This phase I trial is comparing two oral drugs (LXH254 and LTT462) in patients with metastatic (KRAS or BRAF) Non-Small Cell (NSC) Lung CancerA Phase Ib, Open-label, Multicenter Study of Oral LXH254 in Combination With Oral LTT462 in Adult Patients With Advanced or Metastatic KRAS or BRAF Mutant Non-Small Cell Lung Cancer

Exclusion

-Dose expansion - KRAS or NRAS mutant patients groups: Prior treatment with a RAFi (including any BRAFi and pan-RAFi), MEKi and/or ERKi. (Patients with KRAS mutant NSCLC with prior G12C inhibitor treatments are also excluded in the LXH254+trametinib expansion part). BRAF mutant patients group: Prior treatment with any EGFR, ALK, ROS1, KRAS, RAF (both BRAFV600 selective and pan-RAF), MEK1/2 and/or ERK1/2 inhibitors (for patients with BRAF V600 mutant NSCLC, prior treatments with BRAF and MEK1/2 inhibitors are allowed).

Patients who have received more than 3 lines of anti-cancer therapy are excluded.

• History or current evidence of retinal vein occlusion (RVO) or current risk factors for RVO.
• Any medical condition that would, in the investigator's judgment, prevent the patient's participation in the clinical study due to safety concerns or compliance with clinical study procedures.
• Patients receiving proton pump inhibitors (PPI) which cannot be discontinued 3 days prior to the start study treatment and for the duration of the study.
• Patients with Gilbert's syndrome or other heritable diseases of bile processing.

Other protocol-defined inclusion/exclusion criteria may apply