A Global Study of Volrustomig (MEDI5752) for Participants With Unresected Locally Advanced Head and Neck Squamous Cell Carcinoma Following Definitive Concurrent Chemoradiotherapy

Progression-Free Survival (PFS) in participants with unresected LA-HNSCC with PD-L1 expressing tumors

Timeframe: Up to approximately 8 years

PFS is defined as time from randomization until first objective radiological progression per RECIST 1.1 as assessed by Blinded Independent Central Review (BICR), or death due to any cause (in the absence of progression). The analysis will include all randomized participants with PD-L1 expressing tumors.

Progression-Free Survival (PFS) in the unresected LA-HNSCC intent-to-treat (ITT) population

Timeframe: Up to approximately 8 years

PFS is defined as time from randomization until first objective radiological progression per RECIST 1.1 as assessed by BICR, or death due to any cause (in the absence of progression). The analysis will include all randomized participants.

Landmark Progression-Free Survival (PFS) Rates

Timeframe: Up to approximately 8 years

PFS is defined as time from randomization until first objective radiological progression per RECIST 1.1 as assessed by BICR, or death due to any cause (in the absence of progression). These analyses will include participants with PD-L1 expressing tumors and all randomized participants.

Overall Survival (OS) in participants with unresected LA-HNSCC with PD-L1 expressing tumors

Timeframe: Up to approximately 8 years

Overall survival (OS) is defined as the time from randomization until the date of death due to any cause. The analysis will include all randomized participants with PD-L1 expressing tumors.

Landmark Overall Survival (OS) Rates

Timeframe: Up to approximately 8 years

OS is defined as the time from randomization until the date of death due to any cause. These analyses will include participants with PD-L1 expressing tumors as randomized and all randomized participants.

Overall Survival (OS) in the unresected LA-HNSCC ITT population

Timeframe: Up to approximately 8 years

OS is defined as the time from randomization until the date of death due to any cause. The analysis will include all randomized participants.

Progression Free Survival 2 (PFS2)

Timeframe: Up to approximately 8 years

PFS2 is defined as the time from randomization until the earliest of the progression event (following the initial investigator-assessed progression), after the start of the first subsequent therapy, or death from any cause, whichever occurs first. The date of the second progression will be recorded by the investigator in the eCRF and defined according to local standard clinical practice. These analyses will include participants with PD-L1 expressing tumors as randomized and all randomized participants.

Presence of Anti-Drug-Antibodies (ADAs) against volrustomig in serum

Timeframe: Up to approximately 8 years

To investigate the immunogenicity of volrustomig.

Participant-reported physical functioning

Timeframe: Up to approximately 8 years

Change from baseline of physical functioning as measured by scores on the Patient-Reported Outcomes Measurement Information System (PROMIS) Short Form v.20 - Physical Function 8c are reported on a T score metric (mean = 50 and SD = 10), with higher scores reflecting better physical functioning. The analysis will include all randomized participants.

Participant-reported global health status (GHS)/quality of life (QoL)

Timeframe: Up to approximately 8 years

Change from baseline of Global Health Status/Quality of Life subscale scores as measured by the European Organization for Research and Treatment of Cancer (EORTC) Item Library 172 are transformed to a 0-100 range; a higher score represents higher quality of life. The analysis will include all randomized participants.

Percentage of participants with Adverse Events

Timeframe: Up to approximately 8 years

Adverse Events as assessed by Common Terminology Criteria for Adverse Events (CTCAE).

Area under the curve (AUC)

Timeframe: Up to approximately 8 years

The concentration of Volrustomig in serum will be determined. Area under the curve is the integral of the concentration-time curve. The AUC reflects the actual body exposure to drug after administration. The AUC is dependent on the rate of elimination of the drug from the body and the dose administered.

Maximum plasma concentration of the drug (Cmax)

Timeframe: Up to approximately 8 years

The concentration of Volrustomig in serum will be determined (Cmax will be derived).

The time taken to reach the maximum concentration (Tmax)

Timeframe: Up to approximately 8 years

The concentration of Volrustomig in serum will be determined (Tmax will be derived).