BBP-398 in Combination With Osimertinib in Locally Advanced or Metastatic NSCLC Patients With EGFR Mutations

BBP-398 (formerly known as IACS-15509) is a potent, selective, orally active allosteric inhibitor of SHP2, a tyrosine phosphatase that plays a key role in the RTK -MAPK signal transduction pathway. Key components of the MAPK pathway include the small GTPase RAS, the serine/threonine-protein kinase RAF, mitogen-activated protein kinase (MEK) and ERK. In cells, SHP2 binds to phosphorylated tyrosine residues in the intracellular domain of RTKs such as the EGFR, leading to activation of the downstream MAPK signaling pathway.

Osimertinib is a mutant-selective, third-generation EGFR inhibitor that targets both EGFR-activating mutations (e.g., exon 19 deletion and L858R) and EGFR-dependent on-target resistance mutation toward the 1st generation EGFR inhibitor (i.e., T790M). It is currently a first-line therapy for EGFR-mutant (EGFRmut) NSCLC, with average progression-free survival of approximately 19 months in previously untreated subjects.