Significance of tyrosine kinase inhibitors in the treatment of metastatic breast cancer

C Mundhenke, A Strauss, C Schem - Breast Care, 2009 - karger.com
C Mundhenke, A Strauss, C Schem
Breast Care, 2009karger.com
Preclinical and clinical trials suggest that tyrosine kinase inhibitors (TKI) could supplement
current therapies in metastatic breast cancer (MBC). HER-2 inhibition is still a main focus.
Numerous agents targeting the epidermal growth factor receptors EGFR and HER-2 are
currently tested after previous trastuzumab treatment. Lapatinib targets HER-2 and EGFR.
As monotherapy, clinical activity was low. Combined with cytotoxic agents, lapatinib showed
good activity (overall response rate (ORR) 24–27%) and moderate toxicity. Neratinib, a pan …
Abstract
Preclinical and clinical trials suggest that tyrosine kinase inhibitors (TKI) could supplement current therapies in metastatic breast cancer (MBC). HER-2 inhibition is still a main focus. Numerous agents targeting the epidermal growth factor receptors EGFR and HER-2 are currently tested after previous trastuzumab treatment. Lapatinib targets HER-2 and EGFR. As monotherapy, clinical activity was low. Combined with cytotoxic agents, lapatinib showed good activity (overall response rate (ORR) 24–27%) and moderate toxicity. Neratinib, a pan-ErbB TKI, showed an ORR of 26%. Neratinib combined with trastzumab was well tolerated and active (ORR = 27%). After bevacizumab’s proof-of-concept studies, antiang-iogenesis remains of importance. Sunitinib inhibits the vascular endothelial growth factor receptor (VEGFR), the platelet-derived growth factor receptor (PDGFR), c-kit and the colony-stimulating factor 1 (CSF-1) receptor. Monotherapy is tolerated and moderately active in MBC. Combination trials are ongoing. Toxicities of docetaxel ± sunitinib were manageable (ORR 72.2%). Pazopanib tar-gets VEGFR, PDGFR and c-kit. Pazopanib ± lapatinib was superior in combination (progression-free survival (PFS) = 27% vs. 19%). Axitinib has similar targets. Combined with docetaxel, it was superior compared to placebo (ORR 40% vs. 23%), with manageable toxicity. Imatinib inhibits PDGFR and c-kit. As monotherapy, it showed no clinical activity. Combination trials with chemotherapy are ongoing.
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