D-1553 (Garsorasib), a Potent and Selective Inhibitor of KRASG12C in Patients With NSCLC: Phase 1 Study Results

STAT3 Inhibition Prevents Adaptive Resistance and Augments NK Cell Cytotoxicity to KRASG12C Inhibitors in Nonsmall Cell Lung Cancer

KRASG12C inhibitors exhibit conspicuous clinical response in KRASG12C-mutant lung cancer, yet adaptive resistance, the rapid onset of intrinsic resistance, dampens their therapeutic success. Rational combination strategies could tackle this challenging problem. A high-throughput screening of a pharmacological library with 423 compounds revealed that napabucasin, a signal transducer and activator of transcription 3 (STAT3) inhibitor, synergistically potentiated the growth inhibition effect of the KRASG12C inhibitor sotorasib in sensitive and resistant KRASG12C NSCLC cell lines. Functional assays further revealed that the coordinated targeting of KRAS with STAT3 improved the inhibitory effect on tumor growth and augmented the infiltration and activation of natural killer (NK) cells within the tumor microenvironment. Mechanistically, KRASG12C inhibition induced compensatory activation of STAT3, contingent on concomitant suppression of downstream ERK signaling, abrogated by napabucasin. Moreover, we unveiled and verified the binding site of phosphorylated STAT3 at the HLA-B promoter, an inhibitor ligand for NK cells. Our study dissected an unknown mechanism of adaptive resistance to KRASG12C inhibitors, with the STAT3 activation sustaining the regrowth of tumor cells under KRAS inhibition and up-regulating HLA-B transcription to dampen the cytotoxicity of infiltrated NK cells.

Emerging Targeted Therapies in Non-Small-Cell Lung Cancer (NSCLC)

Targeted therapies have changed the treatment landscape of non-small-cell lung cancer and led to improved patient survival across all stages of lung cancer. Newer advances in common and novel oncogenic drivers continue to occur at vigorous speed, making it challenging to stay up to date with the rapidly evolving field. In this article, we review the emerging perspectives in the treatment of actionable targets in lung cancer. We focus on the development of newer KRAS-directed therapies, particularly on non-G12C mutations, pan-RAS inhibitors, and RAS-GTP inhibitors. We also describe the current standard of care for EGFR- and ALK-altered NSCLC and dive into the novel treatments expected to be in the clinic soon. A similar approach is taken toward MET, HER2, RET, ROS1, and FGFR alterations as emerging targets in non-small-cell lung cancer. Finally, we conclude this review with the current body of evidence for targeting TROP-2 as a novel target, potentially of importance in post-targeted therapy scenarios.

Advancements in gene therapies targeting mutant KRAS in cancers

Mutations in the KRAS gene are well-known tumourigenic drivers of colorectal, pancreatic and lung cancers. Mechanistically, these mutations promote uncontrolled cell proliferation and alter the tumour microenvironment during early carcinoma stages. Given their critical carcinogenic functions, significant progress has been made in developing KRAS inhibitors for cancer treatment. However, clinical applications of these KRAS inhibitor compounds are limited to specific cancer types which carry the relevant KRAS mutations. Additionally, clinical findings have shown that these compounds can induce moderate to serious side effects. Therefore, new approaches have emerged focusing on the development of universal therapeutics capable of targeting a wider range of KRAS mutations, minimising toxicity and enhancing the therapeutic efficacy. This review aims to examine these therapeutic strategies in the context of cancer treatment. It firstly provides an overview of fundamental KRAS biology within the cell signalling landscape and how KRAS mutations are associated with cancer pathogenesis. Subsequently, it introduces the development of current KRAS inhibitors which target certain KRAS mutants in different types of cancer. It then explores the potential of gene therapy approaches, including siRNA, miRNA and CRISPR methodologies. Furthermore, it discusses the use of lipid-based nanocarriers to deliver gene cargos for targeting KRAS gene mutants. Finally, it provides the insights into the future prospects for combatting KRAS mutation-associated cancers.

The continually evolving landscape of novel therapies in oncogene-driven advanced non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is a highly heterogeneous disease that is frequently associated with a host of known oncogenic alterations. Advances in molecular diagnostics and drug development have facilitated the targeting of novel alterations such that the majority of NSCLC patients have driver mutations that are now clinically actionable. The goal of this review is to gain insights into clinical research and development principles by summary, analysis, and discussion of data on agents targeting known alterations in oncogene-driven, advanced NSCLC beyond those in the epidermal growth factor receptor (EGFR) and the anaplastic lymphoma kinase (ALK). A search of published and presented literature was conducted to identify prospective trials and integrated analyses reporting outcomes for agents targeting driver gene alterations (except those in EGFR and ALK) in molecularly selected, advanced NSCLC. Clinical efficacy data were extracted from eligible reports and summarized in text and tables. Findings show that research into alteration-directed therapies in oncogene-driven, advanced NSCLC is an extremely active research field. Ongoing research focuses on the expansion of new agents targeting both previously identified targets (particularly hepatocyte growth factor receptor (MET), human epidermal growth factor receptor 2 (HER2), and Kirsten rat sarcoma viral oncogene homolog (KRAS)) as well as novel, potentially actionable targets (such as neuregulin-1 (NRG1) and phosphatidylinositol 3-kinase (PI3K)). The refinement of biomarker selection criteria and the development of more selective and potent agents are allowing for increasingly specific and effective therapies and the expansion of clinically actionable alterations. Clinical advances in this field have resulted in a large number of regulatory approvals over the last 3 years. Future developments should focus on the continued application of alteration therapy matching principles and the exploration of novel ways to target oncogene-driven NSCLC.

Development and safety of investigational and approved drugs targeting the RAS function regulation in RAS mutant cancers

The RAS gene family holds a central position in controlling key cellular activities such as migration, survival, metabolism, and other vital biological processes. The activation of RAS signaling cascades is instrumental in the development of various cancers. Although several RAS inhibitors have gained approval from the US Food and Drug Administration for their substantial antitumor effects, their widespread and severe adverse reactions significantly curtail their practical usage in the clinic. Thus, there exists a pressing need for a comprehensive understanding of these adverse events, ensuring the clinical safety of RAS inhibitors through the establishment of precise management guidelines, suitable intermittent dosing schedules, and innovative combination regimens. This review centers on the evolution of RAS inhibitors in cancer therapy, delving into the common adverse effects associated with these inhibitors, their underlying mechanisms, and the potential strategies for mitigation.

RAS signaling in carcinogenesis, cancer therapy and resistance mechanisms

Variants in the RAS family (HRAS, NRAS and KRAS) are among the most common mutations found in cancer. About 19% patients with cancer harbor RAS mutations, which are typically associated with poor clinical outcomes. Over the past four decades, KRAS has long been considered an undruggable target due to the absence of suitable small-molecule binding sites within its mutant isoforms. However, recent advancements in drug design have made RAS-targeting therapies viable, particularly with the approval of direct KRASG12C inhibitors, such as sotorasib and adagrasib, for treating non-small cell lung cancer (NSCLC) with KRASG12C mutations. Other KRAS-mutant inhibitors targeting KRASG12D are currently being developed for use in the clinic, particularly for treating highly refractory malignancies like pancreatic cancer. Herein, we provide an overview of RAS signaling, further detailing the roles of the RAS signaling pathway in carcinogenesis. This includes a summary of RAS mutations in human cancers and an emphasis on therapeutic approaches, as well as de novo, acquired, and adaptive resistance in various malignancies.

Advances in the Management of Lung Cancer Brain Metastases

Lung cancer, both non-small cell and small cell, harbors a high propensity for spreading to the central nervous system. Radiation therapy remains the backbone of the management of brain metastases. Recent advances in stereotactic radiosurgery have expanded its indications and ongoing studies seek to elucidate optimal fractionation and coordination with systemic therapies, especially targeted inhibitors with intracranial efficacy. Efforts in whole-brain radiotherapy aim to preserve neurocognition and to investigate the need for prophylactic cranial irradiation. As novel combinatorial strategies are tested and prognostic/predictive biomarkers are identified and tested, the management of brain metastases in lung cancer will become increasingly personalized to optimally balance intracranial efficacy with preserving neurocognitive function and patient values.

Potent covalent irreversible inhibitor of KRAS G12C IBI351 in patients with advanced solid tumors: First-in-human phase I study

BACKGROUND

IBI351 is an irreversible and covalent inhibitor of KRAS G12C. Despite FDA approval of two KRAS G12C inhibitors, there are still significant unmet clinical needs in Chinese patients and ongoing concerns about the optimal dosage. Herein, we presented the phase Ia/Ib study of IBI351 monotherapy in Chinese patients with advanced solid tumors harboring KRAS G12C mutation.

METHODS

In phase Ia dose escalation, IBI351 at 250/450/700/900 mg once daily and 450/600/750 mg twice daily (BID) were evaluated. Potentially efficacious doses and optimal recommended phase 2 dose (RP2D) were further evaluated in patients with advanced non-small cell lung cancer (NSCLC) in phase Ia dose expansion and phase Ib. Safety, pharmacokinetics, and investigator-assessed tumor response were evaluated.

RESULTS

As of June 13, 2023, 176 patients were enrolled. IBI351 was well tolerated with no dose-limiting toxicity reported across all evaluated doses. The RP2D was determined as 600 mg BID by considering safety, efficacy and pharmacokinetics. A total of 168 patients (95.5 %) had at least one treatment-related adverse event (TRAE), and 64 patients (36.4 %) had grade 3 or higher TRAEs, most commonly gamma-glutamyl transferase increased (10.2 %) and anemia (6.8 %). For patients with NSCLC, the confirmed objective response rate (ORR) was 45.5 % across all doses. At 600 mg BID, the confirmed ORR was 46.8 % and median progression-free survival was 9.6 months with a median follow-up of 6.9 months.

CONCLUSIONS

IBI351 was well tolerated in patients with advanced solid tumors and showed promising antitumor activity in advanced NSCLC patients with KRAS G12C mutation.

Adagrasib in KRYSTAL-12 has Broken the KRAS G12C Enigma Code in Non-Small Cell Lung Carcinoma

Kirsten rat sarcoma viral oncogene homolog (KRAS) G12C-mutant non-small cell lung carcinoma (NSCLC) accounts for approximately 10-13% of advanced nonsquamous NSCLC cases in Western populations, presenting a significant therapeutic challenge owing to the difficulty of directly targeting KRAS. Adagrasib, an oral small-molecule covalent inhibitor, irreversibly and selectively targets KRASG12C in its inactive state. It received accelerated Food and Drug Administration (FDA) approval on December 12, 2022, following the KRYSTAL-1 Phase II trial. The Phase III KRYSTAL-12 trial demonstrated that adagrasib significantly improved median progression-free survival (mPFS) compared with docetaxel (HR, 0.58; 95% CI: 0.45-0.76; P<0.0001) and increased the intracranial objective response rate (ORR) to 40% in the central nervous system (CNS) evaluable population. This paper evaluates the clinical efficacy of adagrasib in KRAS G12C-mutated advanced NSCLC discussing its potential advantages over other inhibitors such as sotorasib. Despite not reaching the 6-month mPFS benchmark, adagrasib offers significant clinical benefits, particularly for the management of CNS metastases. In this pros and cons debate, we argue that adagrasib has broken the KRAS G12C enigma code in NSCLC.

Beyond KRAS(G12C): Biochemical and Computational Characterization of Sotorasib and Adagrasib Binding Specificity and the Critical Role of H95 and Y96

Mutated KRAS proteins are frequently expressed in some of the most lethal human cancers and thus have been a target of intensive drug discovery efforts for decades. Lately, KRAS(G12C) switch-II pocket (SII-P)-targeting covalent small molecule inhibitors have finally reached clinical practice. Sotorasib (AMG-510) was the first FDA-approved covalent inhibitor to treat KRAS(G12C)-positive nonsmall cell lung cancer (NSCLC), followed soon by adagrasib (MRTX849). Both drugs target the GDP-bound state of KRAS(G12C), exploiting the strong nucleophilicity of acquired cysteine. Here, we evaluate the similarities and differences between sotorasib and adagrasib in their RAS SII-P binding by applying biochemical, cellular, and computational methods. Exact knowledge of SII-P engagement can enable targeting this site by reversible inhibitors for KRAS mutants beyond G12C. We show that adagrasib is strictly KRAS- but not KRAS(G12C)-specific due to its strong and unreplaceable interaction with H95. Unlike adagrasib, sotorasib is less dependent on H95 for its binding, making it a RAS isoform-agnostic compound, having a similar functionality also with NRAS and HRAS G12C mutants. Our results emphasize the accessibility of SII-P beyond oncogenic G12C and aid in understanding the molecular mechanism behind the clinically observed drug resistance, associated especially with secondary mutations on KRAS H95 and Y96.

Emerging Targets in Non-Small Cell Lung Cancer

Lung cancer is responsible for a high burden of disease globally. Over the last two decades, the discovery of targetable oncogenic genomic alterations has revolutionized the treatment landscape for early-stage and advanced non-small cell lung cancer (NSCLC). New molecular drivers continue to emerge as promising therapeutic targets, including KRAS non-G12C, RAF/MEK, HER3, Nectin-4, folate receptor alpha, ITGB6, and PRMT5. In this review, we summarize the emerging molecular targets with a potential clinical impact in advanced NSCLC, elaborating on their clinical characteristics and specific mechanisms and molecular pathways for which targeted treatments are currently available. Additionally, we present an aggregate of ongoing clinical trials investigating the available treatment options targeting such alterations, in addition to their current recruitment status and preliminary efficacy data. These advancements may guide further research endeavors and inform future treatment strategies to improve the management of and transform outcomes for patients with advanced NSCLC.

D3S-001, a KRAS G12C Inhibitor with Rapid Target Engagement Kinetics, Overcomes Nucleotide Cycling, and Demonstrates Robust Preclinical and Clinical Activities

First-generation KRAS G12C inhibitors, such as sotorasib and adagrasib, are limited by the depth and duration of clinical responses. One potential explanation for their modest clinical activity is the dynamic "cycling" of KRAS between its guanosine diphosphate (GDP)- and guanosine triphosphate (GTP)-bound states, raising controversy about whether targeting the GDP-bound form can fully block this oncogenic driver. We herein report that D3S-001, a next-generation GDP-bound G12C inhibitor with faster target engagement (TE) kinetics, depletes cellular active KRAS G12C at nanomolar concentrations. In the presence of growth factors, such as epithelial growth factor and hepatocyte growth factor, the ability of sotorasib and adagrasib to inhibit KRAS was compromised whereas the TE kinetics of D3S-001 was nearly unaffected, a unique feature differentiating D3S-001 from other GDP-bound G12C inhibitors. Furthermore, the high covalent potency and cellular TE efficiency of D3S-001 contributed to robust antitumor activity preclinically and translated into promising clinical efficacy in an ongoing phase 1 trial (NCT05410145). Significance: The kinetic study presented in this work unveils, for the first time, that a GDP-bound conformation-selective KRAS G12C inhibitor can potentially deplete cellular active KRAS in the presence of growth factors and offers new insights into the critical features that drive preclinical and clinical efficacy for this class of drugs.

KRASG12C Inhibitors in Non-Small Cell Lung Cancer: A Review

Rat sarcoma virus (RAS) GTPase is one of the most important drivers of non-small cell lung cancer (NSCLC). RAS has three different isoforms (Harvey rat sarcoma viral oncogene homolog [HRAS], Kirsten rat sarcoma viral oncogene homolog [KRAS] and Neuroblastoma ras viral oncogene homolog [NRAS]), of which KRAS is most commonly mutated in NSCLC. The mutated KRAS protein was historically thought to be "undruggable" until the development of KRASG12C inhibitors. In this review, from the aspect of brain metastasis, we aim to provide an overview of the advances in therapies that target KRASG12C, the limitations of the current treatments, and future prospects in patients with KRAS p.G12C mutant NSCLC.

Drug development and evidence for lung cancer targeted therapy in Eastern Asia

The development of targeted drugs in the Eastern Asia region is going through a flourishing stage. With the continuous advancement of technology and medical research, biotechnology companies and research institutions in the region have made significant progress in cancer field. The Eastern Asian region not only actively participates in clinical trials, but is also committed to developing personalized medical plans to meet the diverse genotypes and phenotypes of patients. The governments and enterprises are increasingly valuing innovation, strengthening international cooperation, and promoting drug development. This paper summarizes the development of genetic testing technology, targeted drugs approval, ongoing promising clinical trials in the field of lung cancer and the important progress made by governments in the Eastern Asian region, and proposed key factors that will contribute to the promising future prospects in the region. The targeted drug market in the Eastern Asian region is expected to drive the medical field forward.

Garsorasib in patients with KRASG12C-mutated non-small-cell lung cancer in China: an open-label, multicentre, single-arm, phase 2 trial

BACKGROUND

Garsorasib (D-1553; InventisBio, Shangai, China), a potent KRASG12C inhibitor, has shown promising antitumour activity in patients with KRASG12C-mutated (ie, Gly12Cys) non-small-cell lung cancer (NSCLC) in a phase 1 study. We report results from a phase 2 study conducted to evaluate the efficacy and safety of garsorasib in patients with locally advanced or metastatic KRASG12C-mutated NSCLC.

METHODS

This open-label, multicentre, single-arm, phase 2 trial enrolled adult patients with KRASG12C-mutated NSCLC who had previously been treated with platinum-based chemotherapy and immune checkpoint inhibitors from 43 hospitals in China. Participants received 600 mg garsorasib orally twice per day. Tumour assessments were performed at baseline, at the end of every two cycles (of 21 days) for the first eight cycles, and at the end of every three cycles thereafter. The primary endpoint was objective response rate (ORR) as assessed by an independent review committee (IRC) following the guidelines in Response Evaluation Criteria in Solid Tumours, version 1.1. Efficacy and safety were assessed in all patients who received at least one dose of garsorasib. This trial is registered at ClinicalTrials.gov, NCT05383898, and is active but no longer recruiting.

FINDINGS

From June 17, 2022, to May 17, 2023, of 225 patients screened for eligibility, 123 patients were enrolled and treated with garsorasib. Of these 123 participants, the median age was 64 years (IQR 59-68), 108 (88%) were male and 15 (12%) were female. At data cutoff (Nov 17, 2023), the median follow-up duration was 7·9 months (IQR 6·3-10·4), and 82 (67%) of 123 patients had discontinued treatment. The IRC-confirmed ORR was 50% (61 of 123 patients; 95% CI 41-59). 117 (95%) of 123 patients reported treatment-related adverse events, with 61 (50%) experiencing grade 3 or higher events. The most common types of adverse events of grade 3 or higher associated with garsorasib were hepatic and gastrointestinal events, including increased liver enzymes, such as aspartate aminotransferase (21 [17%] of 123 participants), alanine aminotransferase (19 [15%] of 123 participants), and gamma-glutamyltransferase (28 [23%] of 123 participants); nausea (2 [2%] of 123 participants); and vomiting (2 [2%] of 123 participants). No new safety signals were identified, and most of the adverse events were well managed.

INTERPRETATION

The results show that garsorasib has a high response rate, long duration of response, and an acceptable and manageable safety profile in patients with previously treated KRASG12C-mutated NSCLC. Garsorasib potentially provides a promising treatment option for this patient population.

FUNDING

InventisBio.

Efficacy and toxicity of KRASG12C inhibitors in advanced solid tumors: a meta-analysis

BACKGROUND

The efficacy and toxicity of KRASG12C inhibitors were evaluated for advanced solid tumors in several studies; however, the results were not fully consistent.

METHODS

Clinical trials evaluating KRASG12C inhibitors for advanced solid tumors were searched from PubMed, Embase, and Cochrane Library online databases up to 31st December 2023. The characteristics of the studies and the results of objective response rate (ORR), disease control rate (DCR), duration of response (DoR), progression-free survival (PFS) rate, overall survival (OS) rate, and treatment-related adverse events (trAEs) were extracted.

RESULTS

Ten studies with 925 heavily pretreated advanced patients harboring KRASG12C mutation were included. For total population, the pooled analysis of ORR was 28.6% (95%CI, 21.2-36.6%), DCR was 85.5% (95%CI, 82.2-88.6%), PFS rate at 6 months (PFS6) was 49.6% (95%CI, 41.4-57.9%), PFS rate at 12 months (PFS12) was 26.7% (95%CI, 19.8-34.1%), OS rates at 6 months (OS6) was 76.2% (95%CI, 68.8-82.9%), OS rates at 12 months (OS12) was 47.8% (95%CI, 38.6-57.0%). The pooled analysis of any grade trAEs was 79.3% (95%CI, 66.2-90.0%) and grade three or more trAEs was 24.4% (95%CI, 16.7-32.9%). The median time to response and DoR results from individual data were 1.39 months (95%CI, 1.37-1.41 months) and 10.54 months (95%CI, 7.72-13.36 months). Sotorasib had significantly lower pooled incidences of any trAEs (OR, 0.07, 95%CI, 0.03-0.14) and grade three or more trAES (OR, 0.34, 95%CI, 0.24-0.49) compared with adagrasib.

CONCLUSIONS

KRASG12C inhibitors have good ORR, DCR, PFS rate, OS rate, tolerable trAEs, and early response with long duration in advanced solid tumors; however, most of the pooled results were heterogeneous. Sotorasib has shown better safety results.

The next-generation KRAS inhibitors…What comes after sotorasib and adagrasib?

The Kirsten rat sarcoma viral oncogene homolog (KRAS) is one of the first driver oncogenes identified in human cancer in the early 1980s. However, it has been deemed 'undruggable' for nearly four decades until the discovery of KRAS G12C covalent inhibitors, which marked a pivotal breakthrough. Currently, sotorasib and adagrasib have been approved by the US FDA to treat patients with non-small cell lung cancer (NSCLC) harboring KRAS G12C mutation. However, their efficacy is somewhat limited compared to that of other targeted therapies owing to intrinsic resistance or early acquisition of resistance. While G12C is the predominant subtype of KRAS mutations in NSCLC, G12D/V is prevalent in colorectal and pancreatic cancers. These facts have spurred active research to develop more potent KRAS G12C inhibitors as well as inhibitors targeting non-G12C KRAS mutations. Novel approaches, such as molecular shielding or targeted protein degradation, are also under development. Combining KRAS inhibitors with inhibitors of the receptor-tyrosine kinase-RAS-mitogen-activated protein kinase (MAPK) pathway is underway to counteract redundant feedback mechanisms. Additionally, immunological approaches utilizing T-cell receptor (TCR)-engineered T cell therapy or vaccines, and Hapimmune antibodies are ongoing. This review delineates the recent advancements in KRAS inhibitor development in the post-sotorasib/adagrasib era, with a focus on NSCLC.

Resistance to KRAS inhibition in advanced non-small cell lung cancer

Lung cancer remains the leading cause of cancer death globally. More than 50% of new cases are diagnosed in an advanced or metastatic stage, thus contributing to the poor survival of such patients. Mutations in the KRAS (Kirsten rat sarcoma virus) gene occur in nearly a third of lung adenocarcinoma and have for decades been deemed an 'undruggable' target. Yet, in recent years, a growing number of small molecules, such as the GTPase inhibitors, has been investigated in clinical trials of lung cancer patients harboring KRAS mutations, yielding promising results with improved outcomes. Currently, there are only two approved targeted therapies (adagrasib and sotorasib) for advanced or metastatic KRAS-mutated NSCLC from the second-line setting onwards. In this narrative review, we will focus on KRAS, its molecular basis, the role of its co-mutations, clinical evidence for its inhibition, putative mutation to resistance, and future strategies to overcome resistance to KRAS inhibition.

Targeting RAF dimers in RAS mutant tumors: From biology to clinic

RAS mutations occur in approximately 30% of tumors worldwide and have a poor prognosis due to limited therapies. Covalent targeting of KRAS G12C has achieved significant success in recent years, but there is still a lack of efficient therapeutic approaches for tumors with non-G12C KRAS mutations. A highly promising approach is to target the MAPK pathway downstream of RAS, with a particular focus on RAF kinases. First-generation RAF inhibitors have been authorized to treat BRAF mutant tumors for over a decade. However, their use in RAS-mutated tumors is not recommended due to the paradoxical ERK activation mainly caused by RAF dimerization. To address the issue of RAF dimerization, type II RAF inhibitors have emerged as leading candidates. Recent clinical studies have shown the initial effectiveness of these agents against RAS mutant tumors. Promisingly, type II RAF inhibitors in combination with MEK or ERK inhibitors have demonstrated impressive efficacy in RAS mutant tumors. This review aims to clarify the importance of RAF dimerization in cellular signaling and resistance to treatment in tumors with RAS mutations, as well as recent progress in therapeutic approaches to address the problem of RAF dimerization in RAS mutant tumors.

Divarasib in the Evolving Landscape of KRAS G12C Inhibitors for NSCLC

Kristen Rat Sarcoma viral oncogene (KRAS) mutations are one of the most common oncogenic drivers found in 12-14% of non-small cell lung cancer (NSCLC) and 4% of colorectal cancer tumors. Although previously difficult to target, sotorasib and adagrasib are now approved for previously treated NSCLC patients with KRAS G12C mutations. In preclinical studies, divarasib was 5 to 20 times as potent and up to 50 times as selective as sotorasib and adagrasib. While sotorasib met its primary endpoint in the phase III second line study against docetaxel, the progression-free survival (PFS) benefit was small and no overall survival (OS) benefit was observed. Adagrasib has demonstrated clinical benefit in the phase I/II KRYSTAL-1 study setting, however, 44.8% of patients reported grade 3 or higher toxicities. Divarasib has been studied in a phase I dose expansion cohort with promising efficacy [objective response (ORR) 53.4% and PFS 13.1 months]. Although most patients reported toxicities, the majority were low-grade and manageable with supportive care. Here we discuss these results in the context of the evolving KRAS G12C landscape.

Management of sotorasib-related adverse events and hepatotoxicities following anti-PD-(L)1 therapy: Experience with sotorasib in two French anti-cancer centers and practical guidance proposal

INTRODUCTION

Sotorasib is a first-in-class KRASG12C inhibitor that showed significant clinical activity in KRASG12C-mutated non-small cell lung cancer (NSCLC). The most frequent grade 3 or 4 sotorasib-related adverse events (AEs) were diarrhea (4-12 %) and hepatotoxicity (10.1-15.1 %). Data is lacking about the management of these AEs, especially in patients receiving sequential anti-PD-(L)1 and sotorasib therapy. Our aim was to report the management of grade ≥ 2 sotorasib-related AEs in real-world setting and to propose practical guidance for the management of grade ≥ 2 sotorasib-related AEs and more generally KRASG12C inhibitors-related AEs.

MATERIALS AND METHODS

Records from all consecutive patients who initiated sotorasib through expanded access program in two French anti-cancer centers from January 1st 2021 to April 1st 2023 were reviewed to identify and grade sotorasib-related AEs, according to NCI-CTCAE v5.0., and to collect AEs management data. Patients were included in the analysis if they presented a grade ≥ 2 sotorasib-related AE.

RESULTS

From 57 patients identified, 21 met inclusion criteria including eighteen (86 %) who received sequential anti-PD-(L)1 and sotorasib therapy. Hepatotoxicity (76 %) and diarrhea (24 %) were the most common grade ≥ 2 sotorasib-related AEs. Among the 16 patients with a grade ≥ 2 hepatotoxicity, 12 (75 %) definitely discontinued sotorasib, among which 9 (56 %) after dose reductions and rechallenge, and five (32 %) received corticosteroids, allowing only one patient to resume sotorasib. Diarrhea and nausea were usually manageable and not associated with sotorasib discontinuation. We propose a step-by-step management practical guidance for sotorasib-related hepatotoxicity based on dose-reduction and careful monitoring. Liver biopsy is strongly encouraged for grade 3 and 4 hepatotoxicity to assess candidates for corticosteroids.

DISCUSSION

The experience with sotorasib might help better prevent, screen and manage sotorasib-related and other KRASG12C inhibitors-related AEs, particularly hepatotoxicity.

Targeting KRASG12C in Non-Small-Cell Lung Cancer: Current Standards and Developments

Among the most common molecular alterations detected in non-small-cell lung cancer (NSCLC) are mutations in Kristen Rat Sarcoma viral oncogene homolog (KRAS). KRAS mutant NSCLC is a heterogenous group of diseases, different from other oncogene-driven tumors in terms of biology and response to therapies. Despite efforts to develop drugs aimed at inhibiting KRAS or its signaling pathways, KRAS had remained undruggable for decades. The discovery of a small pocket in the binding switch II region of KRASG12C has revolutionized the treatment of KRASG12C-mutated NSCLC patients. Sotorasib and adagrasib, direct KRASG12C inhibitors, have been approved by the US Food and Drug Administration (FDA) and other regulatory agencies for patients with previously treated KRASG12C-mutated NSCLC, and these advances have become practice changing. However, first-line treatment in KRASG12C-mutated NSCLC does not differ from NSCLC without actionable driver genomic alterations. Treatment with KRASG12C inhibitors is not curative and patients develop progressive disease, so understanding associated mechanisms of drug resistance is key. New KRASG12C inhibitors and several combination therapy strategies, including with immune checkpoint inhibitors, are being studied in clinical trials. The aim of this review is to explore the clinical impact of KRAS, and outline different treatment approaches, focusing on the novel treatment of KRASG12C-mutated NSCLC.

The golden key to open mystery boxes of SMARCA4-deficient undifferentiated thoracic tumor: focusing immunotherapy, tumor microenvironment and epigenetic regulation

SMARCA4-deficient undifferentiated thoracic tumor is extremely invasive. This tumor with poor prognosis is easily confused with SMARCA4-deficent non-small cell lung cancer or sarcoma. Standard and efficient treatment has not been established. In this review, we summarized the etiology, pathogenesis and diagnosis, reviewed current and proposed innovative strategies for treatment and improving prognosis. Immunotherapy, targeting tumor microenvironment and epigenetic regulator have improved the prognosis of cancer patients. We summarized clinicopathological features and immunotherapy strategies and analyzed the progression-free survival (PFS) and overall survival (OS) of patients with SMARCA4-UT who received immune checkpoint inhibitors (ICIs). In addition, we proposed the feasibility of epigenetic regulation in the treatment of SMARCA4-UT. To our knowledge, this is the first review that aims to explore innovative strategies for targeting tumor microenvironment and epigenetic regulation and identify potential benefit population for immunotherapy to improve the prognosis.

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.

From bench to bedside: current development and emerging trend of KRAS-targeted therapy

Kirsten rat sarcoma 2 viral oncogene homolog (KRAS) is the most frequently mutated oncogene in human cancers with mutations predominantly occurring in codon 12. These mutations disrupt the normal function of KRAS by interfering with GTP hydrolysis and nucleotide exchange activity, making it prone to the GTP-bound active state, thus leading to sustained activation of downstream pathways. Despite decades of research, there has been no progress in the KRAS drug discovery until the groundbreaking discovery of covalently targeting the KRASG12C mutation in 2013, which led to revolutionary changes in KRAS-targeted therapy. So far, two small molecule inhibitors sotorasib and adagrasib targeting KRASG12C have received accelerated approval for the treatment of non-small cell lung cancer (NSCLC) harboring KRASG12C mutations. In recent years, rapid progress has been achieved in the KRAS-targeted therapy field, especially the exploration of KRASG12C covalent inhibitors in other KRASG12C-positive malignancies, novel KRAS inhibitors beyond KRASG12C mutation or pan-KRAS inhibitors, and approaches to indirectly targeting KRAS. In this review, we provide a comprehensive overview of the molecular and mutational characteristics of KRAS and summarize the development and current status of covalent inhibitors targeting the KRASG12C mutation. We also discuss emerging promising KRAS-targeted therapeutic strategies, with a focus on mutation-specific and direct pan-KRAS inhibitors and indirect KRAS inhibitors through targeting the RAS activation-associated proteins Src homology-2 domain-containing phosphatase 2 (SHP2) and son of sevenless homolog 1 (SOS1), and shed light on current challenges and opportunities for drug discovery in this field.

Recent advances of anti-angiogenic inhibitors targeting VEGF/VEGFR axis

Vascular endothelial growth factors (VEGF), Vascular endothelial growth factor receptors (VEGFR) and their downstream signaling pathways are promising targets in anti-angiogenic therapy. They constitute a crucial system to regulate physiological and pathological angiogenesis. In the last 20 years, many anti-angiogenic drugs have been developed based on VEGF/VEGFR system to treat diverse cancers and retinopathies, and new drugs with improved properties continue to emerge at a fast rate. They consist of different molecular structures and characteristics, which enable them to inhibit the interaction of VEGF/VEGFR, to inhibit the activity of VEGFR tyrosine kinase (TK), or to inhibit VEGFR downstream signaling. In this paper, we reviewed the development of marketed anti-angiogenic drugs involved in the VEGF/VEGFR axis, as well as some important drug candidates in clinical trials. We discuss their mode of action, their clinical benefits, and the current challenges that will need to be addressed by the next-generation of anti-angiogenic drugs. We focus on the molecular structures and characteristics of each drug, including those approved only in China.

Polyradiculitis as a Neurological Complication Associated with Adagrasib: A Case Report

Introduction

Adagrasib is an upcoming anticancer treatment for KRAS G12C-mutated non-small-cell lung carcinoma, colorectal cancer and potentially other solid tumors harboring this mutation. It is generally well-tolerated and reports of neurological adverse events so far have been limited.

Case Presentation

We present to our best knowledge the first case of a 70-year-old woman who was admitted with polyradiculitis as a treatment-related complication of adagrasib. Symptoms resolved after treatment with prednisone and therapy interruption of adagrasib followed by a permanent dose reduction. After the dose reduction, there was an ongoing effective tumor response at follow-up, and serum concentrations of adagrasib remained within the therapeutic index.

Conclusion

Through this case report, we aim to bring attention to the possibility of this side effect, as we believe it is important to be aware of it for future patients undergoing treatment with adagrasib.

Nucleic Acid-Based Approaches to Tackle KRAS Mutant Cancers

Activating mutations in KRAS are highly relevant to various cancers, driving persistent efforts toward the development of drugs that can effectively inhibit KRAS activity. Previously, KRAS was considered 'undruggable'; however, the recent advances in our understanding of RNA and nucleic acid chemistry and delivery formulations have sparked a paradigm shift in the approach to KRAS inhibition. We are currently witnessing a large wave of next-generation drugs for KRAS mutant cancers-nucleic acid-based therapeutics. In this review, we discuss the current progress in targeting KRAS mutant tumors and outline significant developments in nucleic acid-based strategies. We delve into their mechanisms of action, address existing challenges, and offer insights into the current clinical trial status of these approaches. We aim to provide a thorough understanding of the potential of nucleic acid-based strategies in the field of KRAS mutant cancer therapeutics.

Targeted Therapies for Kirsten Rat Sarcoma (KRAS) G12C Mutant Metastatic Non-Small-Cell Lung Cancers

Non-small-cell lung cancer (NSCLC) is a prevalent and often fatal malignancy. Advancements in targeted therapies have improved outcomes for NSCLC patients in the last decade. Kirsten rat sarcoma virus (KRAS) is a commonly mutated oncogene in NSCLC, contributing to tumorigenesis and proliferation. Though classically difficult to target, recently developed KRAS G12C inhibitors (sotorasib and adagrasib) have now overcome this therapeutic hurdle. We discuss the evidence for these medications, their pitfalls and adverse effects, as well as future directions in this space. Though these medications demonstrate substantial response rates in a heavily pre-treated advanced NSCLC cohort, as phase-3 evidence does not yet demonstrate an overall survival benefit versus standard-of-care chemotherapy, docetaxel. Additionally, these medications appear to have a negative interaction in combination with immunotherapies, with substantially greater hepatotoxicity rates observed. Despite this, it is undeniable that these medications represent an important advancement in targeted and personalised oncological treatment. Current and future trials assessing these medications in combination and through sequencing strategies will likely yield further clinically meaningful outcomes to guide treatment in this patient cohort.

The current landscape of using direct inhibitors to target KRASG12C-mutated NSCLC

Mutation in KRAS protooncogene represents one of the most common genetic alterations in NSCLC and has posed a great therapeutic challenge over the past ~ 40 years since its discovery. However, the pioneer work from Shokat's lab in 2013 has led to a recent wave of direct KRASG12C inhibitors that utilize the switch II pocket identified. Notably, two of the inhibitors have recently received US FDA approval for their use in the treatment of KRASG12C mutant NSCLC. Despite this success, there remains the challenge of combating the resistance that cell lines, xenografts, and patients have exhibited while treated with KRASG12C inhibitors. This review discusses the varying mechanisms of resistance that limit long-lasting effective treatment of those direct inhibitors and highlights several novel therapeutic approaches including a new class of KRASG12C (ON) inhibitors, combinational therapies across the same and different pathways, and combination with immunotherapy/chemotherapy as possible solutions to the pressing question of adaptive resistance.

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.

Efficacy and toxicity of drugs targeting KRASG12C mutation in non-small cell lung cancer: a meta-analysis

OBJECTIVE

To systematically analyze the efficacy and toxicity of drugs targeting KRASG12C mutation in non-small cell lung cancer (NSCLC).

METHODS

The candidate studies were identified in PubMed, Embase, Cochrane Library, CNKI, and Wanfang databases up to 1 June 2023. Data on efficacy, prognosis, and adverse events (AEs) were extracted and calculated by meta-analysis.

RESULTS

Six eligible prospective studies were included in this meta-analysis, including 563 patients with advanced or metastatic NSCLC. For patients with NSCLC, the objective response rate (ORR) of drugs targeting KRASG12C mutation was 37% (95%CI 31-43), median duration of response (DOR) was 8.89 months (95%CI 7.96-9.83), and median progression-free survival (PFS) was 6.40 months (95%CI 5.86-6.93). The overall incidence of AEs was 88% (95%CI 79-96) and the incidence of grade ≥3 AEs was 44% (95%CI 24-64). The most common AEs were diarrhea, nausea, fatigue, and vomiting. The most common grade ≥3 AEs were Alaninetransaminase (ALT) or Aspartatetransaminase (AST) increased and diarrhea.

CONCLUSION

Sotorasib, Adagrasib, and Garsorasib as the drugs of choice for patients with KRASG12C mutation NSCLC, have definite efficacy and acceptable safety, especially for patients with advanced or metastatic disease and within posterior line therapy.