Landscape of KRASG12C, Associated Genomic Alterations, and Interrelation With Immuno-Oncology Biomarkers in KRAS-Mutated Cancers

State-of-the-Art Management of Colorectal Cancer: Treatment Advances and Innovation

Colorectal cancer (CRC) remains a significant global health challenge, ranking among the leading causes of cancer-related morbidity and mortality worldwide. Recent advancements in molecular characterization have revolutionized our understanding of the heterogeneity within colorectal tumors, particularly in the context of tumor sidedness. Tumor sidedness, referring to the location of the primary tumor in either the right or left colon, has emerged as a critical factor influencing prognosis and treatment responses in metastatic CRC. Molecular underpinnings of CRC, the impact of tumor sidedness, and how this knowledge guides therapeutic decisions in the era of precision medicine have led to improved outcomes and better quality of life in patients. The emergence of circulating tumor DNA as a prognostic and predictive tool in CRC heralds promising advancements in the diagnosis and monitoring of the disease. This innovation facilitates better patient selection for exploration of additional treatment options. As the field progresses, with investigational agents demonstrating potential as future treatments for refractory metastatic CRC, new avenues for enhancing outcomes in this challenging disease are emerging.

Validation of a good manufacturing practice procedure for the production of [11C]AZD4747, a CNS penetrant KRASG12c inhibitor

AZD4747 is a KRASG12C inhibitor recently shown to cross the non-human primate blood-brain barrier efficiently. In the current study, a GMP-compliant production of [11C]AZD4747 was developed to enable PET studies in human subjects. The validated procedure afforded [11C]AZD4747 as an injectable solution in good radioactivity yield (1656 ± 532 MBq), excellent radiochemical purity (100%), and a molar activity of 77 ± 13 GBq/μmol at the end of the synthesis, which took 46 ± 1 min from the end of the bombardment. Quality control on the final product was performed satisfactorily and met all acceptance criteria.

Precision medicine for pancreatic cancer: Characterizing the clinico-genomic landscape and outcomes of KRAS G12C-mutated disease

BACKGROUND

Mutated KRAS is the most common oncogene alteration in pancreatic cancer (PDAC), and KRAS G12C mutations (KRAS G12Cmut) are observed in 1-2%. Several inhibitors of KRAS G12C have recently demonstrated promise in solid tumors, including PDAC. Little is known regarding clinical, genomics and outcome data of this population.

METHODS

Patients with PDAC and KRAS G12Cmut were identified at Memorial Sloan Kettering Cancer Center (MSK), and via the AACR Project GENIE database. Clinical, treatment, genomic and outcomes data were analysed. A cohort of patients at MSK with non-G12C KRAS PDAC was included for comparison.

RESULTS

Among 3,571 patients with PDAC, 39 with KRAS G12Cmut were identified (1.1%). Median age was 67 years, 56% were female. Median BMI was 29.2 kg/m2, 67% had a smoking history. Median OS 13 months (9.4, not reached (NR)) for stage IV, and 26 months (23, NR) for stage I-III. Complete genomic data (via AACR GENIE) was available for N = 74. Most common co-alterations included: TP53 (73%), CDKN2A (33%), SMAD4 (28%), and ARID1A (21%). Compared with a large cohort (N = 2931) of non-G12C KRAS-mutated PDAC, ARID1A co-mutations were more frequent in KRAS G12Cmut (P < .05). OS did not differ between KRAS G12Cmut and non-G12C KRAS PDAC. Germline pathogenic variants were identified in 17%. N = 2 received KRAS G12C-directed therapy.

CONCLUSION

PDAC and KRAS G12Cmut may be associated with a distinct clinical phenotype. Genomic features are similar to non-G12C KRAS-mutated PDAC, although enrichment of ARID1A co-mutations was observed. Targeting of KRAS G12C in PDAC provides a precedent for broader KRAS targeting in PDAC.

Emerging Therapies in Kirsten Rat Sarcoma Virus (+) Non-Small-Cell Lung Cancer

Kirsten rat sarcoma virus (KRAS) is the most frequently found oncogene in human cancers, including non-small-cell lung cancer (NSCLC). For many years, KRAS was considered "undruggable" due to its structure and difficult targeting. However, the discovery of the switch II region in the KRAS-G12C-mutated protein has changed the therapeutic landscape with the design and development of novel direct KRAS-G12C inhibitors. Sotorasib and adagrasib are FDA-approved targeted agents for pre-treated patients with KRAS-G12C-mutated NSCLC. Despite promising results, the efficacy of these novel inhibitors is limited by mechanisms of resistance. Ongoing studies are evaluating combination strategies for overcoming resistance. In this review, we summarize the biology of the KRAS protein and the characteristics of KRAS mutations. We then present current and emerging therapeutic approaches for targeting KRAS mutation subtypes intending to provide individualized treatment for lung cancer harboring this challenging driver mutation.

Targeting KRAS in cancer

RAS family variants-most of which involve KRAS-are the most commonly occurring hotspot mutations in human cancers and are associated with a poor prognosis. For almost four decades, KRAS has been considered undruggable, in part due to its structure, which lacks small-molecule binding sites. But recent developments in bioengineering, organic chemistry and related fields have provided the infrastructure to make direct KRAS targeting possible. The first successes occurred with allele-specific targeting of KRAS p.Gly12Cys (G12C) in non-small cell lung cancer, resulting in regulatory approval of two agents-sotorasib and adagrasib. Inhibitors targeting other variants beyond G12C have shown preliminary antitumor activity in highly refractory malignancies such as pancreatic cancer. Herein, we outline RAS pathobiology with a focus on KRAS, illustrate therapeutic approaches across a variety of malignancies, including emphasis on the 'on' and 'off' switch allele-specific and 'pan' RAS inhibitors, and review immunotherapeutic and other key combination RAS targeting strategies. We summarize mechanistic understanding of de novo and acquired resistance, review combination approaches, emerging technologies and drug development paradigms and outline a blueprint for the future of KRAS therapeutics with anticipated profound clinical impact.

If it's a target, it's a pan-cancer target: Tissue is not the issue

Cancer is traditionally diagnosed and treated on the basis of its organ of origin (e.g., lung or colon cancer). However, organ-of-origin diagnostics does not reveal the underlying oncogenic drivers. Fortunately, molecular diagnostics have advanced at a breathtaking pace, and it is increasingly apparent that cancer is a disease of the genome. Hence, we now have multiple genomic biomarker-based, tissue-agnostic Food and Drug Administration approvals for both gene- and immune-targeted therapies (larotrectinib/entrectinib, for NTRK fusions; selpercatinib, RET fusions; dabrafenib plus trametinib, BRAFV600E mutations; pembrolizumab/dostarlimab, microsatellite instability; and pembrolizumab for high tumor mutational burden; pemigatinib is also approved for FGFR1-rearranged myeloid/lymphoid neoplasms). There are emerging targets as well, including but not limited to ALK, BRCA and/or homologous repair deficiency, ERBB2 (HER2), IDH1/2, KIT, KRASG12C, NRG1, and VHL. Many tissue-agnostic approvals center on rare/ultra-rare biomarkers (often < 1 % of cancers), necessitating screening hundreds of tumors to find a single one harboring the cognate molecular alteration. Approval has generally been based on small single-arm studies (<30-100 patients) with high response rates (>30 % to > 75 %) of remarkable durability. Because of biomarker rarity, single-gene testing is not practical; next generation sequencing of hundreds of genes must be performed to obtain timely answers. Resistance to biomarker-driven therapeutics is often due to secondary mutations or co-driver gene defects; studies are now addressing the need for customized drug combinations matched to the complex molecular alteration portfolio in each tumor. Future investigation should expand tissue-agnostic therapeutics to encompass both hematologic and solid malignancies and include biomarkers beyond those that are DNA-based.

Targeting KRAS mutations in pancreatic cancer: opportunities for future strategies

Targeting the RAS pathway remains the holy grail of precision oncology. In the case of pancreatic ductal adenocarcinomas (PDAC), 90-92% harbor mutations in the oncogene KRAS, triggering canonical MAPK signaling. The smooth structure of the altered KRAS protein without a binding pocket and its affinity for GTP have, in the past, hampered drug development. The emergence of KRASG12C covalent inhibitors has provided renewed enthusiasm for targeting KRAS. The numerous pathways implicated in RAS activation do, however, lead to the development of early resistance. In addition, the dense stromal niche and immunosuppressive microenvironment dictated by oncogenic KRAS can influence treatment responses, highlighting the need for a combination-based approach. Given that mutations in KRAS occur early in PDAC tumorigenesis, an understanding of its pleiotropic effects is key to progress in this disease. Herein, we review current perspectives on targeting KRAS with a focus on PDAC.

Recent Advances in Therapeutic Strategies to Improve Colorectal Cancer Treatment

Colorectal cancer (CRC) is the second-leading cause of cancer-related mortality worldwide. CRC mortality results almost exclusively from metastatic disease (mCRC) for which systemic chemotherapy is often a preferred therapeutic option. Biomarker-based stratification of mCRC enables the use of precision therapy based on individual tumor mutational profiles. Activating mutations in the RAS/RAF/MAPK pathway downstream of EGFR signaling have, until recently, limited the use of EGFR-targeted therapies for mCRC; however, the development of anti-RAS and anti-RAF therapies together with improved strategies to limit compensatory signaling pathways is resulting in improved survival rates in several highly lethal mCRC sub-types (e.g., BRAF-mutant). The use of fluoropyrimidine (FP)-based chemotherapy regimens to treat mCRC continues to evolve contributing to improved long-term survival. Future advances in chemotherapy for mCRC will need to position development relative to the advances made in precision oncology.

[Advances in the targeted treatment of non-small cell lung cancer]

Non-small cell lung cancer (NSCLC) paradigmatically shows the potential of personalized and therefore precise cancer treatment. For around one third of the patients, predominantly suffering from adenocarcinoma, targetable driver mutations could be characterized in the meantime. Targeted therapies, mostly with kinase inhibitors, achieve impressive advances in the prolongation of overall survival often over many years and excellent quality of life in patients with advanced NSCLC. Targeted treatment is also increasingly evaluated as adjuvant or neoadjuvant treatment in early inoperable stages of NSCLC. An absolute prerequisite for the use of personalized treatment is upfront broad molecular diagnostics before the decision on first line treatment. The limitations of personalized treatment are the so far unavoidable development of resistance mutations and increasing clonal heterogeneity during the course of the treatment. Approaches to further improve treatment results comprise the development of next-generation inhibitors, the combination of targeted substances, also with chemotherapy and the use of new immunoconjugates.

Engineered a dual-targeting HA-TPP/A nanoparticle for combination therapy against KRAS-TP53 co-mutation in gastrointestinal cancers

KRAS-TP53 co-mutation is strongly associated with poor prognosis and high malignancy in gastrointestinal cancers. Therefore, a novel approach to oncotherapy may lie in combination therapy targeting both KRAS and TP53. Herein, we present a novel self-assembled nanoparticle (HA-TPP/A) that are functionalized nano-carrier hyaluronic acid (HA)-TPP conjugate (HA-TPP) to degrade mutant p53 proteins (mutp53) and co-deliver AMG510 for treating KRAS-TP53 co-alteration of gastrointestinal cancers by inhibiting the mutant KRAS and mutp53 signaling pathways. The HA-TPP/A nanoparticles led to ubiquitination-dependent proteasomal degradation of mutp53 by targeting damage to mitochondria. Furthermore, these nanoparticles abrogated the gain-of-function (GOF) phenotypes of mutp53 and increased sensitivity to AMG510-induced cell killing, thereby reducing cell proliferation and migration in gastrointestinal cancer with KRAS-TP53 co-mutation. The co-loaded HA-TPP/A nanoparticles demonstrated remarkable therapeutic efficacy in a tumor-bearing mouse model, particularly in KRAS-TP53 double mutant expressing cancer cells, compared with single drug and combined free drug groups. Notably, HA-TPP/A is the first reported nanoparticle with an ability to co-target KRAS-TP53, providing a promising approach for therapy in highly malignant gastrointestinal tumors and potentially expanding clinical indications for AMG510 targeted therapies in gastrointestinal tumors.

Metastatic Pancreatic Cancer: Where Are We?

Pancreatic cancer is one of the most lethal neoplasms worldwide; it is aggressive in nature and has a poor prognosis. The overall survival rate for pancreatic cancer is low. Most patients present non-specific symptoms in the advanced stages, which generally leads to late diagnosis, at which point there is no option for curative surgery. The treatment of metastatic pancreatic cancer includes systemic therapy, in some cases radiotherapy, and more recently, molecular targeted therapies, which can positively impact cancer control and improve quality of life. This review provides an overview of the molecular landscape of pancreatic cancer based on the most recent literature, as well as current treatment options for patients with metastatic pancreatic cancer.

Next-generation therapies for pancreatic cancer

INTRODUCTION

Pancreas ductal adenocarcinoma (PDAC) is a frequently lethal malignancy that poses unique therapeutic challenges. The current mainstay of therapy for metastatic PDAC (mPDAC) is cytotoxic chemotherapy. NALIRIFOX (liposomal irinotecan, fluorouracil, leucovorin, oxaliplatin) is an emerging standard of care in the metastatic setting. An evolving understanding of PDAC pathogenesis is driving a shift toward targeted therapy. Olaparib, a poly-ADP-ribose polymerase (PARP) inhibitor, has regulatory approval for maintenance therapy in BRCA-mutated mPDAC along with other targeted agents receiving disease-agnostic approvals including for PDAC with rare fusions and mismatch repair deficiency. Ongoing research continues to identify and evaluate an expanding array of targeted therapies for PDAC.

AREAS COVERED

This review provides a brief overview of standard therapies for PDAC and an emphasis on current and emerging targeted therapies.

EXPERT OPINION

There is notable potential for targeted therapies for KRAS-mutated PDAC with opportunity for meaningful benefit for a sizable portion of patients with this disease. Further, emerging approaches are focused on novel immune, tumor microenvironment, and synthetic lethality strategies.

Facts and Hopes on RAS Inhibitors and Cancer Immunotherapy

Although the past decade has seen great strides in the development of immunotherapies that reactivate the immune system against tumors, there have also been major advances in the discovery of drugs blocking oncogenic drivers of cancer growth. However, there has been very little progress in combining immunotherapies with drugs that target oncogenic driver pathways. Some of the most important oncogenes in human cancer encode RAS family proteins, although these have proven challenging to target. Recently drugs have been approved that inhibit a specific mutant form of KRAS: G12C. These have improved the treatment of patients with lung cancer harboring this mutation, but development of acquired drug resistance after initial responses has limited the impact on overall survival. Because of the immunosuppressive nature of the signaling network controlled by oncogenic KRAS, targeted KRAS G12C inhibition can indirectly affect antitumor immunity, and does so without compromising the critical role of normal RAS proteins in immune cells. This serves as a rationale for combination with immune checkpoint blockade, which can provide additional combinatorial therapeutic benefit in some preclinical cancer models. However, in clinical trials, combination of KRAS G12C inhibitors with PD-(L)1 blockade has yet to show improved outcome, in part due to treatment toxicities. A greater understanding of how oncogenic KRAS drives immune evasion and how mutant-specific KRAS inhibition impacts the tumor microenvironment can lead to novel approaches to combining RAS inhibition with immunotherapies.

Anti-epidermal growth factor receptor treatment for patients with NeoRAS wild-type metastatic colorectal cancer: a case report of two cases

The NeoRAS phenomenon is defined as the conversion of tumor RAS status from mutant-type (MT) to wild-type (WT) after systemic chemotherapy in metastatic colorectal cancer (mCRC). Cetuximab, an anti-epidermal growth factor receptor (EGFR) antibody, is effective in patients with RAS WT mCRC but ineffective in those with RAS MT mCRC; however, its outcome in patients with NeoRAS WT mCRC is unclear. Herein, we report two cases of NeoRAS WT mCRC that responded clinically to anti-EGFR treatment. The first was a 40-year-old man with synchronous peritoneal metastatic rectosigmoid cancer. The first RAS testing on tumor tissue revealed a KRAS G12C mutation, which was converted to RAS WT after two lines of chemotherapy, as assessed by liquid biopsy. After initiating irinotecan plus cetuximab treatment, a computed tomography (CT) scan revealed that malignant ascites had resolved. The treatment was discontinued after 4 months because of disease progression. The second was a 68-year-old male patient with synchronous liver metastasis from sigmoid colon cancer. The KRAS G12D mutation, initially detected in tumor tissue, was not detected by liquid biopsy after six lines of chemotherapy. Cetuximab monotherapy was initiated, and the liver metastases shrank significantly. The patient continued cetuximab monotherapy for 8 months without disease progression. Our cases demonstrate the efficacy of anti-EGFR therapy for NeoRAS WT mCRC and highlight the importance of capturing the gene mutation profile throughout the clinical course for optimal treatment selection.

Mass spectrometry quantifies target engagement for a KRASG12C inhibitor in FFPE tumor tissue

BACKGROUND

Quantification of drug-target binding is critical for confirming that drugs reach their intended protein targets, understanding the mechanism of action, and interpreting dose-response relationships. For covalent inhibitors, target engagement can be inferred by free target levels before and after treatment. Targeted mass spectrometry assays offer precise protein quantification in complex biological samples and have been routinely applied in pre-clinical studies to quantify target engagement in frozen tumor tissues for oncology drug development. However, frozen tissues are often not available from clinical trials so it is critical that assays are applicable to formalin-fixed, paraffin-embedded (FFPE) tissues in order to extend mass spectrometry-based target engagement studies into clinical settings.

METHODS

Wild-type RAS and RASG12C was quantified in FFPE tissues by a highly optimized targeted mass spectrometry assay that couples high-field asymmetric waveform ion mobility spectrometry (FAIMS) and parallel reaction monitoring (PRM) with internal standards. In a subset of samples, technical reproducibility was evaluated by analyzing consecutive tissue sections from the same tumor block and biological variation was accessed among adjacent tumor regions in the same tissue section.

RESULTS

Wild-type RAS protein was measured in 32 clinical non-small cell lung cancer tumors (622-2525 amol/µg) as measured by FAIMS-PRM mass spectrometry. Tumors with a known KRASG12C mutation (n = 17) expressed a wide range of RASG12C mutant protein (127-2012 amol/µg). The variation in wild-type RAS and RASG12C measurements ranged 0-18% CV across consecutive tissue sections and 5-20% CV among adjacent tissue regions. Quantitative target engagement was then demonstrated in FFPE tissues from 2 xenograft models (MIA PaCa-2 and NCI-H2122) treated with a RASG12C inhibitor (AZD4625).

CONCLUSIONS

This work illustrates the potential to expand mass spectrometry-based proteomics in preclinical and clinical oncology drug development through analysis of FFPE tumor biopsies.

Targeting KRAS in Pancreatic Ductal Adenocarcinoma: The Long Road to Cure

Pancreatic ductal adenocarcinoma (PDAC) remains an important cause of cancer-related mortality, and it is expected to play an even bigger part in cancer burden in the years to come. Despite concerted efforts from scientists and physicians, patients have experienced little improvement in survival over the past decades, possibly because of the non-specific nature of the tested treatment modalities. Recently, the discovery of potentially targetable molecular alterations has paved the way for the personalized treatment of PDAC. Indeed, the central piece in the molecular framework of PDAC is starting to be unveiled. KRAS mutations are seen in 90% of PDACs, and multiple studies have demonstrated their pivotal role in pancreatic carcinogenesis. Recent investigations have shed light on the differences in prognosis as well as therapeutic implications of the different KRAS mutations and disentangled the relationship between KRAS and effectors of downstream and parallel signaling pathways. Additionally, the recognition of other mechanisms involving KRAS-mediated pathogenesis, such as KRAS dosing and allelic imbalance, has contributed to broadening the current knowledge regarding this molecular alteration. Finally, KRAS G12C inhibitors have been recently tested in patients with pancreatic cancer with relative success, and inhibitors of KRAS harboring other mutations are under clinical development. These drugs currently represent a true hope for a meaningful leap forward in this dreadful disease.

KRAS G12C in advanced NSCLC: Prevalence, co-mutations, and testing

KRAS is the most commonly mutated oncogene in advanced, non-squamous, non-small cell lung cancer (NSCLC) in Western countries. Of the various KRAS mutants, KRAS G12C is the most common variant (~40%), representing 10-13% of advanced non-squamous NSCLC. Recent regulatory approvals of the KRASG12C-selective inhibitors sotorasib and adagrasib for patients with advanced or metastatic NSCLC harboring KRASG12C have transformed KRAS into a druggable target. In this review, we explore the evolving role of KRAS from a prognostic to a predictive biomarker in advanced NSCLC, discussing KRAS G12C biology, real-world prevalence, clinical relevance of co-mutations, and approaches to molecular testing. Real-world evidence demonstrates significant geographic differences in KRAS G12C prevalence (8.9-19.5% in the US, 9.3-18.4% in Europe, 6.9-9.0% in Latin America, and 1.4-4.3% in Asia) in advanced NSCLC. Additionally, the body of clinical data pertaining to KRAS G12C co-mutations such as STK11, KEAP1, and TP53 is increasing. In real-world evidence, KRAS G12C-mutant NSCLC was associated with STK11, KEAP1, and TP53 co-mutations in 10.3-28.0%, 6.3-23.0%, and 17.8-50.0% of patients, respectively. Whilst sotorasib and adagrasib are currently approved for use in the second-line setting and beyond for patients with advanced/metastatic NSCLC, testing and reporting of the KRAS G12C variant should be included in routine biomarker testing prior to first-line therapy. KRAS G12C test results should be clearly documented in patients' health records for actionability at progression. Where available, next-generation sequencing is recommended to facilitate simultaneous testing of potentially actionable biomarkers in a single run to conserve tissue. Results from molecular testing should inform clinical decisions in treating patients with KRAS G12C-mutated advanced NSCLC.

Adagrasib in Advanced Solid Tumors Harboring a KRASG12C Mutation

PURPOSE

Adagrasib, a KRASG12C inhibitor, has demonstrated clinical activity in patients with KRASG12C-mutated non-small-cell lung cancer (NSCLC) and colorectal cancer (CRC). KRASG12C mutations occur rarely in other solid tumor types. We report evaluation of the clinical activity and safety of adagrasib in patients with other solid tumors harboring a KRASG12C mutation.

METHODS

In this phase II cohort of the KRYSTAL-1 study (ClinicalTrials.gov identifier: NCT03785249; phase Ib cohort), we evaluated adagrasib (600 mg orally twice daily) in patients with KRASG12C-mutated advanced solid tumors (excluding NSCLC and CRC). The primary end point was objective response rate. Secondary end points included duration of response, progression-free survival (PFS), overall survival, and safety.

RESULTS

As of October 1, 2022, 64 patients with KRASG12C-mutated solid tumors were enrolled and 63 patients treated (median follow-up, 16.8 months). The median number of prior lines of systemic therapy was 2. Among 57 patients with measurable disease at baseline, objective responses were observed in 20 (35.1%) patients (all partial responses), including 7/21 (33.3%) responses in pancreatic and 5/12 (41.7%) in biliary tract cancers. The median duration of response was 5.3 months (95% CI, 2.8 to 7.3) and median PFS was 7.4 months (95% CI, 5.3 to 8.6). Treatment-related adverse events (TRAEs) of any grade were observed in 96.8% of patients and grade 3-4 in 27.0%; there were no grade 5 TRAEs. TRAEs did not lead to treatment discontinuation in any patients.

CONCLUSION

Adagrasib demonstrates encouraging clinical activity and is well tolerated in this rare cohort of pretreated patients with KRASG12C-mutated solid tumors.

New insights into the biology and development of lung cancer in never smokers-implications for early detection and treatment

Lung cancer is the leading cause of cancer deaths worldwide. Despite never smokers comprising between 10 and 25% of all cases, lung cancer in never smokers (LCNS) is relatively under characterized from an etiological and biological perspective. The application of multi-omics techniques on large patient cohorts has significantly advanced the current understanding of LCNS tumor biology. By synthesizing the findings of multi-omics studies on LCNS from a clinical perspective, we can directly translate knowledge regarding tumor biology into implications for patient care. Primarily focused on never smokers with lung adenocarcinoma, this review details the predominance of driver mutations, particularly in East Asian patients, as well as the frequency and importance of germline variants in LCNS. The mutational patterns present in LCNS tumors are thoroughly explored, highlighting the high abundance of the APOBEC signature. Moreover, this review recognizes the spectrum of immune profiles present in LCNS tumors and posits how it can be translated to treatment selection. The recurring and novel insights from multi-omics studies on LCNS tumor biology have a wide range of clinical implications. Risk factors such as exposure to outdoor air pollution, second hand smoke, and potentially diet have a genomic imprint in LCNS at varying degrees, and although they do not encompass all LCNS cases, they can be leveraged to stratify risk. Germline variants similarly contribute to a notable proportion of LCNS, which warrants detailed documentation of family history of lung cancer among never smokers and demonstrates value in developing testing for pathogenic variants in never smokers for early detection in the future. Molecular driver subtypes and specific co-mutations and mutational signatures have prognostic value in LCNS and can guide treatment selection. LCNS tumors with no known driver alterations tend to be stem-like and genes contributing to this state may serve as potential therapeutic targets. Overall, the comprehensive findings of multi-omics studies exert a wide influence on clinical management and future research directions in the realm of LCNS.

Stratification of patients with KRAS-mutated advanced non-small cell lung cancer: improving prognostics

INTRODUCTION

KRAS is the most frequently mutated oncogene in cancer and encodes a key signaling protein in tumors. Due to its high affinity for GTP and the lack of a large binding pocket that allosteric inhibitors can occupy, KRAS has long been considered 'non-druggable.' Finding effective treatment measures for patients with KRAS mutations is our top priority.

AREAS COVERED

In this article, we will provide an overview of the KRAS pathway and review the current state of therapeutic strategies for targeting oncogenic KRAS, as well as their potential to improve outcomes in patients with KRAS-mutant malignancies. We will also discuss the development of these strategies and gave an outlook on prospects.

EXPERT OPINION

KRAS mutations have posed a significant challenge in the treatment of advanced non-small cell lung cancer (NSCLC) over the past few decades. However, the emergence of immunotherapy and KRAS inhibitors, such as Sotorasib (AMG 510) and Adagrasib (MRTX849), has marked a new era in cancer therapy. As more research and clinical trials continue, we anticipate the development of more effective treatment strategies and better options for lung cancer patients.

Adagrasib: a novel inhibitor for KRASG12C-mutated non-small-cell lung cancer

Adagrasib is a recently US FDA-approved novel KRAS^G12C targeted therapy with clinical efficacy in patients with advanced, pretreated KRAS^G12C-mutated non-small-cell lung cancer. KRYSTAL-I reported an objective response rate of 42.9% with median duration of response of 8.5 months. Treatment-related adverse events were primarily gastrointestinal and occurred in 97.4% of patients, with grade 3+ treatment-related adverse events occurring in 44.8% of patients. This review details the preclinical and clinical data for adagrasib in the treatment of non-small-cell lung cancer. We also outline practical clinical administration guidelines for this novel therapy, including management of toxicities. Finally, we discuss the implications of resistance mechanisms, summarize other KRAS^G12C inhibitors currently in development and outline future directions for adagrasib-based combination therapies.

The Landscape and Therapeutic Targeting of BRCA1, BRCA2 and Other DNA Damage Response Genes in Pancreatic Cancer

Genes participating in the cellular response to damaged DNA have an important function to protect genetic information from alterations due to extrinsic and intrinsic cellular insults. In cancer cells, alterations in these genes are a source of genetic instability, which is advantageous for cancer progression by providing background for adaptation to adverse environments and attack by the immune system. Mutations in BRCA1 and BRCA2 genes have been known for decades to predispose to familial breast and ovarian cancers, and, more recently, prostate and pancreatic cancers have been added to the constellation of cancers that show increased prevalence in these families. Cancers associated with these genetic syndromes are currently treated with PARP inhibitors based on the exquisite sensitivity of cells lacking BRCA1 or BRCA2 function to inhibition of the PARP enzyme. In contrast, the sensitivity of pancreatic cancers with somatic BRCA1 and BRCA2 mutations and with mutations in other homologous recombination (HR) repair genes to PARP inhibitors is less established and the subject of ongoing investigations. This paper reviews the prevalence of pancreatic cancers with HR gene defects and treatment of pancreatic cancer patients with defects in HR with PARP inhibitors and other drugs in development that target these molecular defects.

Cancer immune evasion through KRAS and PD-L1 and potential therapeutic interventions

Oncogenic driver mutations have implications that extend beyond cancer cells themselves. Aberrant tumour cell signalling has various effects on the tumour microenvironment and anti-tumour immunity, with important consequences for therapy response and resistance. We provide an overview of how mutant RAS, one of the most prevalent oncogenic drivers in cancer, can instigate immune evasion programs at the tumour cell level and through remodelling interactions with the innate and adaptive immune cell compartments. Finally, we describe how immune evasion networks focused on RAS, and the immune checkpoint molecule PD-L1 can be disrupted through therapeutic intervention, and discuss potential strategies for combinatorial treatment. Video abstract.

KRAS G12C mutated advanced non-small cell lung cancer (NSCLC): Characteristics, treatment patterns and overall survival from a Danish nationwide observational register study

OBJECTIVES

We aimed to characterize the advanced NSCLC population in terms of KRAS G12C prevalence, patient characteristics, and survival outcomes after the introduction of immunotherapies.

MATERIALS AND METHODS

We identified adult patients diagnosed with advanced NSCLC between January 1, 2018 and June 30, 2021 using the Danish health registries. Patients were grouped by mutational status (any KRAS mutation, KRAS G12C, and KRAS/EGFR/ALK wildtype [Triple WT]). We analyzed KRAS G12C prevalence, patient and tumor characteristics, treatment history, time-to-next-treatment (TTNT), and overall survival (OS).

RESULTS

We identified 7,440 patients of whom 40% (n = 2,969) were KRAS tested prior to the first line of therapy (LOT1). Among the KRAS tested, 11% (n = 328) harbored KRAS G12C. More KRAS G12C patients were women (67%), smokers (86%), had a high (≥50%) level of PD-L1 expression (54%), and more frequently received anti-PD-L1 treatment than any other group. From the date of the mutational test result, OS (7.1-7.3 months) was similar between the groups. OS from LOT1 (14.0 months) and LOT2 (10.8 months), and TTNT from LOT1 (6.9 months) and LOT2 (6.3 months) was numerically longer for the KRAS G12C mutated group compared to any other group. However, from LOT1 and LOT2, the OS and TTNT were comparable when stratifying the groups by PD-L1 expression level. Regardless of the mutational group, OS was markedly longer for patients with high PD-L1 expression.

CONCLUSION

In patients diagnosed with advanced NSCLC after the implementation of anti-PD-1/L1 therapies, the survival in KRAS G12C mutated patients is comparable to patients with any KRAS mutation, Triple WT, and all NSCLC patients.

Therapeutic landscape and future direction of metastatic colorectal cancer

In the era of targeted therapy based on genomic alterations, the treatment strategy for metastatic colorectal cancer (mCRC) has been changing. Before systemic treatment initiation, determination of tumour genomic status for KRAS and NRAS, BRAF^V600E mutations, ERBB2, and microsatellite instability and/or mismatch repair (MMR) status is recommended. In patients with deficient MMR and BRAF^V600E mCRC, randomized phase III trials have established the efficacy of pembrolizumab as first-line therapy and the combination of encorafenib and cetuximab as second-line or third-line therapy. In addition, new agents have been actively developed in other rare molecular fractions such as ERBB2 alterations and KRAS^G12C mutations. In March 2022, the combination of pertuzumab and trastuzumab for ERBB2-positive mCRC was approved in Japan, thereby combining real-world evidence from the SCRUM-Japan Registry. As the populations are highly fragmented owing to rare genomic alterations, various strategies in clinical development are expected. Clinical development of a tumour-agnostic approach, such as NTRK fusion and tumour mutational burden, has successfully introduced corresponding drugs to clinical practice. Considering the difficulty of randomized trials owing to cost-benefit and rarity, a promising solution could be real-world evidence utilized as an external control from the molecular-based disease registry.

Comprehensive pan-cancer genomic landscape of KRAS altered cancers and real-world outcomes in solid tumors

Recent clinical development of KRAS inhibitors has heightened interest in the genomic landscape of KRAS-altered cancers. We performed a pan-cancer analysis of KRAS-altered samples from 426,706 adult patients with solid or hematologic malignancies using comprehensive genomic profiling; additional analyses included 62,369 liquid biopsy and 7241 pediatric samples. 23% of adult pan-cancer samples had KRAS alterations; 88% were mutations, most commonly G12D/G12V/G12C/G13D/G12R, and prevalence was similar in liquid biopsies. Co-alteration landscapes were largely similar across KRAS mutations but distinct from KRAS wild-type, though differences were observed in some tumor types for tumor mutational burden, PD-L1 expression, microsatellite instability, and other mutational signatures. Prognosis of KRAS-mutant versus other genomic cohorts of lung, pancreatic, and colorectal cancer were assessed using a real-world clinicogenomic database. As specific KRAS inhibitors and combination therapeutic strategies are being developed, genomic profiling to understand co-alterations and other biomarkers that may modulate response to targeted or immunotherapies will be imperative.

KRAS in NSCLC: State of the Art and Future Perspectives

In NSCLC, KRAS mutations occur in up to 30% of all cases, most frequently at codon 12 and 13. KRAS mutations have been linked to adenocarcinoma histology, positive smoking history, and Caucasian ethnicity, although differences have been described across KRAS mutational variants subtypes. KRAS mutations often concur with other molecular alterations, notably TP53, STK11, and KEAP1, which could play an important role in treatment efficacy and patient outcomes. For many years, KRAS mutations have been considered undruggable mainly due to a high toxicity profile and low specificity of compounds. Sotorasib and adagrasib are novel KRAS inhibitors that recently gained FDA approval for pre-treated KRAS mutant NSCLC patients, and other molecules such as GDC-6036 are currently being investigated with promising results. Despite their approval, the efficacy of these drugs is lower than expected and progression among responders has been reported. Mechanisms of acquired resistance to anti-KRAS molecules typically involves either on target secondary mutations (e.g., G12, G13, Q61H, R68S, H95, Y96C, V8L) or off-target alterations. Ongoing trials are currently evaluating strategies for implementing efficacy and overcoming acquired resistance to these compounds. Finally, the efficacy of immune-checkpoint inhibitors still needs to be completely assessed and responses to anti-PD-1/PD-L1 agents may strongly depend on concomitant mutations.

Therapeutic Outcomes and Clinical Features of Advanced Non-Small Cell Lung Cancer Carrying KRAS Mutations: A Multicenter Real-life Retrospective Study

INTRODUCTION

Targeting Kirsten Rat Sarcoma (KRAS) has been deemed impossible for long time, but new drugs have recently demonstrated promising results. Evidence on the outcome of KRAS-mutant advanced-NSCLC treated with new standard regimens are still scarce. Thus, we aimed at assessing the incidence and clinical impact of KRAS mutations in a real-life population of advanced-NSCLC, exploring the prognostic significance of distinct alterations.

MATERIALS AND METHODS

The present multicenter retrospective study, conducted by 5 Italian Centers from January 2018 to February 2020, involved 297 advanced KRAS mutant NSCLC. Complete clinico-pathological data were evaluated.

RESULTS

Out of 297 patients, 130 carried KRAS_G12C mutation, while 167 presented with mutations other than G12C. Within KRAS_non-G12C group, 73%, 16.8% and 8.9% harboured G12X, codon 13 and Q61H alterations, respectively. No significant differences in survival outcome and treatment response were documented according to KRAS_G12C versus non-G12C, nor KRAS_G12C versus G12X versus other mutations. On univariate analysis ECOG PS, number and sites of metastatic lesions and PD-L1 status significantly impacted on survival. A clear trend towards worse prognosis was apparent in chemotherapy-treated patients, while immunotherapy-based regimens were associated to prolonged survival. Investigating the outcome of PD-L1 ≥ 50% population, we did not detect any significant difference between KRAS_G12C and non-G12C subsets.

CONCLUSION

Here, we report on real-life data from a large retrospective cohort of advanced NSCLC harbouring KRAS alterations, with particular attention to G12C mutation. Our study offers useful clues on survival outcome, therapeutic response and clinico-pathological correlations in KRAS-mutant setting, especially in the upcoming era of KRAS G12C targeting therapy.

Overview of predictive and prognostic biomarkers and their importance in developing a clinical pharmacology treatment plan in colorectal cancer patients

INTRODUCTION

Colorectal cancer (CRC) is the second most common cause of cancer-related death worldwide. Although overall survival for CRC patients has improved with earlier screening, survival continues to vary substantially across stages. Also, while the introduction of targeted therapies, including VEGF and EGFR inhibitors, has contributed to improving survival, better tools are needed to optimize patient selection and maximize therapeutic benefits. Emerging biomarkers can be used to guide pharmacologic decision-making, as well as monitor treatment response, clarify the need for adjuvant therapies, and indicate early signs of recurrence. This is a narrative review examining the current and evolving use of predictive and prognostic biomarkers in colorectal cancer.

AREAS COVERED

Areas covered include mutations of the MAPK (KRAS, BRAF) and HER2 pathways and their impacts on treatment decisions. In addition, novel methods for assessing tumor mutations and tracking treatment responses are examined.

EXPERT OPINION

The standard of care pathway for staging, and treatment selection and surveillance, of CRC will expand to include novel biomarkers in the next 5 years. It is anticipated that these new biomarkers will assist in decision-making regarding selection of targeted therapies and, importantly, in risk stratification for treatment decisions in patients at high risk for recurrence.

Biomarkers in Metastatic Colorectal Cancer: Status Quo and Future Perspective

Colorectal cancer (CRC) is the third most frequent cancer worldwide, and its incidence is steadily increasing. During the last two decades, a tremendous improvement in outcome has been achieved, mainly due to the introduction of novel drugs, targeted treatment, immune checkpoint inhibitors (CPIs) and biomarker-driven patient selection. Moreover, progress in molecular diagnostics but also improvement in surgical techniques and local ablative treatments significantly contributed to this success. However, novel therapeutic approaches are needed to further improve outcome in patients diagnosed with metastatic CRC. Besides the established biomarkers for mCRC, such as microsatellite instability (MSI) or mismatch repair deficiency (dMMR), RAS/BRAF, sidedness and HER2 amplification, new biomarkers have to be identified to better select patients who derive the most benefit from a specific treatment. In this review, we provide an overview about therapeutic relevant and established biomarkers but also shed light on potential promising markers that may help us to better tailor therapy to the individual mCRC patient in the near future.

KRAS G12C-Mutant Non-Small-Cell Lung Adenocarcinoma: First Documented Report in the Arabian Gulf

We report the first documented case series of two lung adenocarcinoma patients demonstrating Kirsten rat sarcoma viral oncogene homolog (KRAS) G12C mutations by reverse transcription-polymerase chain reaction techniques from Saudi Arabia. Both patients were males aged 64 and 76 years. The first had a heavy smoking history, while the second did not report any history of smoking. The tumor subtype was identified to be non-mucinous lung adenocarcinoma in both cases. The younger patient presented with generalized lymphadenopathy and a right-sided lung mass lesion, while the older patient exhibited stage III-A left lung adenocarcinoma that required rapid response. An initial examination of the first case showed a right-sided mediastinal shift, bilateral neck lymphadenopathy, and poorly differentiated neoplasm from a right supraclavicular core biopsy, leading to treatment with palliatives along with regular checkups. The second case was afebrile after being confirmed to be vitally stable and laboratory testing (Neutr 100). Further studies, specifically on large numbers of patients from the Arabian Gulf, are needed to confirm significant differences between the national and international populations. Additionally, future studies should investigate more differences in the differentiation of KRAS-mutant lung adenocarcinoma between patients from the Arabian Gulf and others.

Characteristics and Treatment Outcomes in Advanced-Stage Non-Small Cell Lung Cancer Patients with a KRAS G12C Mutation: A Real-World Study

About 15% of patients with non-small cell lung cancer (NSCLC) harbor the Kirsten rat sarcoma homolog G12C mutation (KRAS^G12C). Selective KRAS^G12C inhibitors offer new treatment opportunities, but little is known about the prevalence, characteristics, and outcomes of standard-of-care treatment (SOC) in this population. We retrospectively assessed the clinicopathological features of patients with KRAS^G12C-mutated advanced NSCLC and responses to SOC at two high-volume centers in Austria. Out of 2495 NSCLC patients tested, we identified 174 patients with advanced-stage disease carrying a KRAS^G12C mutation. Most patients were ≥65 years old (55%), heavy smokers (55%), and presented with comorbidities. The most frequent co-alteration was TP53 (18%). PD-L1 expression was high (TPS ≥ 50%) in 31%, very high (TPS ≥ 90%) in 11%, and negative in 31% of patients. A total of 138 patients (79%) received oncologic systemic treatment. The most common first-line therapy (1 L) was anti-PD-1/PD-L1 plus platinum-based chemotherapy. Median overall survival measured from 1 L treatment was 15.3 months (95% CI, 8.6–21.9), 9.4 (95% CI, 5.3–13.5) from 2 L treatment, and 8.4 (95% CI, 1.7–15.1) from 3 L treatment. The time-to-next-treatment was 8.4 (95% CI, 5.2–11.6) from 1 L and 6.1 (95% CI, 2.7–9.7) months from 2 L to 3 L. These poor outcomes underscore the need for the implementation of new treatment options and for specific molecular testing.