HER2 Support Group Forums - View Single Post - A better antiangiogenic way to block tumor growth (prevents rebound)!!

Rich66 · 09-23-2010, 06:18 PM

Well...I knew the intermittent part

How much oral TAM does it take to get to that level?

Ok..
Here's the study..and some other related studies:

A Phase I Study of a 2-Day Lapatinib Chemosensitization Pulse Preceding Nanoparticle Albumin-Bound Paclitaxel for Advanced Solid Malignancies

Amy J. Chien1,6, Julie A. Illi6, Andrew H. Ko1,6, Wolfgang M. Korn1,6, Lawrence Fong1,6, Lee-may Chen2,6, Mohammed Kashani-Sabet3,6, Charles J. Ryan1,6, Jonathan E. Rosenberg1,6, Sarita Dubey1,6, Eric J. Small1,6, Thierry M. Jahan1,6, Nola M. Hylton4,6, Benjamin M. Yeh4,6, Yong Huang5, Kevin M. Koch7 and Mark M. Moasser1,6 Authors' Affiliations: Departments of 1 Medicine, 2 Obstetrics, Gynecology, and Reproductive Sciences, 3 Dermatology, 4 Radiology, 5 Biopharmaceutical Sciences, and 6 Helen Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, California and 7 Clinical Pharmacology Modeling and Simulation, GlaxoSmithKline, Research Triangle Park, North Carolina
Requests for reprints: Mark M. Moasser, Helen Diller Comprehensive Cancer Center, University of California, San Francisco, Box 0875, San Francisco, CA 94143-0875. Phone: 415-476-0158; Fax; 415-353-7692; E-mail: mmoasser@medicine.ucsf.edu.
Purpose: Systemic chemotherapy fails to access much of the tumor burden in patients with advanced cancer, significantly limiting its efficacy. In preclinical studies, brief high doses of tyrosine kinase inhibitors (TKI) targeting the human epidermal growth factor receptor (HER) family can prime tumor vasculature for optimal chemotherapeutic delivery and efficacy. This study investigates the clinical relevance of this approach.
Experimental Design: A phase I clinical study of escalating doses of the HER TKI lapatinib given as a 2-day pulse before a weekly infusion of nab-paclitaxel (100 mg/m2) was conducted in patients with advanced solid tumors.
Results: Twenty-five patients were treated. Treatment was associated with grade 1 to 2 toxicities including diarrhea, nausea, rash, neutropenia, neuropathy, fatigue, alopecia, and anemia. The two dose-limiting toxicities were grade 3 vomiting and grade 4 neutropenia, and the maximum tolerated dose of lapatinib was defined as 5250 mg/day in divided doses. Lapatinib concentrations increased with increasing dose. Dynamic Contrast Enhanced Magnetic Resonance Imaging studies in a subset of patients confirmed a decrease in tumor vascular permeability immediately following a lapatinib pulse. Sixty-five percent of evaluable patients experienced a partial or stable response on this therapy, 72% of whom were previously taxane-refractory.
Conclusion: A 2-day pulse of high-dose lapatinib given before weekly nab-paclitaxel is a feasible and tolerable clinical regimen, suitable for testing this novel vascular-priming chemosensitization hypothesis developed in preclinical models. (Clin Cancer Res 2009;15(17):5569–75)

Anticancer Drugs. 2009 Nov;20(10):918-25.
Role of efflux pump activity in lapatinib/caelyx combination in breast cancer cell lines.

Vannini I, Zoli W, Fabbri F, Ulivi P, Tesei A, Carloni S, Brigliadori G, Amadori D.
Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori, Meldola (FC), Italy.
The aim of this study was to investigate, at preclinical level, efflux pump modulation induced by lapatinib, a small-molecule dual inhibitor of the epidermal growth factor receptor (EGFR), in HER2-negative or HER2-positive breast cancer cell lines (SkBr3 and BRC230). We also evaluated the cytotoxic activity and modulation of biomolecular cellular pathways regulated by caelyx and lapatinib, used singly or in combination, at concentrations corresponding to peak plasma level in the two cell lines. Lapatinib was active in the HER2-overexpressing cell line, SkBr3, but not in BRC230 cell line, which does not express HER2. Conversely, caelyx exerted a cytotoxic effect on both the cell lines. Simultaneous exposure to lapatinib and caelyx in SkBr3 cell line produced an additive cytotoxic effect with dephosphorylation of HER2 and EGFR, an upregulation of p21, and an induction of apoptosis through dephosphorylation of BAD and caspase cleavage. In BRC230, simultaneous treatment induced a synergistic effect that was because of, at least in part, an upregulation of p21. Lapatinib also blocked efflux pumps, such as the breast cancer resistance protein I by increasing the length of time in which caelyx was present in tumor cell cytoplasm, which led to caspase cleavage, BAD dephosphorylation, and apoptosis. Our data indicate that lapatinib used in combination with caelyx is active in HER2-expressing cells, probably because of lapatinib-induced dephosphorylation of the HER2-EGFR pathway, and also in non-HER2-expressing cells, possibly because lapatinib blocks efflux pump activity, increasing the length of time of intracellular exposure to caelyx and thereby increasing its cytotoxic effect.

PMID: 19752719 [PubMed - indexed for MEDLINE]

Cancer Res. 2008 Oct 1;68(19):7905-14.
Lapatinib (Tykerb, GW572016) reverses multidrug resistance in cancer cells by inhibiting the activity of ATP-binding cassette subfamily B member 1 and G member 2.

Dai CL, Tiwari AK, Wu CP, Su XD, Wang SR, Liu DG, Ashby CR Jr, Huang Y, Robey RW, Liang YJ, Chen LM, Shi CJ, Ambudkar SV, Chen ZS, Fu LW.
State Key Laboratory for Oncology in South China, Cancer Center, Sun Yat-Sen University, Guangzhou, China.
Erratum in:

Cancer Res. 2008 Dec 15;68(24):10387.

Lapatinib is active at the ATP-binding site of tyrosine kinases that are associated with the human epidermal growth factor receptor (Her-1 or ErbB1) and Her-2. It is conceivable that lapatinib may inhibit the function of ATP-binding cassette (ABC) transporters by binding to their ATP-binding sites. The aim of this study was to investigate the ability of lapatinib to reverse tumor multidrug resistance (MDR) due to overexpression of ABC subfamily B member 1 (ABCB1) and ABC subfamily G member 2 (ABCG2) transporters. Our results showed that lapatinib significantly enhanced the sensitivity to ABCB1 or ABCG2 substrates in cells expressing these transporters, although a small synergetic effect was observed in combining lapatinib and conventional chemotherapeutic agents in parental sensitive MCF-7 or S1 cells. Lapatinib alone, however, did not significantly alter the sensitivity of non-ABCB1 or non-ABCG2 substrates in sensitive and resistant cells. Additionally, lapatinib significantly increased the accumulation of doxorubicin or mitoxantrone in ABCB1- or ABCG2-overexpressing cells and inhibited the transport of methotrexate and E(2)17betaG by ABCG2. Furthermore, lapatinib stimulated the ATPase activity of both ABCB1 and ABCG2 and inhibited the photolabeling of ABCB1 or ABCG2 with [(125)I]iodoarylazidoprazosin in a concentration-dependent manner. However, lapatinib did not affect the expression of these transporters at mRNA or protein levels. Importantly, lapatinib also strongly enhanced the effect of paclitaxel on the inhibition of growth of the ABCB1-overexpressing KBv200 cell xenografts in nude mice. Overall, we conclude that lapatinib reverses ABCB1- and ABCG2-mediated MDR by directly inhibiting their transport function. These findings may be useful for cancer combinational therapy with lapatinib in the clinic.

PMID: 18829547 [PubMed - indexed for MEDLINE]

09-23-2010, 06:18 PM	#8
Rich66 Senior Member Join Date: Feb 2008 Location: South East Wisconsin Posts: 3,431	Re: A better antiangiogenic way to block tumor growth (prevents rebound)!! Well...I knew the intermittent part How much oral TAM does it take to get to that level? Ok.. Here's the study..and some other related studies: A Phase I Study of a 2-Day Lapatinib Chemosensitization Pulse Preceding Nanoparticle Albumin-Bound Paclitaxel for Advanced Solid Malignancies Amy J. Chien1,6, Julie A. Illi6, Andrew H. Ko1,6, Wolfgang M. Korn1,6, Lawrence Fong1,6, Lee-may Chen2,6, Mohammed Kashani-Sabet3,6, Charles J. Ryan1,6, Jonathan E. Rosenberg1,6, Sarita Dubey1,6, Eric J. Small1,6, Thierry M. Jahan1,6, Nola M. Hylton4,6, Benjamin M. Yeh4,6, Yong Huang5, Kevin M. Koch7 and Mark M. Moasser1,6 Authors' Affiliations: Departments of 1 Medicine, 2 Obstetrics, Gynecology, and Reproductive Sciences, 3 Dermatology, 4 Radiology, 5 Biopharmaceutical Sciences, and 6 Helen Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, California and 7 Clinical Pharmacology Modeling and Simulation, GlaxoSmithKline, Research Triangle Park, North Carolina Requests for reprints: Mark M. Moasser, Helen Diller Comprehensive Cancer Center, University of California, San Francisco, Box 0875, San Francisco, CA 94143-0875. Phone: 415-476-0158; Fax; 415-353-7692; E-mail: mmoasser@medicine.ucsf.edu. Purpose: Systemic chemotherapy fails to access much of the tumor burden in patients with advanced cancer, significantly limiting its efficacy. In preclinical studies, brief high doses of tyrosine kinase inhibitors (TKI) targeting the human epidermal growth factor receptor (HER) family can prime tumor vasculature for optimal chemotherapeutic delivery and efficacy. This study investigates the clinical relevance of this approach. Experimental Design: A phase I clinical study of escalating doses of the HER TKI lapatinib given as a 2-day pulse before a weekly infusion of nab-paclitaxel (100 mg/m2) was conducted in patients with advanced solid tumors. Results: Twenty-five patients were treated. Treatment was associated with grade 1 to 2 toxicities including diarrhea, nausea, rash, neutropenia, neuropathy, fatigue, alopecia, and anemia. The two dose-limiting toxicities were grade 3 vomiting and grade 4 neutropenia, and the maximum tolerated dose of lapatinib was defined as 5250 mg/day in divided doses. Lapatinib concentrations increased with increasing dose. Dynamic Contrast Enhanced Magnetic Resonance Imaging studies in a subset of patients confirmed a decrease in tumor vascular permeability immediately following a lapatinib pulse. Sixty-five percent of evaluable patients experienced a partial or stable response on this therapy, 72% of whom were previously taxane-refractory. Conclusion: A 2-day pulse of high-dose lapatinib given before weekly nab-paclitaxel is a feasible and tolerable clinical regimen, suitable for testing this novel vascular-priming chemosensitization hypothesis developed in preclinical models. (Clin Cancer Res 2009;15(17):5569–75) Anticancer Drugs. 2009 Nov;20(10):918-25. Role of efflux pump activity in lapatinib/caelyx combination in breast cancer cell lines. Vannini I, Zoli W, Fabbri F, Ulivi P, Tesei A, Carloni S, Brigliadori G, Amadori D. Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori, Meldola (FC), Italy. The aim of this study was to investigate, at preclinical level, efflux pump modulation induced by lapatinib, a small-molecule dual inhibitor of the epidermal growth factor receptor (EGFR), in HER2-negative or HER2-positive breast cancer cell lines (SkBr3 and BRC230). We also evaluated the cytotoxic activity and modulation of biomolecular cellular pathways regulated by caelyx and lapatinib, used singly or in combination, at concentrations corresponding to peak plasma level in the two cell lines. Lapatinib was active in the HER2-overexpressing cell line, SkBr3, but not in BRC230 cell line, which does not express HER2. Conversely, caelyx exerted a cytotoxic effect on both the cell lines. Simultaneous exposure to lapatinib and caelyx in SkBr3 cell line produced an additive cytotoxic effect with dephosphorylation of HER2 and EGFR, an upregulation of p21, and an induction of apoptosis through dephosphorylation of BAD and caspase cleavage. In BRC230, simultaneous treatment induced a synergistic effect that was because of, at least in part, an upregulation of p21. Lapatinib also blocked efflux pumps, such as the breast cancer resistance protein I by increasing the length of time in which caelyx was present in tumor cell cytoplasm, which led to caspase cleavage, BAD dephosphorylation, and apoptosis. Our data indicate that lapatinib used in combination with caelyx is active in HER2-expressing cells, probably because of lapatinib-induced dephosphorylation of the HER2-EGFR pathway, and also in non-HER2-expressing cells, possibly because lapatinib blocks efflux pump activity, increasing the length of time of intracellular exposure to caelyx and thereby increasing its cytotoxic effect. PMID: 19752719 [PubMed - indexed for MEDLINE] Cancer Res. 2008 Oct 1;68(19):7905-14. Lapatinib (Tykerb, GW572016) reverses multidrug resistance in cancer cells by inhibiting the activity of ATP-binding cassette subfamily B member 1 and G member 2. Dai CL, Tiwari AK, Wu CP, Su XD, Wang SR, Liu DG, Ashby CR Jr, Huang Y, Robey RW, Liang YJ, Chen LM, Shi CJ, Ambudkar SV, Chen ZS, Fu LW. State Key Laboratory for Oncology in South China, Cancer Center, Sun Yat-Sen University, Guangzhou, China. Erratum in: Cancer Res. 2008 Dec 15;68(24):10387. Lapatinib is active at the ATP-binding site of tyrosine kinases that are associated with the human epidermal growth factor receptor (Her-1 or ErbB1) and Her-2. It is conceivable that lapatinib may inhibit the function of ATP-binding cassette (ABC) transporters by binding to their ATP-binding sites. The aim of this study was to investigate the ability of lapatinib to reverse tumor multidrug resistance (MDR) due to overexpression of ABC subfamily B member 1 (ABCB1) and ABC subfamily G member 2 (ABCG2) transporters. Our results showed that lapatinib significantly enhanced the sensitivity to ABCB1 or ABCG2 substrates in cells expressing these transporters, although a small synergetic effect was observed in combining lapatinib and conventional chemotherapeutic agents in parental sensitive MCF-7 or S1 cells. Lapatinib alone, however, did not significantly alter the sensitivity of non-ABCB1 or non-ABCG2 substrates in sensitive and resistant cells. Additionally, lapatinib significantly increased the accumulation of doxorubicin or mitoxantrone in ABCB1- or ABCG2-overexpressing cells and inhibited the transport of methotrexate and E(2)17betaG by ABCG2. Furthermore, lapatinib stimulated the ATPase activity of both ABCB1 and ABCG2 and inhibited the photolabeling of ABCB1 or ABCG2 with [(125)I]iodoarylazidoprazosin in a concentration-dependent manner. However, lapatinib did not affect the expression of these transporters at mRNA or protein levels. Importantly, lapatinib also strongly enhanced the effect of paclitaxel on the inhibition of growth of the ABCB1-overexpressing KBv200 cell xenografts in nude mice. Overall, we conclude that lapatinib reverses ABCB1- and ABCG2-mediated MDR by directly inhibiting their transport function. These findings may be useful for cancer combinational therapy with lapatinib in the clinic. PMID: 18829547 [PubMed - indexed for MEDLINE] __________________ Mom's treatment history (link)