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Study of Pembrolizumab (MK-3475) as Monotherapy in Participants With Previously-Treated Locally Advanced Unresectable or Metastatic Colorectal Cancer (MK-3475-164/KEYNOTE-164)

Phase 2
Completed
Conditions
Colorectal Carcinoma
Interventions
Biological: Pembrolizumab
Registration Number
NCT02460198
Lead Sponsor
Merck Sharp & Dohme LLC
Brief Summary

In this study, participants with previously-treated locally-advanced unresectable or metastatic mismatched repair (MMR) deficient or microsatellite instability-high (MSI-H) colorectal carcinoma (CRC) will be treated with pembrolizumab (MK-3475, KEYTRUDA®) monotherapy.

There will be two cohorts in this study: Cohort A and Cohort B. For Cohort A, participants are required to have been previously treated with standard therapies, which must include fluoropyrimidine, oxaliplatin, and irinotecan. Enrollment into Cohort A has been completed. For Cohort B, participants are required to have been previously treated with at least one line of systemic standard of care therapy: fluoropyrimidine + oxaliplatin or fluoropyrimidine + irinotecan +/ - anti-vascular endothelial growth factor (VEGF)/ epidermal growth factor regulator (EGFR) monoclonal antibody.

The primary hypothesis is that Objective Response Rate (ORR) based on Response Evaluation Criteria in Solid Tumors v 1.1 (RECIST 1.1) assessed by central imaging vendor in participants with locally advanced unresectable or metastatic MMR deficient or MSI high CRC is greater than 15%.

Detailed Description

With protocol amendment 08 (13-Nov-2019), once study participants have achieved the study objective or the study has ended, participants will be discontinued from this study and may be enrolled in a pembrolizumab extension study (NCT03486873) to continue protocol-defined assessments and treatment.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
124
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Cohort A - Pembrolizumab 200 mgPembrolizumabParticipants were previously treated with standard therapies, which must include fluoropyrimidine, oxaliplatin, and irinotecan. Cohort A participants receive pembrolizumab 200 mg intravenously (IV) on Day 1 of every 3-week cycle (Q3W) for up to approximately 52 cycles (up to approximately 3 years).
Cohort B - Pembrolizumab 200 mgPembrolizumabParticipants were previously treated with at least one line of systemic standard of care therapy: fluoropyrimidine + oxaliplatin or fluoropyrimidine + irinotecan +/ - anti vascular endothelial growth factor (VEGF)/ epidermal growth factor regulator (EGFR) monoclonal antibody. Cohort B participants receive pembrolizumab 200 mg IV on Day 1 Q3W for up to approximately 52 cycles (up to approximately 3 years).
Primary Outcome Measures
NameTimeMethod
Objective Response Rate (ORR) - Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1) Assessed by Central Imaging VendorUp to approximately 48 months

Objective response rate was defined as the percentage of the participants in the analysis population who had a complete response (CR) or partial response (PR). Complete Response: disappearance of all target lesions. Partial Response: at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. Responses were based upon blinded central imaging vendor per RECIST 1.1. The point estimate and 95% confidence interval for the ORR, were provided using an exact binomial distribution (Clopper and Pearson method). Participants without response data were counted as nonresponders. The data cutoff date was 09-SEPT-2019.

Secondary Outcome Measures
NameTimeMethod
Progression-Free Survival (PFS) Per RECIST 1.1 Assessed by Central Imaging Vendor.Up to approximately 66 months

PFS is defined as the time from first day of study treatment to the first documented disease progression or death due to any cause, whichever occurs first. Progressive Disease: at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must have also demonstrated an absolute increase of at least 5 mm. (Note: the appearance of one or more new lesions was also considered progression). PFS was summarized by Kaplan-Meier (KM) methods. The data cutoff date was 19-FEB-2021.

Number of Participants Who Discontinued Study Treatment Due to an AE.Up to approximately 36 months

An adverse event (AE) was defined as any unfavorable and unintended sign including an abnormal laboratory finding, symptom or disease associated with the use of a medical treatment or procedure, regardless of whether it was considered related to the medical treatment or procedure, that occurred during the course of the study.

Disease Control Rate (DCR) Per RECIST 1.1 Assessed by Central Imaging Vendor.Up to approximately 66 months

Disease Control Rate was defined as the percentage of participants who achieved confirmed CR or PR or had demonstrated stable disease (SD) for at least 24 weeks prior to any evidence of progression. Complete Response: disappearance of all target lesions. Partial Response: at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. Stable Disease: neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for progressive disease (PD), taking as reference the smallest sum diameters while on study. Progressive Disease: at least a 20% increase in the sum of diameters of target lesions and an absolute increase of at least 5 mm. or the appearance of new lesion(s). Participants in the analysis population with missing DCR were considered as disease not under control. The data cutoff date was 19-Feb-2021.

Number of Participants Who Experienced an Adverse Event (AE).Up to approximately 66 months

An adverse event (AE) was defined as any unfavorable and unintended sign including an abnormal laboratory finding, symptom or disease associated with the use of a medical treatment or procedure, regardless of whether it was considered related to the medical treatment or procedure, that occurred during the course of the study.

Duration of Response (DOR) Per RECIST 1.1 as Assessed by the Central Imaging VendorUp to approximately 66 months

For participants who demonstrated a CR or PR, duration of response was defined as the time from first documented evidence of CR or PR until disease progression or death due to any cause, whichever occurred first. Complete Response: disappearance of all target lesions. Partial Response: at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. Responses were based upon blinded central imaging vendor per RECIST 1.1. Duration of Response was based on Independent radiologist review (IRC) using RECIST 1.1 and was summarized by Kaplan-Meier (KM) methods for censored data. Nonresponders were excluded from the analysis of DOR.

Overall Survival (OS)Up to approximately 66 months

OS is defined as the time from first day of study treatment to death due to any cause. Participants without documented death at the time of analysis are censored at the date of the last follow-up. OS was summarized by Kaplan-Meier (KM) methods. The data cutoff date was 19-FEB-2021.

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