Inclusion Criteria:

• Pathologically documented Stage IIIB, IIIC, or Stage IV non-squamous non-small cell lung cancer (NSCLC) without actionable genomic alterations (AGA) at the time of randomisation and meets the criteria for NSCLC:

  • Participants must have documented negative test results for epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), and ROS proto-oncogene 1 (ROS1) genomic alterations.
  • Has no known tumour genomic alterations in neurotrophic tyrosine receptor kinase (NTRK), proto-oncogene B-raf (BRAF), rearranged during transfection (RET), mesenchymal-epithelial transition (MET) exon 14 skipping, Kirsten rat sarcoma viral oncogene homolog (KRAS) G12C, human epidermal growth factor receptor 2 (HER2) or any other actionable driver oncogenes for which there are locally approved and available targeted first-line therapies.
  • Prospectively assessed trophoblast cell surface protein 2 (TROP2) normalised membrane ratio (NMR) positive.

• Documentation of radiographic disease progression while on or after receiving the most recent treatment regimen for advanced or metastatic NSCLC.

• Participants must have received platinum based chemotherapy (PBC) in combination with anti-programmed death-protein 1 (anti-PD-1)/anti-programmed death-ligand 1 (anti-PD-L1) monoclonal antibody (mAb) as the only prior line of therapy or received PBC and anti-PD-1/anti-PD-L1 monoclonal antibody (in either order) sequentially as the only 2 prior lines of therapy.

• Provision of acceptable formalin fixed and paraffin embedded (FFPE) tumour sample for assessment of TROP2.

• At least one lesion not previously irradiated that qualifies as a Response Evaluation Criteria in Solid Tumours, Version 1.1 (RECIST 1.1) target lesion (TL) at baseline and can be accurately measured at baseline as ≥ 10 mm in the longest diameter (except lymph nodes, which must have short axis ≥ 15 mm) with computed tomography (CT) or magnetic resonance imaging (MRI) and is suitable for accurate repeated measurements.

• Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) of 0 or 1.

• Adequate bone marrow reserve and organ function within 7 days before randomisation.

Exclusion Criteria:

• Squamous, mixed NSCLC, or small cell lung cancer (SCLC) histology.
• NSCLC disease that is eligible for definitive local therapy alone.
• History of another primary malignancy other than NSCLC, except for malignancy treated with curative intent with no known active disease within 3 years before randomisation and of low potential risk for recurrence.
• Spinal cord compression or brain metastases, unless asymptomatic, stable, and not requiring treatment with corticosteroids or anticonvulsants for at least 7 days prior to randomisation.
• Clinically significant corneal disease.
• Has active or uncontrolled hepatitis B or C virus infection.
• Known human immunodeficiency virus (HIV) infection that is not well controlled.
• Uncontrolled infection requiring intravenous (IV) antibiotics, antivirals, or antifungals.
• History of non-infectious interstitial lung disease (ILD)/pneumonitis including radiation pneumonitis that required steroids, has current ILD/pneumonitis, or has suspected ILD/pneumonitis that cannot be ruled out by imaging at screening.
• Severe pulmonary function compromise per Investigator discretion.