Trial Outcomes & Findings for A Study of Pembrolizumab (MK-3475) for First Line Treatment of Recurrent or Metastatic Squamous Cell Cancer of the Head and Neck (MK-3475-048/KEYNOTE-048) (NCT NCT02358031)

Participants with first line recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) were recruited to examine the efficacy and safety of pembrolizumab monotherapy (pembro mono) versus pembrolizumab plus chemotherapy (pembro combo) versus cetuximab plus chemotherapy (control).

Of 1228 participants screened, 882 were randomized to the pembro mono arm, pembro combo arm, or control arm. 22 participants in the control arm that enrolled during an enrollment pause of the pembro combo arm were excluded from efficacy comparisons between the pembro combo arm and control arm. Per protocol, response/progression or adverse events (AEs) that occurred during the second pembrolizumab course were not counted towards efficacy outcome measures or safety outcome measures, respectively.

A Study of Pembrolizumab (MK-3475) for First Line Treatment of Recurrent or Metastatic Squamous Cell Cancer of the Head and Neck (MK-3475-048/KEYNOTE-048)

PFS was defined as the time from randomization to the first documented progressive disease (PD) per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro combo arm was compared to the control arm as a pre-specified primary analysis of the Intent-To-Treat (ITT) population. PFS is reported here for the first course of treatment, for all participants in the pembro combo arm and control arm. Per protocol, PFS was compared separately between all participants of the pembro mono arm and control arm and is presented later in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro combo arm was compared to the control arm as a pre-specified primary analysis of the ITT population. PFS is reported here for the first course of treatment, for all participants in the pembro combo arm and control arm with PD-L1 biomarker positive expression defined by immunohistochemistry (IHC) as Combined Positive Score ≥1 (hereafter referred to as CPS ≥1). Per protocol, PFS was compared separately between CPS ≥1 participants of the pembro mono arm and control arm and is presented later in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro combo arm was compared to the control arm as a pre-specified primary analysis of the ITT population. PFS is reported here for the first course of treatment, for all participants in the pembro combo arm and control arm with PD-L1 biomarker positive expression defined by IHC as Combined Positive Score ≥20 (hereafter referred to as CPS ≥20). Per protocol, PFS was compared separately between CPS ≥20 participants of the pembro mono arm and control arm and is presented later in the record.

OS was defined as the time from randomization to death due to any cause. Participants without documented death at the time of the final analysis were censored at the date of the last follow-up. Per protocol, OS in the pembro combo arm was compared to the control arm as a pre-specified primary analysis of the ITT population. OS is reported here for the first course of treatment, for all participants in the pembro combo arm and control arm. Per protocol, OS was compared separately between all participants of the pembro mono arm and control arm and is presented later in the record.

OS was defined as the time from randomization to death due to any cause. Participants without documented death at the time of the final analysis were censored at the date of the last follow-up. Per protocol, OS in the pembro combo arm was compared to the control arm as a pre-specified primary analysis of the ITT population. OS is reported here for the first course of treatment, for all participants in the pembro combo arm and control arm with PD-L1 biomarker positive expression defined by IHC as CPS ≥1. Per protocol, OS was compared separately between CPS ≥1 participants of the pembro mono arm and control arm and is presented later in the record.

OS was defined as the time from randomization to death due to any cause. Participants without documented death at the time of the final analysis were censored at the date of the last follow-up. Per protocol, OS in the pembro combo arm was compared to the control arm as a pre-specified primary analysis of the ITT population. OS is reported here for the first course of treatment, for all participants in the pembro combo arm and control arm with PD-L1 biomarker positive expression defined by IHC as CPS ≥20. Per protocol, OS was compared separately between CPS ≥20 participants of the pembro mono arm and control arm and is presented later in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro mono arm was compared to the control arm as a pre-specified primary analysis of the ITT population. PFS is reported here for the first course of treatment, for all participants in the pembro mono arm and control arm. Per protocol, PFS was compared separately between all participants of the pembro combo arm and control arm and is presented earlier in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro mono arm was compared to the control arm as a pre-specified primary analysis of the ITT population. PFS is reported here for the first course of treatment, for all participants in the pembro mono arm and control arm with PD-L1 biomarker positive expression defined by IHC as CPS ≥1. Per protocol, PFS was compared separately between CPS ≥1 participants of the pembro combo arm and control arm and is presented earlier in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro mono arm was compared to the control arm as a pre-specified primary analysis of the ITT population. PFS is reported here for the first course of treatment, for all participants in the pembro mono arm and control arm with PD-L1 biomarker positive expression defined by IHC as CPS ≥20. Per protocol, PFS was compared separately between CPS ≥20 participants of the pembro combo arm and control arm and is presented earlier in the record.

OS was defined as the time from randomization to death due to any cause. Participants without documented death at the time of the final analysis were censored at the date of the last follow-up. Per protocol, OS in the pembro mono arm was compared to the control arm as a pre-specified primary analysis of the ITT population. OS is reported here for the first course of treatment, for all participants in the pembro mono arm and control arm. Per protocol, OS was compared separately between all participants of the pembro combo arm and control arm and is presented earlier in the record.

OS was defined as the time from randomization to death due to any cause. Participants without documented death at the time of the final analysis were censored at the date of the last follow-up. Per protocol, OS in the pembro mono arm was compared to the control arm as a pre-specified primary analysis of the ITT population. OS is reported here for the first course of treatment, for all participants in the pembro mono arm and control arm with PD-L1 biomarker positive expression defined by IHC as CPS ≥1. Per protocol, OS was compared separately between CPS ≥1 participants of the pembro combo arm and control arm and is presented earlier in the record.

OS was defined as the time from randomization to death due to any cause. Participants without documented death at the time of the final analysis were censored at the date of the last follow-up. Per protocol, OS in the pembro mono arm was compared to the control arm as a pre-specified primary analysis of the ITT population. OS is reported here for the first course of treatment, for all participants in the pembro mono arm and control arm with PD-L1 biomarker positive expression defined by IHC as CPS ≥20. Per protocol, OS was compared separately between CPS ≥20 participants of the pembro combo arm and control arm and is presented earlier in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro combo arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants with PFS (PFS rate) at 6 months is reported here, for the first course of treatment, out of all participants in the pembro combo arm and control arm. Per protocol, the percentage of participants with PFS at 6 months was compared separately between all participants of the pembro mono arm and control arm and is presented later in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro combo arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants with PFS (PFS rate) at 6 months is reported here, for the first course of treatment, out of all participants with PD-L1 biomarker positive expression defined by IHC as CPS ≥1 in the pembro combo arm and control arm. Per protocol, the percentage of participants with PFS at 6 months was compared separately between CPS ≥1 participants of the pembro mono arm and control arm and is presented later in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro combo arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants with PFS (PFS rate) at 6 months is reported here, for the first course of treatment, out of all participants with PD-L1 biomarker positive expression defined by IHC as CPS ≥20 in the pembro combo arm and control arm. Per protocol, the percentage of participants with PFS at 6 months was compared separately between CPS ≥20 participants of the pembro mono arm and control arm and is presented later in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro combo arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants with PFS (PFS rate) at 12 months is reported here, for the first course of treatment, out of all participants in the pembro combo arm and control arm. Per protocol, the percentage of participants with PFS at 12 months was compared separately between all participants of the pembro mono arm and control arm and is presented later in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro combo arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants with PFS (PFS rate) at 12 months is reported here, for the first course of treatment, out of all participants with PD-L1 biomarker positive expression defined by IHC as CPS ≥1 in the pembro combo arm and control arm. Per protocol, the percentage of participants with PFS at 12 months was compared separately between CPS ≥1 participants of the pembro mono arm and control arm and is presented later in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro combo arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants with PFS (PFS rate) at 12 months is reported here, for the first course of treatment, out of all participants with PD-L1 biomarker positive expression defined by IHC as CPS ≥20 in the pembro combo arm and control arm. Per protocol, the percentage of participants with PFS at 12 months was compared separately between CPS ≥20 participants of the pembro mono arm and control arm and is presented later in the record.

ORR was defined as the percentage of participants in the analysis population who have a Complete Response (CR: disappearance of all target lesions) or a Partial Response (PR: ≥30% decrease in the sum of diameters of target lesions) per RECIST 1.1. based upon BICR. Per protocol, ORR in the pembro combo arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants who experienced CR or PR is reported here as the ORR, for the first course of treatment, for all participants in the pembro combo arm and control arm. Per protocol, ORR was compared separately between all participants of the pembro mono arm and control arm and is presented later in the record.

ORR was defined as the percentage of participants in the analysis population who have a CR (disappearance of all target lesions) or a PR (≥30% decrease in the sum of diameters of target lesions) per RECIST 1.1. based upon BICR. Per protocol, ORR in the pembro combo arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants who experienced CR or PR is reported here as the ORR, for the first course of treatment, for all participants with PD-L1 biomarker positive expression defined by IHC as CPS ≥1 in the pembro combo arm and control arm. Per protocol, ORR was compared separately between CPS ≥1 participants of the pembro mono arm and control arm and is presented later in the record.

ORR was defined as the percentage of participants in the analysis population who have a CR (disappearance of all target lesions) or a PR (≥30% decrease in the sum of diameters of target lesions) per RECIST 1.1. based upon BICR. Per protocol, ORR in the pembro combo arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants who experienced CR or PR is reported here as the ORR, for the first course of treatment, for all participants with PD-L1 biomarker positive expression defined by IHC as CPS ≥20 in the pembro combo arm and control arm. Per protocol, ORR was compared separately between CPS ≥20 participants of the pembro mono arm and control arm and is presented later in the record.

The EORTC-QLQ-C30 is a 30-item questionnaire to assess the quality of life of cancer patients. Participant responses to the Global Health Status (GHS) question "How would you rate your overall health during the past week?" (Item 29) and the Quality of Life (QoL) question "How would you rate your overall quality of life during the past week?" (Item 30) were scored on a 7-point scale (1=Very Poor to 7=Excellent). Using linear transformation, raw scores were standardized so that scores ranged from 0 to 100; a higher score indicating a better overall outcome. Per protocol, change from baseline to Week 15 in the GHS/QoL combined score, for the first course of treatment, was compared between all participants of the pembro combo arm and the control arm as a pre-specified secondary analysis. Per protocol, change from baseline to Week 15 in the GHS/QoL combined score was compared separately between all participants of the pembro mono arm and control arm and is presented later in the record.

EORTC-QLQ-C30 is a 30-item questionnaire to assess the QoL of cancer patients. Participant responses to the GHS question "How would you rate your overall health during the past week?" (Item 29) and the QoL question "How would you rate your overall quality of life during the past week?" (Item 30) were scored on a 7-point scale (1=Very Poor to 7=Excellent). Raw scores were standardized by linear transformation so that scores ranged from 0 to 100; a higher score indicating a better overall outcome. TTD in GHS/QoL defined as the time from baseline to the first onset of a ≥10 point decrease from baseline in GHS/QoL combined score, with confirmation. Per protocol, TTD in GHS/QoL combined score, for first course of treatment, was compared between all participants of pembro combo arm and control arm as a pre-specified secondary analysis; and TTD in GHS/QoL combined score was compared separately between all participants of pembro mono arm and control arm and is presented later in the record.

EORTC QLQ-H\&N35 is a 35-item questionnaire to assess QoL of head and neck cancer participants and consists of 7 multi-item scales that assess pain, swallowing, senses, speech, social eating, social contact and sexuality. Participant responses to the Pain scale (Items 31-34) were scored on a 4-point scale (1=Not at all to 4=Very much). Raw scores were standardized by linear transformation so that scores ranged from 0 to 100, with a higher score indicating more problems. TTD in EORTC QLQ-H\&N35 Pain Score defined as the time from baseline to the first onset of a ≥10 point decrease from baseline, with confirmation. Per protocol, TTD in EORTC QLQ-H\&N35 Pain Score, for the first course of treatment, was compared between all participants of pembro combo arm and control arm as a pre-specified secondary analysis. Also per protocol, TTD in EORTC QLQ-H\&N35 Pain Score was compared separately between all participants of pembro mono arm and control arm and is presented later in the record.

EORTC QLQ-H\&N35 is a 35-item questionnaire developed to assess QoL of head and neck cancer participants and consists of 7 multi-item scales that assess pain, swallowing, senses, speech, social eating, social contact and sexuality. Participant responses to the Swallowing scale (Items 35-38) were scored on a 4-point scale (1=Not at all to 4=Very much). Raw scores were standardized by linear transformation so that scores ranged from 0 to 100; a higher score indicating more problems. TTD in EORTC QLQ-H\&N35 Swallowing Score defined as the time from baseline to the first onset of a ≥10 point decrease from baseline, with confirmation. Per protocol, TTD in EORTC QLQ-H\&N35 Swallowing Score, for the first course of treatment, was compared between all participants of pembro combo arm and control arm as a pre-specified secondary analysis; and compared separately between all participants of pembro mono arm and control arm and is presented later in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro mono arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants with PFS (PFS rate) at 6 months is reported here, for the first course of treatment, out of all participants in the pembro mono arm and control arm. Per protocol, the percentage of participants with PFS at 6 months was compared separately between all participants of the pembro combo arm and control arm and is presented earlier in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro mono arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants with PFS (PFS rate) at 6 months is reported here, for the first course of treatment, out of all participants with PD-L1 biomarker positive expression defined by IHC as CPS ≥1 in the pembro mono arm and control arm. Per protocol, the percentage of participants with PFS at 6 months was compared separately between CPS ≥1 participants of the pembro combo arm and control arm and is presented earlier in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro mono arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants with PFS (PFS rate) at 6 months is reported here, for the first course of treatment, out of all participants with PD-L1 biomarker positive expression defined by IHC as CPS ≥20 in the pembro mono arm and control arm. Per protocol, the percentage of participants with PFS at 6 months was compared separately between CPS ≥20 participants of the pembro combo arm and control arm and is presented earlier in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro mono arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants with PFS (PFS rate) at 12 months is reported here, for the first course of treatment, out of all participants in the pembro mono arm and control arm. Per protocol, the percentage of participants with PFS at 12 months was compared separately between all participants of the pembro combo arm and control arm and is presented earlier in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro mono arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants with PFS (PFS rate) at 12 months is reported here, for the first course of treatment, out of all participants with PD-L1 biomarker positive expression defined by IHC as CPS ≥1 in the pembro mono arm and control arm. Per protocol, the percentage of participants with PFS at 12 months was compared separately between CPS ≥1 participants of the pembro combo arm and control arm and is presented earlier in the record.

PFS was defined as the time from randomization to the first documented PD per RECIST 1.1 based on BICR, or death due to any cause, whichever occurred first. Per RECIST 1.1, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum had to demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered PD. Per protocol, PFS in the pembro mono arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants with PFS (PFS rate) at 12 months is reported here, for the first course of treatment, out of all participants with PD-L1 biomarker positive expression defined by IHC as CPS ≥20 in the pembro mono arm and control arm. Per protocol, the percentage of participants with PFS at 12 months was compared separately between CPS ≥20 participants of the pembro combo arm and control arm and is presented earlier in the record.

ORR was defined as the percentage of participants in the analysis population who have a CR (disappearance of all target lesions) or a PR (≥30% decrease in the sum of diameters of target lesions) per RECIST 1.1. based upon BICR. Per protocol, ORR in the pembro mono arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants who experienced CR or PR is reported here as the ORR, for the first course of treatment, for all participants in the pembro mono arm and control arm. Per protocol, ORR was compared separately between all participants of the pembro combo arm and control arm and is presented earlier in the record.

ORR was defined as the percentage of participants in the analysis population who have a CR (disappearance of all target lesions) or a PR (≥30% decrease in the sum of diameters of target lesions) per RECIST 1.1. based upon BICR. Per protocol, ORR in the pembro mono arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants who experienced CR or PR is reported here as the ORR, for the first course of treatment, for all participants with PD-L1 biomarker positive expression defined by IHC as CPS ≥1 in the pembro mono arm and control arm. Per protocol, ORR was compared separately between CPS ≥1 participants of the pembro combo arm and control arm and is presented earlier in the record.

ORR was defined as the percentage of participants in the analysis population who have a CR (disappearance of all target lesions) or a PR (≥30% decrease in the sum of diameters of target lesions) per RECIST 1.1. based upon BICR. Per protocol, ORR in the pembro mono arm was compared to the control arm as a pre-specified secondary analysis of the ITT population. The percentage of participants who experienced CR or PR is reported here as the ORR, for the first course of treatment, for all participants with PD-L1 biomarker positive expression defined by IHC as CPS ≥20 in the pembro mono arm and control arm. Per protocol, ORR was compared separately between CPS ≥20 participants of the pembro combo arm and control arm and is presented earlier in the record.

The EORTC-QLQ-C30 is a 30-item questionnaire developed to assess the quality of life of cancer patients. Participant responses to the GHS question "How would you rate your overall health during the past week?" (Item 29) and the QoL question "How would you rate your overall quality of life during the past week?" (Item 30) were scored on a 7-point scale (1=Very Poor to 7=Excellent). Using linear transformation, raw scores were standardized so that scores ranged from 0 to 100, with a higher score indicating a better overall outcome. Per protocol, change from baseline to Week 15 in the GHS/QoL combined score, for the first course of treatment, was compared between all participants of the pembro mono arm and the control arm as a pre-specified secondary analysis. As specified by the protocol, change from baseline to Week 15 in the GHS/QoL combined score was compared separately between all participants of the pembro combo arm and control arm and is presented earlier in the record.

EORTC-QLQ-C30 is a 30-item questionnaire to assess the QoL of cancer patients. Participant responses to the GHS question "How would you rate your overall health during the past week?" (Item 29) and the QoL question "How would you rate your overall quality of life during the past week?" (Item 30) were scored on a 7-point scale (1=Very Poor to 7=Excellent). Raw scores were standardized by linear transformation so that scores ranged from 0 to 100; a higher score indicating a better overall outcome. TTD in GHS/QoL defined as the time from baseline to the first onset of a ≥10 point decrease from baseline in GHS/QoL combined score, with confirmation. Per protocol, TTD in GHS/QoL combined score, for the first course of treatment, was compared between all participants of pembro mono arm and control arm as a pre-specified secondary analysis; and compared separately between all participants of pembro combo arm and control arm and is presented earlier in the record.

EORTC QLQ-H\&N35 is a 35-item questionnaire developed to assess QoL of head and neck cancer participants and consists of 7 multi-item scales that assess pain, swallowing, senses, speech, social eating, social contact and sexuality. Participant responses to the Pain scale (Items 31-34) were scored on a 4-point scale (1=Not at all to 4=Very much). Raw scores were standardized by linear transformation so that scores ranged from 0 to 100; a higher score indicating more problems. TTD in EORTC QLQ-H\&N35 Pain Score defined as the time from baseline to the first onset of a ≥10 point decrease from baseline, with confirmation. Per protocol, TTD in EORTC QLQ-H\&N35 Pain Score, for the first course of treatment, was compared between all participants of pembro mono arm and control arm as a pre-specified secondary analysis. Also per protocol, TTD in EORTC QLQ-H\&N35 Pain Score was compared separately between all participants of pembro combo arm and control arm and is presented earlier in the record.

EORTC QLQ-H\&N35 is a 35-item questionnaire developed to assess QoL of head and neck cancer participants and consists of 7 multi-item scales that assess pain, swallowing, senses, speech, social eating, social contact and sexuality. Participant responses to the Swallowing scale (Items 35-38) were scored on a 4-point scale (1=Not at all to 4=Very much). Raw scores were standardized by linear transformation so that scores ranged from 0 to 100; a higher score indicating more problems. TTD in EORTC QLQ-H\&N35 Swallowing Score defined as the time from baseline to the first onset of a ≥10 point decrease from baseline, with confirmation. Per protocol, TTD in EORTC QLQ-H\&N35 Swallowing Score, for the first course of treatment, was compared between all participants of pembro mono arm and control arm as a pre-specified secondary analysis; and compared separately between all participants of pembro combo arm and control arm and is presented earlier in the record.

An AE was defined as any untoward medical occurrence in a participant administered a pharmaceutical product and which did not necessarily have to have a causal relationship with this treatment. An AE could therefore be any unfavourable 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 pre-existing condition that was temporally associated with the use of the Sponsor's product was also an AE. The number of participants that experienced at least one AE, for the first course of treatment, was reported for each arm.

An AE was defined as any untoward medical occurrence in a participant administered a pharmaceutical product and which did not necessarily have to have a causal relationship with this treatment. An AE could therefore be any unfavourable 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 pre-existing condition that was temporally associated with the use of the Sponsor's product was also an AE. The number of participants that discontinued study drug due to an AE, for the first course of treatment, was reported for each arm.