DFS, defined as the number of days from the date of randomisation to the date of tumour recurrence/ Second Primary Tumours (SPT) or death from any cause, whichever occurred first.

For patients with known date of tumour recurrence/SPT (or death), the event date was the date of tumour recurrence/SPT or the date of death, whichever came first, i.e.

DFS [day] = minimum (date of tumour recurrence/SPT, date of death) - date of randomisation +1.

For patients known to be alive and without tumour recurrence/SPT by the end of trial or follow-up visit, they were censored at the date of last imaging when the patient was known to be disease-free and alive:

DFS (censored) [days] = date of last imaging when the patient was known to be diseasefree and alive - date of randomisation + 1. The Kaplan-Meier (KM) method was to be used to estimate the median DFS for each treatment group. 95% confidence interval (CI) was to be constructed using the Greenwood variance estimate.

Randomised Set; This study was early terminated and data was available for less than 2/3rds of participants hence per internal Boehringer Ingelheim rules the analysis was not performed as planned in protocol.

Disease Free Survival (DFS) rate at 2 years is presented

Randomised Set; This study was early terminated and data was available for less than 2/3rds of participants hence per internal Boehringer Ingelheim rules the analysis was not performed as planned in protocol.

OS was defined as time from the date of randomisation until death.

For patients with known date of death (regardless of the cause of death):

OS [days] = date of death - date of randomisation +1

For patients known to be alive by the end of trial:

OS (censored) [days] = the last date when the patient was known to be alive - date of randomisation +1 OS was to be analysed similarly to DFS.

Randomised Set; This study was early terminated and data was available for less than 2/3rds of participants hence per internal Boehringer Ingelheim rules the analysis was not performed as planned in protocol.

The main analysis of HRQOL questionnaires was to focus on the change in score from baseline in the following scales measured on the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30 and EORTC QLQ-H&N35:

• Global Health Status/ Quality of Life (QOL) Scale
• Pain Scale
• Swallowing Scale

Randomised Set; This study was early terminated and data was available for less than 2/3rds of participants hence per internal Boehringer Ingelheim rules the analysis was not performed as planned in protocol.