentage of participants |
| MK-1088 400 mg | Percentage of Participants Discontinuing Study Treatment Due to an AE | 9.1 Percentage of participants |
| MK-1088 600 mg | Percentage of Participants Discontinuing Study Treatment Due to an AE | 0.0 Percentage of participants |
| MK-1088 100 mg + Pembrolizumab | Percentage of Participants Discontinuing Study Treatment Due to an AE | 66.7 Percentage of participants |
| MK-1088 200 mg + Pembrolizumab | Percentage of Participants Discontinuing Study Treatment Due to an AE | 75.0 Percentage of participants |
| MK-1088 100 mg + Pembrolizumab Switchover | Percentage of Participants Discontinuing Study Treatment Due to an AE | 0.0 Percentage of participants |
Primary
Percentage of Participants Experiencing a Dose-limiting Toxicity (DLT)
A DLT is defined as an event with toxicity including the type, severity, time of onset, time of resolution, and the probable association with study treatment that are not due to pre-existing conditions as defined by the Common Terminology Criteria for Adverse Events Version 5.0 (CTCAE 5.0). Per protocol participants who switched over from MK-1088 monotherapy into MK-1088 100 mg + Pembrolizumab combination therapy completed the DLT evaluation period in the monotherapy arm assigned. Percentage of participants who experienced a DLT are presented.
Time frame: Up to 21 days
Population: All participants who received at least one dose of study intervention and met the criteria for DLT evaluability
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| MK-1088 100 mg | Percentage of Participants Experiencing a Dose-limiting Toxicity (DLT) | 0.0 Percentage of Participants |
| MK-1088 200 mg | Percentage of Participants Experiencing a Dose-limiting Toxicity (DLT) | 0.0 Percentage of Participants |
| MK-1088 400 mg | Percentage of Participants Experiencing a Dose-limiting Toxicity (DLT) | 9.09 Percentage of Participants |
| MK-1088 600 mg | Percentage of Participants Experiencing a Dose-limiting Toxicity (DLT) | 0.0 Percentage of Participants |
| MK-1088 100 mg + Pembrolizumab | Percentage of Participants Experiencing a Dose-limiting Toxicity (DLT) | 0.0 Percentage of Participants |
| MK-1088 200 mg + Pembrolizumab | Percentage of Participants Experiencing a Dose-limiting Toxicity (DLT) | 0.0 Percentage of Participants |
Primary
Percentage of Participants Experiencing an Adverse Event (AE)
An AE is any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product or protocol-specified procedure, whether or not considered related to the medicinal product or protocol-specified procedure. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product, is also an AE. Safety data from participants who experienced disease progression in the monotherapy arm and crossed over into the combination arm are summarized in their initial monotherapy dose group until the time of cross over and are summarized separately thereafter. The percentage of participants who experienced an AE are presented.
Time frame: Up to ~13 months
Population: All participants who received at least one dose of study intervention
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| MK-1088 100 mg | Percentage of Participants Experiencing an Adverse Event (AE) | 100.0 Percentage of participants |
| MK-1088 200 mg | Percentage of Participants Experiencing an Adverse Event (AE) | 100.0 Percentage of participants |
| MK-1088 400 mg | Percentage of Participants Experiencing an Adverse Event (AE) | 100.0 Percentage of participants |
| MK-1088 600 mg | Percentage of Participants Experiencing an Adverse Event (AE) | 100.0 Percentage of participants |
| MK-1088 100 mg + Pembrolizumab | Percentage of Participants Experiencing an Adverse Event (AE) | 100.0 Percentage of participants |
| MK-1088 200 mg + Pembrolizumab | Percentage of Participants Experiencing an Adverse Event (AE) | 100.0 Percentage of participants |
| MK-1088 100 mg + Pembrolizumab Switchover | Percentage of Participants Experiencing an Adverse Event (AE) | 100.0 Percentage of participants |
Secondary
Area Under the Plasma Concentration-time Curve (AUC) of MK-1088
AUC of MK-1088 determined by blood samples collected pre-dose and at designated timepoints post-dose are presented.
Time frame: Pre-dose and 1, 2, 4, and 8 hours post-dose on Cycle 1 Day 1 and Cycle 2 Day 1; Pre-dose on Cycle 1 Day 2 and Cycle 2 Day 2; Pre-dose on Cycle 3, Cycle 4 and every 4 cycles up to ~3.5 months. Each cycle = 21 days
Population: All participants who complied with the protocol sufficiently to ensure that their data will be likely to show the effects of treatment, according to the underlying scientific model. Only the per protocol analysis set (excluding the data from the participants after switching over to MK-1088 100 mg and Pembrolizumab) were analyzed for pharmacokinetic (PK) data.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) | Dispersion |
|---|---|---|---|---|
| MK-1088 100 mg | Area Under the Plasma Concentration-time Curve (AUC) of MK-1088 | Cycle 1 | 31.9 hr*μmol/L | Geometric Coefficient of Variation 105.2 |
| MK-1088 100 mg | Area Under the Plasma Concentration-time Curve (AUC) of MK-1088 | Cycle 2 | 39.0 hr*μmol/L | Geometric Coefficient of Variation 46.6 |
| MK-1088 200 mg | Area Under the Plasma Concentration-time Curve (AUC) of MK-1088 | Cycle 1 | 26.1 hr*μmol/L | Geometric Coefficient of Variation 95.1 |
| MK-1088 200 mg | Area Under the Plasma Concentration-time Curve (AUC) of MK-1088 | Cycle 2 | 39.5 hr*μmol/L | Geometric Coefficient of Variation 145.4 |
| MK-1088 400 mg | Area Under the Plasma Concentration-time Curve (AUC) of MK-1088 | Cycle 1 | 98.4 hr*μmol/L | Geometric Coefficient of Variation 38.5 |
| MK-1088 400 mg | Area Under the Plasma Concentration-time Curve (AUC) of MK-1088 | Cycle 2 | 197.0 hr*μmol/L | Geometric Coefficient of Variation 46.4 |
| MK-1088 600 mg | Area Under the Plasma Concentration-time Curve (AUC) of MK-1088 | Cycle 1 | 99.4 hr*μmol/L | Geometric Coefficient of Variation 43.9 |
| MK-1088 600 mg | Area Under the Plasma Concentration-time Curve (AUC) of MK-1088 | Cycle 2 | 188.0 hr*μmol/L | Geometric Coefficient of Variation 90.6 |
| MK-1088 100 mg + Pembrolizumab | Area Under the Plasma Concentration-time Curve (AUC) of MK-1088 | Cycle 1 | 21.8 hr*μmol/L | Geometric Coefficient of Variation 51.2 |
| MK-1088 100 mg + Pembrolizumab | Area Under the Plasma Concentration-time Curve (AUC) of MK-1088 | Cycle 2 | 29.7 hr*μmol/L | Geometric Coefficient of Variation 97.1 |
| MK-1088 200 mg + Pembrolizumab | Area Under the Plasma Concentration-time Curve (AUC) of MK-1088 | Cycle 1 | 49.3 hr*μmol/L | Geometric Coefficient of Variation 50.8 |
| MK-1088 200 mg + Pembrolizumab | Area Under the Plasma Concentration-time Curve (AUC) of MK-1088 | Cycle 2 | 102.0 hr*μmol/L | Geometric Coefficient of Variation 17.6 |
Secondary
Maximum Plasma Concentration (Cmax) of MK-1088
Cmax of MK-1088 determined by blood samples collected pre-dose and at designated timepoints post-dose are presented.
Time frame: Pre-dose and 1, 2, 4, and 8 hours post-dose on Cycle 1 Day 1 and Cycle 2 Day 1; Pre-dose on Cycle 1 Day 2 and Cycle 2 Day 2; Pre-dose on Cycle 3, Cycle 4 and every 4 cycles up to ~3.5 months. Each cycle = 21 days
Population: All participants who complied with the protocol sufficiently to ensure that their data will be likely to show the effects of treatment, according to the underlying scientific model. Only the per protocol analysis set (excluding the data from the participants after switching over to MK-1088 100 mg and Pembrolizumab) were analyzed for pharmacokinetic (PK) data.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) | Dispersion |
|---|---|---|---|---|
| MK-1088 100 mg | Maximum Plasma Concentration (Cmax) of MK-1088 | Cycle 1 | 2.58 μmol/L | Geometric Coefficient of Variation 61.8 |
| MK-1088 100 mg | Maximum Plasma Concentration (Cmax) of MK-1088 | Cycle 2 | 2.82 μmol/L | Geometric Coefficient of Variation 31.9 |
| MK-1088 200 mg | Maximum Plasma Concentration (Cmax) of MK-1088 | Cycle 1 | 2.17 μmol/L | Geometric Coefficient of Variation 50.8 |
| MK-1088 200 mg | Maximum Plasma Concentration (Cmax) of MK-1088 | Cycle 2 | 3.27 μmol/L | Geometric Coefficient of Variation 92 |
| MK-1088 400 mg | Maximum Plasma Concentration (Cmax) of MK-1088 | Cycle 1 | 6.63 μmol/L | Geometric Coefficient of Variation 36.7 |
| MK-1088 400 mg | Maximum Plasma Concentration (Cmax) of MK-1088 | Cycle 2 | 11.6 μmol/L | Geometric Coefficient of Variation 31.8 |
| MK-1088 600 mg | Maximum Plasma Concentration (Cmax) of MK-1088 | Cycle 1 | 7.70 μmol/L | Geometric Coefficient of Variation 46.4 |
| MK-1088 600 mg | Maximum Plasma Concentration (Cmax) of MK-1088 | Cycle 2 | 11.6 μmol/L | Geometric Coefficient of Variation 79.9 |
| MK-1088 100 mg + Pembrolizumab | Maximum Plasma Concentration (Cmax) of MK-1088 | Cycle 1 | 1.41 μmol/L | Geometric Coefficient of Variation 62.4 |
| MK-1088 100 mg + Pembrolizumab | Maximum Plasma Concentration (Cmax) of MK-1088 | Cycle 2 | 1.80 μmol/L | Geometric Coefficient of Variation 117.4 |
| MK-1088 200 mg + Pembrolizumab | Maximum Plasma Concentration (Cmax) of MK-1088 | Cycle 1 | 3.29 μmol/L | Geometric Coefficient of Variation 83.1 |
| MK-1088 200 mg + Pembrolizumab | Maximum Plasma Concentration (Cmax) of MK-1088 | Cycle 2 | 6.32 μmol/L | Geometric Coefficient of Variation 30.2 |
Secondary
Objective Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1) or Prostate Cancer Working Group (PCWG)-Modified RECIST 1.1 as Assessed by Investigator
ORR is defined as the percentage of participants who have a Complete Response (CR: Disappearance of all target lesions) or a Partial Response (PR: At least a 30% decrease in the sum of diameters of target lesions) per RECIST 1.1 or Prostate Cancer Working Group (PCWG)-modified RECIST 1.1 as assessed by investigator. Efficacy data from participants who experienced disease progression in the monotherapy arm and crossed over into the combination arm will be summarized in their initial monotherapy dose group until the time of cross over and will be summarized separately thereafter. The percentage of participants who experience a CR or PR as assessed by the investigator based on RECIST 1.1 is presented.
Time frame: Up to ~13 months
Population: All participants with a screening/baseline scan that showed measurable disease by the investigator's assessment, and received at least 1 dose of study intervention
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| MK-1088 100 mg | Objective Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1) or Prostate Cancer Working Group (PCWG)-Modified RECIST 1.1 as Assessed by Investigator | 0.0 Percentage of participants |
| MK-1088 200 mg | Objective Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1) or Prostate Cancer Working Group (PCWG)-Modified RECIST 1.1 as Assessed by Investigator | 0.0 Percentage of participants |
| MK-1088 400 mg | Objective Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1) or Prostate Cancer Working Group (PCWG)-Modified RECIST 1.1 as Assessed by Investigator | 0.0 Percentage of participants |
| MK-1088 600 mg | Objective Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1) or Prostate Cancer Working Group (PCWG)-Modified RECIST 1.1 as Assessed by Investigator | 0.0 Percentage of participants |
| MK-1088 100 mg + Pembrolizumab | Objective Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1) or Prostate Cancer Working Group (PCWG)-Modified RECIST 1.1 as Assessed by Investigator | 33.3 Percentage of participants |
| MK-1088 200 mg + Pembrolizumab | Objective Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1) or Prostate Cancer Working Group (PCWG)-Modified RECIST 1.1 as Assessed by Investigator | 0.0 Percentage of participants |
| MK-1088 100 mg + Pembrolizumab Switchover | Objective Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1) or Prostate Cancer Working Group (PCWG)-Modified RECIST 1.1 as Assessed by Investigator | 0.0 Percentage of participants |