Osimertinib plus local treatment for brain metastases versus osimertinib alone in patients with EGFR-Mutant Non-Small Cell Lung Cancer.

OBJECTIVES: Osimertinib is a standard treatment for patients with EGFR-mutant non-small cell lung cancer (NSCLC) and is highly effective for brain metastases (BMs). However, it is unclear whether local treatment (LT) for BMs prior to osimertinib administration improves survival in EGFR-mutant NSCLC. We aimed to reveal the survival benefit of upfront local treatment (LT) for BMs in patients treated with osimertinib. MATERIALS AND METHODS: This multicenter retrospective study included consecutive patients with EGFR mutation (19del or L858R)-positive NSCLC who had BMs before osimertinib initiation between August 2018 and October 2021. We compared overall survival (OS) and central nervous system progression-free survival (CNS-PFS) between patients who received upfront LT for BMs (the upfront LT group), and patients who received osimertinib only (the osimertinib-alone group). Inverse-probability treatment weighting (IPTW) analysis was performed to adjust for potential confounding factors. RESULTS: Of the 121 patients analyzed, 57 and 64 patients had 19del and L858R, respectively. Forty-five and 76 patients were included in the upfront LT group and the osimertinib-alone groups, respectively. IPTW-adjusted Kaplan-Meier curves showed that the OS of the upfront LT group was significantly longer than that of the osimertinib-alone group (median, 95 % confidence intervals [95 %CI]: Not reached [NR], NR-NR vs. 31.2, 21.7-33.2; p = 0.021). The hazard ratio (HR) for OS and CNS-PFS was 0.37 (95 %CI, 0.16-0.87) and 0.36 (95 %CI, 0.15-0.87), respectively. CONCLUSIONS: The OS and CNS-PFS of patients who received upfront LT for BMs followed by osimertinib were significantly longer than those of patients who received osimertinib alone. Upfront LT for BMs may be beneficial in patients with EGFR-mutant NSCLC treated with osimertinib.

Incidence of pleural effusion with dasatinib and the effect of switching therapy to a different TKI in patients with chronic phase CML.

Dasatinib is one of the second generation tyrosine kinase inhibitors (TKI) which is approved for the treatment of patients with chronic phase CML (CP-CML) both in the front line and in the second line setting. Pleural effusion (PE) is a unique toxicity associated with dasatinib use. Our aim was to study the incidence of pleural effusion in our cohort of patients who were treated with dasatinib for CP-CML and the safety upon TKI switch. A total of 390 patients were treated with dasatinib during their course of treatment for CP-CML. A total of 69 patients (17.6%) developed any grade of PE. About 33 (48%) patients developed CTCAE grade 2 PE, 34 (49%) grade 3 and only 1 patient developed grade 4 PE. Recurrence of PE was observed in 34 (49%) patients. While only 12 patients (17.3%) continued using dasatinib after development of PE, dasatinib was discontinued in the other 57 patients. Therapy was switched to bosutinib in 13 patients out of which 6 (46%) patients re-developed PE. While only 12.5% patients developed re-accumulation of pleural fluid in patients switched to imatinib, none of the patients switched to nilotinib re-developed PE. A change in TKI to bosutinib was associated with a 46% risk of recurrence of PE in patients who develop PE on dasatinib for the treatment of CP-CML. The incidence of recurrent PE was markedly lower in patient switched to imatinib or nilotinib.

Genome-wide CRISPR screens identify the YAP/TEAD axis as a driver of persister cells in EGFR mutant lung cancer.

Most lung cancer patients with metastatic cancer eventually relapse with drug-resistant disease following treatment and EGFR mutant lung cancer is no exception. Genome-wide CRISPR screens, to either knock out or overexpress all protein-coding genes in cancer cell lines, revealed the landscape of pathways that cause resistance to the EGFR inhibitors osimertinib or gefitinib in EGFR mutant lung cancer. Among the most recurrent resistance genes were those that regulate the Hippo pathway. Following osimertinib treatment a subpopulation of cancer cells are able to survive and over time develop stable resistance. These 'persister' cells can exploit non-genetic (transcriptional) programs that enable cancer cells to survive drug treatment. Using genetic and pharmacologic tools we identified Hippo signalling as an important non-genetic mechanism of cell survival following osimertinib treatment. Further, we show that combinatorial targeting of the Hippo pathway and EGFR is highly effective in EGFR mutant lung cancer cells and patient-derived organoids, suggesting a new therapeutic strategy for EGFR mutant lung cancer patients.

[Acute myeloid leukemia with central nervous system involvement successfully treated with gilteritinib].

A 69-year-old woman was referred to our hospital due to hyperleukocytosis. We diagnosed acute myeloid leukemia and started induction therapy with the CAG regimen (aclarubicin, cytarabine and filgrastim). However, the patient was refractory to the initial treatment and developed quadriplegia, and a cerebrospinal fluid (CSF) test showed elevated blasts. We then performed intrathecal chemotherapy, and the number of blasts in CSF gradually decreased. But only two cycles of intrathecal therapy were possible due to severe methotrexate-induced mucositis. The leukemia cells had fms-like kinase 3-internal tandem duplication (FLT3-ITD), so we started treatment with oral gilteritinib. The patient then achieved hematological complete remission. Her paralysis was also resolving, and the CSF was clear of blasts for more than 6 months. Some reports show that gilteritinib may penetrate the CNS, and this case also supports the effectiveness of gilteritinib on CNS leukemia.

Osimertinib in combination with anti-angiogenesis therapy presents a promising option for osimertinib-resistant non-small cell lung cancer.

BACKGROUND: Osimertinib has become standard care for epidermal growth factor receptor (EGFR)-positive non-small cell lung cancer (NSCLC) patients whereas drug resistance remains inevitable. Now we recognize that the interactions between the tumor and the tumor microenvironment (TME) also account for drug resistance. Therefore, we provide a new sight into post-osimertinib management, focusing on the alteration of TME. METHODS: We conducted a retrospective study on the prognosis of different treatments after osimertinib resistance. Next, we carried out in vivo experiment to validate our findings using a humanized mouse model. Furthermore, we performed single-cell transcriptome sequencing (scRNA-seq) of tumor tissue from the above treatment groups to explore the mechanisms of TME changes. RESULTS: Totally 111 advanced NSCLC patients have been enrolled in the retrospective study. The median PFS was 9.84 months (95% CI 7.0-12.6 months) in the osimertinib plus anti-angiogenesis group, significantly longer than chemotherapy (P = 0.012) and osimertinib (P = 0.003). The median OS was 16.79 months (95% CI 14.97-18.61 months) in the osimertinib plus anti-angiogenesis group, significantly better than chemotherapy (P = 0.026), the chemotherapy plus osimertinib (P = 0.021), and the chemotherapy plus immunotherapy (P = 0.006). The efficacy of osimertinib plus anlotinib in the osimertinib-resistant engraft tumors (R-O+A) group was significantly more potent than the osimertinib (R-O) group (P<0.05) in vitro. The combinational therapy could significantly increase the infiltration of CD4+ T cells (P<0.05), CD25+CD4+ T cells (P<0.001), and PD-1+CD8+ T cells (P<0.05) compared to osimertinib. ScRNA-seq demonstrated that the number of CD8+ T and proliferation T cells increased, and TAM.mo was downregulated in the R-O+A group compared to the R-O group. Subtype study of T cells explained that the changes caused by combination treatment were mainly related to cytotoxic T cells. Subtype study of macrophages showed that proportion and functional changes in IL-1ß.mo and CCL18.mo might be responsible for rescue osimertinib resistance by combination therapy. CONCLUSIONS: In conclusion, osimertinib plus anlotinib could improve the prognosis of patients with a progressed disease on second-line osimertinib treatment, which may ascribe to increased T cell infiltration and TAM remodeling via VEGF-VEGFR blockage.

Senolysis of gemcitabine-induced senescent human pancreatic cancer cells.

INTRODUCTION: Gemcitabine (GEM) is often used to treat pancreatic cancer. Many anti-cancer drugs induce cancer cell death, but some cells survive after cell cycle arrest. Such a response to DNA damage is termed cellular senescence. Certain drugs, including the Bcl-2-family inhibitor ABT-263, kill senescent cells; this is termed senolysis. In this study, we examined the therapeutic benefits of ABT-263 in GEM-induced senescence of human pancreatic cancer cells. METHODS AND RESULTS: Of four pancreatic cancer cell lines (PANC-1, AsPC-1, CFPAC-1, and PANC10.05), GEM induced senescent features in PANC-1 and AsPC-1 cells, including increases in the cell sizes and expression levels of mRNAs encoding interleukin (IL)-6/IL-8 and induction of ß-galactosidase. Successive treatment with GEM and ABT-263 triggered apoptosis in PANC-1 and AsPC-1 cells and suppressed colony formation significantly. Senolysis of GEM-induced senescent pancreatic cancer cells by ABT-263 was triggered by a Bcl-xL inhibitor, but not by a Bcl-2 inhibitor, suggesting a central role for Bcl-xL in senolysis. In a xenograft mouse model, combined treatment with GEM and ABT-737 (an ABT-263 analog exhibiting the same specificity) suppressed in vivo growth of AsPC-1 significantly. CONCLUSION: Together, our results indicate that sequential treatment with GEM and senolytic drugs effectively kill human pancreatic cancer cells.

Clinical outcomes in patients with non-small cell lung cancer harboring EGFR Exon20 in-frame insertions in the near-loop and far-loop: Results from LC-SCRUM-Asia.

OBJECTIVES: In this study, we explored the clinical outcomes of non-small cell lung cancer (NSCLC) patients with EGFR Exon20 in-frame insertions (Exon20ins), and the impact of the location of Exon20ins on these clinical outcomes. MATERIALS AND METHODS: The efficacies of current systemic therapies in NSCLC patients harboring Exon20ins were investigated using a large-scale clinico-genomic database of LC-SCRUM-Asia, and compared with that of amivantamab in the CHRYSALIS trial. RESULTS: Of the 11,397 patients enrolled in LC-SCRUM-Asia, Exon20ins were detected in 189 patients (1.7 %). Treatment with classical EGFR tyrosine-kinase inhibitors (classical TKIs) was associated with a significantly shorter progression-free survival (PFS) in NSCLC patients with Exon20ins as compared with Exon19 deletions and L858R. Post platinum-based chemotherapy, classical TKIs and immune checkpoint inhibitors (ICIs) were associated with a shorter PFS than with docetaxel in patients with Exon20ins (HR [95 % CI]; TKIs vs docetaxel, 2.16 [1.35-3.46]; ICIs vs docetaxel, 1.49 [1.21-1.84]). Patients treated with amivantamab in the CHRYSALIS trial showed a risk reduction in PFS and overall survival as compared with LC-SCRUM-Asia patients treated with docetaxel, classical TKIs, or ICIs. Among the 189 patients, Exon20ins were classified as near-loop or far-loop insertions in 115 (61 %) and 56 (30 %) patients, respectively. Treatment with osimertinib was associated with a longer PFS in patients with Exon20ins in near-loop as compared with far-loop (median, 5.6 vs. 2.0 months; HR [95 % CI], 0.22 [0.07-0.64]). CONCLUSIONS: After platinum-based chemotherapy, classical TKIs and ICIs are less effective in NSCLC patients with Exon20ins, and amivantamab may be a promising targeted therapy. There is a possibility that the location of Exon20ins has an impact on the efficacy of TKIs.

Furmonertinib and intrathecal pemetrexed chemotherapy rechallenges osimertinib-refractory leptomeningeal metastasis in a non-small cell lung cancer patient harboring EGFR20 R776S, C797S, and EGFR21 L858R compound EGFR mutations: a case report.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are considered the first-line treatment for advanced or metastatic non-small cell lung cancer (NSCLC) patients harboring EGFR mutations. However, due to the rarity of cases, the response of EGFR-TKIs in patients harboring uncommon compound EGFR mutations still needs to be determined. Here, we demonstrated the case of a 47-year-old smoker diagnosed with leptomeningeal metastasis from NSCLC and had EGFR20 R776S, C797S, and EGFR21 L858R compound mutations. He was treated with furmonertinib combined with intrathecal pemetrexed chemotherapy following progression on osimertinib, which led to clinical improvement and successfully prolonged his survival by 3 months. Regrettably, the patient eventually died from heart disease. This report provides the first reported evidence for the use of furmonertinib and intrathecal pemetrexed chemotherapy in NSCLC patients harboring EGFR R776S/C797S/L858R mutations who progressed on previous EGFR-TKIs.

Outcomes of patients with advanced epithelial growth factor receptor mutant lung cancer treated with first-line osimertinib who would not have met the eligibility criteria for the FLAURA clinical trial.

OBJECTIVES: Osimertinib is largely used as first-line therapy for metastatic epithelial growth factor receptor (EGFR) mutant lung cancers based on the FLAURA clinical trial. Real-world patient outcomes often differ from clinical trial outcomes. This study evaluated the efficacy of first-line osimertinib in patients treated in British Columbia (BC), Canada. Furthermore, we compared the outcomes of patients who would and would not have been eligible for the original FLAURA trial. METHODS: Consecutive patients receiving first-line osimertinib for metastatic EGFR exon19 or L858R lung cancer were identified using the BC Cancer Pharmacy Database. Patient eligibility for the FLAURA clinical trial were retrospectively reviewed based on the following criteria: ECOG ≥ 2, symptomatic brain metastases or on steroids, hemoglobin < 90 g/L, platelets < 100x109/L, or a creatinine clearance < 50 mL/min. mOS was assessed for the entire population and compared between patients who would have been eligible and ineligible for FLAURA. RESULTS: From January 2020 to October 2021, 311 patients received first-line osimertinib; 44 % (137/311) were deemed FLAURA ineligible, predominantly due to low ECOG (n = 120). After a median follow-up of 26.5 months, the mOS for the entire cohort was 27.4 months (95 %CI 23.8-30.1). The mOS for ineligible patients was 18 months shorter than eligible patients (15.8 vs 34.2, p < 0.001). Ineligible patients had higher rates of de novo stage IV disease, higher rates of stage IVB disease, and more sites of disease than eligible patients. CONCLUSION: In this real-world population, nearly half of patients would have been ineligible for FLAURA. The mOS was one year shorter than reported in FLAURA. However, patients who would have been eligible for the FLAURA clinical trial had similar OS to patients enrolled in FLAURA. Trial ineligible patients had a higher burden of disease at baseline which may have led to inferior outcomes. Further research is needed to improve outcomes in these patients.

Targeting glucosylceramide synthase induces antiproliferative and proapoptotic effects in osimertinib-resistant NSCLC cell models.

The EGFR tyrosine kinase inhibitor osimertinib has been approved for the first-line treatment of EGFR-mutated Non-Small Cell Lung Cancer (NSCLC) patients. Despite its efficacy, patients develop resistance. Mechanisms of resistance are heterogeneous and not fully understood, and their characterization is essential to find new strategies to overcome resistance. Ceramides are well-known regulators of apoptosis and are converted into glucosylceramides (GlcCer) by glucosylceramide synthase (GCS). A higher content of GlcCers was observed in lung pleural effusions from NSCLC patients and their role in osimertinib-resistance has not been documented. The aim of this study was to determine the therapeutic potential of inhibiting GCS in NSCLC EGFR-mutant models resistant to osimertinib in vitro and in vivo. Lipidomic analysis showed a significant increase in the intracellular levels of glycosylceramides, including GlcCers in osimertinib resistant clones compared to sensitive cells. In resistant cells, the GCS inhibitor PDMP caused cell cycle arrest, inhibition of 2D and 3D cell proliferation, colony formation and migration capability, and apoptosis induction. The intratumoral injection of PDMP completely suppressed the growth of OR xenograft models. This study demonstrated that dysregulation of ceramide metabolism is involved in osimertinib-resistance and targeting GCS may be a promising therapeutic strategy for patients progressed to osimertinib.

Activation of free fatty acid receptors, FFAR1 and FFAR4, ameliorates ulcerative colitis by promote fatty acid metabolism and mediate macrophage polarization.

OBJECTIVE: To investigate the mechanism of action of fatty acid receptors, FFAR1 and FFAR4, on ulcerative colitis (UC) through fatty acid metabolism and macrophage polarization. METHODS: Dextran sulfate sodium (DSS)-induced mouse model of UC mice was used to evaluate the efficacy of FFAR1 (GW9508) and FFAR4 (GSK137647) agonists by analyzing body weight, colon length, disease activity index (DAI), and histological scores. Real-time PCR and immunofluorescence analysis were performed to quantify the levels of fatty acid metabolizing enzymes and macrophage makers. FFA-induced lipid accumulation in RAW264.7 cells was visualized by Oil Red O staining analysis, and cells were collected to detect macrophage polarization by flow cytometry. RESULTS: The combination of GW9508 and GSK137647 significantly improved DSS-induced UC symptoms, caused recovery in colon length, and decreased histological injury. GW9508 + GSK137647 treatment upregulated the expressions of CD206, lipid oxidation enzyme (CPT-1α) and anti-inflammatory cytokines (IL-4, IL-10, IL-13) but downregulated those of CD86, lipogenic enzymes (ACC1, FASN, SCD1), and pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α). Combining the two agonists decreased FFA-induced lipid accumulation and increased CD206 expression in cell-based experiments. CONCLUSION: Activated FFAR1 and FFAR4 ameliorates DSS-induced UC by promoting fatty acid metabolism to reduce lipid accumulation and mediate M2 macrophage polarization.

Summary of Research: Overall Survival with Osimertinib in Resected EGFR-Mutated NSCLC.

This is a summary of the original article ?Overall survival with osimertinib in resected EGFR-mutated NSCLC.Ë® Osimertinib blocks the activity of the epidermal growth factor receptor (EGFR) on cancer cells, causing cancer cell death and tumor shrinkage, and is an effective treatment for EGFR-mutated non-small cell lung cancer (NSCLC). The ADAURA study assessed the effects of osimertinib versus placebo in patients with EGFR-mutated (exon 19 deletion or L858R) early stage (IB-IIIA) NSCLC removed by surgery (resected). Previous results from ADAURA demonstrated that patients treated with osimertinib stayed alive and cancer-free (disease-free survival) significantly longer than patients who received placebo. Recent data showed the overall length of time patients were alive after starting treatment (overall survival). In both the primary stage II-IIIA and overall stage IB-IIIA populations, patients in the osimertinib group had a significant 51% reduction in the risk of death compared with the placebo group. The data demonstrated that osimertinib after surgery significantly improved overall survival in patients with resected, EGFR-mutated, stage IB-IIIA NSCLC.

Delayed cardiotoxicity following osimertinib therapy in non-small cell lung cancer: a unique case report.

This case report features a 62-year-old male with stage IB lung adenocarcinoma harboring an epidermal growth factor receptor exon 19 deletion, who underwent treatment with osimertinib following a left upper lobectomy and lymph node dissection. Despite a history of smoking and well-managed type 2 diabetes, the patient developed heart failure 18 months post-initiation of osimertinib therapy, marking one of the latest occurrences of heart failure following osimertinib treatment documented in limited literature. Cardiac MRI revealed significant left ventricular enlargement, lateral wall myocardial thinning, and localized myocardial fibrosis without perfusion defects, a finding not previously reported in literature. This case underscores the severe and unusual cardiac effects of osimertinib in patients with latent risk factors, highlighting the importance of vigilant cardiac monitoring and a multidisciplinary management approach.

Phase I/II Study of Combined BCL-xL and MEK Inhibition with Navitoclax and Trametinib in KRAS or NRAS Mutant Advanced Solid Tumors.

PURPOSE: MEK inhibitors (MEKi) lack monotherapy efficacy in most RAS-mutant cancers. BCL-xL is an anti-apoptotic protein identified by a synthetic lethal shRNA screen as a key suppressor of apoptotic response to MEKi. PATIENTS AND METHODS: We conducted a dose escalation study (NCT02079740) of the BCL-xL inhibitor navitoclax and MEKi trametinib in patients with RAS-mutant tumors with expansion cohorts for: pancreatic, gynecologic (GYN), non-small cell lung cancer (NSCLC), and other cancers harboring KRAS/NRAS mutations. Paired pretreatment and day 15 tumor biopsies and serial cell-free (cf)DNA were analyzed. RESULTS: A total of 91 patients initiated treatment, with 38 in dose escalation. Fifty-eight percent had ≥3 prior therapies. A total of 15 patients (17%) had colorectal cancer, 19 (11%) pancreatic, 15 (17%) NSCLC, and 32 (35%) GYN cancers. The recommended phase II dose (RP2D) was established as trametinib 2 mg daily days 1 to 14 and navitoclax 250 mg daily days 1 to 28 of each cycle. Most common adverse events included diarrhea, thrombocytopenia, increased AST/ALT, and acneiform rash. At RP2D, 8 of 49 (16%) evaluable patients achieved partial response (PR). Disease-specific differences in efficacy were noted. In patients with GYN at the RP2D, 7 of 21 (33%) achieved a PR and median duration of response 8.2 months. No PRs occurred in patients with colorectal cancer, NSCLC, or pancreatic cancer. MAPK pathway inhibition was observed in on-treatment tumor biopsies. Reductions in KRAS/NRAS mutation levels in cfDNA correlated with clinical benefit. CONCLUSIONS: Navitoclax in combination with trametinib was tolerable. Durable clinical responses were observed in patients with RAS-mutant GYN cancers, warranting further evaluation in this population.

ASCL1 Drives Tolerance to Osimertinib in EGFR Mutant Lung Cancer in Permissive Cellular Contexts.

The majority of EGFR mutant lung adenocarcinomas respond well to EGFR tyrosine kinase inhibitors (TKI). However, most of these responses are partial, with drug-tolerant residual disease remaining even at the time of maximal response. This residual disease can ultimately lead to relapses, which eventually develop in most patients. To investigate the cellular and molecular properties of residual tumor cells in vivo, we leveraged patient-derived xenograft (PDX) models of EGFR mutant lung cancer. Subcutaneous EGFR mutant PDXs were treated with the third-generation TKI osimertinib until maximal tumor regression. Residual tissue inevitably harbored tumor cells that were transcriptionally distinct from bulk pretreatment tumor. Single-cell transcriptional profiling provided evidence of cells matching the profiles of drug-tolerant cells present in the pretreatment tumor. In one of the PDXs analyzed, osimertinib treatment caused dramatic transcriptomic changes that featured upregulation of the neuroendocrine lineage transcription factor ASCL1. Mechanistically, ASCL1 conferred drug tolerance by initiating an epithelial-to-mesenchymal gene-expression program in permissive cellular contexts. This study reveals fundamental insights into the biology of drug tolerance, the plasticity of cells through TKI treatment, and why specific phenotypes are observed only in certain tumors. SIGNIFICANCE: Analysis of residual disease following tyrosine kinase inhibitor treatment identified heterogeneous and context-specific mechanisms of drug tolerance in lung cancer that could lead to the development of strategies to forestall drug resistance. See related commentary by Rumde and Burns, p. 1188.

Clinical Activity of TGF-ß Inhibitor Vactosertib in Combination with Imatinib in Desmoid Tumors: A Multicenter Phase Ib/II Study.

PURPOSE: The study was to determine the activity and safety of the TGF-ß inhibitor vactosertib in combination with imatinib in patients with desmoid tumors. PATIENTS AND METHODS: In this investigator-initiated, open-label, multicenter, phase Ib/II trial, patients with desmoid tumors not amenable to locoregional therapies (surgery and/or radiotherapy) or with disease progression following at least one treatment were enrolled. Participants were administered 400 mg imatinib daily in combination with vactosertib (5 days on and 2 days off, twice a day) every 28 days. In phase Ib, the vactosertib dose was set at 100 mg (level -1) and 200 mg (level 1) to determine the recommended phase II dose (RP2D). Phase II assessed the efficacy, with the primary endpoint being progression-free rate (PFR) at 16 weeks. RESULTS: No dose-limiting toxicities were observed during phase Ib; therefore RP2D was defined at doses of 400 mg imatinib daily in combination with 200 mg vactosertib. Of the 27 patients evaluated, 7 (25.9%) achieved a confirmed partial response and 19 (70.4%) were stable. The PFR at 16 weeks and 1 year were 96.3% and 81.0%, respectively. Most toxicities were mild to moderate myalgia (n = 10, 37%), anemia (n = 10, 37%), and nausea (n = 9, 33.3%). Common grade 3 to 4 toxicities included neutropenia (n = 6, 22.2%) and anemia (n = 5, 18.5%). CONCLUSIONS: The vactosertib and imatinib combination was well tolerated, with promising clinical activity in patients with progressive, locally advanced desmoid tumors. This is the first study investigating a novel target agent, a TGF-ß inhibitor, in this rare and difficult-to-treat desmoid tumor.