Tyrosine Kinase Inhibitors Treatment Research Articles

EGFR mutation based on lung laterality in adenocarcinoma type of non-small cell lung cancer

Targeted therapies have shown promise in improving survival rates for lung adenocarcinoma, a common and deadly malignancy. EGFR-targeting tyrosine kinase inhibitors (TKIs) are particularly effective among these therapies in cases with EGFR mutations. Detecting these mutations before TKI treatment is essential. Various radiological features have been linked to EGFR mutations. However, the relationship between tumor location and mutation types in Indonesian lung adenocarcinoma patients remains unexplored. This study aimed to identify the frequency of EGFR mutation in local lung adenocarcinoma cases based on the tumor location. Clinical data of lung adenocarcinoma patients (n = 272) diagnosed between 2018 and 2022 were retrospectively taken from the Department of Anatomical Pathology, Dr. Sardjito General Hospital, Yogyakarta. The qRT-PCR data of EGFR mutation status was obtained from the Department of Anatomical Pathology, Faculty of Medicine, Public Health, and Nursing, Universitas Gadjah Mada, Yogyakarta. Descriptive analysis was performed using STATA version 14.0. EGFR mutations were found in 60.7% of patients, with 58.2% having exon 19 mutations and 21.2% exhibiting exon 21 L858R mutations. Mutation status was found to be significantly different based on the patient's gender (p = 0.022) and age (p = 0.029) but not with lung laterality (p = 0.093). The proportion of exon 19, exon 21 L858R, and uncommon mutations in the right and left lung adenocarcinoma was similar across all samples. This study found no difference between specific EGFR mutation types and tumor location in lung adenocarcinoma.

CML-282 Asciminib Once-Daily (QD) Dosing Demonstrates Comparable Tolerability and Efficacy to Twice-Daily (BID) Dosing: Updated Results From the AIM4CML Study in Patients With Chronic Myeloid Leukemia in Chronic Phase (CML-CP) With Prior Tyrosine Kinase Inhibitor (TKI) Treatment

CML-282 Asciminib Once-Daily (QD) Dosing Demonstrates Comparable Tolerability and Efficacy to Twice-Daily (BID) Dosing: Updated Results From the AIM4CML Study in Patients With Chronic Myeloid Leukemia in Chronic Phase (CML-CP) With Prior Tyrosine Kinase Inhibitor (TKI) Treatment

Asciminib Once-Daily (QD) Dosing Demonstrates Comparable Tolerability and Efficacy to Twice-Daily (BID) Dosing: Updated Results From the AIM4CML Study in Patients With Chronic Myeloid Leukemia in Chronic Phase (CML-CP) With Prior Tyrosine Kinase Inhibitor (TKI) Treatment

Asciminib Once-Daily (QD) Dosing Demonstrates Comparable Tolerability and Efficacy to Twice-Daily (BID) Dosing: Updated Results From the AIM4CML Study in Patients With Chronic Myeloid Leukemia in Chronic Phase (CML-CP) With Prior Tyrosine Kinase Inhibitor (TKI) Treatment

IVAC-XS15-CLL01: personalized multi-peptide vaccination in combination with the TLR1/2 ligand XS15 in CLL patients undergoing BTK-inhibitor-based regimens.

Chronic lymphocytic leukemia (CLL) is the most common form of leukemia among adults in Western countries. Despite the introduction of targeted therapies, including first-line Bruton's tyrosine kinase inhibitor (BTKi) treatment, CLL remains largely incurable. Frequent disease relapses occur due to remaining treatment-resistant CLL cells, calling for novel therapies to eliminate minimal residual disease (MRD). Peptide-based vaccination targeting human leucocyte antigen (HLA)-presented CLL-associated antigens represents a promising, low-side-effect therapeutic option to optimize treatment responses and eliminate residual tumor cells by inducing an anti-leukemic immune response. The iVAC-XS15-CLL01 trial is an open-label, first-in-human (FIH) Phase I trial, evaluating the CLL-VAC-XS15 vaccine in CLL patients undergoing BTKi-based therapy. The vaccine was developed from HLA-presented CLL-associated antigen peptides, identified through comparative mass-spectrometry-based immunopeptidome analyses of CLL versus healthy samples in a previous study. To facilitate rapid and cost-effective deployment, vaccine peptides are selected for each patient from a pre-manufactured "peptide warehouse" based on the patient's individual HLA allotype and CLL immunopeptidome. The trial enrolls 20 CLL patients, who receive up to three doses of the vaccine, adjuvanted with the toll-like-receptor (TLR) 1/2 ligand XS15 and emulsified in Montanide ISA 51 VG. The primary objective of the iVAC-XS15-CLL01 trial is to assess the safety and immunogenicity of the CLL-VAC-XS15 vaccine. Secondary objectives are to evaluate the vaccine impact on MRD, progression-free survival, and overall survival, as well as comprehensive immunophenotyping to characterize vaccine-induced T-cell responses. This Phase I trial aims to advance CLL treatment by enhancing immune-mediated disease clearance and guiding the design of subsequent Phase II/III trials to implement a new therapeutic strategy for CLL patients.

Combination Therapy of Atezolizumab, Bevacizumab, Carboplatin, and Paclitaxel for Metastatic Non-squamous Non-small Cell Lung Cancer With Epidermal Growth Factor Receptor (EGFR)-Tyrosine Kinase Inhibitor Resistance and EGFR Mutations.

Atezolizumab, bevacizumab, carboplatin, and paclitaxel (ABCP) combination therapyhas a potential efficacy in a specific subset of non-squamous non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations following tyrosine kinase inhibitor (TKI) treatment. However, there is a dearth of investigations on the effectiveness of ABCP therapy as the primary outcome of EGFR-TKI use. A single-center retrospective analysis was performed on 24 cases of stage IV EGFR-positive non-squamous NSCLC patients who received one or more lines of EGFR-TKItherapy and subsequently initiated ABCP therapy within the timeframe of April 1, 2019, to April 30, 2023. This study assessed overall survival and progression-free survival associated with ABCP therapy, further analyzing the overall survival data based on EGFR subgroups. The mean age of the cohort was 65 ± 9 years with 14 females (58%). The performance status (PS) was recorded as 0 in 13 out of 24 patients (54%) and 1 in 11 out of 24 patients (46%). Thirteen (54%) patients had a history of smoking. Adenocarcinoma histology was prevalent in all cases. The EGFR mutations included Ex19del in 14 patients (58%) and L858R in 10 (42%) patients. At ABCP therapy initiation, liver metastases were evident in three cases (13%) and brain metastases in eight (33%). Programmed death ligand 1 (22C3) expression levels varied, with <1%, 1-49%, and ≥50% observed in five, 11, and five cases, respectively, while data were missing for three cases. The median follow-up duration was 14.1 months, with median overall survival estimated at 23.6 months (95% CI: 14.5 months - not reached) and median progression-free survival at 5.6 months (95% CI: 4.9-11.5 months). The EGFR L858R mutation showed a favorable trend in overall survival compared with the EGFR Ex19del mutation (not evaluated vs. 23.6 months). ABCP therapy for EGFR-positive non-squamous NSCLC is a promising option, similar to immune checkpoint inhibitor-free platinum-based combination therapy. Therefore, prospective trials are necessary to confirm the efficacy of these treatments.

Lazertinib in EGFR-Variant Non–Small Cell Lung Cancer With CNS Failure to Prior EGFR Tyrosine Kinase Inhibitors

EGFR-variant non-small cell lung cancer (NSCLC) is associated with a high rate of central nervous system (CNS) metastases, even with treatment with first-generation or second-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). To investigate CNS activity with lazertinib, a third-generation EGFR TKI. This multicenter single-arm, phase 2 nonrandomized controlled trial was conducted in South Korea and included patients with EGFR-variant NSCLC who had asymptomatic or mildly symptomatic brain metastases after unsuccessful treatment with first-generation or second-generation EGFR TKIs. Data were collected from June 2021 to April 2022, with a data cutoff date of December 15, 2022. Lazertinib, 240 mg, once daily. The primary end point was intracranial objective response rate (iORR) in the evaluable population according to the Response Evaluation Criteria in Solid Tumours version 1.1 assessed by the investigators. Secondary end points included intracranial progression-free survival (iPFS) and iORR in patients with T790M-negative disease and isolated CNS progression as well as overall ORR, duration of response, intracranial duration of response, disease control rate, overall survival, cerebrospinal fluid penetration of lazertinib, and safety. Among 40 included patients, 25 (63%) were women, and the median (range) age was 63 (29-85) years. A total of 38 patients were evaluable for tumor response, including 12 patients with leptomeningeal metastases. At data cutoff, the median (range) follow-up was 13.6 (2.9-17.7) months. The iORR for the evaluable population was 55% (21 of 38; 95% CI, 38.3-71.4); for patients with T790M-positive disease, 80% (4 of 5; 95% CI, 28.4-99.5); for patients with T790M-negative disease, 43% (9 of 21; 95% CI, 21.8-66.0); and for patients with T790M-unknown disease, 67% (8 of 12; 95% CI, 34.9-90.1). The median iPFS was 15.8 months (95% CI, 15.2-not reached) for the evaluable population, 15.2 months (95% CI, 4.2-not reached) for the T790M-positive subgroup, 15.4 months (95% CI, 7.9-not reached) for the T790M-negative subgroup, and 18.0 months (95% CI, 3.9-not reached) for the T790M-unknown subgroup. The cerebrospinal fluid penetration rate of lazertinib was 46.2% (95% CI, 10.0-49.6), providing further support for its mechanism of intracranial response. Most adverse events were grade 1 or 2. In this study, lazertinib had substantial CNS activity, regardless of T790M status, against the progression of intracranial metastases with or without leptomeningeal metastases after unsuccessful treatment with first-generation or second-generation EGFR TKIs in patients with metastatic EGFR-variant NSCLC. These results suggest that using lazertinib instead of brain local treatment could be a potential strategy in patients with EGFR-variant NSCLC whose CNS metastases progressed after prior EGFR TKI treatment. ClinicalTrials.gov Identifier: NCT05326425.

Global Trial Representation and Availability of Tyrosine Kinase Inhibitors for Treatment of Chronic Myeloid Leukemia.

Background: Evaluating clinical trial representation for countries with different socio-demographic index (SDI) and tyrosine kinase inhibitor (TKI) availability for chronic myeloid leukemia (CML). Methods: CML incidence rates (IRs) and disability-adjusted life years (DALYs) (1999-2019) from the Institute of Health Metrics and Evaluation were analyzed. Trials investigating TKI use in CML were obtained from ClinicalTrials.gov. Site data for eligible trials (N = 30) and DALYs were analyzed. TKI approvals, DALYs, and IRs were summarized by SDI. Results: North America (NA) had significant decreases in annual percent change (APC) in DALYs and incidence rates from 1999 to 2004. IRs were highest in Europe and Central Asia (ECA) and NA, while DALYs were highest in South Asia (SAsia) and Sub-Saharan Africa (SSA). Countries in the high-SDI quintile were likely to have lower DALYs than lower-SDI quintiles. Differences in regional DALYs vs. sites in TKI trials were significant for SAsia, SSA, and ECA. High-SDI countries were included in all 30 trials, and TKI approvals were prominent in high-SDI (142) vs. low-SDI (14) countries. Conclusions: The inclusion of disproportionately affected countries during the design of and recruitment into clinical trials should occur, as should TKI availability. The lack of representation demonstrates healthcare disparities.

An observational study on the relationship between tyrosine kinase inhibitor treatment-free remission and cytotoxic T-lymphocytes in patients with chronic phase chronic myeloid leukemia.

171 Background: Since the introduction of tyrosine kinase inhibitors (TKIs), the effectiveness of treating chronic phase chronic myeloid leukemia has seen remarkable improvement. A current challenge in TKI therapy is achieving treatment-free remission (TFR) safely. Numerous TKI-stop trials and translational studies have investigated factors influencing TFR, including TKI treatment duration, duration of deep molecular response (DMR), cellular immunity activation, and bcr::abl1 transcript type. However, identifying reliable markers for achieving TFR safely remains uncertain. In this multicenter study, we focused on examining the association between TFR and cytotoxic T-lymphocytes (CTLs). Methods: Between June 2020 and March 2022, a total of 45 patients were enrolled: 38 patients with DMR for at least 1 year on TKIs (on TKI group) and 7 patients with DMR for at least 1 year after discontinuing TKIs (off TKI group). The study included 30 males, with a median age of 59 years (range: 29–87). Median TKI treatment duration was 7.7 years (range: 1.5–18.3), and median TKI cessation duration in the off TKI group was 4.9 years (range: 1.7–7.1). Molecular response and cellular immunity were monitored over 12 months post-consent for patients in the off TKI group and after TKI discontinuation for patients in the on TKI group. Results: During the observation period, 25 patients (65.8%) in the on TKI group maintained DMR, while 13 patients (34.2%) lost DMR. Conversely, all patients in the off TKI group sustained DMR. The median TKI treatment duration in the group maintaining DMR (9.45 years, range: 3.3–18.3, N = 32) significantly exceeded that in the group losing DMR (4.9 years, range: 1.5–11.9, N = 13) (P = 0.0048). Patients taking TKIs for over 7 years with a higher percentage of total memory CTLs than total effector CTLs maintained DMR. Conversely, patients losing DMR despite over 10 years of TKI treatment had a higher percentage of total effector CTLs than total memory CTLs. Among the 32 patients maintaining DMR, 19 exhibited a higher percentage of total effector CTLs than total memory CTLs, with 15 (78.9%) maintaining MR5 throughout the study. Furthermore, of the six patients maintaining DMR with relatively short TKI administration (median 5.5 years, range: 3.3–6.4), three displayed a higher percentage of total memory CTLs than total effector CTLs. Among the remaining three patients, two showed strong CTL activation, with one patient having an effector CTL clone over 30% and the other having a memory CTL clone over 30%. Conclusions: This study indicates that a sufficiently prolonged TKI treatment duration (&gt;7 years) and maintaining deeper DMR (≥ MR4.5, preferably MR5) are conducive to safely achieving TFR. Furthermore, a high percentage of total memory CTLs and intense CTL activation may serve as meaningful markers for TFR.

REZILIENT3: Phase 3 study of zipalertinib plus chemotherapy in patients with previously untreated, advanced nonsquamous non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) exon 20 insertions (ex20ins) mutations.

TPS219 Background: Despite recent advances, tolerable and effective treatments for patients with NSCLC harboring EGFR ex20ins mutations are needed, particularly in the first-line setting where platinum-based chemotherapy remains the standard of care. Zipalertinib (CLN-081/TAS6417), an oral tyrosine kinase inhibitor (TKI) of EGFR with broad activity against EGFR mutations, showed encouraging antitumor activity in heavily pretreated patients with EGFR ex20ins–mutant NSCLC, leading to ‘Breakthrough Therapy’ designation by the U.S. Food and Drug Administration in January 2022. Data suggest that combining EGFR TKIs with chemotherapy can improve antitumor efficacy versus chemotherapy or TKI treatment alone in patients with EGFR-mutated nonsquamous NSCLC. REZILIENT3 is a pivotal phase 3 study designed to compare the efficacy and safety of zipalertinib plus first-line standard-of-care platinum-based chemotherapy versus chemotherapy alone in previously untreated patients with nonsquamous NSCLC harboring EGFR ex20ins mutations. Methods: This randomized, controlled, open-label, phase 3 study (NCT05973773) will be conducted in two parts. Part A (safety lead-in) will confirm the safety of zipalertinib 100 mg twice daily as the recommended dose in combination with chemotherapy in patients with locally advanced or metastatic nonsquamous NSCLC harboring EGFR ex20ins mutations or other uncommon single/compound EGFR mutations. In Part B (randomized part), patients with EGFR ex20ins mutations and at least one measurable lesion (per Response Evaluation Criteria in Solid Tumours, version 1.1) will be randomized 1:1 to zipalertinib plus chemotherapy or chemotherapy alone, stratified by Eastern Cooperative Oncology Group performance status (0/1), brain metastases (yes/no), and geography (Asia/rest of world). Zipalertinib will be administered orally at a starting dose of 100 mg twice daily (pending confirmation in Part A). Chemotherapy (pemetrexed 500 mg/m² plus cisplatin 75 mg/m² or carboplatin area under the curve 5 mg/mL/min) will be administered intravenously on Day 1 of each cycle (carboplatin/cisplatin for four cycles). Patients randomized to chemotherapy alone will be allowed to cross over to zipalertinib monotherapy after documented progressive disease. The primary endpoint in Part B is progression-free survival assessed by blinded independent central review. Secondary endpoints include overall survival, investigator-assessed progression-free survival, objective response rate, duration of response, disease control rate, safety, intracranial efficacy endpoints, and quality of life. Part A is anticipated to enroll between 6 and 12 patients, while Part B is estimated to enroll approximately 260 patients. Enrollment started in June 2023. Clinical trial information: NCT05973773 .

SKF-96365 Expels Tyrosine Kinase Inhibitor-Treated CML Stem and Progenitor Cells from the HS27A Stromal Cell Niche in a RhoA-Dependent Mechanism.

A major issue in Chronic Myeloid Leukemia (CML) is the persistence of quiescent leukemia stem cells (LSCs) in the hematopoietic niche under tyrosine kinase inhibitor (TKI) treatment. Here, using CFSE sorting, we show that low-proliferating CD34+ cells from CML patients in 3D co-culture hide under HS27A stromal cells during TKI treatment-a behavior less observed in untreated cells. Under the same conditions, Ba/F3p210 cells lose their spontaneous motility. In CML CD34+ and Ba/F3p210 cells, while Rac1 is completely inhibited by TKI, RhoA remains activated but is unable to signal to ROCK. Co-incubation of Ba/F3p210 cells with TKI, SKF-96365 (a calcium channel inhibitor), and EGF restores myosin II activation and amoeboid motility to levels comparable to untreated cells, sustaining the activation of ROCK. In CFSE+ CD34+ cells containing quiescent leukemic stem cells, co-incubation of TKI with SKF-96365 induced the expulsion of these cells from the HS27A niche. This study underscores the role of RhoA in LSC behavior under TKI treatment and suggests that SKF-96365 could remobilize quiescent CML LSCs through reactivation of the RhoA/ROCK pathway.

Electrochemical sensing technology based on a ligation-initiated LAMP-assisted CRISPR/Cas12a system for high-specificity detection of EGFR E746–A750 deletion mutation

Epidermal growth factor receptor (EGFR) mutation status is pivotal in predicting the efficacy of tyrosine kinase inhibitor treatments against tumors. Among EGFR mutations, the E746–A750 deletion is particularly common and accurately quantifying it can guide targeted therapies. This study introduces a novel visual sensing technology using the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a system guided by ligation-initiated loop-mediated isothermal amplification (LAMP) to detect the del E746–A750 mutation in EGFR. Conventional LAMP primers were simplified by designing a pair of target-specific stem-loop DNA probes, enabling selective amplification of the target DNA. The CRISPR/Cas12a system was employed to identify the target nucleic acid and activate Cas12a trans-cleavage activity, thereby enhancing the specificity of the assay. Furthermore, the biosensor utilized high-performance nanomaterials such as triangular gold nanoparticles and graphdiyne, known for their large specific surface area, to enhance sensitivity effectively as a sensing platform. The proposed biosensor demonstrated outstanding specificity, achieving a low detection limit of 17 fM (S/N = 3). Consequently, this innovative strategy not only expands the application scope of CRISPR/Cas12a technology but also introduces a promising approach for clinical diagnostics in modern medicine.

Computed tomography-based radiomics and clinical-genetic features for brain metastasis prediction in patients with stage III/IV epidermal growth factor receptor-mutant non-small-cell lung cancer.

To evaluate the value of computed tomography (CT)-based radiomics combined with clinical-genetic features in predicting brain metastasis in patients with stage III/IV epidermal growth factor receptor (EGFR)-mutant non-small-cell lung cancer (NSCLC). The study included 147 eligible patients treated at our institution between January 2018 and May 2021. Patients were randomly divided into two cohorts for model training (n = 102) and validation (n = 45). Radiomics features were extracted from the chest CT images before treatment, and a radiomics signature was constructed using the Least Absolute Shrinkage and Selection Operator regression. Kaplan-Meier survival analysis was used to describe the differences in brain metastasis-free survival (BM-FS) risk. A clinical-genetic model was developed using Cox regression analysis. Radiomics, genetic, and combined prediction models were constructed, and their predictive performances were evaluated by the concordance index (C-index). Patients with a low radiomics score had significantly longer BM-FS than those with a high radiomics score in both the training (p < 0.0001) and the validation (p = 0.0016) cohorts. The C-indices of the nomogram, which combined the radiomics signature and N stage, overall stage, third-generation tyrosine kinase inhibitor treatment, and EGFR mutation status, were 0.886 (95% confidence interval [CI] 0.823-0.949) and 0.811 (95% CI 0.719-0.903) in the training and validation cohorts, respectively. The combined model achieved a higher discrimination and clinical utility than the single prediction models. The combined radiomics-genetic model could be used to predict BM-FS in stage III/IV NSCLC patients with EGFR mutations.

Real-world treatment sequencing and effectiveness of second- and third-generation ALK tyrosine kinase inhibitors for ALK-positive advanced non-small cell lung cancer

IntroductionWith multiple targeted therapies approved for anaplastic lymphoma kinase (ALK)-positive metastatic non-small cell lung cancer (NSCLC), it is increasingly important to understand outcomes with various sequences of next-generation ALK tyrosine kinase inhibitors (TKIs). We describe contemporary sequencing patterns and treatment effectiveness of first-line (1L) and second-line (2L) treatments in patients who received second-generation ALK TKIs in the 1L treatment of ALK-positive NSCLC in the United States. MethodsA cohort of adults with ALK-positive advanced NSCLC who initiated treatment with 1L alectinib or brigatinib between June 2017 and April 2021 in the Flatiron Health electronic health record–derived de-identified database were followed through April 2023. Time to treatment discontinuation (TTD) in 1L and 2L, TTD on 1L plus 2L sequential therapy (TTD2), and total time on sequential ALK TKI therapy (including beyond 2L) were evaluated. ResultsPatients (N=273) were followed up for a median duration of 28.9 months. Among patients who discontinued 1L therapy, 22% died after 1L discontinuation (median time from discontinuation to death, 4.0 months) without receiving 2L therapy. Median (95% confidence interval [CI]) TTD was 21.9 (15.2–25.8) and 7.3 (5.3–10.2) months in 1L and 2L, respectively. Median (95% CI) TTD2 was 29.4 (25.1–36.1) months and total time on sequential ALK TKI treatment was 28.0 (23.6–32.9) months. ConclusionsIn this large real-world study, TTD2 and the total time on sequential ALK TKIs was approximately 2.5 years. The high attrition rate from 1L to 2L and the longest clinical benefit observed with 1L therapy support using the drug with the longest 1L effectiveness up front in patients with ALK-positive advanced NSCLC.

Outcomes in non-small cell lung cancer with uncommon epidermal growth factor receptor L858 substitutions under first-line epidermal growth factor receptor tyrosine kinase inhibitors: A large real-world cohort study.

Atypical L858R or other L858X mutations in the epidermal growth factor receptor (EGFR) gene, beyond the classical EGFRL858R mutation caused by c.2573 T > G, have been identified in non-small cell lung cancer (NSCLC), yet their genomic features and survival benefits with EGFR tyrosine kinase inhibitor (TKI) treatment have not been fully explored. We retrospectively enrolled 489 NSCLC patients with baseline tumor tissue/plasma samples carrying uncommon EGFRL858R (N = 124), EGFRL858Q/M (N = 17), or classical EGFRL858R mutations (N = 348). The comparison of molecular features was performed using treatment-naïve tumor tissues. Survival benefits and resistance mechanisms of first-line EGFR TKI treatment were studied in an advanced disease subcohort. NSCLCs harboring uncommon EGFRL858R had lower TP53 mutation prevalence (p = 0.04) and chromosome instability scores (p = 0.02) than those with classical EGFRL858R. Concomitant EGFRL861Q mutations were enriched in NSCLCs with EGFRL858Q/M (p < 0.01), with cooccurrence in those carrying EGFRL858M. Patients with uncommon EGFRL858R experienced improved progression-free survival (PFS) compared to those with classical EGFRL858R (median: 13.0 vs. 10.0 months, hazard ratio [HR]: 0.57, 95% confidence interval [CI]: 0.41-0.80). The association remained significant when adjusting for sex, age, histological subtype, TKI category, and anti-vascular therapy (HR: 0.55, 95% CI: 0.39-0.77). Furthermore, EGFRL858Q/M patients showed enhanced first-line PFS (vs. classical EGFRL858R, HR: 0.26, 95% CI: 0.10-0.67), potentially benefiting more from afatinib. Additionally, NSCLCs with uncommon EGFRL858R and classical EGFRL858R had similar resistance profiles to EGFR TKIs. In conclusion, NSCLCs carrying atypical EGFR L858 aberrations, which had fewer TP53 mutations and higher chromosome stability, exhibited improved PFS under first-line EGFR TKIs than those with the classical EGFRL858R.

GSTO1 aggravates EGFR-TKIs resistance and tumor metastasis via deglutathionylation of NPM1 in lung adenocarcinoma.

Despite significantly improved clinical outcomes in EGFR-mutant lung adenocarcinoma, all patients develop acquired resistance and malignancy on the treatment of EGFR tyrosine kinase inhibitors (EGFR-TKIs). Understanding the resistance mechanisms is crucial to uncover novel therapeutic targets to improve the efficacy of EGFR-TKI treatment. Here, integrated analysis using RNA-Seq and shRNAs metabolic screening reveals glutathione S-transferase omega 1 (GSTO1) as one of the key metabolic enzymes that is required for EGFR-TKIs resistance in lung adenocarcinoma cells. Aberrant upregulation of GSTO1 confers EGFR-TKIs resistance and tumor metastasis in vitro and in vivo dependent on its active-site cysteine 32 (C32). Pharmacological inhibition or knockdown of GSTO1 restores sensitivity to EGFR-TKIs and synergistically enhances tumoricidal effects. Importantly, nucleophosmin 1 (NPM1) cysteine 104 is deglutathionylated by GSTO1 through its active C32 site, which leads to activation of the AKT/NF-κB signaling pathway. In addition, clinical data illustrates that GSTO1 level is positively correlated with NPM1 level, NF-κB-mediated transcriptions and progression of human lung adenocarcinoma. Overall, our study highlights a novel mechanism of GSTO1 mediating EGFR-TKIs resistance and malignant progression via protein deglutathionylation, and GSTO1/NPM1/AKT/NF-κB axis as a potential therapeutic vulnerability in lung adenocarcinoma.

Discontinuation of Tyrosine Kinase Inhibitor Therapy and Treatment Free Remission (TFR) in Chronic Myeloid Leukemia: Successful Achievement of TFR in More Than Two-Third of Patients in a Real-World Practice

BackgroundDiscontinuation of TKI therapy and treatment-free remission (TFR) have become new goals for chronic-phase chronic myeloid leukemia (CP-CML). The aim of this study was to estimate the TFR post discontinuation of TKI therapy at 3 tertiary-care centers. Patients and MethodsCP-CML patients aged ≥16 years who had an attempt to discontinue TKI therapy till June 2022, were eligible. The collected data included patients’ demographics, prognostic score, type and duration of TKI therapy, response dates, relapse dates, response to re-initiation of TKI therapy, and risk factors for relapse. ResultsFifty-five patients (35, 63.6% females) with a median age of 40 (range 16-74) years at diagnosis discontinued therapy. Forty-eight (87.3%) patients received imatinib as first line therapy. Twenty-nine (52.7%) patients were receiving imatinib at the time of TKI-discontinuation. Median time from diagnosis to TKI discontinuation was 86 months (IQR 60;132) and median duration of TKI therapy after achieving DMR was 66 months (IQR 47;114). After a median follow up of 34 (IQR 12;68) months, 15 (27.3%) patients relapsed. Median time to relapse was 5 months (range 2-38). Most of the relapses occurred during the first 6 months except 3 (20%) patients. All the relapsed patients achieved MMR after a median of 3 (range 2-6) months after restarting TKI therapy. None of the patients progressed to advanced-phase. ConclusionOur experience confirms that discontinuation of TKI therapy in CP-CML patients is feasible and safe in routine clinical practice, and can achieve TFR in more than two-third of carefully selected patients.

Lefamulin Overcomes Acquired Drug Resistance via Regulating Mitochondrial Homeostasis by Targeting ILF3 in Hepatocellular Carcinoma.

Acquired resistance represents a critical clinical challenge to molecular targeted therapies such as tyrosine kinase inhibitors (TKIs) treatment in hepatocellular carcinoma (HCC). Therefore, it is urgent to explore new mechanisms and therapeutics that can overcome or delay resistance. Here, a US Food and Drug Administration (FDA)-approved pleuromutilin antibiotic is identified that overcomes sorafenib resistance in HCC cell lines, cell line-derived xenograft (CDX) and hydrodynamic injection mouse models. It is demonstrated that lefamulin targets interleukin enhancer-binding factor 3 (ILF3) to increase the sorafenib susceptibility of HCC via impairing mitochondrial function. Mechanistically, lefamulin directly binds to the Alanine-99 site of ILF3 protein and interferes with acetyltransferase general control non-depressible 5 (GCN5) and CREB binding protein (CBP) mediated acetylation of Lysine-100 site, which disrupts the ILF3-mediated transcription of mitochondrial ribosomal protein L12 (MRPL12) and subsequent mitochondrial biogenesis. Clinical data further confirm that high ILF3 or MRPL12 expression is associated with poor survival and targeted therapy efficacy in HCC. Conclusively, this findings suggest that ILF3 is a potential therapeutic target for overcoming resistance to TKIs, and lefamulin may be a novel combination therapy strategy for HCC treatment with sorafenib and regorafenib.

HDAC8 Enhances the Function of HIF-2α by Deacetylating ETS1 to Decrease the Sensitivity of TKIs in ccRCC.

Drug resistance after long-term use of Tyrosine kinase inhibitors (TKIs) has become an obstacle for prolonging the survival time of patients with clear cell renal cell carcinoma (ccRCC). Here, genome-wide CRISPR-based screening to reveal that HDAC8 is involved in decreasing the sensitivity of ccRCC cells to sunitinib is applied. Mechanically, HDAC8 deacetylated ETS1 at the K245 site to promote the interaction between ETS1 and HIF-2α and enhance the transcriptional activity of the ETS1/HIF-2α complex. However, the antitumor effect of inhibiting HDAC8 on sensitized TKI is not very satisfactory. Subsequently, inhibition of HDAC8 increased the expression of NEK1, and up-regulated NEK1 phosphorylated ETS1 at the T241 site to promote the interaction between ETS1 and HIF-2α by impeded acetylation at ETS1-K245 site is showed. Moreover, TKI treatment increased the expression of HDAC8 by inhibiting STAT3 phosphorylation in ccRCC cells is also found. These 2 findings highlight a potential mechanism of acquired resistance to TKIs and HDAC8 inhibitors in ccRCC. Finally, HDAC8-in-PROTACs to optimize the effects of HDAC8 inhibitors through degrading HDAC8 and overcoming the resistance of ccRCC to TKIs are synthesized. Collectively, the results revealed HDAC8 as a potential therapeutic candidate for resistance to ccRCC-targeted therapies.

CD44-hyaluronan mediating endocytosis of iron-platinum alloy nanoparticles induces ferroptotic cell death in mesenchymal-state lung cancer cells with tyrosine kinase inhibitor resistance

While tyrosine kinase inhibitor resistance in cancer is a critical issue in the medical field, it is important for clinical testing as well, since it affects the ultimate outcome of cancer therapy. Yet, no effective solutions have been implemented till date. Clinical observations after tyrosine kinase inhibitor treatment reveal that acquired resistance inevitably limits the curative effects of non-small cell lung cancer treatment because of mutations in the epidermal growth factor receptor gene, which are accompanied by epithelial-mesenchymal transition. Here, for the first time, we report that the transmembrane glycoprotein CD44, which is associated with epithelial-mesenchymal transition, chemoresistance, and cancer progression, mediates enhanced endocytosis of iron-platinum alloy nanoparticles (FePt NPs) in the mesenchymal-state gefitinib-resistant (GR+ and M6) cells, via the binding of the CD44 ligand, hyaluronan, to the surface-absorbed hyaluronan-binding protein 2. Upon treatment with FePt NPs, there was higher cellular uptake in mesenchymal-state GR+ and M6 cells, resulting from cell death through ferroptosis and mitochondrial dysfunction, as compared to that observed in the epithelial-state cells. Mechanistically, inactivation of dihydroorotate dehydrogenase elevated the production of mitochondrial lipid peroxidation, and enhanced the cell death in the epithelial-state HCC827 cells, thereby indicating its role in defense against FePt NPs-induced ferroptosis. Furthermore, induction of ferroptosis has been shown to specifically promote the cell death of drug-tolerant “persister” cells and reverse their resistance as well. Therefore, we concluded that FePt NPs preferentially target mesenchymal drug-tolerant “persister” cells and promote ferroptosis, to overcome their resistance. Statement of significanceIn the present study, we identified FePt NPs as an innovative agent for cancer treatment, particularly in mesenchymal-state cells that exhibit TKI resistance. Mesenchymal-state cancer cells showed enhanced uptake of FePt NPs via CD44-HA-mediated endocytosis, accompanied by severe cell death and mitochondrial morphology alterations, in comparison to epithelial-state cells. We further elucidated the mechanism underlying FePt NPs-induced ferroptotic cell death as via a burst of mitochondrial LPO and DHODH protein inactivation. In addition, we found that FePt NPs inhibit tumor growth in TKI-resistant mesenchymal GR+ cell-bearing mice with better efficacy than the ferroptotic inducer RSL3. Our current findings on using FePt NPs to overcome TKI resistance through ferroptosis activation may offer a alternative strategy for improved cancer treatment.

Superior detection of low-allele burden Janus kinase 2 V617F mutation and monitoring clonal evolution in myeloproliferative neoplasms using chip-based digital PCR

The JAK2 V617F is a prevalent driver mutation in Philadelphia chromosome-negative myeloproliferative neoplasms (Ph−MPNs), significantly affecting disease progression, immunophenotype, and patient outcomes. The World Health Organization (WHO) guidelines highlight the JAK2 V617F mutation as one of the key diagnostic criterions for Ph−MPNs. In this study, we analyzed 283 MPN samples with the JAK2 V617F mutation to assess the effectiveness of three detection technologies: chip-based digital PCR (cdPCR), real-time quantitative PCR (qPCR), and next-generation sequencing (NGS). Additionally, we investigated the relationship between JAK2 V617F mutant allele burden (% JAK2 V617F) and various laboratory characteristics to elucidate potential implications in MPN diagnosis. Our findings demonstrated high conformance of cdPCR with qPCR/NGS for detecting % JAK2 V617F, but the mutant allele burdens detected by qPCR/NGS were lower than those detected by cdPCR. Moreover, the cdPCR exhibited high sensitivity with a limit of detection (LoD) of 0.08% and a limit of quantification (LoQ) of 0.2% for detecting % JAK2 V617F in MPNs. Clinical implications were explored by correlating % JAK2 V617F with various laboratory characteristics in MPN patients, revealing significant associations with white blood cell counts, lactate dehydrogenase levels, and particularly β2-microglobulin (β2-MG) levels. Finally, a case report illustrated the application of cdPCR in detecting low-allele burdens in a de novo chronic myeloid leukemia (CML) patient with a hidden JAK2 V617F subclone, which expanded during tyrosine kinase inhibitor (TKI) treatment. Our findings underscore the superior sensitivity and accuracy of cdPCR, making it a valuable tool for early diagnosis and monitoring clonal evolution.