Breaking the ‘Undruggable’ Barrier: Anti-PD-1/PD-L1 Immunotherapy for Non-Small Cell Lung Cancer Patients with KRAS Mutations—A Comprehensive Review and Description of Single Site Experience

SIMPLE SUMMARY: KRAS gene mutations are among the most common oncogenic lesions in NSCLC patients. For many years, they were considered “incurable”. This is now changing and therapeutic options are available for NSCLC patients with mutated KRAS. It is likely that the effectiveness of immunotherapy in KRAS(mut) NSCLC patients does not depend only on the presence of druggable lesions in this gene, but also on the molecular background—co-mutations in the STK11, KEAP1 and TP53 genes. This article reviews the literature on the efficacy of immunotherapy in NSCLC patients with KRAS mutation. It also presents our own experience with the use of immunotherapy in patients with KRAS(mut) NSCLC. ABSTRACT: Kirsten rat sarcoma viral oncogene homologue (KRAS) gene mutations are among the most commonly found oncogenic alterations in non-small cell lung cancer (NSCLC) patients. Unfortunately, KRAS mutations have been considered “undruggable” for many years, making treatment options very limited. Immunotherapy targeting programmed death-ligand 1 (PD-L1), programmed death 1 (PD-1) and cytotoxic T lymphocyte antigen 4 (CTLA-4) has emerged as a promising therapeutic option for NSCLC patients. However, some studies have suggested a lower response rate to immunotherapy in KRAS-mutated NSCLC patients with the coexistence of mutations in the STK11 (Serine/Threonine Kinase 11) gene. However, recent clinical trials have shown promising results with the combination of immunotherapy and chemotherapy or immunotherapy and KRAS inhibitors (sotorasib, adagrasib) in such patients. In other studies, the high efficacy of immunotherapy has been demonstrated in NSCLC patients with mutations in the KRAS gene that do not coexist with other mutations or coexist with the TP53 gene mutations. In this paper, we review the available literature on the efficacy of immunotherapy in KRAS-mutated NSCLC patients. In addition, we presented single-site experience on the efficacy of immunotherapy in NSCLC patients with KRAS mutations. The effectiveness of chemoimmunotherapy or immunotherapy as well as KRAS inhibitors extends the overall survival of advanced NSCLC patients with the G12C mutation in the KRAS gene to 2–3 years. This type of management has become the new standard in the treatment of NSCLC patients. Further studies are needed to clarify the potential benefits of immunotherapy in KRAS-mutated NSCLC patients and to identify potential biomarkers that may help predict response to therapy.