Differential Outcomes in Codon 12/13 and Codon 61 NRAS-Mutated Cancers in the Phase II NCI-MATCH Trial of Binimetinib in Patients with NRAS-Mutated Tumors

Novel Histologic Features in Ameloblastoma With RASQ61R Mutation

Ameloblastoma is characterized histologically by evidence of ameloblastic differentiation and molecularly by MAPK pathway alterations, most frequently BRAFV600E mutation and RAS mutations, as well as by SMO mutations. This mutational profile is present across all histologic variants, including those occasionally lacking overt histologic evidence of ameloblastic differentiation, such as desmoplastic ameloblastoma and granular cell ameloblastoma. Recently, we have come across 4 cases of maxillary ameloblastoma demonstrating peculiar histologic features not accounted for by recognized histologic variants. Three intraosseous tumors were remarkably similar in histologic appearance and demonstrated a proliferation of spindled to basaloid cells in solid/sheet-like, cystic, and ribbon-like growth patterns within dense fibrous connective tissue. One case had numerous squamous morules and only 1 case, focally, demonstrated ameloblastic differentiation, yet all 3 cases harbored NRASQ61R mutation. A fourth case harbored HRASQ61R mutation and arose peripherally, in palatal (maxillary) gingiva, as a follicular-patterned neoplasm with bland squamoid morphology and scattered foci of ameloblastic differentiation. RAS Q61R immunohistochemistry was positive in both the tumor and overlying surface epithelium, in support of surface derivation. These 4 cases demonstrate that ameloblastoma may occasionally present with non-traditional histologic features, lacking categorization into known histologic variants and sometimes lacking any evidence of ameloblastic differentiation. In this setting, the differential diagnosis may be broad and include more indolent odontogenic neoplasms such as adenomatoid odontogenic tumor or squamous odontogenic tumor, odontogenic carcinomas, and non-odontogenic neoplasms. A high index of suspicion, followed by confirmatory molecular testing or mutation-specific immunohistochemistry, is necessary for accurate diagnosis.

Trends in Research of Odontogenic Keratocyst and Ameloblastoma

Odontogenic keratocyst (OKC) and ameloblastoma (AM) are common jaw lesions with high bone-destructive potential and recurrence rates. Recent advancements in technology led to significant progress in understanding these conditions. Single-cell and spatial omics have improved insights into the tumor microenvironment and cellular heterogeneity in OKC and AM. Fibroblast subsets in OKC and tumor cell subsets in AM have been analyzed, revealing mechanisms behind their biological behaviors, including OKC's osteolytic features and AM's recurrence tendencies. Spatial transcriptomics studies of AM have identified engineered fibroblasts and osteoblasts contributing to matrix remodeling gene and oncogene expression at the invasion frontier, driving AM progression. Three-dimensional culture technologies such as organoid models have refined analysis of AM subtypes; uncovered the role of AM fibroblasts in promoting tumor cell proliferation and invasion; and identified signaling pathways such as FOSL1, BRD4, EZH2, and Wnt as potential therapeutic targets. Organoid models also served as preclinical platforms for testing potential therapies. Although preclinical models for AM exist, reliable in vitro and in vivo models for OKC remain scarce. Promising mimic models, including human embryonic stem cells-derived epithelial cells, human oral keratinocytes, human immortalized oral epithelial cells, and HaCaT keratinocytes, show promise, but the advancements in 3-dimensional culture technology are expected to lead to further breakthroughs in this area. Artificial intelligence, including machine learning and deep learning, has enhanced radiomics-based diagnostic accuracy, distinguishing OKC and AM beyond clinician capability. Pathomics-based models further predict OKC prognosis and differentiate AM from ameloblastic carcinoma. Clinical studies have shown positive outcomes with targeted therapies. In a study investigating SMO-targeted treatments for nevoid basal cell carcinoma syndrome, nearly all OKC lesions resolved in 3 patients. A recent clinical trial with neoadjuvant BRAF-targeted therapy for AM demonstrated promising radiologic responses, potentially enabling organ preservation. This review highlights recent advancements and trends in OKC and AM research, aiming to inspire further exploration and progress in these fields.

From pathogenesis to precision medicine: Transformative advances in research and treatment of ameloblastoma

Odontogenic neoplasms of the jaw are dominated by ameloblastoma (AM), a locally aggressive epithelial tumor with a significant propensity for recurrence. The World Health Organization's 2022 update to the AM classification system underscores recent progress in comprehending its underlying mechanisms and refining clinical approaches. Contemporary research has yielded significant insights into the genetic underpinnings of AM, paving the way for the development of precision-based treatment strategies. Advanced genetic profiling has revealed a significant frequency of BRAF (V-raf murine sarcoma viral oncogene homolog) V600E and SMO (Smoothened) gene alterations in AM. Importantly, therapeutic interventions specifically designed to target these genetic aberrations, including BRAF and MEK pathway blockers, have shown encouraging results in terms of both effectiveness and tolerability, as documented in individual case reports and small-scale clinical investigations. This comprehensive review summarizes the recent modifications to the World Health Organization's categorization of AMs, explores progress in elucidating their underlying molecular pathways, and evaluates emerging targeted treatment modalities. Our objective is to present a thorough synthesis of contemporary scientific discoveries and therapeutic interventions, potentially paving the way for more efficacious and individualized clinical management protocols for this complex neoplasm.

Mediating kinase activity in Ras-mutant cancer: potential for an individualised approach?

It is widely acknowledged that there is a considerable number of oncogenic mutations within the Ras superfamily of small GTPases which are the driving force behind a multitude of cancers. Ras proteins mediate a plethora of kinase pathways, including the MAPK, PI3K, and Ral pathways. Since Ras was considered undruggable until recently, pharmacological targeting of pathways downstream of Ras has been attempted to varying success, though drug resistance has often proven an issue. Nuances between kinase pathway activation in the presence of various Ras mutants are thought to contribute to the resistance, however, the reasoning behind activation of different pathways in different Ras mutational contexts is yet to be fully elucidated. Indeed, such disparities often depend on cancer type and disease progression. However, we are in a revolutionary age of Ras mutant targeted therapy, with direct-targeting KRAS-G12C inhibitors revolutionising the field and achieving FDA-approval in recent years. However, these are only beneficial in a subset of patients. Approximately 90% of Ras-mutant cancers are not KRAS-G12C mutant, and therefore raises the question as to whether other distinct amino acid substitutions within Ras may one day be targetable in a similar manner, and indeed whether better understanding of the downstream pathways these various mutants activate could further improve therapy. Here, we discuss the favouring of kinase pathways across an array of Ras-mutant oncogenic contexts and assess recent advances in pharmacological targeting of various Ras mutants. Ultimately, we will examine the utility of individualised pharmacological approaches to Ras-mediated cancer.

Anti-MAPK Targeted Therapy for Ameloblastoma: Case Report with a Systematic Review

Ameloblastoma, a benign yet aggressive odontogenic tumor known for its recurrence and the severe morbidity from radical surgeries, may benefit from advancements in targeted therapy. We present a case of a 15-year-old girl with ameloblastoma successfully treated with targeted therapy and review the literature with this question: Is anti-MAPK targeted therapy safe and effective for treating ameloblastoma? This systematic review was registered in PROSPERO, adhered to PRISMA guidelines, and searched multiple databases up to December 2023, identifying 13 relevant studies out of 647 records, covering 23 patients treated with MAPK inhibitor therapies. The results were promising as nearly all patients showed a positive treatment response, with four achieving complete radiological remission and others showing substantial reductions in primary, recurrent, and metastatic ameloblastoma sizes. Side effects were mostly mild to moderate. This study presents anti-MAPK therapy as a significant shift from invasive surgical treatments, potentially enhancing life quality and clinical outcomes by offering a less invasive yet effective treatment alternative. This approach could signify a breakthrough in managing this challenging tumor, emphasizing the need for further research into molecular-targeted therapies.

MEK Inhibition for RASopathy-Associated Hypertrophic Cardiomyopathy: Clinical Application of a Basic Concept

The term "RASopathies" designates a group of developmental syndromes that are caused by activating variants of the rat sarcoma virus protein (RAS)/mitogen-activated protein kinase (MAPK) cascade. The most prevalent clinical diagnosis is Noonan syndrome, and other, less prevalent conditions include Noonan syndrome with multiple lentigines, Costello syndrome, cardiofaciocutaneous syndrome, and others. Hypertrophic cardiomyopathy occurs in 10% of these patients and can be severe and life-threating. Recently, repurposing of medications inhibiting the RAS/MAPK on a compassionate use basis has emerged as a promising concept to improve the outcome of these patients. Herein, we specifically review the role of the RAS/MAPK pathway in RASopathy-associated cardiomyopathy, and discuss the role of small-molecule inhibition in the treatment of this condition. We describe how drug repurposing of trametinib (mitogen-activated protein/extracellular signal-regulated kinase inhibition) and sirolimus/everolimus (mammalian target of rapamycin inhibition) was performed, how genotype-specific therapies are chosen and followed, as well as initial outcomes from early case series. Finally, we lay out the challenges and opportunities for trials that aim to quantify the benefits of this approach.

Molecular pathogenesis of ameloblastoma

Ameloblastoma (AM) is a benign, although aggressive, epithelial odontogenic tumour originating from tooth-forming tissues or remnants. Its aetiopathogenesis remains unclear; however, molecular analysis techniques have allowed researchers to progress in understanding its genetic basis. The high frequency of BRAF p.V600E as a main driver mutation in AM is well established; nevertheless, it is insufficient to explain its tumourigenesis. In this review, we aimed to integrate the current knowledge about the biology of AM and to describe the main genetic alterations reported, focusing on the findings of large-scale sequencing and gene expression profiling techniques. Current evidence shows that besides BRAF mutation and activation of the MAPK pathway, alterations in Hedgehog and Wnt/β-catenin pathway-related genes are also involved in AM pathogenesis. Recently, a tumour suppressor gene, KMT2D, has been reported as mutated by different research groups. The biological impact of these mutations in the pathogenesis of AM has yet to be elucidated. Further studies are needed to clarify the impact of these findings in the identification of novel biomarkers that could be useful for diagnosing, classifying, and molecular targeting this neoplasm.

Tumor-Specific Activity of Precision Medicines in the NCI-MATCH Trial

PURPOSE

National Cancer Institute Molecular Analysis for Therapy Choice (NCI-MATCH) is a precision medicine basket trial designed to test the effectiveness of treating cancers based on specific genetic changes in patients' tumors, regardless of cancer type. Multiple subprotocols have each tested different targeted therapies matched to specific genetic aberrations. Most subprotocols exhibited low rates of tumor shrinkage as evaluated across all tumor types enrolled. We hypothesized that these results may arise because these precision cancer therapies have tumor type-specific efficacy, as is common among other cancer therapies.

EXPERIMENTAL DESIGN

To test the hypothesis that certain tumor types are more sensitive to specific therapies than other tumor types, we applied permutation testing to tumor volume change and progression-free survival data from 10 published NCI-MATCH subprotocols (together n = 435 patients). FDR was controlled by the Benjamini-Hochberg procedure.

RESULTS

Six of ten subprotocols exhibited statistically significant evidence of tumor-specific drug sensitivity, four of which were previously considered negative based on response rate across all tumors. This signal-finding analysis highlights potential uses of FGFR tyrosine kinase inhibition in urothelial carcinomas with actionable FGFR aberrations and MEK inhibition in lung cancers with BRAF non-V600E mutations. In addition, it identifies low-grade serious ovarian carcinoma with BRAF v600E mutation as especially sensitive to BRAF and MEK co-inhibition (dabrafenib plus trametinib), a treatment that received accelerated FDA approval for advanced solid tumors with BRAF v600E mutation.

CONCLUSIONS

These findings support the value of basket trials because even when precision medicines do not have tumor-agnostic activity, basket trials can identify tumor-specific activity for future study.

Home-run trials for rare cancers: giving the right drug(s) to the right patients at the right time and in the right place

In oncology clinical trials, many patients spend their final months at a central clinical trial facility far from home for "mandatory" protocol visits/diagnostic testing. Studies suggest that the travel strain may be greatest among patients living in low-income areas and/or participating in early-phase studies. In this regard, rare cancers constitute a special unmet need with limited therapeutic options and few trials. Though individually uncommon, rare cancers as a group constitute ~22% of the cancer burden; the portion of cancer burden may even be greater if biomarker-defined rare subsets of either a single cancer type or a tissue-agnostic subgroup are included. Exacerbating the access issue is the fact that, in addition to the paucity of trials, many centers will not activate existing single-arm trials, often due to accrual concerns, which may further disadvantage this patient group and also jeopardize trial completion. Decentralized clinical trials may resolve some of these challenges by allowing patients to participate from close to home. Decentralized clinical trials can take the form of being site-less, with the coordinating body working remotely and care provided by the home oncologist, or by taking the tack of National Cancer Institute/cooperative groups (e.g., NCI-MATCH genomics matching trial or SWOG1609 [NCI] DART immunotherapy rare cancer trial) using a platform design with multiple cohorts and opening at >1000 sites. Decentralized trials now also have supportive FDA guidance. Importantly, home-run trials permit clinical trial access to underserved groups, including those in rural areas and patients financially unable to travel to a central facility.

Treatment options for advanced ameloblastoma in the era of precision medicine: A brief review

Although complete excision is the standard of care for ameloblastoma, a subset of recurrent and/or metastasizing ameloblastomas are difficult to treat surgically. Over the past decade, several recurrent mutations in the mitogen-activated protein kinase pathway genes have been identified in ameloblastoma, based on which the efficacy of targeted therapy has been investigated. However, most of the literature has focused on BRAF V600E mutations, the most common oncogenic mutations in ameloblastoma. Hence, this study aims to review the current knowledge of targetable genetic alterations in ameloblastoma from a broader perspective. In addition, the therapeutic potential of immunotherapy for ameloblastoma will be briefly discussed in the context of tumoral PD-L1 expression and the tumor immune microenvironment.

The NCI-MATCH trial: lessons for precision oncology

The NCI-MATCH (Molecular Analysis for Therapy Choice) trial ( NCT02465060 ) was launched in 2015 as a genomically driven, signal-seeking precision medicine platform trial-largely for patients with treatment-refractory, malignant solid tumors. Having completed in 2023, it remains one of the largest tumor-agnostic, precision oncology trials undertaken to date. Nearly 6,000 patients underwent screening and molecular testing, with a total of 1,593 patients (inclusive of continued accrual from standard next-generation sequencing) being assigned to one of 38 substudies. Each substudy was a phase 2 trial of a therapy matched to a genomic alteration, with a primary endpoint of objective tumor response by RECIST criteria. In this Perspective, we summarize the outcomes of the initial 27 substudies in NCI-MATCH, which met its signal-seeking objective with 7/27 positive substudies (25.9%). We discuss key aspects of the design and operational conduct of the trial, highlighting important lessons for future precision medicine studies.

National Cancer Institute Combination Therapy Platform Trial with Molecular Analysis for Therapy Choice (ComboMATCH)

Over the past decade, multiple trials, including the precision medicine trial National Cancer Institute-Molecular Analysis for Therapy Choice (NCI-MATCH, EAY131, NCT02465060) have sought to determine if treating cancer based on specific genomic alterations is effective, irrespective of the cancer histology. Although many therapies are now approved for the treatment of cancers harboring specific genomic alterations, most patients do not respond to therapies targeting a single alteration. Further, when antitumor responses do occur, they are often not durable due to the development of drug resistance. Therefore, there is a great need to identify rational combination therapies that may be more effective. To address this need, the NCI and National Clinical Trials Network have developed NCI-ComboMATCH, the successor to NCI-MATCH. Like the original trial, NCI-ComboMATCH is a signal-seeking study. The goal of ComboMATCH is to overcome drug resistance to single-agent therapy and/or utilize novel synergies to increase efficacy by developing genomically-directed combination therapies, supported by strong preclinical in vivo evidence. Although NCI-MATCH was mainly comprised of multiple single-arm studies, NCI-ComboMATCH tests combination therapy, evaluating both combination of targeted agents as well as combinations of targeted therapy with chemotherapy. Although NCI-MATCH was histology agnostic with selected tumor exclusions, ComboMATCH has histology-specific and histology-agnostic arms. Although NCI-MATCH consisted of single-arm studies, ComboMATCH utilizes single-arm as well as randomized designs. NCI-MATCH had a separate, parallel Pediatric MATCH trial, whereas ComboMATCH will include children within the same trial. We present rationale, scientific principles, study design, and logistics supporting the ComboMATCH study.

KRAS mutated colorectal cancers with or without PIK3CA mutations: Clinical and molecular profiles inform current and future therapeutics

BACKGROUND

Colorectal cancer is one of the most prevalent malignancies and its molecular pathogenesis has been intensely investigated for several decades. As a result, great progress has been made and targeted therapies have been introduced in the clinic. This paper examines colorectal cancers based on two of the most common molecular alterations, KRAS and PIK3CA mutations as a basis for therapeutic targeting.

METHODS

Two publicly available genomic series with clinical data were evaluated for prevalence and characteristics of cases with and without KRAS and PIK3CA mutations and the literature was reviewed for relevant information on the therapeutic implication of these alterations as well as other coincident alterations to derive therapeutic individualized options of targeted treatments.

RESULTS

Colorectal cancers without KRAS and PIK3CA mutations represent the most prevalent group (48% to 58% of patients) and present therapeutic targeted opportunities with BRAF inhibitors and immune checkpoint inhibitors in the subsets with BRAF mutations (15% to 22%) and Microsatellite Instability (MSI, 14% to 16%), respectively. The second most prevalent sub-set, with KRAS mutations and PIK3CA wild type, representing 20% to 25% of patients, has currently few targeted options, besides specific KRAS G12C inhibitors for the small percentage of cases (9%-10%) that bear this mutation. Cancers with KRAS wild type and PIK3CA mutations are observed in 12% to 14% of colorectal cancer patients, harbor the highest percentage of cases with BRAF mutations and Microsatellite Instability (MSI), and are candidates for the respective targeted therapies. New targeted therapies in development, such as ATR inhibitors could be effective in cases with ATM mutations and ARID1A mutations that are also most prevalent in this sub-group (14% to 22% and 30%, respectively). KRAS and PIK3CA double mutant cancers have also few targeted options currently and could benefit from combination therapies with PI3K inhibitors and new KRAS inhibitors in development.

CONCLUSION

The backbone of common KRAS and PIK3CA mutations is a rational frame for development of therapeutic algorithms in colorectal cancer and can help guide new drug therapies development. In addition, the prevalence of different molecular groups presented here may help with planning of combination clinical trials by providing estimations of sub-sets with more than one alteration.

Association between homologous recombination gene variants and efficacy of oxaliplatin-based chemotherapy in advanced pancreatic cancer: prospective multicenter observational study

Next-generation sequencing (NGS)-based gene profiling can identify patients with pancreatic cancer with homologous recombinant repair gene pathogenic variants (HRRv). Several retrospective studies have reported a positive association between HRRv and the efficacy of platinum-based chemotherapy. However, this association remains to be validated in a prospective study. This multicenter, prospective, observational study included patients with histologically confirmed unresectable or recurrent pancreatic cancer who required systemic chemotherapy. Patients who were oxaliplatin-naïve patients were eligible. The HRRv status was measured using a College of American Pathologists-accredited NGS panel. One-year overall survival rate (1yr-OS%) was calculated after initiation of oxaliplatin-based chemotherapy and was set as the primary endpoint. Forty patients were enrolled between August 2018 and March 2020. The NGS success rate was 95% (38/40). HRRv was detected in 11 patients (27.5%). Oxaliplatin-based chemotherapy was administered to 9 of 11 patients with HRRv (81.8%) and 15 of 29 patients with non-HRRv (51.7%). The 1yr-OS% after initiation of oxaliplatin-based chemotherapy was 44.4% [95% confidence interval (CI) 13.7-71.9] and 57.1% (95% CI 28.4-78.0) in HRRv-positive and -negative cohorts, respectively. These data suggested that HRRv status alone could not be a potential predictive marker of oxaliplatin-based chemotherapy in patients with advanced pancreatic cancer. These results were in line with the results of a recent phase II study reporting the limited efficacy of poly(adenosine diphosphate-ribose) polymerase inhibitor in patients with pancreatic cancer who harbored HRRv other than BRCA. Future studies investigating patients with biallelic HRRv in the first-line setting are warranted.Trial registration UMIN000033655.

Genomic profiling and precision medicine in complex ameloblastoma

BACKGROUND

Ameloblastoma may present a significant treatment challenge in the locally advanced, recurrent and metastatic setting. Comprehensive genomic profiling (CGP) can identify targetable genomic alterations to aid in treatment.

METHODS

Ameloblastoma samples were sequenced using hybrid-capture based sequencing. A systematic literature review was performed to examine outcomes in studies employing targeted treatment in ameloblastoma.

RESULTS

We reviewed 14 cases of Ameloblastoma using CGP. There were six patients with activating BRAF mutations, five with PIK3CA, five with SMO, four with FGFR2, one with EGFR, and one with ROS1. All cases were MSI stable and the median TMB was 2.5 mutations/Mb. A separate literature review of clinical outcomes in ameloblastoma showed a predominance of at least partial response to targeted treatment (7/12 cases).

CONCLUSION

CGP is helpful in identifying specific driver mutations in patients with complex ameloblastoma. Targeted treatment has been employed with success in achieving treatment response.

Tumor-specific activity of precision medicines in the NCI-MATCH trial

Background

NCI-MATCH is a precision medicine basket trial designed to test the effectiveness of treating cancers based on specific genetic changes in patients' tumors, regardless of cancer type. Multiple subprotocols have each tested different targeted therapies matched to specific genetic aberrations. Most subprotocols exhibited low rates of tumor shrinkage as evaluated across all tumor types enrolled. We hypothesized that these results may arise because these precision cancer therapies have tumor type-specific efficacy, as is common among other cancer therapies.

Methods

To test the hypothesis that certain tumor types are more sensitive to specific therapies than other tumor types, we applied permutation testing to tumor volume change and progression-free survival data from ten published NCI-MATCH subprotocols (together n=435 patients). False discovery rate was controlled by the Benjamini-Hochberg procedure.

Results

Six of ten subprotocols exhibited statistically significant evidence of tumor-specific drug sensitivity, four of which were previously considered negative based on response rate across all tumors. This signal-finding analysis highlights potential uses of FGFR tyrosine kinase inhibition in urothelial carcinomas with actionable FGFR aberrations, MEK inhibition in lung cancers with BRAF non-V600E mutations, and MEK inhibition in cholangiocarcinomas with NRAS mutations.

Conclusions

These findings support the value of basket trials because even when precision medicines do not have tumor-agnostic activity, basket trials can identify tumor-specific activity for future study.

Precision Oncology: Evolving Clinical Trials across Tumor Types

Advances in molecular technologies and targeted therapeutics have accelerated the implementation of precision oncology, resulting in improved clinical outcomes in selected patients. The use of next-generation sequencing and assessments of immune and other biomarkers helps optimize patient treatment selection. In this review, selected precision oncology trials including the IMPACT, SHIVA, IMPACT2, NCI-MPACT, TAPUR, DRUP, and NCI-MATCH studies are summarized, and their challenges and opportunities are discussed. Brief summaries of the new ComboMATCH, MyeloMATCH, and iMATCH studies, which follow the example of NCI-MATCH, are also included. Despite the progress made, precision oncology is inaccessible to many patients with cancer. Some patients' tumors may not respond to these treatments, owing to the complexity of carcinogenesis, the use of ineffective therapies, or unknown mechanisms of tumor resistance to treatment. The implementation of artificial intelligence, machine learning, and bioinformatic analyses of complex multi-omic data may improve the accuracy of tumor characterization, and if used strategically with caution, may accelerate the implementation of precision medicine. Clinical trials in precision oncology continue to evolve, improving outcomes and expediting the identification of curative strategies for patients with cancer. Despite the existing challenges, significant progress has been made in the past twenty years, demonstrating the benefit of precision oncology in many patients with advanced cancer.

BRAF and MEK Inhibitors and Their Toxicities: A Meta-Analysis

PURPOSE

This meta-analysis summarizes the incidence of treatment-related adverse events (AE) of BRAFi and MEKi.

METHODS

A systematic search of Medline/PubMed was conducted to identify suitable articles published in English up to 31 December 2021. The primary outcomes were profiles for all-grade and grade 3 or higher treatment-related AEs, and the analysis of single side effects belonging to both categories.

RESULTS

The overall incidence of treatment-related all-grade Aes was 99% for Encorafenib (95% CI: 0.97-1.00) and 97% for Trametinib (95% CI: 0.92-0.99; I² = 66%) and Binimetinib (95% CI: 0.94-0.99; I² = 0%). In combined therapies, the rate was 98% for both Vemurafenib + Cobimetinib (95% CI: 0.96-0.99; I² = 77%) and Encorafenib + Binimetinib (95% CI: 0.96-1.00). Grade 3 or higher adverse events were reported in 69% of cases for Binimetinib (95% CI: 0.50-0.84; I² = 71%), 68% for Encorafenib (95% CI: 0.61-0.74), and 72% for Vemurafenib + Cobimetinib (95% CI: 0.65-0.79; I² = 84%). The most common grade 1-2 AEs were pyrexia (43%) and fatigue (28%) for Dabrafenib + Trametinib and diarrhea for both Vemurafenib + Cobimetinib (52%) and Encorafenib + Binimetinib (34%). The most common AEs of grade 3 or higher were pyrexia, rash, and hypertension for Dabrafenib + Trametinib (6%), rash and hypertension for Encorafenib + Binimetinib (6%), and increased AST and ALT for Vemurafenib + Cobimetinib (10%).

CONCLUSIONS

Our study provides comprehensive data on treatment-related adverse events of BRAFi and MEKi combination therapies, showing related toxicity profiles to offer a helpful tool for clinicians in the choice of therapy.

New prospectives on treatment opportunities in RASopathies

The RASopathies are a group of clinically defined developmental syndromes caused by germline variants of the RAS/mitogen-activated protein (MAPK) cascade. The prototypic RASopathy is Noonan syndrome, which has phenotypic overlap with related disorders such as cardiofaciocutaneous syndrome, Costello syndrome, Noonan syndrome with multiple lentigines, and others. In this state-of-the-art review, we summarize current knowledge on unmet therapeutic needs in these diseases and novel treatment approaches informed by insights from RAS/MAPK-associated cancer therapies, in particular through inhibition of MEK1/2 and mTOR in patients with severe disease manifestations. We explore the possibilities of integrating a larger arsenal of molecules currently under development into future care plans. Lastly, we describe both medical and ethical challenges and opportunities for future clinical trials in the field.

Secondary IDH1 resistance mutations and oncogenic IDH2 mutations cause acquired resistance to ivosidenib in cholangiocarcinoma

The mutant IDH1 inhibitor ivosidenib improves outcomes for patients with IDH1-mutated cholangiocarcinoma, but resistance inevitably develops. Mechanisms of resistance and strategies to overcome resistance are poorly understood. Here we describe two patients with IDH1 R132C-mutated metastatic cholangiocarcinoma who developed acquired resistance to ivosidenib. After disease progression, one patient developed an oncogenic IDH2 mutation, and the second patient acquired a secondary IDH1 D279N mutation. To characterize the putative IDH1 resistance mutation, cells expressing the double-mutant were generated. In vitro, IDH1 R132H/D279N produces (R)-2HG less efficiently than IDH1 R132H. However, its binding to ivosidenib is impaired and it retains the ability to produce (R)-2HG and promote cellular transformation in the presence of ivosidenib. The irreversible mutant IDH1 inhibitor LY3410738 binds and blocks (R)-2HG production and cellular transformation by IDH1 R132H/D279N. These resistance mechanisms suggest that IDH1-mutated cholangiocarcinomas remain dependent on (R)-2HG even after prolonged ivosidenib treatment. Sequential mutant IDH inhibitor therapy should be explored as a strategy to overcome acquired resistance to mutant IDH inhibitors.

Genomic and transcriptomic determinants of response to neoadjuvant therapy in rectal cancer

The incidence of rectal cancer is increasing in patients younger than 50 years. Locally advanced rectal cancer is still treated with neoadjuvant radiation, chemotherapy and surgery, but recent evidence suggests that patients with a complete response can avoid surgery permanently. To define correlates of response to neoadjuvant therapy, we analyzed genomic and transcriptomic profiles of 738 untreated rectal cancers. APC mutations were less frequent in the lower than in the middle and upper rectum, which could explain the more aggressive behavior of distal tumors. No somatic alterations had significant associations with response to neoadjuvant therapy in a treatment-agnostic manner, but KRAS mutations were associated with faster relapse in patients treated with neoadjuvant chemoradiation followed by consolidative chemotherapy. Overexpression of IGF2 and L1CAM was associated with decreased response to neoadjuvant therapy. RNA-sequencing estimates of immune infiltration identified a subset of microsatellite-stable immune hot tumors with increased response and prolonged disease-free survival.

Somatic Genomic Testing in Patients With Metastatic or Advanced Cancer: ASCO Provisional Clinical Opinion

PURPOSE

An ASCO provisional clinical opinion offers timely clinical direction to ASCO's membership following publication or presentation of potentially practice-changing data from major studies. This provisional clinical opinion addresses the appropriate use of tumor genomic testing in patients with metastatic or advanced solid tumors.

CLINICAL CONTEXT

An increasing number of therapies are approved to treat cancers harboring specific genomic biomarkers. However, there is a lack of clarity as to when tumor genomic sequencing should be ordered, what type of assays should be performed, and how to interpret the results for treatment selection.

PROVISIONAL CLINICAL OPINION

Patients with metastatic or advanced cancer should undergo genomic sequencing in a certified laboratory if the presence of one or more specific genomic alterations has regulatory approval as biomarkers to guide the use of or exclusion from certain treatments for their disease. Multigene panel-based assays should be used if more than one biomarker-linked therapy is approved for the patient's disease. Site-agnostic approvals for any cancer with a high tumor mutation burden, mismatch repair deficiency, or neurotrophic tyrosine receptor kinase (NTRK) fusions provide a rationale for genomic testing for all solid tumors. Multigene testing may also assist in treatment selection by identifying additional targets when there are few or no genotype-based therapy approvals for the patient's disease. For treatment planning, the clinician should consider the functional impact of the targeted alteration and expected efficacy of genomic biomarker-linked options relative to other approved or investigational treatments.Additional information is available at www.asco.org/assays-and-predictive-markers-guidelines.

A state-of-the-art review of stratified medicine in cancer: towards a future precision medicine strategy in cancer

BACKGROUND

Building on the success of targeted therapy in certain well-defined cancer genotypes, three platform studies-NCI-MATCH, LUNG-MAP and The National Lung Matrix Trial (NLMT)-have attempted to discover new genotype-matched therapies for people with cancer.

PATIENTS AND METHODS

We review the outputs from these platform studies. This review led us to propose a series of recommendations and considerations that we hope will inform future precision medicine programmes in cancer.

RESULTS

The three studies collectively screened over 13 000 patients. Across 37 genotype-matched cohorts, there have been 66/875 responders, with an overall response rate of 7.5%. Targeting copy number gain yielded 5/199 responses across nine biomarker-drug matched cohorts, with a response rate of 2.5%.

CONCLUSIONS

The majority of these studies used single-agent targeted therapies. Whilst preclinical data can suggest rational combination treatment to reverse adaptive resistance or block parallel activated pathways, there is an essential need for accurate modelling of the toxicity-activity trade-off of combinations. Agent selection is often suboptimal; dose expansion should only be carried out with agents with clear clinical proof of mechanism and high target selectivity. Targeting copy number change has been disappointing; it is crucial to define the drivers on shared amplicons that include the targeted aberration. Maximising outcomes with currently available targeted therapies requires moving towards a more contextualised stratified medicine acknowledging the criticality of the genomic, transcriptional and immunological context on which the targeted aberration is inscribed. Genomic complexity and instability is likely to be a leading cause of targeted therapy failure in genomically complex cancers. Preclinical models must be developed that more accurately capture the genomic complexity of human disease. The degree of attrition of studies carried out after standard-of-care therapy suggests that serious efforts be made to develop a suite of precision medicine studies in the minimal residual disease setting.