Study of GSK3359609 and Pembrolizumab in Programmed Death Receptor 1-ligand 1 (PD-L1) Positive Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma

PFS per iRECIST was defined as the interval of time from the date of randomization to the date of the first documented disease progression confirmed consecutively per iRECIST based on investigator assessment, or death due to any cause, whichever occurs first. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells. Kaplan-Meier estimate for the median PFS is presented, along with associated 95% confidence interval, estimated using the Brookmeyer-Crowley method.

PFS per RECIST v1.1 was defined as the time from the date of randomization to the date of first documented disease progression per RECIST v1.1. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells. Kaplan-Meier estimate for the median PFS is presented, along with associated 95% confidence interval, estimated using the Brookmeyer-Crowley method.

PFS per iRECIST was defined as the interval of time from the date of randomization to the date of the first documented disease progression confirmed consecutively per iRECIST based on investigator assessment, or death due to any cause, whichever occurs first. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells. Kaplan-Meier estimate for the median PFS is presented, along with associated 95% confidence interval, estimated using the Brookmeyer-Crowley method.

Milestone OS rate at 12 months was estimated using the Kaplan-Meier method. Associated 95% confidence intervals are estimated using the Brookmeyer-Crowley method. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Milestone OS rate at 24 months was not evaluated. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Milestone OS rate at 12 months was estimated using the Kaplan-Meier method. Associated 95% confidence intervals are estimated using the Brookmeyer-Crowley method. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Milestone OS rate at 24 months was not evaluated. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

ORR per RECIST v1.1 was defined as the proportion of the participants who have a complete response (CR) or partial response (PR) as the best overall response per RECIST v1.1 based upon investigator assessment. As a randomized double-blind study in which primary endpoints are OS and PFS, the confirmation of CR and PR was not required. Rate and associated 2-sided 95 percent Exact (Clopper-Pearson) Confidence Intervals are provided for each treatment arm which are unadjusted. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

ORR per RECIST v1.1 was defined as the proportion of the participants who have a CR or PR as the best overall response per RECIST v1.1 based upon investigator assessment. As a randomized double-blind study in which primary endpoints are OS and PFS, the confirmation of CR and PR was not required. Rate and associated 2-sided 95 percent Exact (Clopper-Pearson) Confidence Intervals are provided for each treatment arm which are unadjusted. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

DCR per RECIST v1.1 based upon investigator assessment, was defined as the percentage of participants with a best overall response of CR or PR at any time plus stable disease (SD) meeting the minimum time of 15 weeks. A status of SD≥15 weeks will be assigned if the follow-up disease assessment has met the SD criteria at least once after the date of randomization at a minimum of 14 weeks (98 days) considering a one-week visit window. Rate and associated 2-sided 95 percent Exact (Clopper-Pearson) Confidence Intervals are provided for each treatment arm which are unadjusted. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

DCR per RECIST v1.1 based upon investigator assessment, was defined as the percentage of participants with a best overall response of CR or PR at any time plus stable disease (SD) meeting the minimum time of 15 weeks. A status of SD≥15 weeks will be assigned if the follow-up disease assessment has met the SD criteria at least once after the date of randomization at a minimum of 14 weeks (98 days) considering a one-week visit window. Rate and associated 2-sided 95 percent Exact (Clopper-Pearson) Confidence Intervals are provided for each treatment arm which are unadjusted. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

DoR per RECIST v1.1 is defined as the time from first documented evidence of CR or PR until first documented disease progression per RECIST v1.1 based upon investigator assessment or death due to any cause, whichever occurs first, among participants who demonstrated CR or PR as the best overall response per RECIST v1.1. Kaplan-Meier estimate for the median DoR is presented, along with associated 95% confidence interval, estimated using the Brookmeyer-Crowley method. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

DoR per RECIST v1.1 is defined as the time from first documented evidence of CR or PR until first documented disease progression per RECIST v1.1 based upon investigator assessment or death due to any cause, whichever occurs first, among participants who demonstrated CR or PR as the best overall response per RECIST v1.1. Kaplan-Meier estimate for the median DoR is presented, along with associated 95% confidence interval, estimated using the Brookmeyer-Crowley method. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study intervention, whether or not considered related to the study intervention. An SAE was defined as any untoward medical occurrence that, at any dose results in death, is life-threatening, requires in-patient hospitalization or prolongation of existing hospitalization, results in persistent disability/incapacity, is a congenital anomaly/birth defect, any other situation such as important medical events according to medical or scientific judgement.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study intervention, whether or not considered related to the study intervention. Severity of each AE was reported during the study and was assigned a grade according to the National Cancer Institute- Common Toxicity Criteria for Adverse Events (NCI-CTCAE). AEs severity were graded on a 5-point scale as: 1 = mild; discomfort noticed, but no disruption to daily activity, 2 = moderate; discomfort sufficient to reduce or affect normal daily activity, 3 = severe; inability to work or perform normal daily activity, 4 = life-threatening consequences and 5 = death related to AE.

An SAE was defined as any untoward medical occurrence that, at any dose results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent disability/incapacity, is a congenital anomaly/birth defect, any other situation such as important medical events according to medical or scientific judgement. Severity of each SAE was reported during the study and was assigned a grade according to the NCI-CTCAE. SAEs severity were graded on a 5-point scale as: 1 = mild; discomfort noticed, but no disruption to daily activity, 2 = moderate; discomfort sufficient to reduce or affect normal daily activity, 3 = severe; inability to work or perform normal daily activity, 4 = life-threatening consequences and 5 = death related to AE. Data of participants experiencing SAEs of Grade ≥3 have been presented.

AESI were defined as events of potential immunologic etiology, including immune-related AEs (irAEs). Such events recently reported after treatment with other immune modulatory therapy include colitis, uveitis, hepatitis, pneumonitis, diarrhea, endocrine disorders, and specific cutaneous toxicities, as well as other events that may be immune mediated.

AESI were defined as events of potential immunologic etiology, including immune-related AEs (irAEs). Such events recently reported after treatment with other immune modulatory therapy include colitis, uveitis, hepatitis, pneumonitis, diarrhea, endocrine disorders, and specific cutaneous toxicities, as well as other events that may be immune mediated. Severity of each AESI was reported during the study and was assigned a grade according to the NCI-CTCAE. AESIs severity were graded on a 5-point scale as: 1 = mild; discomfort noticed, but no disruption to daily activity, 2 = moderate; discomfort sufficient to reduce or affect normal daily activity, 3 = severe; inability to work or perform normal daily activity, 4 = life-threatening consequences and 5 = death related to AE. Data of participants experiencing AESIs of Grade ≥3 have been presented.

Number of participants with dose modifications (including dose interruptions, dose delays and treatment discontinuations) were reported by each interventional component.

TTD in pain is defined as the time from randomization to the first definitive meaningful deterioration from baseline in the European Organization for Research and Treatment of Cancer Item Library(EORTC IL51) pain domain, i.e. an increase from baseline of at least 8.33 observed at all subsequent non-missing visits. The EORTC Quality of Life Questionnaire 35-Item Head and Neck Module (QLQ-H\&N35) is a head and neck specific module with multi-item scales. The questionnaire scores for each scale and single-item measure are averaged and transformed linearly to present a score ranging from 0-100. A high score represents a high/healthy level of functioning. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

TTD in pain is defined as the time from randomization to the first definitive meaningful deterioration from baseline in the EORTC IL51 pain domain, i.e. an increase from baseline of at least 8.33 observed at all subsequent non-missing visits. The EORTC QLQ-H\&N35 is a head and neck specific module with multi-item scales. The mouth pain, swallowing, speech problems, opening mouth, coughing, feeding tube, and trouble with social eating domains were administered and referred to as the EORTC IL51. The questionnaire scores for each scale and single-item measure are averaged and transformed linearly to present a score ranging from 0-100. A high score represents a high/healthy level of functioning. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

TTD in physical function is defined as the time from randomization to the first definitive meaningful deterioration from baseline in the PF T-score, i.e. a decrease from baseline of at least 2.4 observed at all subsequent non-missing visits, as measured by the PROMIS PF 8c. The PROMIS PF 8c is an 8-item fixed length short form derived from the PROMIS Physical Function item bank. It includes a 5-point scale with three sets of response options. Scores on the PROMIS PF 8c are reported on a T score metric (mean = 50 and SD = 10), with higher scores reflecting better physical functioning. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

TTD in physical function is defined as the time from randomization to the first definitive meaningful deterioration from baseline in the PF T-score, i.e. a decrease from baseline of at least 2.4 observed at all subsequent non-missing visits, as measured by the PROMIS PF 8c. The PROMIS PF 8c is an 8-item fixed length short form derived from the PROMIS Physical Function item bank. It includes a 5-point scale with three sets of response options. Scores on the PROMIS PF 8c are reported on a T score metric (mean = 50 and SD = 10), with higher scores reflecting better physical functioning. Data are presented for the PD-L1 CPS >=1 participants from mITT population. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.