Search results for "Lapatinib"

Protonation of Tyrosine Kinase Inhibitor Lapatinib: A Theoretical and Experimental Study

2019

The protonation process of tyrosine kinase inhibitor lapatinib was studied by means of 1HNMR and UV/Vis spectroscopy joint with the theoretical calculations at DFT and semi-empirical levels. DFT/M06-2X geometries were used to describe and compare the different cationic forms of lapatinib, while ZINDO/S-CI method performed on those geometries allowed for the interpretation of experimental UV/Vis spectra of lapatinib at various pH. We found that at low pH two different dicationic forms (N2N1 and N1N3) of lapatinib were present in ethanol and DMSO-d6 solutions. The first protonation, however, occurred on the aliphatic N1 in DMSO-d6, while in ethanol solutions most probably the quinazoline nitr…

NRF2 through RPS6 Activation Is Related to Anti-HER2 Drug Resistance in HER2-Amplified Gastric Cancer

2019

Abstract Purpose: Despite the clinical advantage of the combination of trastuzumab and platinum-based chemotherapy in HER2-amplified tumors, resistance will eventually develop. The identification of molecular mechanisms related to primary and acquired resistance is needed. Experimental Design: We generated lapatinib- and trastuzumab-resistant clones deriving from two different HER2-amplified gastric cancer cell lines. Molecular changes such as protein expression and gene-expression profile were evaluated to detect alterations that could be related to resistance. Functional studies in vitro were corroborated in vivo. The translational relevance of our findings was verified in a patient cohor…

Tumor-Associated Fibroblasts Promote HER2-Targeted Therapy Resistance through FGFR2 Activation

2020

AbstractPurpose:Despite the therapeutic success of existing HER2-targeted therapies, tumors invariably relapse. This study aimed at identifying new mechanisms responsible for HER2-targeted therapy resistance.Experimental Design:We have used a platform of HER2-targeted therapy–resistant cell lines and primary cultures of healthy and tumor-associated fibroblasts (TAF) to identify new potential targets related to tumor escape from anti-HER2 therapies.Results:We have shown that TAFs promote resistance to HER2-targeted therapies. TAFs produce and secrete high levels of FGF5, which induces FGFR2 activation in the surrounding breast cancer cells. FGFR2 transactivates HER2 via c-Src, leading to res…

Current treatment options for HER2-positive breast cancer patients with brain metastases

2020

Abstract Brain metastases (BMs) are frequently associated with HER2+ breast cancer (BC). Their management is based on a multi-modal strategy including both local treatment and systemic therapy. Despite therapeutic advance, BMs still have an adverse impact on survival and quality of life and the development of effective systemic therapy to prevent and treat BMs from HER2 + BC represents an unmet clinical need. Trastuzumab-based therapy has long been the mainstay of systemic therapy and over the last two decades other HER2-targeted agents including lapatinib, pertuzumab and trastuzumab emtansine, have been introduced in the clinical practice. More recently, novel agents such as neratinib, tuc…

Development of a method to determine axitinib, lapatinib and afatinib in plasma by micellar liquid chromatography and validation by the European Medi…

2017

A method based on micellar liquid chromatography to quantify the tyrosine kinase inhibitors axitinib, lapatinib and afatinib in plasma is reported. The sample pretreatment was a simple 1/5-dilution in a pure micellar solution, filtration and direct injection, without requiring extraction or purification steps. The three drugs were resolved from the matrix in 17 min, using an aqueous solution of 0.07 M sodium dodecyl sulfate – 6.0% 1-pentanol, buffered at pH 7 with 0.01 M phosphate salt as mobile phase, running under isocratic mode at 1 mL/min through a C18 column. The detection was performed by absorbance at 260 nm. An accurate mathematical relationship was established between the retention…

Gene expression changes responsible for lapatinib acquired resistance in HER2 positive gastric cancer cell lines: a microarray analysis

2017

The HERBA Study: A Retrospective Multi-Institutional Italian Study on Patients With Brain Metastases From HER2-Positive Breast Cancer

2019

There is no sufficient evidence to establish a standard of care for patients with brain metastases (BM) from HER2Data of 154 patients were retrospectively collected at 14 Italian institutions through a specifically designed database.Median overall survival (OS) was 24.5 months. Patients receiving surgery/stereotactic radiosurgery experienced longer OS compared to those receiving whole-brain radiotherapy or no treatment (33.5 vs. 11.4 months; hazard ratio = 0.34; 95% confidence interval, 0.22-0.52; P .001). Interestingly, whole-brain radiotherapy did not improve OS compared to no treatment (11.4 vs. 9.8 months; hazard ratio = 0.99; 95% confidence interval, 0.62-1.62; P = .99). HER2-targeted …

Abstract LB-146: A phase II randomized placebo-controlled study of AZD8931, an inhibitor of EGFR, HER2, and HER3 signaling, plus paclitaxel (P) vs P …

2013

Abstract Background: AZD8931 is an oral, equipotent inhibitor of EGFR, HER2, and HER3 signaling. Preclinical evidence indicates that AZD8931 may be particularly potent when HER signaling is ligand driven, which is thought to be the signaling mechanism that is more prevalent in low HER2-expressing BC. Methods: In this double-blind multicenter phase II study, women with low HER2- expressing locally advanced or metastatic BC (ineligible by HER2 status for either trastuzumab or lapatinib) were randomized 1:1 to AZD8931 40mg bid + P (90mg/m2; d1, 8 and 15, q4 weeks) or matched placebo + P (NCT00900627). The primary objective was prolonged progression-free survival (PFS; assessed by RECIST v1.1);…

Characterization of Locally Excited and Charge-Transfer States of the Anticancer Drug Lapatinib by Ultrafast Spectroscopy and Computational Studies

2020

[EN] Lapatinib (LAP) is an anticancer drug, which is metabolized to theN- and O-dealkylated products (N-LAP andO-LAP, respectively). In view of the photosensitizing potential of related drugs, a complete experimental and theoretical study has been performed on LAP,N-LAP andO-LAP, both in solution and upon complexation with human serum albumin (HSA). In organic solvents, coplanar locally excited (LE) emissive states are generated; they rapidly evolve towards twisted intramolecular charge-transfer (ICT) states. By contrast, within HSA only LE states are detected. Accordingly, femtosecond transient absorption reveals a very fast switching (ca. 2 ps) from LE (lambda(max)=550 nm) to ICT states (…

Novel therapeutic strategies for patients with NSCLC that do not respond to treatment with EGFR inhibitors

2014

Abstract: Introduction: Treatment with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) yields tumour responses in non-small cell lung cancer (NSCLC) patients harbouring activating EGFR mutations. However, even in long-lasting responses, resistance to EGFR TKIs invariably occurs. Areas covered: This review examines resistance mechanisms to EGFR TKI treatment, which mainly arise from secondary EGFR mutations. Other resistance-inducing processes include mesenchymal-epithelial transition factor (MET) amplification, epithelial-mesenchymal transformation, phenotypic change from NSCLC to small-cell lung carcinoma, and modifications in parallel signalling pathways. Current…