This phase Ib open-label trial (NCT02974725) explored LXH254 combinations; here we report on LXH254 + LTT462 dose escalation. Patients (pts) with advanced/metastatic KRAS- or BRAF-mutant NSCLC received oral LXH254 (50–350 mg once daily [QD] or 300–600 mg twice daily [BID]) and oral LTT462 (100–300 mg QD)....16 pts (33%; including the 2 uPRs) had stable disease; of those, 2 BRAF-mutant pts (V600E, G466A) had tumor shrinkage ≥25%.