Acquired Tyrosine Kinase Inhibitor Research Articles

Impact of Tumor-intrinsic Molecular Features on Survival and Acquired Tyrosine Kinase Inhibitor Resistance in ALK-positive NSCLC.

In a large-scale, contemporary cohort of patients with advanced ALK-positive NSCLC, we evaluated molecular characteristics and their impact on acquired resistance mutations and clinical outcomes. Our findings that certain ALK variants and co-mutations are associated with differential survival and specific TKI-relevant resistance patterns highlight potential molecular underpinnings of the heterogenous response to ALK TKIs and nominate biomarkers that may inform patient selection for first-line and consolidative therapies.

Metabolic Plasticity Is an Essential Requirement of Acquired Tyrosine Kinase Inhibitor Resistance in Chronic Myeloid Leukemia.

Simple SummaryTyrosine kinase inhibitors (TKIs), such as imatinib, have become the standard initial treatment of choice for chronic myeloid leukemia (CML) patients. However, one obstacle to face is that a significant proportion of patients presents poor response to TKIs, or acquires resistance resulting in disease relapses. Mutations in BCR-ABL1 protein are a well described mechanism of resistance but other not well established mechanisms outside BCR-ABL1 mutations are emerging as important in the acquisition of resistance. Abnormal metabolism of CML cells that acquire resistance to imatinib has been pointed out as a putative downstream key event, but deep studies aimed to unveil metabolic adaptations associated with acquired resistance are still lacking. Here, we perform an exhaustive study on metabolic reprogramming associated with acquired imatinib resistance and we identify metabolic vulnerabilities of CML imatinib resistant cells that could pave the way for new therapies targeting TKI failure. Tyrosine kinase inhibitors (TKIs) are currently the standard chemotherapeutic agents for the treatment of chronic myeloid leukemia (CML). However, due to TKI resistance acquisition in CML patients, identification of new vulnerabilities is urgently required for a sustained response to therapy. In this study, we have investigated metabolic reprogramming induced by TKIs independent of BCR-ABL1 alterations. Proteomics and metabolomics profiling of imatinib-resistant CML cells (ImaR) was performed. KU812 ImaR cells enhanced pentose phosphate pathway, glycogen synthesis, serine-glycine-one-carbon metabolism, proline synthesis and mitochondrial respiration compared with their respective syngeneic parental counterparts. Moreover, the fact that only 36% of the main carbon sources were utilized for mitochondrial respiration pointed to glycerol-phosphate shuttle as mainly contributors to mitochondrial respiration. In conclusion, CML cells that acquire TKIs resistance present a severe metabolic reprogramming associated with an increase in metabolic plasticity needed to overcome TKI-induced cell death. Moreover, this study unveils that KU812 Parental and ImaR cells viability can be targeted with metabolic inhibitors paving the way to propose novel and promising therapeutic opportunities to overcome TKI resistance in CML.

Neuropilin-2b facilitates resistance to tyrosine kinase inhibitors in non–small cell lung cancer

ObjectiveInnate and acquired resistance is the principle factor limiting the efficacy of tyrosine kinase inhibitors in lung cancer. We have observed a dramatic upregulation of the cell surface co-receptor neuropilin-2b in lung cancers clinically treated with tyrosine kinase inhibitors correlating with acquired resistance. We hypothesize that neuropilin-2b plays a functional role in acquired tyrosine kinase inhibitor resistance. MethodsNon–small cell lung cancer proliferation and survival were determined during chronic tyrosine kinase inhibitor exposure in the presence or absence of neuropilin-2b knock-down. Interactions of neuropilin-2a and neuropilin-2b isoforms with PTEN and GSK3β were assessed by immunoprecipitation. Neuropilin-2a and neuropilin-2b mutants deleted for their cytoplasmic domains were used to identify regions responsible for neuropilin-2b–GSK3β interaction. Because GSK3β is known to phosphorylate and degrade PTEN, phospho-PTEN and total PTEN levels were assessed after transfection of neuropilin-2a and neuropilin-2b wild-type and mutant constructs. ResultsNon–small cell lung cancer cells chronically treated with gefitinib or osimertinib developed drug resistance and exhibited logarithmic growth in the presence of endothelial growth factor receptor tyrosine kinase inhibitors. However, neuropilin-2b knockdown cells remained sensitive to gefitinib. Likewise, neuropilin-2b knockdown suppressed and neuropilin-2a knockdown enhanced cellular migration. Acquired drug resistance and cell migration correlated with neuropilin-2b-dependent AKT activation with the intermediate step of GSK3β-dependent PTEN degradation. A specific binding site for GSK3β on the cytoplasmic domain of neuropilin-2b was identified with truncated protein constructs and computer modeling. ConclusionsNeuropilin-2b facilitates non–small cell lung cancer resistance to tyrosine kinase inhibitors, and this biological effect relates to AKT activation. Neuropilin-2b GSK3β interactions appear to be essential for PTEN degradation and AKT activation in lung cancer cells. Disruption of the neuropilin-2b GSK3β interaction may represent a novel treatment strategy to preserve sensitivity to tyrosine kinase inhibitors in non–small cell lung cancer.

Phase 1 trial of dasatinib combined with afatinib for epidermal growth factor receptor- (EGFR-) mutated lung cancer with acquired tyrosine kinase inhibitor (TKI) resistance

BackgroundBypass activation of Src family kinases can confer resistance to EGFR tyrosine kinase inhibitors (TKIs) based on preclinical models. We prospectively assessed the safety and clinical activity of dasatinib and afatinib in combination for patients with resistant EGFR-mutant lung cancer.MethodsAn open-label, dose-escalation phase 1/2 trial (NCT01999985) with 2-stage expansion was conducted with 25 lung cancer patients. Dose expansion required activating EGFR mutations and progression following prior EGFR TKI.ResultsPatients were 72% Caucasian and received median of 2 prior lines of therapy. Maximum-tolerated dose was 30 mg afatinib with 100 mg dasatinib. New or increased pleural effusions were observed in 56% of patients. No radiologic responses were observed, although several EGFR-mutant TKI-resistant patients (26%) had prolonged stable disease over 6 months. The combination reduced the EGFR mutation and T790M variant allele frequency in cell-free DNA (p < .05). Nonetheless, the threshold for futility was met, based on 6-month progression-free survival. For EGFR TKI-resistant patients, median progression-free survival was 3.7 months (95% confidence interval (CI), 2.3–5.0) and overall survival was 14.7 months (95% CI, 8.5–20.9).ConclusionsThe combination had a manageable toxicity profile and in vivo T790M modulation, but no objective clinical responses were observed.

Fatty acid synthase mediates EGFR palmitoylation in EGFR mutated non-small cell lung cancer.

Metabolic reprogramming is widely known as a hallmark of cancer cells to allow adaptation of cells to sustain survival signals. In this report, we describe a novel oncogenic signaling pathway exclusively acting in mutated epidermal growth factor receptor (EGFR) non‐small cell lung cancer (NSCLC) with acquired tyrosine kinase inhibitor (TKI) resistance. Mutated EGFR mediates TKI resistance through regulation of the fatty acid synthase (FASN), which produces 16‐C saturated fatty acid palmitate. Our work shows that the persistent signaling by mutated EGFR in TKI‐resistant tumor cells relies on EGFR palmitoylation and can be targeted by Orlistat, an FDA‐approved anti‐obesity drug. Inhibition of FASN with Orlistat induces EGFR ubiquitination and abrogates EGFR mutant signaling, and reduces tumor growths both in culture systems and in vivo. Together, our data provide compelling evidence on the functional interrelationship between mutated EGFR and FASN and that the fatty acid metabolism pathway is a candidate target for acquired TKI‐resistant EGFR mutant NSCLC patients.

Clinical Implications of the T790M Mutation in Disease Characteristics and Treatment Response in Patients With Epidermal Growth Factor Receptor (EGFR)-Mutated Non–Small-Cell Lung Cancer (NSCLC)

BackgroundThe secondary T790M mutation accounts for more than 50% of acquired tyrosine kinase inhibitor (TKI) resistance in patients with EGFR-mutated non–small-cell lung cancer (NSCLC). Recent reports suggest this resistance mutation may be more common among patients with longer progression-free survival (PFS) on first-line TKI therapy, but much is still unknown. Materials and MethodsOur group collected medical records from patients who underwent a biopsy for T790M mutation testing while screening for clinical trials involving the drug rociletinib (CO-1686), a T790M mutation–specific TKI. Medical records were retrospectively analyzed for demographic data, PFS, and best response to previous therapies. ResultsOur patient cohort included 69 T790M+ patients and 28 T790M− patients. Patients who later developed a T790M mutation had a longer PFS on first-line TKI therapy (12.0 vs. 9.0 months, P = .021), but overall response rate (ORR) was the same (75.0% vs. 81.0%, P = .76). There was no difference in PFS on TKI rechallenge (4.0 vs. 3.0 months, P = .94), although there was a trend toward higher ORR in T790M+ patients (22.2% vs. 0%, P = .12). T790M+ patients had a longer PFS on initial chemotherapy treatment (5.0 vs. 4.0 months, P = .025) and a trend toward higher ORR (40.0% vs. 21.4%, P = .31). ConclusionOur study confirms that tumors expressing T790M have a more indolent progression of disease compared with their T790M− counterparts when treated with both first-line TKI and cytotoxic chemotherapy.

Clinical implications of the T790M mutation in disease characteristics and treatment response in patients with EGFR-mutated NSCLC.

9031 Background: The secondary T790M mutation accounts for more than 50% of acquired tyrosine kinase inhibitor (TKI) resistance in epidermal growth factor receptor (EGFR)-mutant NSCLC patients. Recent reports suggest this resistance mutation may be more common among patients with longer progression-free survival (PFS) on first-line TKI therapy, but much is still unknown about this resistance mechanism’s association with response to other therapies. Methods: Our group collected medical records from patients who underwent a biopsy for T790M mutation testing in the process of screening for clinical trials involving third generation EGFR inhibitors. Medical records were retrospectively analyzed for demographic data, PFS, best response (BR) to previous therapies, and presence or absence of an acquired T790M mutation. Progression-free survival was estimated using the Kaplan-Meier method and compared across two groups using the log-ranked test followed by univariate and multivariate cox proportional hazard regression analysis. Response rates were compared using Fisher’s exact test. Results: Out of 102 patients who obtained a diagnostic biopsy, 73 patients had a T790M mutation. Patients who later developed a T790M mutation had a longer PFS on first-line TKI therapy (12.0 months in T790M+ vs. 8.0 months in T790M-, p = 0.038, HR 1.66, 95% CI 1.03-2.67), though there was no difference in response rate (75.5% in T790M+ vs 77.3% in T790M-, p = 1.00). T790M+ patients also had a longer PFS on initial chemotherapy treatment (5.0 months in T790M+ vs. 4.0 months in T790M-, p = 0.020, HR 1.97, 95% CI 1.11-3.49) and a higher response rate to chemotherapy (22.7% in T790M+ vs 0% in T790M-, p = 0.033). Median PFS was short (3.0 months) for patients treated with immunotherapy with no difference based on T790M mutation status (p = 0.33). Conclusions: Our study confirms that tumors expressing T790M have a more indolent progression of disease compared to their T790M negative counterparts when treated with both first-line TKI and cytotoxic chemotherapy. This data provides context for therapeutic decision making in EGFR-mutant NSCLC patients.

Abstract CT060: Efficacy, safety and tolerability of dasatinib combined with afatinib: a phase I trial in patients with epidermal growth factor receptor mutant (EGFRm) advanced non-small-cell lung cancer (NSCLC) after acquired tyrosine kinase inhibitor (TKI) resistance

Abstract Background: Combining the Src family kinase inhibitor dasatinib and irreversible EGFR inhibitor afatinib results in enhanced antitumor activity in proliferation and apoptosis assays with EGFRm, TKI-resistant cell lines. Moreover, this combination results in higher tumor regression than either drug alone in PC9GR xenograft studies. We hypothesized that this drug combination would arrest progression in EGFRm NSCLC with acquired resistance. Therefore, we initiated a phase I open-label trial (NCT01999985) to evaluate dasatinib in combination with afatinib for patients (pts) with EGFRm advanced NSCLC who had progressed on previous EGFR TKIs. Methods: A phase I dose-escalation cohort with 3+3 design included patients (pts) with refractory NSCLC and ECOG performance status (PS) ? 1. Pts received continuous oral afatinib daily followed by addition of continuous oral dasatinib daily beginning on Day 8. After determination of maximum tolerated dose (MTD), a phase I cohort was expanded to include only pts with activating EGFR mutation who had acquired resistance to previous EGFR TKI. Safety, median progression-free survival (PFS), and tumor response were investigated. Plasma before and during treatment was collected for sequencing of circulating cell-free tumor DNA. Cox regression was performed. All statistical tests were 2-sided. Interim results are reported. Results: Of 31 pts screened, 25 were treated. Characteristics: 63% were female, median age was 66.8 years (range 53 - 81), and 72% were ECOG PS 1. Race: 75% Caucasian, 16% African-american. Median prior lines of therapy was 3. For EGFRm pts (n = 16), 56% had exon 19 deletion, 43% exon 21 mutation. In addition, 31% also had T790M detected in tumor prior to treatment. No significant interactions were observed with dasatinib and afatinib. Dose escalation halted at 40 mg afatinib and 100 mg dasatinib when 2 patients at this level experienced grade 2 or 3 diarrhea despite optimal supportive care. The most common drug-related adverse events of any grade from dose escalation included 63% diarrhea, 45% rash, 27% nausea, 18% oral mucositis, and fatigue. The MTD was 30 mg afatinib with 100 mg dasatinib. The PFS for EGFRm pts was 5.5 months (95% confidence interval 2.6 - 8.5). A trend toward more favorable PFS for T790M was observed (7.0 vs. 2.8 months, p = 0.06) in evaluable subjects. No confirmed partial or complete responses have been observed. Conclusions: Afatinib plus dasatinib was acceptably tolerated in pts with NSCLC in the escalation phase. Clinical benefit has been observed in the expansion phase, although without objective radiologic responses. Preliminary data support continued evaluation of afatinib 30 mg plus dasatinib 100 mg as the expansion phase dose in pts with EGFRm NSCLC with acquired TKI resistance. Citation Format: Ben Creelan, Jhanelle Gray, Diana Lima, Scott Antonia, Alberto Chiappori, Tawee Tanvetyanon, Rebecca DeVane, Charles Williams, Eric Haura. Efficacy, safety and tolerability of dasatinib combined with afatinib: a phase I trial in patients with epidermal growth factor receptor mutant (EGFRm) advanced non-small-cell lung cancer (NSCLC) after acquired tyrosine kinase inhibitor (TKI) resistance. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT060.

3,6,2′,4′,5′-Pentahydroxyflavone, an Orally Bioavailable Multiple Protein Kinase Inhibitor, Overcomes Gefitinib Resistance in Non-small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is the most lethal cancer, causing more than 150,000 deaths in the United States in 2013. The receptor tyrosine kinase inhibitors such as gefitinib are not perfect clinical therapeutic agents for NSCLC treatment due to primary or acquired tyrosine kinase inhibitor resistance. Herein, 3,6,2',4',5'-pentahydroxyflavone (36245-PHF) was identified as a multiple kinase inhibitor for NSCLC treatment based on the computational screening of a natural products database. 36245-PHF was shown to inhibit PI3K and Aurora A and B kinases and overcome gefitinib-resistant NSCLC growth. Our data clearly showed that 36245-PHF markedly inhibited anchorage-independent growth of gefitinib-resistant NSCLC cell lines and exerted a substantial chemotherapeutic effect following oral administration in a gefitinib-resistant NSCLC xenograft model. The evidence from three different subsequent methodological approaches, in vitro, ex vivo, and in vivo, all confirmed that 36245-PHF as a multiple protein kinase inhibitor. Overall, we identified 36245-PHF as a multiple protein kinase inhibitor and as a novel therapeutic agent to overcome gefitinib-resistant NSCLC growth, which could provide a new option for clinical NSCLC oral treatment.

Management of acquired resistance to epidermal growth factor receptor kinase inhibitors in patients with advanced non-small cell lung cancer.

The widespread adoption of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors for the first-line treatment of patients with advanced EGFR-mutated non-small cell lung cancer has resulted in acquired tyrosine kinase inhibitor resistance becoming a ubiquitous clinical problem. The identification of specific mechanisms of acquired resistance has allowed a better understanding of the biology and natural history of resistant disease, but is only now starting to impact treatment decisions. Strategies for managing acquired resistance in patients with advanced non-small cell lung cancer are complex and must be adapted to the individual characteristics of each patient's cancer. Although combination chemotherapy is the presumed standard of care for most patients, prospective trial data are lacking, highlighting the importance of offering patients participation in clinical trials in this setting. Emerging data from trials of third-generation mutant-specific EGFR kinase inhibitors suggests particular promise with this class of agents.

Subsequent chemotherapy reverses acquired tyrosine kinase inhibitor resistance and restores response to tyrosine kinase inhibitor in advanced non-small-cell lung cancer

BackgroundPatients with advanced or metastatic non-small cell lung cancer (NSCLC) can develop acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (TKIs) erlotinib and gefitinib. Here, we report the successful treatment with alternating chemotherapy and TKIs of two cases of advanced NSCLC who developed resistance to TKI.Case presentationTwo patients with advanced or metastatic NSCLC were treated with palliative chemotherapy followed by erlotinib/gefitinib. When TKI therapy failed, two cycles of chemotherapy were provided, which were followed by re-challenge with erlotinib or gefitinib.ConclusionNSCLC patients with acquired TKI resistance should be managed aggressively whenever possible. Subsequent chemotherapy and target treatment is one of the reasonable choices for those with an initial dramatic clinical response with erlotinib/gefitinib treatment. Further studies are warranted to substantiate the association of erlotinib /gefitinib treatment with the efficacy of NSCLC patients with acquired TKI failure.

Subsequent Chemotherapy Improves Survival Outcome in Advanced Non–Small-Cell Lung Cancer With Acquired Tyrosine Kinase Inhibitor Resistance

Background Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) provide promising effect against non–small-cell lung cancer (NSCLC), although most tumors acquire resistance. Our objective was to assess the survival outcome of patients with NSCLC with or without subsequent chemotherapy after acquired TKI resistance. Patients and Methods A total of 114 patients with pathologically confirmed stage IIIB or IV NSCLC who had had disease control with TKIs were retrospectively reviewed. After acquired TKI resistance, patients received either best supportive care (BSC) only or BSC plus subsequent chemotherapy. Both groups were well balanced in regard to performance status, age, sex, histology subtype, and smoking status. Results Sixty-seven patients (58.8%) received subsequent chemotherapy, and 47 patients (41.2%) received BSC only. The median overall survival (OS) and progression-free survival (PFS) from the time of TKI resistance in the subsequent-chemotherapy group (11.2 months and 3.5 months, respectively) were longer than those of the BSC group (3.8 months and 1.5 months, respectively; P < .01). Patients who subsequently received taxane-based chemotherapy exhibited higher a response rate and disease control rate (48.7% and 79.5%, respectively) than patients treated with a nontaxane regimen (21.4% and 53.5%, respectively; P < .05). Overall survival and PFS in patients after taxane-based subsequent chemotherapy (12.7 months and 5.1 months, respectively) were longer than those of patients given a nontaxane regimen (7 months and 1.8 months, respectively; P < .01). Conclusion This study suggests that acquired TKI resistance should be managed aggressively. The higher antitumor response and survival outcome with a taxane-based regimen in this retrospective study could encourage further prospective investigation to confirm the efficacy of taxane over nontaxane chemotherapy in patients with NSCLC whose disease progresses with EGFR TKI treatment.