Response and acquired resistance to savolitinib in a patient with pulmonary sarcomatoid carcinoma harboring MET exon 14 skipping mutation: a case report

Predicting MET exon 14 skipping mutation in pulmonary sarcomatoid carcinoma by whole-tumour texture analysis combined with clinical and conventional contrast-enhanced computed tomography features

Background

Pulmonary sarcomatoid carcinoma (PSC) is a rare, highly malignant type of non-small cell lung cancer (NSCLC) with a poor prognosis. Targeted drugs for MET exon 14 (METex14) skipping mutation can have considerable clinical benefits. This study aimed to predict METex14 skipping mutation in PSC patients by whole-tumour texture analysis combined with clinical and conventional contrast-enhanced computed tomography (CECT) features.

Methods

This retrospective study included 56 patients with PSC diagnosed by pathology. All patients underwent CECT before surgery or other treatment, and both targeted DNA- and RNA-based next-generation sequencing (NGS) were used to detect METex14 skipping mutation status. The patients were divided into two groups: METex14 skipping mutation and nonmutation groups. Overall, 1,316 texture features of the whole tumour were extracted. We also collected 12 clinical and 20 conventional CECT features. After dimensionality reduction and selection, predictive models were established by multivariate logistic regression analysis. Models were evaluated using the area under the curve (AUC), and the clinical utility of the model was assessed by decision curve analysis.

Results

METex14 skipping mutation was detected in 17.9% of PSCs. Mutations were found more frequently in those (I) who had smaller long- or short-axis diameters (P=0.02, P=0.01); (II) who had lower T stages (I, II) (P=0.02); and (III) with pseudocapsular or annular enhancement (P=0.03). The combined model based on the conventional and texture models yielded the best performance in predicting METex14 skipping mutation with the highest AUC (0.89). The conventional and texture models also had good performance (AUC =0.83 conventional; =0.88 texture).

Conclusions

Whole-tumour texture analysis combined with clinical and conventional CECT features may serve as a noninvasive tool to predict the METex14 skipping mutation status in PSC.

Dramatic response and acquired resistance to savolitinib in advanced intrahepatic cholangiocarcinoma with MET amplification: a case report and literature review

Background

Cholangiocarcinoma (CCA) is an aggressive disease with limited treatment options. Despite substantial efforts to explore better regimens, gemcitabine-based chemotherapy has been the standard first-line treatment for decades. With the growing field of precision medicine, biomarker-guided treatments are gaining popularity. MET alteration is a frequent occurrence in various cancer types, making it a promising target.

Case presentation

A 53-year-old man visited our hospital with a complaint of upper abdominal pain. Advanced CCA was diagnosed based on the biopsy of the metastatic lymph nodes and immunohistochemistry. Next-generation sequencing revealed MET amplification. As the patient was intolerant to traditional chemotherapy, savolitinib (a c-MET inhibitor) was administered. Partial response was achieved, and the treatment was well tolerated. After 1 year, the patient developed progressive disease, to which the emergence of epidermal growth factor receptor amplification may have contributed.

Conclusion

Our study verified the therapeutic value of a c-MET inhibitor in advanced CCA-harboring MET amplification and provides an alternative strategy for patients who are intolerant to chemotherapy.

An advanced pulmonary sarcomatoid carcinoma patient harboring a BRAFV600E mutation responds to dabrafenib and trametinib: a case report and literature review

Background

The pulmonary sarcomatoid carcinoma (PSC) is a rare and aggressive subtype of NSCLC with rapid progression and poor prognosis, and is resistant to conventional chemotherapy. Most PSC cases have potential targetable genomic alterations. Approximately 7% of PSC patients have BRAF mutations, and the efficacy of dabrafenib and trametinib in BRAFV600E mutated PSC is unclear.

Case presentation

Our report describes a patient with mutated BRAFV600E PSC who underwent surgery and adjuvant chemotherapy early but quickly relapsed. Both chemotherapy and immunotherapy were ineffective for him, combined dabrafenib and trametinib produced a 6-month progression-free survival, and a partial response was observed in the tumor response evaluation. As a result of financial pressure, he stopped taking the targeted drugs, and his disease rapidly progressed.

Conclusion

Dabrafenib combined with trametinib provides partial remission in patients with advanced PSC with BRAFV600E mutations, and large-scale NGS panels could offer more options for PSC treatment.

Targeted therapy for rare lung cancers: Status, challenges, and prospects

Lung cancer causes the most cancer-related deaths worldwide. In recent years, molecular and immunohistochemical techniques have rapidly developed, further inaugurating an era of personalized medicine for lung cancer. The rare subset of lung cancers accounts for approximately 10%, each displaying distinct clinical characteristics. Treatments for rare lung cancers are mainly based on evidence from common counterparts, which may lead to unsolid clinical benefits considering intertumoral heterogeneity. The increasing knowledge of molecular profiling of rare lung cancers has made targeting genetic alterations and immune checkpoints a powerful strategy. Additionally, cellular therapy has emerged as a promising way to target tumor cells. In this review, we first discuss the current status of targeted therapy and preclinical models for rare lung cancers, as well as provide mutational profiles by integrating the results of existing cohorts. Finally, we point out the challenges and future directions for developing targeted agents for rare lung cancer.

Recent progress in targeted therapy for non-small cell lung cancer

The high morbidity and mortality of non-small cell lung cancer (NSCLC) have always been major threats to people's health. With the identification of carcinogenic drivers in non-small cell lung cancer and the clinical application of targeted drugs, the prognosis of non-small cell lung cancer patients has greatly improved. However, in a large number of non-small cell lung cancer cases, the carcinogenic driver is unknown. Identifying genetic alterations is critical for effective individualized therapy in NSCLC. Moreover, targeted drugs are difficult to apply in the clinic. Cancer drug resistance is an unavoidable obstacle limiting the efficacy and application of targeted drugs. This review describes the mechanisms of targeted-drug resistance and newly identified non-small cell lung cancer targets (e.g., KRAS G12C, NGRs, DDRs, CLIP1-LTK, PELP1, STK11/LKB1, NFE2L2/KEAP1, RICTOR, PTEN, RASGRF1, LINE-1, and SphK1). Research into these mechanisms and targets will drive individualized treatment of non-small cell lung cancer to generate better outcomes.

Circulating tumour DNA biomarkers in savolitinib-treated patients with non-small cell lung cancer harbouring MET exon 14 skipping alterations: a post hoc analysis of a pivotal phase 2 study

Background

Savolitinib, a selective MET inhibitor, showed efficacy in patients with non-small cell lung cancer (NSCLC), including pulmonary sarcomatoid carcinoma (PSC), harbouring MET exon 14 skipping alteration (METex14).

Objective

To analyse post hoc, the association between circulating tumour DNA (ctDNA) biomarkers and clinical outcomes, including resistance, with savolitinib.

Design

A multicentre, single-arm, open-label phase 2 study.

Methods

All enrolled patients with baseline plasma samples were included. Outcomes were objective response rate (ORR), progression-free survival (PFS) and overall survival (OS) by baseline METex14 and post-treatment clearance, coexisting gene alterations at baseline and disease progression.

Results

Among 66 patients with baseline ctDNA sequencing, 46 (70%) had detectable METex14. Frequent coexisting baseline gene alterations included TP53 and POT1 mutations. Patients with detectable baseline METex14 exhibited worse PFS [hazard ratio (HR), 1.77; 95% confidence interval (CI), 0.88-3.57; p = 0.108] and OS (HR, 3.26; 95% CI, 1.35-7.89; p = 0.006) than those without, despite showing a numerically higher ORR. Among 24 patients with baseline detectable METex14 and evaluable postbaseline samples, 13 achieved METex14 clearance post-treatment. Median time to first clearance was 1.3 months (range, 0.7-1.5). METex14 post-treatment clearance was associated with better ORR (92.3%; 95% CI, 64.0-99.8 versus 36.4%; 95% CI, 10.9-69.2; p = 0.0078), PFS (HR, 0.44; 95% CI, 0.2-1.3; p = 0.1225) and OS (HR, 0.31; 95% CI, 0.1-1.0; p = 0.0397) versus non-clearance. Among 22 patients with disease progression, 10 acquired pathway alterations (e.g. in RAS/RAF and PI3K/PTEN) alone or with secondary MET mutations (D1228H/N and Y1230C/H/S).

Conclusion

ctDNA biomarkers may allow for longitudinal monitoring of clinical outcomes with savolitinib in patients with METex14-positive PSC and other NSCLC subtypes. Specifically, undetectable baseline METex14 or post-treatment clearance may predict favourable clinical outcomes, while secondary MET mutations and other acquired gene alterations may explain resistance to savolitinib.

Registration

The trial was registered with ClinicalTrials.gov (NCT02897479) on 13 September 2016.

Multimodality Treatment of Pulmonary Sarcomatoid Carcinoma: A Review of Current State of Art

Pulmonary sarcomatoid carcinoma (PSC) is an unconventional non-small-cell lung cancer (NSCLC) that is currently managed under guidelines used for conventional NSCLC and has poor survival. Surgery is the optimal choice for resectable PSC, and the prevalence of mutations in this type of tumor laid the foundation for novel systemic therapies such as targeted therapy and immunotherapy. PSC is resistant to chemotherapy and radiotherapy, and the effects of the 2 therapies are controversial. Targeted therapies have been reported to confer survival benefits, and savolitinib, an oral selective MET tyrosine-kinase inhibitor, has been approved in metastatic patients with MET exon 14 skipping mutations. Expression and positive rate of programmed death ligand 1 in PSC are high; our previous research has also revealed a high mutational burden and a T-cell-inflamed microenvironment of PSC. Correspondingly, immune checkpoint inhibitors have shown preliminary antitumor effects (overall response rates of 40.5% (15/37) and 31.6% (6/19) in two retrospective studies, respectively) in PSC patients. In summary, patients should receive operations at an early stage and multimodality treatments are needed to maximize the benefits of patients with advanced disease.

The treatment of advanced pulmonary sarcomatoid carcinoma

Pulmonary sarcomatoid carcinoma (PSC) is a pathological subtype of non-small cell lung cancer. Although the incidence of PSC in lung cancer is very low, it is an aggressive cancer, leading to a poor prognosis. Currently, there is no standard treatment for advanced PSC. Targeted therapy can be used for patients with MET exon 14 mutations and patients with other driver gene mutations may also benefit from treatment. The emergence of immune checkpoint inhibitors also provides potential options for advanced PSC treatment, but more clinical data is needed. Additionally, more research may be warranted to explore the effects of chemotherapy, radiotherapy and antiangiogenic therapy. In this review, the authors summarize the research regarding the treatment of advanced PSC.

Therapeutic strategies in METex14 skipping mutated non-small cell lung cancer

METex14 skipping mutations occur in about 3–4% of lung adenocarcinoma patients and 1–2% of patients with other lung cancer histology. The MET receptor tyrosine kinase and its ligand hepatocyte growth factor (HGF) are established oncogenic drivers of NSCLC. A mutation that results in loss of exon 14 in the MET gene leads to dysregulation and inappropriate signaling that is associated with increased responsiveness to MET TKIs. Results from GEOMETRY mono-1 and VISION Phase I/II clinical trials demonstrated significant clinical activity in patients treated with the MET Exon 14 skipping mutation inhibitors capmatinib and tepotinib with tolerable toxicity profile. In the GEOMETRY mono-1 trial, capmatinib was especially active in treatment-naïve patients supporting the upfront testing of this oncogenic driver. Tepotinib demonstrated superior activity in the pretreated patients in the VISION trial. Savolitinib is another MET TKI that has shown efficacy in the first- and second-line settings, including patients with aggressive pulmonary sarcomatoid carcinoma. These studies have demonstrated that these TKIs can cross the blood brain barrier and demonstrated some activity toward CNS metastases. MET Exon 14 skipping mutation is detected by NGS-based testing of liquid or tissue biopsies, with preference for RNA-based NGS. The activity of capmatinib and tepotinib is limited by the development of acquired resistance. Current research is focused on strategies to overcome resistance and improve the effectiveness of these agents. Our aim is to review the current status of MET Exon 14 skipping mutation as it pertains NSCLC.

Once-daily savolitinib in Chinese patients with pulmonary sarcomatoid carcinomas and other non-small-cell lung cancers harbouring MET exon 14 skipping alterations: a multicentre, single-arm, open-label, phase 2 study

BACKGROUND

Savolitinib is a selective MET tyrosine-kinase inhibitor. We investigated the activity and safety of savolitinib in patients with pulmonary sarcomatoid carcinoma and other non-small-cell lung cancer (NSCLC) subtypes positive for MET exon 14 skipping alterations (METex14-positive).

METHODS

We did a multicentre, single-arm, open-label, phase 2 study across 32 hospitals in China. Eligible patients were 18 years or older with locally advanced or metastatic METex14-positive pulmonary sarcomatoid carcinoma or other NSCLC subtypes, had either presented with disease progression or toxicity intolerance towards one or more standard treatments or were deemed clinically unsuitable for standard treatment, were MET inhibitor-naive, and had measurable disease. Patients received either 600 mg (bodyweight ≥50 kg) or 400 mg (bodyweight <50 kg) of oral savolitinib once daily until disease progression, death, intolerable toxicity, initiation of other anti-tumour therapy, non-compliance, patient withdrawal, or patient discontinuation. Radiographic tumour evaluation was done at baseline, every 6 weeks within 1 year of the first dose, and every 12 weeks thereafter. The primary endpoint was objective response rate, defined as the proportion of patients with confirmed complete or partial responses by independent review committee (IRC) assessment. The primary endpoint was assessed in the tumour response evaluable set, which comprised all treated patients with a measurable lesion at baseline and at least one adequate scheduled post-baseline tumour assessment or the presence of radiological disease progression, with a sensitivity analysis done in the full analysis set, which comprised all patients who received at least one dose of savolitinib. Safety was also evaluated in the full analysis set. This study is registered with ClinicalTrials.gov, NCT02897479, and recruitment is complete, with treatment and follow-up ongoing.

FINDINGS

From Nov 8, 2016, to Aug 3, 2020, 84 patients with METex14 skipping alterations were screened for eligibility, of whom 70 were enrolled, received savolitinib, and comprised the full analysis set. The IRC-assessed tumour response evaluable set comprised 61 patients. At a median follow-up of 17·6 months (IQR 14·2-24·4), the IRC-assessed objective response rate was 49·2% (36·1-62·3; 30 of 61 patients) in the tumour response evaluable set and 42·9% (95% CI 31·1-55·3; 30 of 70 patients) in the full analysis set. All 70 patients reported at least one treatment-related adverse event. Treatment-related adverse events of grade 3 or more occurred in 32 (46%) patients, the most frequent of which were increased aspartate aminotransferase (n=9), increased alanine aminotransferase (n=7), and peripheral oedema (n=6). Treatment-related serious adverse events occurred in 17 (24%) patients, the most common being abnormal hepatic function (n=3) and hypersensitivity (n=2). One death due to tumour lysis syndrome in a patient with pulmonary sarcomatoid carcinoma was assessed to be probably related to savolitinib by the investigator.

INTERPRETATION

Savolitinib yielded promising activity and had an acceptable safety profile in patients with pulmonary sarcomatoid carcinoma and other NSCLC subtypes positive for METex14 skipping alterations. Savolitinib could therefore be a novel treatment option in this population.

FUNDING

Hutchison MediPharma and AstraZeneca.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Parent and Metabolite Concentration-QT Modeling to Evaluate QT-Interval Prolongation at Savolitinib Therapeutic Doses

Savolitinib is an oral, potent, and highly selective MET-tyrosine kinase inhibitor under investigation in various tumor types. A thorough QT study evaluated effects on QT interval after a 600-mg single savolitinib dose in healthy subjects. We report exposure-response (E-R) modeling from this study to characterize the effects of savolitinib and its metabolites, M2 and M3, on QTc changes. In a novel application, in vitro potencies against hERG current provided mechanistic support to model the metabolites' effects. The hERG IC50 estimates (95% CI) were 25.8 (22.2-29.9) and 22.6 (14.7-34.6) μM for parent and M2, respectively. The E-R was described by both linear and E_max models, with exposure captured by an active moiety that consisted of savolitinib and M2 concentrations, weighted by the hERG IC50 ratio (1.14). The maximal increase in ΔΔQTcF and EC50 estimates (95% CI) was 18.5 (9.2-27.7) ms and 5709 (2889-8529) nM, respectively. Ignoring M2 contribution resulted in under prediction of QTcF prolongation in the hypothetical case of inhibited M2 clearance; at 300 mg C_max, the mean (90% CI) of ∆∆QTcF was 9.0 (5.7-12.6) and 5.9 (2.9-8.9) ms using the hERG-informed and parent-only linear models, respectively. Simulations in normal setting confirmed modest QTcF prolongation with 600 mg, but not 300 mg. Using the linear model, the mean (90% CI) maximum ΔΔQTcF were 12.3 (8.6-16.2) and 5.5 (2.6-8.5) ms for 600 and 300 mg, respectively. Further clinical studies will monitor cardiac safety to assess the clinical significance of QT-interval prolongation with savolitinib.

A narrative review of MET inhibitors in non-small cell lung cancer with MET exon 14 skipping mutations

Treatment of advanced non-small cell lung cancer (NSCLC) has radically improved in the last years due to development and clinical approval of highly effective agents including immune checkpoint inhibitors (ICIs) and oncogene-directed therapies. Molecular profiling of lung cancer samples for activated oncogenes, including epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS1) and BRAF, is routinely performed to select the most appropriate up-front treatment. However, the identification of new therapeutic targets remains a high priority. Recently, MET exon 14 skipping mutations have emerged as novel actionable oncogenic alterations in NSCLC, sensitive to MET inhibition. In this review we discuss: (I) MET gene and MET receptor structure and signaling pathway; (II) MET exon 14 alterations; (III) current data on MET inhibitors, mainly focusing on selective MET tyrosine kinase inhibitors (TKIs), in the treatment of NSCLC with MET exon 14 skipping mutations. We identified the references for this review through a literature search of papers about MET, MET exon 14 skipping mutations, and MET inhibitors, published up to September 2020, by using PubMed, Scopus and Web of Science databases. We also searched on websites of main international cancer congresses (ASCO, ESMO, IASLC) for ongoing studies presented as abstracts. MET exon 14 skipping mutations have been associated with clinical activity of selective MET inhibitors, including capmatinib, that has recently received approval by FDA for clinical use in this subgroup of NSCLC patients. A large number of trials are testing MET inhibitors, also in combinatorial therapeutic strategies, in MET exon 14-altered NSCLC. Results from these trials are eagerly awaited to definitively establish the role and setting for use of these agents in NSCLC patients.

Targeted drug therapy in non-small cell lung cancer: Clinical significance and possible solutions-Part I

INTRODUCTION

Non-small cell lung cancer (NSCLC) comprises of 84% of all lung cancer cases. The treatment options for NSCLC at advanced stages are chemotherapy and radiotherapy. Chemotherapy involves conventional nonspecific chemotherapeutics, and targeted-protein/receptor-specific small molecule inhibitors. Biologically targeted therapies such as an antibody-based immunotherapy have been approved in combination with conventional therapeutics. Approved targeted chemotherapy is directed against the kinase domains of mutated cellular receptors such as epidermal growth factor receptor (EGFR), anaplastic lymphoma kinases (ALK), neurotrophic receptor kinases (NTRK) and against downstream signaling molecules such as BRAF (v-raf murine sarcoma viral oncogene homolog B1). Approved biologically targeted therapy involves the use of anti-angiogenesis antibodies and antibodies against immune checkpoints.

AREAS COVERED

The rationale for the employment of targeted therapeutics and the resistance that may develop to therapy are discussed. Novel targeted therapeutics in clinical trials are also included.

EXPERT OPINION

Molecular and histological profiling of a given tumor specimen to determine the aberrant onco-driver is a must before deciding a targeted therapeutic regimen for the patient. Periodic monitoring of the patients response to a given therapeutic regimen is also mandatory so that any semblance of resistance to therapy can be deciphered and the regimen may be accordingly altered.

Pulmonary sarcomatoid carcinoma: progress, treatment and expectations

Pulmonary sarcomatoid carcinoma (PSC) is a unique, highly invasive pulmonary malignancy with a poor prognosis, representing 0.1-0.4% of all malignant lung tumors. Because of its highly aggressive character and propensity for frequent metastasis, PSC shows low response rates to traditional treatments such as chemotherapy, radiotherapy, and neoadjuvant therapy. In recent years, considerable progress has been made in gene sequencing, targeted therapies, and immunotherapies. One of the most promising treatment approaches is the selection of mono-targeted or multi-targeted drugs according to tumor gene-mutation sites, such as epidermal growth factor receptor or vascular endothelial growth factor receptor 2 (EGFR/VEGFR2), anaplastic lymphoma kinase (ALK), and others. Another approach is the activation of therapeutic anti-tumor immunity via pathways including programmed cell-death protein-1/programmed cell-death ligand-1 (PD-1/PD-L1), which has been used in individual cases. In this review, we will introduce the clinicopathologic features, molecular typing, and traditional treatments. We will also review the biological characteristics and the latest therapies for PSC. These novel therapies show promise in the management of PSC, and the outcomes of investigative trials will hopefully reveal a variety of treatment options for patients with PSC.

Management of Non-small Cell Lung Cancer Patients with MET Exon 14 Skipping Mutations

OPINION STATEMENT

The MET exon 14 skipping mutation is found in approximately 3% of lung adenocarcinomas and slightly more than 2% of lung squamous cell carcinomas. In recent years, more and more evidence has shown that MET inhibitors have achieved good anti-tumor effect in patients with MET exon 14 skipping mutation, suggesting that MET exon 14 skipping mutation may be a new target for NSCLC patients. Patients with positive MET exon 14 skipping mutation are recommended to be administered MET inhibitors, and crizotinib is recommended by the NCCN guideline. Due to the presence of gene amplification, second site mutation, bypass activation, and pathological type transformation, one of the inevitable problems of targeted therapy is drug resistance. If type I MET inhibitors (crizotinib, capmatinib, tepotinib, savolitinib) drug resistance is developed, type II MET inhibitors (cabozantinib, glesatinib, merestinib) can be considered.