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198 An epigenetic mechanism for capecitabine resistance in mesothelioma
S48
Saturday, October 21, 2006 / Poster Session: Chemotherapy
Saturday, October 21, 2006
Conclusions: Methylation of TP, the final step in the metabolic activation of capecitabine leads to transcriptional silencing of TP and may explain the lack of any effect of capecitabine, especially when compared to pemetrexed.
POSTER SESSION
Chemotherapy
197
Pemetrexed (MTA) and carboplatin (CBDCA) in advanced pleural mesothelioma (MPM): Evaluation of the activity and toxicity in a series of 178 chemonaive patients
C. Bruno 1 , C.G. Luca 2 , M. Manlio 3 , Z. Paolo 2 , B.P. Giacomo 4 , F.A. Gino 5 , G. Francesco 6 , B. Mario 1 . 1 Casale Monferrato Hospital, Italy; 2 Istituto Humanitas Milano, Italy; 3 Sampierdarena Hospital Genova, Italy; 4 Alessandria Hospital, Italy; 5 Busonera Hospital, Padova, Italy; 6 Istituto Nazionale Ricerca sul Cancro Genova, Italy Background: Aim of this study was to evaluate the activity and toxicity of MTA and CBDCA combination as first line chemotherapy in advanced MPM. Methods: On behalf of Italian Group of Interdisciplinary Research on Mesothelioma (GIRMI) a retrospective analysis was carried out on a pooled database including patients (pts) enrolled in two large trials of this regimen in advanced MPM. Chemonaive pts with histologically proven MPM, measurable advanced disease and an ECOG performance status (PS) of 0-2 were considered. Pemetrexed 500 mg/m2 and CBDA AUC 5 were given intravenously every 21 days. Results: From November 2002 to July 2005 178 pts (131 M, 47 F) were treated. Median age was 65 years (range 38-79); PS was 0/1/2 in 68/97/13 pts; histology was epithelial in 137 (76%), mixed in 21 (12%), sarcomatous in 10 (6%), and unspecified in 10 (6%) pts. Seven (4%) pts were stage I, 17 (10%) stage II, 61 (34%) stage III and 93 (52%) stage IV. A total of 1019 cycles was administered (median 6, range 1 to 13). Grade 3/4 hematologic toxicities were: neutropenia in 30 (17%), thrombocytopenia in 18 (10%), and anemia in 19 (11%). The most common nonhematologic events were grade 3 nausea/vomiting in 10 (6%), diarrhoea in 5 (3%) and fatigue in 5 (3%) pts. 177 pts were evaluable for response. There were 33 (19%) PR and 5 (3%) CR for an overall response rate of 22%. Stable disease was reported in 77 (43%) pts. Median time to progression and median overall survival time were estimated at 7 and 12 months respectively. Conclusions: The results of this study indicate that, at this dose and schedule, the combination of CBDCA and MTA is moderately active in pts with advanced MPM, with an acceptable toxicity profile.
198
An epigenetic mechanism for capecitabine resistance in mesothelioma
K.V. Kosuri, X. Wu, G. Otterson. Ohio State University, Columbus, USA Background: Malignant mesothelioma is an uncommon malignancy whose global incidence continues to rise. The current therapeutic standard for advanced disease is intravenous pemetrexed in combination with cisplatin. The antifolate, capecitabine has proven to be significantly less effective than pemetrexed. The enzymatic balance between thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), and thymidine phosphatase (TP) is critical to the efficacy of capecitabine. Specifically, for capecitabine to be converted into its active cytotoxic agent, the enzyme TP must be present and active. DPD denatures the active form of the drug, and TS is its target. The three genes which code for the enzymes (TS, DPD, and TP) were screened for methylation in 4 mesothelioma cell lines. Methods: Cells were treated with and without the drug, decitabine, a DNA methyltransferase inhibitor (DNMT-I) under standard conditions. DNA, RNA, and protein lysates were collected after 72 hours of exposure to the drug or under control conditions. DNA was bisultfite treated and examined by MS-PCR for evidence of methylation of the TS, DPD, and TP. RNA was obtained for real time PCR analysis to detect the relative difference in mRNA. Protein lysates were made and a Western immunoblot was performed to evaluate the differences in protein expression between treated and untreated cells. Cytotoxicity was assessed by MTT assay, comparing the cytotoxicity of decitabine pretreated cells with untreated cells when exposed to the active capecitabine metabolite, dioxyfluridine (DFUR), 5-FU, and pemetrexed. Results: One of the four mesothelioma cell lines tested (H290) was methylated for the gene that encodes for TP, extracellular growth factor-1 (ECGF-1). This corresponded to a lack of TP expression by real time PCR and Western immunoblot. The addition of 1uM decitabine to the cell lines increased relative mRNA quantity in H290, whose change in protein expression by Western immunoblot analysis. DFUR, the substrate for TP, subsequently shows increased cytotoxicity by MTT assay when delivered after decitabine exposure in the methylated cell line. There was no difference in any of the unmethylated cell lines when cells were exposed to 5-FU or pemetrexed with or without decitabine.
199
Sequential topoisomerase targeting triplet chemotherapy with irinotecan/cisplatin followed by doxorubicin in patients with malignant pleural mesothelioma: A pilot phase II study
T. Nakano, K. Fukuoka, K. Kuribayashi, A. Uesaka, S. Miyata, M. Miyake. Hyogo College of Medicine, Hyogo, Japan Background: Irinotecan (CPT-11) is a potent DNA Topoisomerase 1 (Topo-1) inhibitor and has a definite cytotoxic activity against mesothelioma in preclinical studies. A moderate dose of CPT-11 (125 mg/m2 ) seems to have minimal single-agent activity in patients with malignant mesothelioma, however, low dose CPT-11 in combination with cisplatin (CDDP) has a response rate of 26% for pleural and 24% for peritoneal mesothelioma. CPT-11/CDDP has 41% response rate in triplet chemotherapy with MMC. Pre-treatment of Topo-1 inhibitor enhances Topo-2 mRNA expression in tumor cells, and sequential inhibition of both enzymes has demonstrated synergism. We have conducted a pilot phase 2 trial of low-dose Topo-1 inhibitor CPT-11 (60mg/m2 , day-1, 8) in combination with CDDP (60mg/m2 , day-1, 8) followed by Topo-2 inhibitor doxorubicin (40mg/m2 , day-2,9) in 11 patients with malignant pleural mesothelioma. Toxicity was well tolerated and there were no treatment-related deaths, and the RR was 36%. Study is on-going with further patients being treated with this sequential topoisomerase targeting chemotherapy.
200
Treatment of malignant pleural mesothelioma with gemcitabine, carboplatin and liposomized doxorubicin (Caelyx® ): The CCG study from the Nordic mesothelioma groups
G. Hillerdal 1 , J.B. Sorensen 2 , S. Sundstrom 3 , H. Riska 4 , A. Vikstrom 5 . 1 Karolinska University Hospital, Stockholm, Sweden; 2 National University Hospital, Copenhagen, Denmark; 3 Regional Hospital, Trondheim, Norway; 4 University Hospital, Helsinki, Finland; 5 University Hospital, Linkoping, Sweden Background: In 2000 when this study was planned there was no standard treatment for malignant mesothelioma. The Nordic Mesothelioma Groups had recently finished a study with single-drug Caelyx® , and though there were few responses a prolonged time of stable disease and survival was felt to occur. At this time, a small study from Australia reported high incidence of responses (but not so good survival) with the combination of Gemcitabine and Cisplatin, and it was decided to try a triple combination in a small phase II study. Methods: Gemcitabine 100 mg/m2 , Caelyx 30 mg/m2 , Carboplatin 5 AUC (Calvert), aim 6 courses with modifications of dosage if toxicity, possibility to continue with further courses if so wished by patient. Results: Due to fairly high response rate (and no other treatment available at the time) the ethical committee agreed to include further patients. From 2001 to 2003, 167 evaluable patients enrolled, making it one of the biggest studies published. 94 patients (56%) received 6 courses or more, 14 with up to 12 courses, and 73% at least 5 courses. 23% stopped treatment because of toxicity, mainly haematological, the majority after 5 courses, 14% because of progression. There were 56 PR and 1 CR (33% responses); 12 months survival was 50% and 17% 2-year survival.
201
Treatment with gemcitabine and vinorelbine (GEMVIN) as second-line chemotherapy in pemetrexed-pretreated patients with malignant pleural mesothelioma (MPM)
P.A. Zucali, I. Garassino, G.L. Ceresoli, F. De Vincenzo, R. Cavina, E. Campagnoli, S. Salaminia, H.J. Soto-Parra, A. Santoro. Instituto Clinico Humanitas, Milan, Italy Background: Pemetrexed-based chemotherapy is considered the standard of care in up-front treatment of unresectable MPM. Optimal second-line therapy has not been defined yet. Gemcitabine and vinorelbine have shown activity in first-line setting in this disease. Aim of this study was to evaluate the activity and toxicity of GEMVIN as second line chemotherapy in pemetrexed-pretreated MPM pts. Methods: From 1/04 to 6/06, 28 consecutive pts progressing after pemetrexedbased chemotherapy were enrolled. Gemcitabine 1000 mg/m2 and vinorelbine 25 mg/m2 were administered on days 1 and 8 every three weeks. Treatment was repeated for a maximum of 6 cycles or until progression or unacceptable toxicity. Results: Pts characteristics were: M/F 21/7; median age 66 years (range: 4685); PS 0/1/2 9/14/5. Histology was epithelial in 19, sarcomatoid in 2, mixed in 5, unclassified in 2. Twenty-six pts are evaluable for response; 1 is still on
Saturday, October 21, 2006 / Poster Session: Chemotherapy
Saturday, October 21, 2006
Conclusions: Methylation of TP, the final step in the metabolic activation of capecitabine leads to transcriptional silencing of TP and may explain the lack of any effect of capecitabine, especially when compared to pemetrexed.
POSTER SESSION
Chemotherapy
197
Pemetrexed (MTA) and carboplatin (CBDCA) in advanced pleural mesothelioma (MPM): Evaluation of the activity and toxicity in a series of 178 chemonaive patients
C. Bruno 1 , C.G. Luca 2 , M. Manlio 3 , Z. Paolo 2 , B.P. Giacomo 4 , F.A. Gino 5 , G. Francesco 6 , B. Mario 1 . 1 Casale Monferrato Hospital, Italy; 2 Istituto Humanitas Milano, Italy; 3 Sampierdarena Hospital Genova, Italy; 4 Alessandria Hospital, Italy; 5 Busonera Hospital, Padova, Italy; 6 Istituto Nazionale Ricerca sul Cancro Genova, Italy Background: Aim of this study was to evaluate the activity and toxicity of MTA and CBDCA combination as first line chemotherapy in advanced MPM. Methods: On behalf of Italian Group of Interdisciplinary Research on Mesothelioma (GIRMI) a retrospective analysis was carried out on a pooled database including patients (pts) enrolled in two large trials of this regimen in advanced MPM. Chemonaive pts with histologically proven MPM, measurable advanced disease and an ECOG performance status (PS) of 0-2 were considered. Pemetrexed 500 mg/m2 and CBDA AUC 5 were given intravenously every 21 days. Results: From November 2002 to July 2005 178 pts (131 M, 47 F) were treated. Median age was 65 years (range 38-79); PS was 0/1/2 in 68/97/13 pts; histology was epithelial in 137 (76%), mixed in 21 (12%), sarcomatous in 10 (6%), and unspecified in 10 (6%) pts. Seven (4%) pts were stage I, 17 (10%) stage II, 61 (34%) stage III and 93 (52%) stage IV. A total of 1019 cycles was administered (median 6, range 1 to 13). Grade 3/4 hematologic toxicities were: neutropenia in 30 (17%), thrombocytopenia in 18 (10%), and anemia in 19 (11%). The most common nonhematologic events were grade 3 nausea/vomiting in 10 (6%), diarrhoea in 5 (3%) and fatigue in 5 (3%) pts. 177 pts were evaluable for response. There were 33 (19%) PR and 5 (3%) CR for an overall response rate of 22%. Stable disease was reported in 77 (43%) pts. Median time to progression and median overall survival time were estimated at 7 and 12 months respectively. Conclusions: The results of this study indicate that, at this dose and schedule, the combination of CBDCA and MTA is moderately active in pts with advanced MPM, with an acceptable toxicity profile.
198
An epigenetic mechanism for capecitabine resistance in mesothelioma
K.V. Kosuri, X. Wu, G. Otterson. Ohio State University, Columbus, USA Background: Malignant mesothelioma is an uncommon malignancy whose global incidence continues to rise. The current therapeutic standard for advanced disease is intravenous pemetrexed in combination with cisplatin. The antifolate, capecitabine has proven to be significantly less effective than pemetrexed. The enzymatic balance between thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), and thymidine phosphatase (TP) is critical to the efficacy of capecitabine. Specifically, for capecitabine to be converted into its active cytotoxic agent, the enzyme TP must be present and active. DPD denatures the active form of the drug, and TS is its target. The three genes which code for the enzymes (TS, DPD, and TP) were screened for methylation in 4 mesothelioma cell lines. Methods: Cells were treated with and without the drug, decitabine, a DNA methyltransferase inhibitor (DNMT-I) under standard conditions. DNA, RNA, and protein lysates were collected after 72 hours of exposure to the drug or under control conditions. DNA was bisultfite treated and examined by MS-PCR for evidence of methylation of the TS, DPD, and TP. RNA was obtained for real time PCR analysis to detect the relative difference in mRNA. Protein lysates were made and a Western immunoblot was performed to evaluate the differences in protein expression between treated and untreated cells. Cytotoxicity was assessed by MTT assay, comparing the cytotoxicity of decitabine pretreated cells with untreated cells when exposed to the active capecitabine metabolite, dioxyfluridine (DFUR), 5-FU, and pemetrexed. Results: One of the four mesothelioma cell lines tested (H290) was methylated for the gene that encodes for TP, extracellular growth factor-1 (ECGF-1). This corresponded to a lack of TP expression by real time PCR and Western immunoblot. The addition of 1uM decitabine to the cell lines increased relative mRNA quantity in H290, whose change in protein expression by Western immunoblot analysis. DFUR, the substrate for TP, subsequently shows increased cytotoxicity by MTT assay when delivered after decitabine exposure in the methylated cell line. There was no difference in any of the unmethylated cell lines when cells were exposed to 5-FU or pemetrexed with or without decitabine.
199
Sequential topoisomerase targeting triplet chemotherapy with irinotecan/cisplatin followed by doxorubicin in patients with malignant pleural mesothelioma: A pilot phase II study
T. Nakano, K. Fukuoka, K. Kuribayashi, A. Uesaka, S. Miyata, M. Miyake. Hyogo College of Medicine, Hyogo, Japan Background: Irinotecan (CPT-11) is a potent DNA Topoisomerase 1 (Topo-1) inhibitor and has a definite cytotoxic activity against mesothelioma in preclinical studies. A moderate dose of CPT-11 (125 mg/m2 ) seems to have minimal single-agent activity in patients with malignant mesothelioma, however, low dose CPT-11 in combination with cisplatin (CDDP) has a response rate of 26% for pleural and 24% for peritoneal mesothelioma. CPT-11/CDDP has 41% response rate in triplet chemotherapy with MMC. Pre-treatment of Topo-1 inhibitor enhances Topo-2 mRNA expression in tumor cells, and sequential inhibition of both enzymes has demonstrated synergism. We have conducted a pilot phase 2 trial of low-dose Topo-1 inhibitor CPT-11 (60mg/m2 , day-1, 8) in combination with CDDP (60mg/m2 , day-1, 8) followed by Topo-2 inhibitor doxorubicin (40mg/m2 , day-2,9) in 11 patients with malignant pleural mesothelioma. Toxicity was well tolerated and there were no treatment-related deaths, and the RR was 36%. Study is on-going with further patients being treated with this sequential topoisomerase targeting chemotherapy.
200
Treatment of malignant pleural mesothelioma with gemcitabine, carboplatin and liposomized doxorubicin (Caelyx® ): The CCG study from the Nordic mesothelioma groups
G. Hillerdal 1 , J.B. Sorensen 2 , S. Sundstrom 3 , H. Riska 4 , A. Vikstrom 5 . 1 Karolinska University Hospital, Stockholm, Sweden; 2 National University Hospital, Copenhagen, Denmark; 3 Regional Hospital, Trondheim, Norway; 4 University Hospital, Helsinki, Finland; 5 University Hospital, Linkoping, Sweden Background: In 2000 when this study was planned there was no standard treatment for malignant mesothelioma. The Nordic Mesothelioma Groups had recently finished a study with single-drug Caelyx® , and though there were few responses a prolonged time of stable disease and survival was felt to occur. At this time, a small study from Australia reported high incidence of responses (but not so good survival) with the combination of Gemcitabine and Cisplatin, and it was decided to try a triple combination in a small phase II study. Methods: Gemcitabine 100 mg/m2 , Caelyx 30 mg/m2 , Carboplatin 5 AUC (Calvert), aim 6 courses with modifications of dosage if toxicity, possibility to continue with further courses if so wished by patient. Results: Due to fairly high response rate (and no other treatment available at the time) the ethical committee agreed to include further patients. From 2001 to 2003, 167 evaluable patients enrolled, making it one of the biggest studies published. 94 patients (56%) received 6 courses or more, 14 with up to 12 courses, and 73% at least 5 courses. 23% stopped treatment because of toxicity, mainly haematological, the majority after 5 courses, 14% because of progression. There were 56 PR and 1 CR (33% responses); 12 months survival was 50% and 17% 2-year survival.
201
Treatment with gemcitabine and vinorelbine (GEMVIN) as second-line chemotherapy in pemetrexed-pretreated patients with malignant pleural mesothelioma (MPM)
P.A. Zucali, I. Garassino, G.L. Ceresoli, F. De Vincenzo, R. Cavina, E. Campagnoli, S. Salaminia, H.J. Soto-Parra, A. Santoro. Instituto Clinico Humanitas, Milan, Italy Background: Pemetrexed-based chemotherapy is considered the standard of care in up-front treatment of unresectable MPM. Optimal second-line therapy has not been defined yet. Gemcitabine and vinorelbine have shown activity in first-line setting in this disease. Aim of this study was to evaluate the activity and toxicity of GEMVIN as second line chemotherapy in pemetrexed-pretreated MPM pts. Methods: From 1/04 to 6/06, 28 consecutive pts progressing after pemetrexedbased chemotherapy were enrolled. Gemcitabine 1000 mg/m2 and vinorelbine 25 mg/m2 were administered on days 1 and 8 every three weeks. Treatment was repeated for a maximum of 6 cycles or until progression or unacceptable toxicity. Results: Pts characteristics were: M/F 21/7; median age 66 years (range: 4685); PS 0/1/2 9/14/5. Histology was epithelial in 19, sarcomatoid in 2, mixed in 5, unclassified in 2. Twenty-six pts are evaluable for response; 1 is still on