Lapatinib

Lapatinib (also known as GW572016), a member of the 4-anilinoquinazoline class of kinase inhibitors, is a potent, reversible and selective small-molecule inhibitor of both epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER-2) tyrosine kinases that inhibits recombinant EGFR and HER-2 tyrosine kinases in cell-free biochemical kinase assays with values of 50% inhibition concentration IC₅₀ of 10.8 nmol/L and 9.3 nmol/L respectively. Lapatinib interferes with the adenosine triphosphate binding in the tyrosine kinases domains of both EGFR and HER-2 resulting in the inhibition of auto-phosphorylation and resultant downstream signaling activities (such as cellular proliferation and survival).

Reference

Alison Reid, Laura Vidal, Heather Shaw and Johann de Bono. Dual inhibition of ErbB1 (EGFR/HER1) and ErbB2 (HER2/neu). European Journal of Cancer 43 (2007) 481-489

Norio Kondo, Mamoru Tsukuda, Yukari Ishiguro, Machiko Kimura, Kyoko Fujita, Atsuko Sakakibara, Hideaki Takahashi, Gabor Toth and Hideki Matsuda. Antitumor effects of lapatinib (GW572016), a dual inhibitor of EGFR and HER-2, in combination with cisplatin or paclitaxel on head and neck squamous cell carcinoma. Oncology Reports 23: 957-963, 2010

Zev A. Wainberg, Adrian Anghel, Amrita J. Desai, Raul Ayala, Tong Luo, Brent Safran, Marlena S. Fejzo, J. Randolph Hecht, Denni J. Slamon and Richard S. Finn. Lapatinib, a dual EGFR and HER2 kinase inhibitor, selectively inhibits HER2-amplified human gastric cancer cells and is synergistic with trastuzumab in vitro and in vivo. Clin Cancer Res 2010; 16(5): 1509-1519

Phase Ib dose-finding trial of lapatinib plus pegylated liposomal doxorubicin in advanced HER2-positive breast cancer.[Pubmed:28341957]

Cancer Chemother Pharmacol. 2017 May;79(5):863-871.

PURPOSE: Combination of anthracyclines with trastuzumab is hampered by cardiotoxicity. Pegylated liposomal doxorubicin and Lapatinib could represent a safer alternative to combination therapy. METHODS: In this phase Ib study with 3 + 3 dose escalation design, patients with HER2-positive advanced breast cancer received pegylated liposomal doxorubicin 30 mg/m(2) intravenously on day 1 plus Lapatinib 1250 (level 1) or 1500 (level 2) mg/day orally on days 1-21 of each 21-day cycle. The aims were to establish the maximum tolerated dose at first cycle, and the activity and safety of multiple cycles. RESULTS: Nine patients out of 11 enrolled were evaluable: 3 at level 1 and 6 at level 2. No dose-limiting toxicities occurred at dose level 1, while 1 (grade 3 diarrhea) occurred at dose level 2, leading to the expansion of this cohort to 6 patients, with no further dose-limiting toxicities. Main grade 1-2 toxicities at first cycle were leucopenia, diarrhea, elevated transaminases, mucositis. Three patients had grade 3 toxicities at subsequent cycles, including colitis, anorexia, stomatitis plus hand-foot syndrome. One partial response, 5 disease stabilizations, and 3 disease progressions were reported. CONCLUSIONS: Combination of pegylated liposomal doxorubicin and Lapatinib is feasible and potentially active in pretreated HER2-positive advanced breast cancer patients. TRIAL REGISTRATION: NCT02131506 (ClinicalTrials.gov identifier).

FOXO1 Suppression is a Determinant of Acquired Lapatinib-Resistance in HER2-Positive Gastric Cancer Cells Through MET Upregulation.[Pubmed:28343375]

Cancer Res Treat. 2018 Jan;50(1):239-254.

PURPOSE: Lapatinib is a candidate drug for treatment of trastuzumab-resistant, human epidermal growth factor receptor 2 (HER2)-positive gastric cancer (GC). Unfortunately, Lapatinib resistance renders this drug ineffective. The present study investigated the implication of forkhead box O1 (FOXO1) signaling in the acquired Lapatinib resistance in HER2-positive GC cells. MATERIALS AND METHODS: Lapatinib-resistant GC cell lines (SNU-216 LR2-8) were generated in vitro by chronic exposure of Lapatinib-sensitive, HER2-positive SNU-216 cells to Lapatinib. SNU-216 LR cells with FOXO1 overexpression were generated by stable transfection of a constitutively active FOXO1 mutant (FOXO1A3). HER2 and MET in SNU-216 LR cells were downregulated using RNA interference. The sensitivity of GC cells to Lapatinib and/or cisplatin was determined by crystal violet assay. In addition, Western blot analysis, luciferase reporter assay and reverse transcription-polymerase chain reaction were performed. RESULTS: SNU-216 LR cells showed upregulations of HER2 and MET, but downregulation of FOXO1 compared to parental SNU-216 cells. FOXO1 overexpression in SNU-216 LR cells significantly suppressed resistance to Lapatinib and/or cisplatin. In addition, FOXO1 negatively controlled HER2 and MET at the transcriptional level and was negatively controlled by these molecules at the post-transcriptional level. A positive crosstalk was shown between HER2 and MET, each of which increased resistance to Lapatinib and/or cisplatin. CONCLUSION: FOXO1 serves as an important linker between HER2 and MET signaling pathways through negative crosstalks and is a key regulator of the acquired Lapatinib resistance in HER2-positive GC cells. These findings provide a rationale for establishing a novel treatment strategy to overcome Lapatinib resistance in a subtype of GC patients.

HR+HER2- breast cancers with growth factor receptor-mediated EMT have a poor prognosis and lapatinib downregulates EMT in MCF-7 cells.[Pubmed:28349782]

Tumour Biol. 2017 Mar;39(3):1010428317695028.

Despite an overall good prognosis, a significant proportion of patients with hormone receptor positive human epidermal growth factor receptor 2 negative breast cancers develop distant metastases. The metastatic potential of epithelial cells is known to be regulated by tumor-stromal interaction and mediated by epithelial-to-mesenchymal transition. Hormone receptor positive human epidermal growth factor receptor 2 negative tumors were used to estimate markers of epithelial-to-mesenchymal transition, and the luminal breast cancer cell line MCF-7 was used to examine the interactions between integrins and growth factor receptors in causation of epithelial-to-mesenchymal transition. A total of 140 primary tumors were sub-divided into groups enriched for the markers of epithelial-to-mesenchymal transition (snail family transcriptional repressor 2 and integrin beta6) versus those with low levels. Within the epithelial-to-mesenchymal transition+ tumors, there was a positive correlation between the transcripts of integrin beta6 and growth factor receptors-human epidermal growth factor receptor 2 and epidermal growth factor receptor. In tumors enriched for epithelial-to-mesenchymal transition markers, patients with tumors with the highest quartile of growth factor receptor transcripts had a shorter disease-free survival compared to patients with low growth factor receptor expression by Kaplan-Meier analysis (log rank, p = 0.03). Epithelial-to-mesenchymal transition was induced in MCF-7 cells by treatment with transforming growth factor beta 1 and confirmed by upregulation of SNAI1 and SNAI2 transcripts, increase of vimentin and integrin beta6 protein, and repression of E-cadherin. Treatment of these cells with the dual-specificity tyrosine-kinase inhibitor Lapatinib led to downregulation of epithelial-to-mesenchymal transition as indicated by lower levels of SNAI1 and SNAI2 transcripts, integrin alphavbeta6, and matrix metalloproteinase 9 protein. The results suggest that synergistic interactions between growth factor receptors and integrin beta6 could mediate epithelial-to-mesenchymal transition and migration in a subset of luminal breast cancers and Lapatinib might be effective in disrupting this interaction.

Lapatinib (GW572016) is a potent inhibitor of the ErbB-2 and EGFR tyrosine kinase domains with IC50 values against purified EGFR and ErbB-2 of 10.2 and 9.8 nM, respectively.

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