Summary
Eligible participants will be randomly allocated to one of three treatment groups.
Group 1 will receive the antibody-drug conjugate Dato-DXd + osimertinib combination therapy. Dato-DXd will be given as an intravenous (IV) infusion on Day 1 of every 21-day cycle (every 3 weeks) and osimertinib will be given once daily as an oral tablet.
Group 2 will receive Dato-DXd by itself (monotherapy), which will be given as an IV infusion every 3 weeks.
Group 3 will receive platinum-based doublet chemotherapy. This will consist of pemetrexed in combination with either carboplatin (AUC5) or cisplatin as IV infusion every 3 weeks for 4 cycles, followed by pemetrexed maintenance therapy as an IV infusion every 3 weeks.
After study intervention discontinuation, all participants will undergo an end of treatment visit within 35 days of discontinuation and will be followed up for safety assessments 28 (+7) days after their last dose of study intervention.