Abnormalities in the KRAS Gene and Treatment Options for NSCLC Patients with the G12C Mutation in This Gene-A Literature Review and Single-Center Experience.

Mutations in the KRAS gene are among the most common mutations observed in cancer cells, but they have only recently become an achievable goal for targeted therapies. Two KRAS inhibitors, sotorasib and adagrasib, have recently been approved for the treatment of patients with advanced non-small cell lung cancer with the KRAS G12C mutation, while studies on their efficacy are still ongoing. In this work, we comprehensively analyzed RAS gene mutations' molecular background, mutation testing, KRAS inhibitors' effectiveness with an emphasis on non-small cell lung cancer, the impact of KRAS mutations on immunotherapy outcomes, and drug resistance problems. We also summarized ongoing trials and analyzed emerging perspectives on targeting KRAS in cancer patients.

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.

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.

Effectiveness of ALK inhibitors in treatment of CNS metastases in NSCLC patients.

Metastases to the central nervous system (CNS) in patients with non-small cell lung cancer constitute an extremely difficult clinical problem, and their occurrence is associated with a poor prognosis. Due to the existence of the blood-brain barrier (BBB) and the action of proteins responsible for the transport of drugs, e.g. P-glycoprotein (P-gp), the penetration of drugs into the CNS is insufficient. Until recently, the only method of CNS metastases treatment was radiotherapy and neurosurgery. The advancement of molecular biology allowed discover targets for molecularly targeted therapies. One of targets is abnormal anaplastic lymphoma kinase, which results from the rearrangement of the ALK gene in patients with non-small cell lung cancer (NSCLC). ALK rearrangement occurs in only about 4.5% of NSCLC patients, but its presence favors brain metastases. The ALK inhibitors (ALKi) were modified to obtain molecules with high ability to penetrate into the CNS. This was achieved by modifying the structure of individual molecules, which became, inter alia, less substrates for P-gp. These modifications caused that less than 10% of patients experience progression in CNS during new ALK inhibitors treatment. This review summarizes the knowledge about the action of BBB, the pharmacodynamics and pharmacokinetics of ALKi, with particular emphasis on their ability to penetrate the CNS and the intracranial activity of individual drugs from different generations of ALK inhibitors.

ALK gene rearrangement favors the development of central nervous system (CNS) metastases in patients with NSCLC. New generations of ALK inhibitors penetrate the CNS and induce an intracranial response and protect against new brain lesions.

Crizotinib efficacy in advanced non-squamous NSCLC patients with ALK or ROS1 rearrangement.

In patients with advanced non-small cell lung cancer (NSCLC), comprehensive genetic diagnostics is currently carried out in order to qualify for molecularly targeted therapies and immunotherapy. The aim of the study was to assess the usefulness of the reverse transcriptase (RT-PCR) method in the diagnosis of gene rearrangements, the effectiveness of EGFR, ALK, ROS1, and PD-L1 inhibitors in first-line treatment in NSCLC patients. We enrolled 95 non-squamous NSCLC patients with known status of EGFR, ALK, ROS1, MET and RET genes and PD-L1 protein expression. We used the real time PCR, fluorescence in situ hybridization (FISH), immunohistochemistry (IHC) and RT-PCR techniques for determination of predictive factors. In patients with ALK and ROS1 genes alteration, the median overall survival was 34 months in crizotinib treated patients and 6 months in patients who received chemotherapy (HR = 0.266, p = 0.0056). The risk of death was lower in patients treated with molecularly targeted therapies or immunotherapy compared to patients with predictive factors without personalized treatment (HR = 0.265, 95% CI 0.116-0.606) and to patient without predictive factors who received chemotherapy (HR = 0.42, 95% CI 0.162-1.09). Diagnosis of predictive factors and implementation of personalized treatment are key to prolonging the survival in advanced NSCLC patients.

Immunoprofiling: An Encouraging Method for Predictive Factors Examination in Lung Cancer Patients Treated with Immunotherapy.

The efficiency of immunotherapy using monoclonal antibodies that inhibit immune checkpoints has been proven in many clinical studies and well documented by numerous registration approaches. To date, PD-L1 expression on tumor and immune cells, tumor mutation burden (TMB), and microsatellite instability (MSI) are the only validated predictive factors used for the qualification of cancer patients for immunotherapy. However, they are not the ideal predictive factors. No response to immunotherapy could be observed in patients with high PD-L1 expression, TMB, or MSI. On the other hand, the effectiveness of this treatment method also may occur in patients without PD-L1 expression or with low TMB and with microsatellite stability. When considering the best predictive factor, we should remember that the effectiveness of immunotherapy relies on an overly complex process depending on many factors. To specifically stimulate lymphocytes, not only should their activity in the tumor microenvironment be unlocked, but above all, they should recognize tumor antigens. The proper functioning of the anticancer immune system requires the proper interaction of many elements of the specific and non-specific responses. For these reasons, a multi-parameter analysis of the immune system at its different activity levels is considered a very future-oriented predictive marker. Such complex immunological analysis is performed using modern molecular biology techniques. Based on the gene expression studies, we can determine the content of individual immune cells within the tumor, its stroma, and beyond. This includes all cell types from active memory cytotoxic T cells, M1 macrophages, to exhausted T cells, regulatory T cells, and M2 macrophages. In this article, we summarize the possibilities of using an immune system analysis to predict immunotherapy efficacy in cancer patients. Moreover, we present the advantages and disadvantages of immunoprofiling as well as a proposed future direction for this new method of immune system analysis in cancer patients who receive immunotherapy.

Two Complementarity Immunotherapeutics in Non-Small-Cell Lung Cancer Patients-Mechanism of Action and Future Concepts.

Due to the limited effectiveness of immunotherapy used as first-line monotherapy in patients with non-small-cell lung cancer (NSCLC), the concepts of combining classical immunotherapy based on immune checkpoint antibodies with other treatment methods have been developed. Pembrolizumab and atezolizumab were registered in combination with chemotherapy for the treatment of metastatic NSCLC, while durvalumab found its application in consolidation therapy after successful chemoradiotherapy in patients with locally advanced NSCLC. Exceptionally attractive, due to their relatively low toxicity and high effectiveness, are treatment approaches in which a combination of two different immunotherapy methods is applied. This method is based on observations from clinical trials in which nivolumab and ipilimumab were used as first-line therapy for advanced NSCLC. It turned out that the dual blockade of immune checkpoints activated T lymphocytes in different compartments of the immune response, at the same time affecting the downregulation of immune suppressor cells (regulatory T cells). These experiments not only resulted in the registration of combination therapy with nivolumab and ipilimumab, but also initiated other clinical trials using immune checkpoint inhibitors (ICIs) in combination with other ICIs or activators of costimulatory molecules found on immune cells. There are also studies in which ICIs are associated with molecules that modify the tumour environment. This paper describes the mechanism of the synergistic effect of a combination of different immunotherapy methods in NSCLC patients.

Impact of copy number variant and single nucleotide polymorphism of the programmed death-ligand 1 gene, programmed death-ligand 1 protein expression and therapy regimens on overall survival in a large group of Caucasian patients with non-small cell lung carcinoma.

Anti-programmed death-1 or anti-programmed death-ligand 1 (PD-L1) blockade may be ineffective in some patients with non-small cell lung cancer (NSCLC) with high percentage of tumor cells with PD-L1 expression. In addition, immunotherapy may provide great benefits in patients without PD-L1 expression. The present study assessed PD-L1 protein expression by immunohistochemistry, copy number variation (CNV) of PD-L1 and two single nucleotide polymorphisms (SNPs), rs822335 and rs822336, in the promoter of PD-L1 by quantitative PCR in 673 patients with NSCLC. Overall survival time of patients with NSCLC depending on the assessed predictive factors (PD-L1 CNV or SNP) and the treatment methods (immunotherapy in first/second line of treatment or chemotherapy) was analyzed. The present study revealed significantly higher PD-L1 copies number in patients with ≥10% and ≥50% of tumor cells with PD-L1 expression compared to patients with lower percentage of PD-L1-positive tumor cells (P=0.02 and P=0.0002, respectively). There was a significant positive correlation (R=0.2; P=0.01) between number of PD-L1 copies and percentage of tumor cells with PD-L1 protein expression. Percentage of tumor cells with PD-L1 expression was lower in patients with TT genotype of the rs822335 polymorphism compared to those with CC genotype (P=0.03). The present study observed significantly higher risk of death in patients treated with chemotherapy compared to those treated with immunotherapy (P<0.0001; hazard ratio=2.4768; 95% confidence interval, 2.0120-3.0490). The present study demonstrated a close relationship between PD-L1 copies number, genotype of rs822335 PD-L1 polymorphism and PD-L1 protein expression on tumor cells. However, the impact of CNV and SNPs of PD-L1 on overall survival of patients with NSCLC requires further investigation.