Role of savolitinib in advanced gastric adenocarcinoma with meningeal carcinomatosis and cerebellar metastasis: A case report

BACKGROUND

Brain metastases (BM) are very rare in gastric adenocarcinoma (GaC), and patients with BMs have a higher mortality rate due to stronger tumor aggressiveness. However, its pathogenesis remains unclear. Genetic testing revealed cellular-mesenchymal epithelial transition factor receptor (MET) amplification. Therefore, treatment with savolitinib, a small molecule inhibitor of c-Met, was selected.

CASE SUMMARY

A 66-year-old woman was diagnosed with advanced GaC 6 months prior to presentation due to back pain. Cerebellar and meningeal metastases were observed during candonilimab combined with oxaliplatin and capecitabine therapy. The patient experienced frequent generalized seizures and persistent drowsiness in the emergency department. Genetic testing of cerebrospinal fluid and peripheral blood revealed increased MET amplification. After discussing treatment options with the patient, savolitinib tablets were administered. After a month of treatment, the intracranial lesions shrank considerably.

CONCLUSION

BM is very rare in advanced GaC, especially in meningeal cancer, that is characterized by rapid disease deterioration. There are very few effective treatment options available; however, technological breakthroughs in genomics have provided a basis for personalized treatment. Furthermore, MET amplification may be a key driver of BM in gastric cancer; however, this conclusion requires further investigation.

Case report: Response to Savolitinib/EGFR-TKI combination in NSCLC patients harboring concurrent primary MET amplification/overexpression and EGFR mutation

Lung cancer is the leading cause of cancer death, accounting for one-third of all cancer deaths worldwide. The MET (c-MET) gene, as one of the therapeutic target spots of NSCLC, has become increasingly more important. MET amplification/overexpression was divided into primary (intrinsic) and secondary (acquired). Studies indicated that the combination of Osimertinib and Savolitinib was safe and showed promising antitumor effect in NSCLC patients with secondary MET amplification after EGFR mutations. However, NSCLC patients with primary MET amplification/overexpression and EGFR mutations are rare in clinics, and the efficacy of dual-target therapy combined with EGFR-TKI and Savolitinib for them has not been studied yet. Here, we reported two NSCLC patients with primary MET amplification/overexpression and EGFR mutation, who benefited from T+S therapy (the dual-target therapy of EGFR-TKI plus Savolitinib) and achieved a progression-free survival (PFS) of approximately 5 months. The two cases indicated that T+S therapy has an acceptable safety profile and encouraging antitumor efficacy in NSCLC patients harboring concurrent primary MET amplification/overexpression and EGFR mutation. Meanwhile, the observation stresses the importance of genetic testing, and the MET gene needs to be detected at first diagnosis for the best choice of targeted therapies.

[Chinese multidisciplinary expert consensus on the management of adverse drug reactions associated with savolitinib]

MET gene is a proto-oncogene, which encodes MET protein with tyrosine kinase activity. After binding to its ligand, hepatocyte growth factor, MET protein can induce MET dimerization and activate downstream signaling pathways, which plays a crucial role in tumor formation and metastasis. Savolitinib, as a specific tyrosine kinase inhibitor (TKI) targeting MET, selectively inhibits the phosphorylation of MET kinase with a significant inhibitory effect on tumors with MET abnormalities. Based on its significant efficacy shown in the registration studies, savolitinib was approved for marketing in China on June 22, 2021 for the treatment of advanced non-small cell lung cancer with MET 14 exon skipping mutations. In addition, many studies have shown that MET TKIs are equally effective in patients with advanced solid tumors with MET gene amplification or MET protein overexpression, and relevant registration clinical studies are ongoing. The most common adverse reactions during treatment with savolitinib include nausea, vomiting, peripheral edema, pyrexia, and hepatotoxicity. Based on two rounds of extensive nationwide investigations to guide clinicians, the consensus is compiled to use savolitinib rationally, prevent and treat various adverse reactions scientifically, and improve the clinical benefits and quality of life of patients. This consensus was prepared under the guidance of multidisciplinary experts, especially including the whole-process participation and valuable suggestions of experts in Traditional Chinese Medicine, thus reflecting the clinical treatment concept of integrated Chinese and western medicines.

Savolitinib for non-small cell lung cancer

Savolitinib is a highly selective MET tyrosine kinase inhibitor. MET is involved in numerous cellular processes such as proliferation, differentiation and the formation of distant metastases. MET amplification and MET overexpression are quite common in many cancers, but MET exon 14 skipping alteration is most common in non-small cell lung cancer (NSCLC). The role of MET signaling as a bypass pathway in the development of acquired resistance to tyrosine kinase inhibitor (TKI) epidermal growth factor receptor (EGFR) therapy in cancer patients with EGFR gene mutation was documented. Potential beneficiaries of savolitinib therapy are patients with NSCLC and initial diagnosis of MET ex 14 skipping mutation. Savolitinib therapy can be effective in NSCLC patients with EGFR-mutant MET with progression during first-line treatment with an EGFR-TKI. Antitumor activity of savolitinib in combination with osimertinib is very promising as first-line therapy of patients with advanced EGFR-mutated NSCLC, initially with MET expression. The safety profile of savolitinib as monotherapy and in combination with osimertinib or gefitinib is so favorable in all available studies that this drug has become a very promising therapeutic option and is being intensively investigated in ongoing clinical trials.

The safety and feasibility of preoperative induction therapy of Savolitinib in non-small cell lung cancer patients with MET exon 14 skipping mutation

PURPOSE

Neoadjuvant therapy followed by surgical resection is one of the preferred treatment option for locally advanced non-small cell lung cancer (NSCLC). For patients with mesenchymal-epithelial transition (MET) factor exon 14 skipping (METex14) mutations, the use of MET-tyrosine kinase inhibitors (TKIs) showed high efficiency and reduced toxicity compared with first-line standard chemotherapy. However, it is unknown whether preoperative induction targeted therapy of MET-TKIs is feasible and safe.

METHODS

Here, we reported 3 cases of locally advanced unresectable NSCLC with METex14 mutations receiving induction therapy of MET-TKI savolitinib as first-line therapy or second-line therapy when they experienced disease progression after preoperative chemotherapy.

RESULTS

All these 3 patients achieved significant tumor size shrinkage and their unresectable tumors became resectable after the treatment of savolitinib. No serious adverse events were observed during the treatment. They recovered well postoperatively, and no significant events were identified.

CONCLUSIONS

Preoperative induction treatment with MET-TKI savolitinib showed its safety and effectiveness and may be an alternative option for neoadjuvant therapy for NSCLC patients with METex14 mutations.

Case Report: A Lung Adenocarcinoma With Brain Metastasis Harbored Novel MET 14 Skipping Alteration Sensitive to Savolitinib

A splice-site mutation that results in a loss of transcription of exon 14 in the oncogenic driver MET occurs in 3 to 4% of patients with non-small-cell lung cancer (NSCLC). Several MET exon 14 skipping alterations have been identified, but different MET exon splice variants tend to have different clinical outcomes which deserve concern. Herein, based on NGS panel analysis, we firstly described a 61-year-old woman with lung adenocarcinoma who harbored a novel MET exon 14 skipping (c.3004_3028+3del) concurrent MET amplification (copy number: 3.91) and benefited from Savolitinib treatment. Moreover, CytoTest MET/CCP7 FISH Probe (c-MET/CCP7 Ratio:1.41 and mean gene copy number:6) and qPCR which based on ABI 7500 also were performed to confirm these two MET alterations. After 2 months of Savolitinib treatment, the clinical evaluation was a partial response (PR). In summary, our finding not only expanded the spectrum of the MET exon14 variant (METex14). Targeted NGS analysis could improve detection of MET alterations in routine practice.

Matching-Adjusted Indirect Comparison (MAIC) of Tepotinib with Other MET Inhibitors for the Treatment of Advanced NSCLC with MET Exon 14 Skipping Mutations

INTRODUCTION

MET exon 14 skipping in patients with advanced non-small cell lung cancer (aNSCLC), can be targeted with MET inhibitors including tepotinib, capmatinib, savolitinib, and crizotinib. Matching-adjusted indirect comparison (MAIC) methodology was used to compare outcomes data between agents and to address bias from differences in baseline characteristics.

METHODS

Patient-level data from the VISION study (tepotinib) were weighted for comparison with aggregate data from the GEOMETRY mono-1 (capmatinib), NCT02897479 (savolitinib) and PROFILE 1001 (crizotinib) studies in patients with aNSCLC, using baseline characteristics prognostic for overall survival (OS) in VISION. Overall response rate (ORR), OS, progression-free survival (PFS), and duration of response (DOR) were compared. Patients were stratified by line of therapy: overall (all lines), previously treated, and treatment-naïve.

RESULTS

Improvements in ORR and all time-to-event endpoints were predicted for tepotinib compared with crizotinib and savolitinib in the different populations, although comparisons with savolitinib were hindered by considerable differences in baseline patient populations. Tepotinib appeared to be associated with prolonged PFS and OS compared with capmatinib in previously treated patients (PFS HR 0.54; 95% CI 0.36-0.83; OS HR 0.66; 95% CI 0.42-1.06) and the overall populations (PFS HR 0.60; 95% CI 0.43-0.86; OS HR 0.72; 95% CI 0.49-1.05), with smaller improvements in DOR. The ORR comparisons between tepotinib and capmatinib identified a swing of up to ± 6 percentage points in the weighted tepotinib ORR depending on the population studied (treatment-naïve vs. previously treated patients).

CONCLUSIONS

The MAIC identified potential differences in efficacy endpoints with the different MET inhibitors, and predicted prolonged PFS and OS with tepotinib compared with capmatinib and crizotinib. Although MAIC cannot balance for unobserved factors, it remains an informative method to contextualize single-arm studies, where head-to-head trials are unlikely to be feasible.

Brief Report: Heterogeneity of Acquired Resistance Mechanisms to Osimertinib and Savolitinib

Introduction

MET amplification is a frequently observed mechanism of resistance to osimertinib, and coinhibition strategy of MET and EGFR revealed promising results in recent clinical trials. Nevertheless, acquired resistance mechanisms to combined EGFR and MET inhibition are poorly understood. In this study, we investigated the mechanisms of acquired resistance to osimertinib and savolitinib by using pretreatment and post-treatment tissue analysis.

Methods

Whole-exome sequencing was performed in EGFR-mutant, MET-amplified patients who received osimertinib and savolitinib using tissues obtained both before and after therapy. All patients achieved partial response or durable stable disease to osimertinib and savolitinib before developing acquired resistance.

Results

After progression on osimertinib and savolitinib, whole-exome analysis revealed MET-dependent mechanisms of resistance, such as acquired MET p.D1246H mutation, MET p.Y1230C mutation, and MET copy number gain. As for MET-independent mechanisms, development of ERBB2 mutation and amplification and copy number gains in amplifications in CCNE, CCND1, CDK6, and EGFR were observed. Patient 2 harbored an acquired PIK3CA p.H1047R mutation in which resistance could be overcome with combination of PI3K inhibitor and osimertinib in the patient-derived xenograft model.

Conclusions

Our study reveals that acquired resistance to savolitinib plus osimertinib can occur from both MET-dependent and MET-independent mechanisms.

[Progress on Mechanism of MET Gene Mutation and Targeted Drugs in Non-small Cell Lung Cancer]

间质-上皮细胞转化因子（mesenchymal-epithelial transition factor, MET）基因是非小细胞肺癌（non-small cell lung cancer, NSCLC）的一种重要肿瘤驱动基因，针对MET 14外显子的跳跃突变的靶向治疗药物给患者带来新的希望。目前已经上市或者即将上市的MET抑制剂包括：克唑替尼、卡博替尼、沃利替尼和Tepotinib等。MET抑制剂的客观缓解率较高，并且安全性良好。但是，MET抑制剂的耐药不可避免，因此需要重视对于耐药机制的研究。肝细胞生长因子（hepatocyte growth factor, HGF）/MET信号通路抑制剂与其他药物的联合应用，对于抑制和逆转耐药可能发挥重要作用。

A phase Ib study of the highly selective MET-TKI savolitinib plus gefitinib in patients with EGFR-mutated, MET-amplified advanced non-small-cell lung cancer

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are recommended first-line treatments in EGFR-mutated (EGFRm) non-small-cell lung cancer (NSCLC). However, acquired resistance (e.g. MET amplification) is frequently observed. Savolitinib (volitinib, HMPL-504, AZD6094) is an oral, potent, and highly selective MET-TKI. In this phase Ib, open-label, multicenter study, we enrolled Chinese patients with EGFRm advanced NSCLC, whose disease progressed following prior EGFR-TKI treatment. In the safety run-in, patients received savolitinib 600 or 800 mg plus gefitinib 250 mg orally once daily, and dose-limiting toxicities were recorded. In the expansion phase, patients with MET amplification received savolitinib plus gefitinib. The primary endpoint was safety/tolerability. Secondary endpoints included antitumor activity. Thirteen patients were enrolled in the safety phase (median age 52 years, 46% female) and 51 enrolled in the expansion phase (median age 61 years, 67% female). No dose-limiting toxicities were reported in either dose group during the safety run-in. Adverse events of grade ≥ 3 in the safety run-in and expansion phases (n = 57) were reported in 21 (37%) patients. The most frequently reported adverse events (all grades) were: vomiting (n = 26, 46%), nausea (n = 23, 40%), increased aspartate aminotransferase (n = 22, 39%). Of four deaths, none were treatment-related. The objective response rates in EGFR T790M-negative, -positive, and -unknown patients were 52% (12/23), 9% (2/23), and 40% (2/5), respectively. Savolitinib 600 mg plus gefitinib 250 mg once daily had an acceptable safety profile and demonstrated promising antitumor activity in EGFRm, MET-amplified advanced NSCLC patients who had disease progression on EGFR-TKIs. NCT02374645, Date of registration: March 2nd 2015.

Preclinical pharmacokinetics, disposition, and translational pharmacokinetic/pharmacodynamic modeling of savolitinib, a novel selective cMet inhibitor

Savolitinib is a novel small-molecule selective cMet inhibitor. This work characterized its pharmacokinetics in preclinical phase, established the preclinical relationships between PK, cMet modulation and anti-tumor efficacy. In vitro and in vivo animal studies were performed for PK characterization. Savolitinib showed good absorption, moderate tissue distribution, low to intermediate clearance, and low accumulation. Hepatic oxidative metabolism followed by urinary and biliary excretions was the major elimination pathway. Based on preclinical PK data, human PK profiles were predicted using empirical methods. Pharmacodynamic studies for evaluating cMet inhibition and anti-tumor efficacy were conducted in nude mice bearing Hs746t xenograft. PK/PD models were built to link the PD measurements to nude mouse PK. The established integrated preclinical PK/PD model contained a two-compartment non-linear PK model, a biomarker link model and a tumor growth transit model. The IC₅₀ of cMet inhibition and the concentration achieving half of the maximal Hs746t tumor reduction by savolitinib were equal to 12.5 and 3.7 nM (free drug), respectively. Based on the predicted human PK data, as well as the established PK/PD model in nude mouse, the human PD (cMet inhibition) profiles were also simulated. This research supported clinical development of savolitinib. Understanding the preclinical PK/PD relationship of savolitinib provides translational insights into the cMet-targeted drug development.