A Study to Investigate Safety and Efficacy of Osimertinib and Amivantamab in Participants With Non-small Cell Lung Cancer With Common Epidermal Growth Factor Receptor Mutations

Inclusion Criteria:

* Histologically or cytologically documented non-squamous NSCLC. NSCLC of mixed histology is allowed.
* Newly diagnosed locally advanced or metastatic NSCLC or recurrent non-squamous NSCLC, not amenable to curative surgery or radiotherapy.
* WHO PS of 0 to 1 with no deterioration over the 2 weeks prior to enrolment.
* Minimum life expectancy \> 12 weeks at Day 1.
* Confirmation by the local laboratory that the tumour harbours one of the 2 common EGFRm known to be associated with (Epidermal Growth Factor Receptor- Tyrosine Kinase Inhibitor) EGFR-TKI sensitivity.
* At least 1 lesion that can be accurately measured at baseline as ≥10 mm in the longest diameter with computed tomography (CT) or magnetic resonance imaging (MRI) and that is suitable for accurate repeated measurements.
* Contraceptive use by males or females should be consistent with local regulations

Exclusion Criteria:

* Any evidence of diseases, history of allogenic organ transplant, which in the investigator's opinion makes it undesirable for the participant to participate in the study or would jeopardise compliance with protocol.
* Refractory nausea and vomiting, chronic gastrointestinal diseases, inability to swallow the osimertinib, or previous significant bowel resection that would preclude adequate absorption distribution, metabolism, or excretion of osimertinib.
* History of another primary malignancy except for malignancy treated with curative intent with no known active disease ≥2 years.
* Any unresolved toxicities from prior therapy with Common Terminology Criteria for Adverse Events CTCAE) Grade ≥1, at the time of first dose of study intervention, with the exception of alopecia and Grade 2 prior platinum therapy related neuropathy.
* Spinal cord compression or brain metastases unless asymptomatic, stable, and not requiring corticosteroids for at least 2 weeks prior to start of study intervention.
* Active infection, including tuberculosis and infections with HBV (verified by known positive HBsAg result) or HCV.
* Should participants with HIV infection be included, patients are only eligible if they meet the criteria per protocol.
* Patient with protocol defined cardiac issue.
* History of interstitial lung disease (ILD), drug-induced ILD, radiation pneumonitis that required steroid treatment, or any evidence of clinically active ILD.
* Any concomitant medications known to be associated with Torsade de Pointes.
* Prior exposure to any systemic anti-cancer therapy for advanced NSCLC not amenable to curative surgery or radiation including chemotherapy, biologic therapy, immunotherapy, or any investigational drug.
* Any concurrent anti-cancer treatment without an adequate washout period prior to the first dose of study intervention.
* Palliative radiotherapy with a limited field of radiation within 2 weeks, or with wide field of radiation or to more than 30% of the bone marrow within 4 weeks, prior to the first dose of study intervention.
* Major surgical procedure or significant traumatic injury.
* Current use of medications or herbal supplements known to be strong inducers of CYP 3A4.
* Prior treatment with an EGFR-TKI.
* Participants with a history of hypersensitivity, or intolerance to the active or inactive excipients of osimertinib, amivantamab, or recommended pre-treatments of amivantamab or drugs with a similar chemical structure or class to these drugs.