Osimertinib

PFS is defined as time from randomisation until progression per RECIST 1.1 as assessed by BICR, or death due to any cause (in the absence of progression).

Safety and tolerability of osimertinib will be assessed.

DFS is defined as the time from the date of randomisation until the date of disease recurrence or date of death (by any cause in the absence of recurrence), whichever occurs first. Stratification to the high risk stratum will be based on pathologic features assessed by central pathology review during screening.

Defined as ≤10% viable cancer cells in the surgical specimen, as assessed per central pathology laboratory post-surgery (IASLC method). Patients will only be considered to have an MPR if they also have an R0 margin result.

Defined as ≤10% viable cancer cells in the surgical specimen, as assessed per central pathology laboratory post-surgery (chemotherapy method). Patients will only be considered to have an MPR if they also have an R0 margin result.

Adverse events were summarized by maximum reported Common Terminology Criteria for Adverse Event (CTCAE) grade, version 5.0. Grade 1 (Mild): asymptomatic or mild symptoms; clinical or diagnostic observations only; intervention not indicated. Grade 2 (Moderate): minimal, local or noninvasive intervention indicated; limiting age-appropriate instrumental activities of daily living. Grade 3 (Severe or medically significant but not immediately life-threatening): hospitalization or prolongation of hospitalization indicated; disabling; limiting self-care activities of daily living. Grade 4 (Life-threatening consequences): urgent intervention indicated. Grade 5: Death related to AE. Includes adverse events with onset date on or after the date of first dose and up to and including 28 days following discontinuation of treatment but prior to the start of a new anti-cancer therapy.

Progression-free survival (PFS) using Investigator assessment as defined by RECIST 1.1. Median progression free survival (months) calculated using the Kaplan-Meier method. Progression-free survival (PFS) is defined as the time from randomization until the date of objective disease progression or death (by any cause in the absence of progression), regardless of whether the patient withdraws from randomized therapy or receives another anti-cancer therapy prior to progression. Patients who have not progressed or died at the time of analysis will be censored at the time of the latest date of assessment from their last evaluable RECIST assessment. The primary efficacy analysis of the investigator-assessed progression-free survival will be performed when approximately 278 PFS events and at least 16 months of follow-up after Last subject in, has occurred in the 556 randomized patients.

Sensitivity analysis for progression-free survival (PFS) by blinded independent central review (BICR) using Investigator assessment as defined by RECIST 1.1. Median progression free survival (months) calculated using the Kaplan-Meier method. Progression-free survival (PFS) is defined as the time from randomization until the date of objective disease progression or death (by any cause in the absence of progression), regardless of whether the patient withdraws from randomized therapy or receives another anti-cancer therapy prior to progression. Patients who have not progressed or died at the time of analysis will be censored at the time of the latest date of assessment from their last evaluable RECIST assessment. The primary efficacy analysis of the investigator-assessed progression-free survival will be performed when approximately 278 PFS events and at least 16 months of follow-up after Last subject in, has occurred in the 556 randomized patients.

Time from randomisation until the date of objective disease progression or death (by any cause in the absence of progression) regardless of whether the patient withdraws from randomised therapy or receives another anti-cancer therapy prior to progression, based on BICR assessment according to RECIST v1.1

PFS is defined as the time from date of first dose until progression per RECIST 1.1 as assessed by the investigator at the local site, or death due to any cause.

To assess the safety and tolerability of osimertinib plus amivantamab in participants with EGFR mutation-positive, locally advanced, or metastatic NSCLC.

The time from date of first dose of study intervention until progression per RECIST 1.1 as assessed by the investigator at the local site, or death due to any cause. The analysis will include all dosed participants. All events will be included, regardless of whether the participant withdraws from therapy, receives another anti-cancer therapy or clinically progresses prior to RECIST 1.1.

Defined as time from date of first dose until disease recurrence, or death due to any cause in the absence of recurrence.

DFS is defined as the time from the first dosing of study treatment until the date of disease recurrence by investigator assessment or death by any cause in the absence of disease recurrence. DFS rate at 3 years is defined as the proportion of patients alive and disease free at 3 years from the first dosing of study treatment as estimated by Kaplan-Meier method, respectively. Patients who are disease-free and alive at the time of analysis will be censored at the date of their latest follow-up assessment known to be disease-free

Percentage of evaluable patients with an Investigator-assessed visit response of complete response (CR) or partial response (PR). CR defined as disappearance of all target and non-target lesions and no new lesions. PR defined as \>= 30% decrease in the sum of diameters of target lesions (compared to baseline) and no new non-target lesions. Overall Response (OR) = CR + PR.

Absence of progressive brain metastases according to the Response Assessment in Neuro-Oncology Brain Metastasis (RANO-BM criteria)

Percentage of subjects with a confirmed Objective Response (OR) per Response Evaluation Criteria In Solid Tumors (RECIST 1.1). OR includes Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: ≥30% decrease in target lesion diameters). OR must be recorded at one visit and confirmed by repeat imaging at least 4 weeks later, with no disease progression between initial and confirmation visits.

Percentage of subjects with a confirmed Objective Response (OR) per Response Evaluation Criteria In Solid Tumors (RECIST 1.1). OR includes Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: ≥30% decrease in target lesion diameters). OR must be recorded at one visit and confirmed by repeat imaging at least 4 weeks later, with no disease progression between initial and confirmation visits.

The frequency of genetic and proteomic markers at disease progression regardless of their prevalence was evaluated.

The primary endpoint is defined as the proportion of patients at 18 months who are alive and did not experience an event for PFS by RECIST 1.1 while receiving osimertinib (PFS-OSI). Specifically, it relates to progression of disease according to RECIST 1.1 or death after switching to osimertinib in arms "Gefitinib till + blood test/progression then Osimertinib" and "Gefitinib till progression then Osimertinib". It is formally assessed in these two arms, whilst only provided as a reference for the "Osimertinib till progression" arm, in which progression of disease or death is measured from baseline considering that patients start with osimertinib.

Per Response Evaluation Criteria in Solid Tumours (RECIST v1.1) assessed by MRI or CT: Complete Response (CR): Disappearance of all target and non-target lesions and no new lesions; Partial Response (PR): \>= 30% decrease in the sum of diameters of Target Lesions (compared to baseline) and no new lesions. ORR is the percentage of patients with at least 1 visit response of CR or PR (according to independent review) that was confirmed at least 4 weeks later, prior to progression or further anti-cancer therapy.

During the PET examination time, a series of arterial blood samples were taken to measure Cmax, %ID brain of \[11C\]osimertinib.

During the PET examination time, a series of arterial blood samples were taken to measure Cmax, SUV brain of \[11C\]osimertinib.

The Tmax, brain was determined directly from the observed concentration versus time data.

The Kp was defined as ratio of radiolabeled drug in brain to that in plasma calculated as area under the brain radioactivity concentration-time curve between 0 and 90 minutes/area under the plasma radioactivity concentration-time curve between 0 and 90 minutes.