Combination Of Topotecan Research Articles

The Anti-Proliferative and Pro-apoptotic Effect of Topotecan in Combination With Thymoquinone in Acute Myelogenous Leukemia

Topotecan (a novel topoisomerase I inhibitor and a water-soluble camptothecin analog) is active against numerous human tumor cell lines, and has shown promising antineoplastic activity in solid tumors and acute leukemia. Due to the primary dose-limiting toxicity of topotecan which is myelosuppression, it is necessary to identify other chemotherapeutic agents that can work synergistically with topotecan, potentially increasing its efficacy while limiting its toxicity. Many studies showed synergism upon combination of topotecan with other chemotherapeutic agents like Gemcitabine, bortezomin and CP-4055. Other studies report the increase in growth inhibition of gemcitabine or oxaliplatin when cells are pre-exposed to naturally occurring drugs such as thymoquinone.

Icotinib antagonizes ABCG2-mediated multidrug resistance, but not the pemetrexed resistance mediated by thymidylate synthase and ABCG2.

ABCG2 is a potential biomarker causing multidrug resistance (MDR) in Non-Small Cell Lung Cancer (NSCLC). We conducted this study to investigate whether Icotinib, a small-molecule inhibitor of EGFR tyrosine kinase, could interact with ABCG2 transporter in NSCLC. Our results showed that Icotinib reversed ABCG2-mediated MDR by antagonizing the drug efflux function of ABCG2. Icotinib stimulated the ATPase activity in a concentration-dependent manner and inhibited the photolabeling of ABCG2 with [125I]-Iodoarylazidoprazosin, demonstrating that it interacts at the drug-binding pocket. Homology modeling predicted the binding conformation of Icotinib at Asn629 centroid-based grid of ABCG2. However, Icotinib at reversal concentration did not affect the expression levels of AKT and ABCG2. Furthermore, a combination of Icotinib and topotecan exhibited significant synergistic anticancer activity against NCI-H460/MX20 tumor xenografts. However, the inhibition of transport activity of ABCG2 was insufficient to overcome pemetrexed resistance in NCI-H460/MX20 cells, which was due to the co-upregulated thymidylate synthase (TS) and ABCG2 expression. This is the first report to show that the up-regulation of TS in ABCG2-overexpressing cell line NCI-H460/MX20 may play a role of resistance to pemetrexate. Our findings suggested different possible strategies of overcoming the resistance of topotecan and pemetrexed in the NSCLC patients.

Randomized phase III trial in extensive-disease small cell lung cancer comparing first-line etoposide to topotecan in combination with platinum.

7519 Background: Randomized trials in extensive disease (ED) small cell lung cancer (SCLC) comparing the camptothecins to standard etoposide based chemotherapy have reached conflicting results. Her...

Phase I Clinical Trial of the Mammalian Target of Rapamycin Inhibitor Everolimus in Combination With Oral Topotecan for Recurrent and Advanced Endometrial Cancer

Preclinical data suggest that mammalian target of rapamycin inhibitors may potentiate the efficacy of topotecan. We evaluated the optimal schedule of oral topotecan in combination with everolimus in patients with endometrial cancer. Women with a history of advanced or recurrent endometrial cancer were enrolled. Escalating dose of oral topotecan (1.5 mg/m, 1.9 mg/m, and 2.3 mg/m) daily on days 1 to 5 and everolimus (5 mg every other day, 5 mg daily, and 10 mg daily) were administered in a 21-day cycle. A "run-in" treatment of topotecan daily for 5 days followed by everolimus for 7 days (4-7 doses depending on dose level) was administered for the purpose of pharmacokinetic assessments. Ten patients were enrolled on the study, and 9 were evaluable for safety analysis. A total of 28 cycles were administered (range, 1-10 cycles per patient). The patients had a median age of 73 years (range, 42-79 years). Previous lines of chemotherapy were 1 (n = 2), 2 (n = 5), 3 (n = 2), and 4 (n = 1). Seven patients had previous vaginal brachytherapy, and 2 had pelvic external beam radiation therapy. The median number of cycles (including cycle 1) is 2 (range, 1-10). Dose-limiting toxicity occurred in 3 patients (1 patient treated with 1.9-mg/m topotecan and 5-mg everolimus given every other day as well as 2 patients treated with 1.9-mg/m topotecan and 5-mg of everolimus daily) and included neutropenia and thrombocytopenia. Seven patients were evaluable for response. Stable disease was the best response in 3 patients who completed the 3, 4, and 10 cycles each. The dose-limiting toxicity for the combination of oral topotecan and everolimus was myelosuppression. The maximum tolerated dose was topotecan 1.9 mg/m on days 1 to 5 in combination with oral everolimus 5 mg every other day. Administration of higher dose of each agent in combination was limited because of overlapping myelosuppression.

Phase I dosage finding and pharmacokinetic study of intravenous topotecan and oral erlotinib in adults with refractory solid tumors

Topotecan is widely used for refractory solid tumors but multi-drug resistance may occur due to tumor expression of ATP-binding cassette (ABC) transporters. Since erlotinib, an inhibitor of the epidermal growth factor receptor, also inhibits several ABC transporters, we performed a phase I study to evaluate the safety, efficacy, and pharmacokinetics of intravenous topotecan given in combination with erlotinib. Patients received 150 mg of oral erlotinib daily and a 30 min intravenous infusion of topotecan on days 1-5 of a 21-day cycle. Dosage escalation of topotecan occurred with a starting dosage of 0.75 mg/m(2). The pharmacokinetics of topotecan was evaluated on day 1 of cycle 1 without erlotinib and on day 1 of cycle 2 or 3 with erlotinib. Twenty-nine patients were enrolled. The maximum tolerated dosage was determined to be 1.0 mg/m(2). Dose-limiting toxicities included neutropenia and thrombocytopenia. The average duration of treatment was 97 days. Two partial responses were observed. Topotecan clearance and exposure were similar with and without erlotinib. The combination of topotecan and erlotinib is tolerable at clinically effective doses. Erlotinib does not affect the disposition of topotecan to a clinically significant extent.

TDP1/TOP1 Ratio as a Promising Indicator for the Response of Small Cell Lung Cancer to Topotecan.

Background and objectiveSmall cell lung cancer (SCLC) is one of the most challenging tumors to treat due to high proliferation rate, early metastatic dissemination and rapid development of chemotherapy resistance. The current treatment protocols involve the use of topoisomerase 1 (TOP1) poisons such as irinotecan and topotecan in combination with platinum-based compounds. TOP1 poisons kill cancer cells by trapping TOP1 on DNA, generating lethal DNA double-strand breaks. A potential mechanism employed by cancer cells to resist killing by TOP1 poisons is to overexpress enzymes involved in the repair of TOP1-DNA breaks. Tyrosyl DNA phosphodiesterase 1 (TDP1) is a key player in this process and despite its importance, no data is currently available to correlate TDP1 protein and mRNA levels with catalytic activity in SCLC. In addition, it is not known if TDP1 and TOP1 protein levels correlate with the cellular response of SCLC to TOP1 based therapies.Methods and resultsWe report a remarkable variation in TDP1 and TOP1 protein levels in a panel of SCLC cell lines. TDP1 protein level correlates well with TDP1 mRNA and TDP1 catalytic activity, as measured by two newly developed independent activity assays, suggesting the potential utility of immunohistochemistry in assessing TDP1 levels in SCLC tissues. We further demonstrate that whilst TDP1 protein level alone does not correlate with topotecan sensitivity, TDP1/TOP1 ratio correlates well with sensitivity in 8 out of 10 cell lines examined.ConclusionThis study provides the first cellular analyses of TDP1 and TOP1 in SCLC and suggests the potential utility of TDP1/TOP1 ratio to assess the response of SCLC to topotecan. The establishment and validation of an easy-to-use TDP1 enzymatic assay in cell extracts could be exploited as a diagnostic tool in the clinic. These findings may help in stratifying patients that are likely to benefit from TOP1 poisons and TDP1 inhibitors currently under development.

Phase II study of temozolomide in combination with topotecan (TOTEM) in relapsed or refractory neuroblastoma: A European Innovative Therapies for Children with Cancer-SIOP-European Neuroblastoma study

PurposeTo assess objective response rate (ORR) after two cycles of temozolomide in combination with topotecan (TOTEM) in children with refractory or relapsed neuroblastoma. Patients and MethodsThis multicenter, non-randomised, phase II study included children with neuroblastoma according to a two-stage Simon design. Eligibility criteria included relapsed or refractory, measurable or metaiodobenzylguanidine (mIBG) evaluable disease, no more than two lines of prior treatment. Temozolomide was administered orally at 150mg/m2 followed by topotecan at 0.75mg/m2 intravenously for five consecutive days every 28days. Tumour response was assessed every two cycles according to International Neuroblastoma Response Criteria (INRC), and reviewed independently. ResultsThirty-eight patients were enroled and treated in 15 European centres with a median age of 5.4years. Partial tumour response after two cycles was observed in 7 out of 38 evaluable patients [ORR 18%, 95% confidence interval (CI) 8–34%]. The best ORR whatever the time of evaluation was 24% (95% CI, 11–40%) with a median response duration of 8.5months. Tumour control rate (complete response (CR)+partial response (PR)+mixed response (MR)+stable disease (SD)) was 68% (95% CI, 63–90%). The 12-months Progression-Free and Overall Survival were 42% and 58% respectively. Among 213 treatment cycles (median 4, range 1–12 per patient) the most common treatment-related toxicities were haematologic. Grade 3/4 neutropenia occurred in 62% of courses in 89% of patients, grade 3/4 thrombocytopenia in 47% of courses in 71% of patients; three patients (8%) had febrile neutropenia. ConclusionTemozolomide–Topotecan combination results in very encouraging ORR and tumour control in children with heavily pretreated recurrent and refractory neuroblastoma with favourable toxicity profile.

Response of Children with Stage IV Soft Tissue Sarcoma to Topotecan and Carboplatin: A Phase II Window Trial of the Cooperative Soft Tissue Sarcoma Group

To investigate antitumor activity and toxicity associated with combined topotecan and carboplatin treatment in children and adolescents with metastasized, untreated soft tissue sarcoma (STS).Patients (n=34) less than 21 years old and untreated, stage IV STS. Patients were treated with topotecan (1 mg/m²/d for 4 days) and carboplatin (150 mg/m²/d for 4 days) (TC course) during week 1 and 4 of a chemotherapy window trial, which was followed by chemotherapy and local therapy from week 6 on. We evaluated the side effects, toxicity and tumor response (using RECIST criteria) 6 weeks after starting the 2 TC chemotherapy courses.The objective response rate (ORR) was 38% (n=13 patients with a partial response (PR)), and a stable disease (SD) was reached in 11 cases. No patient showed a complete response (CR) of all metastatic lesions, although 1 patient showed a CR of the target lesion. 2 patients died of progress of disease (PD). Toxicity was mainly hematological (grade III/IV toxicity 79%), and nonhematological toxicities mainly included infection, fever, nausea,and vomiting. Regarding adverse events, 4 probable and 8 possible events related to study medication occurred among the 66 courses of TC.In conclusion, TC was potent against high-risk STS, but results and toxicity data were not superior to former published monotherapeutic topotecan therapies.

Tumor Dynamics in Response to Antiangiogenic Therapy with Oral Metronomic Topotecan and Pazopanib in Neuroblastoma Xenografts

Metronomic chemotherapy, combined with targeted antiangiogenic drugs, has demonstrated significant anticancer efficacy in various studies. Though, tumors do acquire resistance. Here, we have investigated the effect of prolonged therapy with oral metronomic topotecan and pazopanib on tumor behavior in a neuroblastoma mouse xenograft model. SK-N-BE(2) xenograft-bearing mice were treated with either of the following regimens (daily, orally): vehicle (control), 150 mg/kg pazopanib, 1.0 mg/kg topotecan, and combination of topotecan and pazopanib. Planned durations of treatment for each regimen were 28, 56, and 80 days or until the end point, after which animals were sacrificed. We found that only combination-treated animals survived until 80 days. Combination halted tumor growth for up to 50 days, after which gradual growth was observed. Unlike single agents, all three durations of combination significantly lowered microvessel densities compared to the control. However, the tumors treated with the combination for 56 and 80 days had higher pericyte coverage compared to control and those treated for 28 days. The proliferative and mitotic indices of combination-treated tumors were higher after 28 days of treatment and comparable after 56 days and 80 days of treatment compared to control. Immunohistochemistry,Western blot, and real-time polymerase chain reaction revealed that combination treatment increased the hypoxia and angiogenic expression. Immunohistochemistry for Glut-1 and hexokinase II expression revealed a metabolic switch toward elevated glycolysis in the combination-treated tumors. We conclude that prolonged combination therapy with metronomic topotecan and pazopanib demonstrates sustained antiangiogenic activity but also incurs resistance potentially mediated by elevated glycolysis.

Synergistic Effect of Combination Topotecan and Chronomodulated Radiation Therapy on Xenografted Human Nasopharyngeal Carcinoma

To investigate the in vivo chronomodulated radiosensitizing effect of topotecan (TPT) on human nasopharyngeal carcinoma (NPC) and its possible mechanisms. Xenografted BALB/c (nu/nu) NPC mice were synchronized with an alternation of 12 hours of light from 0 to 12 hours after light onset (HALO) and 12 hours of darkness to establish a unified biological rhythm. Chronomodulated radiosensitization of TPT was investigated by analysis of tumor regrowth delay (TGD), pimonidazole hydrochloride, histone H2AX phosphorylation, (γ-H2AX) topoisomerase I (Top I), cell cycle, and apoptosis after treatment with (1) TPT (10 mg/kg) alone; (2) radiation therapy alone (RT); and (3) TPT+RT at 3, 9, 15, and 21 HALO. The tumor-loaded mice without any treatment were used as controls. The TPT+RT combination was more effective than TPT or RT as single agents. The TPT+RT combination at 15 HALO was best (TGD = 58.0 ± 3.6 days), and TPT+RT at 3 HALO was worst (TGD = 35.0 ± 1.5 days) among the 4 TPT+RT groups (P<.05). Immunohistochemistry analysis revealed a significantly increased histone H2AX phosphorylation expression and decreased pimonidazole hydrochloride expression in the TPT+RT group at the same time point. The results suggested that the level of tumor hypoxia and DNA damage varied in a time-dependent manner. The expression of Top I in the TPT+RT group was also significantly different from the control tumors at 15 HALO (P<.05). Cell apoptosis index was increased and the proportion of cells in S phase was decreased (P<.05) with the highest value in 15 HALO and the lowest in 3 HALO. This study suggested that TPT combined with chronoradiotherapy could enhance the radiosensitivity of xenografted NPC. The TPT+RT group at 15 HALO had the best therapeutic effect. The chronomodulated radiosensitization mechanisms of TPT might be related to circadian rhythm of tumor hypoxia, cell cycle redistribution, DNA damage, and expression of Top I.

Cyclophosphamide and Topotecan as First-line Salvage Therapy in Patients With Relapsed Ewing Sarcoma at a Single Institution

The combination of cyclophosphamide and topotecan (cyclo/topo) has shown objective responses in relapsed Ewing sarcoma, but the response duration is not well documented. We reviewed characteristics and outcome of 14 patients with Ewing sarcoma, treated uniformly at a single institution and offered cyclo/topo at first relapse. Six patients (43%) had relapse at distant sites. All patients received first-line salvage therapy with cyclophosphamide 250 mg/m and topotecan 0.75 mg/m, daily for 5 days repeated every 21 days. The median number of cycles was 4 (range 1 to 10). All toxicities were manageable, the most common being transient cytopenias. There were also 4 episodes of febrile neutropenia, and 3 episodes of gross hematuria. Response was assessable in 13 patients and showed progressive disease in 6 (46%), stable disease in 4 (31%), and partial response in 3 (23%). Nine patients had local control, consisting of radical surgery in 2, radiation in 3, and a combination in 4 patients. Response, when it occurred, was maintained for a median of 8 months (range, 4 to 28 mo). Four patients (29%) are alive at 3, 7, 9, and 110 months after relapse; 1 is receiving cyclo/topo, 1 is on third-line therapy, and 2 are in second and fourth remission. The low toxicity of this combination, and the lack of sustained responses, warrant its investigation in combination with targeted or novel therapeutic agents in relapsed disease.

Phase II Study of Topotecan and Bevacizumab in Advanced, Refractory Non–Small-Cell Lung Cancer

BackgroundThis clinical trial evaluated whether topotecan in combination with bevacizumab improved progression-free survival (PFS) in patients with advanced, refractory non–small-cell lung cancer in a second-line setting. Patient and MethodsPatients aged 18 years old and older received topotecan (4.0 mg/m2) on days 1, 8, and 15, and bevacizumab (10 mg/kg) on days 1 and 15 as intravenous infusions on a 28-day treatment cycle. Available tumor specimens were analyzed for ISG15 gene expression as a biomarker of response to topotecan. ResultsForty-two patients were enrolled in the study, with a median age of 62.5 years and a median of 3 (range, 1-7) prior treatment regimens. Almost half (n = 18, 42.9%) of the patients received prior bevacizumab therapy. PFS was 5.1 months (95% CI, 3.7-7.8 months), and overall survival was 11.5 months (95% CI, 6.8-15.5 months). Response rates were as follows: 14.3% partial response, 54.8% stable disease, and 28.6% progressive disease. Hematologic toxicities included grade 3 thrombocytopenia (n = 7, 16.7%), neutropenia (n = 4, 9.5%), and anemia (n = 2, 4.8%). One toxic death occurred due to pulmonary hemorrhage, and one patient experienced a grade 4 pulmonary embolism. Grade 3 nonhematologic adverse events were uncommon (< 8%). There was a trend for improved median PFS, 3.5 months vs. 1.8 months (P = .26), in patients with high ISG15 expression. ConclusionBevacizumab in combination with topotecan as a salvage therapy for metastatic non–small-cell lung cancer is well tolerated and is worthy of further investigation.

Multicenter phase I/II trial of topotecan (T) and ifosfamide (I) combination as second-line therapy for pediatric solid cancer: Phase II results.

10050 Background: Both of T and I are key drugs for recurrent pediatric solid malignancies but rarely used in combination. Results of the phase I portion of the combination of T and I chemotherapy (TI) which is dose-finding study by CRM method in ASCO 2010. We hereby report the results of efficacy and safety screening of TI conducted as a phase II portion. Methods: Recurrent pediatric solid malignancies with history of chemotherapy no more than 20 cycles (Cs) are eligible. Combination of I (1.2g/m2/day) and T (0.6 mg/m2/day) were administered day 1 through 5 up to six Cs. In the phase II portion, a Simon optimal two-stage design was adopted using treatment compliance with 4 Cs of TI as primary endpoint. Unacceptable compliance was set at 20% and promising one at 40%. If more than two patients (pts) among initial 13-15 pts successfully complete 4 Cs, patients’ enrollment is allowed to continue until a total of 33 pts in the phase II portion. Complete or Partial Response (CR+PR) was evaluated according to RECIST 1.0 criteria and toxicity, CTCAE v3.0. Results: 35 pts, median age 12 years (range 1-28) has been registered in both phase I and II between March 2008 and January 2013 in 8 centers: 7 neuroblastoma (NB), 8 rhabdomyosarcoma (RMS), 8 osteosarcoma (OS), 6 Ewing’s sarcoma (ES), 2 hepatoblastoma (HB), and 4 others. 13 pts out of total 34 pts (38%) completed 6 Cs. 13 pts out of 28 pts (36%, the phaseII portion) received more than 4 Cs without meeting stopping criteria of protocol treatment. This has reached the predefined efficient level. No Grade 4 non-hematological toxicity occurred. Grade 2-4 fatigue, anorexia, and nausea were 20% or less. Grade 3 or 4 neutropenia was frequent (105/127 Cs, 83%), though only 9 % (12 Cs) developed febrile neutropenia. 2 CR (HB, ES) and 2 PR (RMS, OS) were observed at best response among 22 pts with measurable disease, leading to an estimated OR rate of 18% (95%CI 5-40%). 14 patients had disease stabilization. One year progression-free survival rate and overall survival rate are 21% and 64%. Conclusions: TI achieved very good compliance and favorable toxicity as well as good tumor control rate. This combination is a new promising 2nd line therapy for pediatric solid malignancies. Clinical trial information: UMIN000001037.

Abstract 962: Prolonged antiangiogenic therapy with oral metronomic topotecan and pazopanib in pediatric solid tumor mouse model.

Abstract Background: We have previously observed that the combination of daily oral Low Dose Metronomic (LDM) Topotecan (TP) and Pazopanib (PZ) significantly delayed the tumor growth and enhanced the survival in neuroblastoma (NB) mouse models (Kumar et al, 2011). However, this combination (TP+PZ) did not stop tumor growth and the animals eventually died due to disease during the course of therapy. Therefore, we planned to investigate the factors contributing to resistance to this antiangiogenic therapy in NB mouse model. Objectives: To investigate the effect of prolonged TP+PZ therapy on angiogenesis by testing the effect of therapy at different durations in NB mice xenograft model. Methods: Mice bearing subcutaneous SK-N-BE(2) NB xenografts were treated with either of the four regimens, daily, orally: vehicle (untreated), PZ (150 mg pazopanib), TP (1.0 mg/Kg topotecan), TP+PZ (combination of topotecan and pazopanib, same doses as single agents). Durations of treatment planned for each regimen were 28 days, 56 days and 80 days. Animals were sacrificed after these durations or upon end point, whichever was earlier. The criteria for end point are tumor sizes exceeding 2.0 cms in diameter or animals showing signs of morbidity. Results: The animals in control, PZ, TP reached the end point after 23d, 28d and 46d respectively. TP+PZ halted the tumor growth for up to 40 days, after which gradual growth was observed. The mean tumor diameters in the third TP+PZ group reached 1.8 cms at the day 80. CD31 immunofluorescence revealed that all the three durations of TP+PZ significantly lowered microvessel densities compared to the control (P= 0.02, 0.04 and 0.009 respectively for 28, 56 and 80 days respectively). However the ratio of CD31 to α- smooth muscle actin (pericyte marker) stained areas were significantly higher in animals treated with TP+PZ for 56 and 80days, compared to control (P=0.0006; 56d and 0.004; 80d) indicating higher pericyte coverage. TP+PZ (28d) showed signs of necrosis and cell cycle arrest (Ki67 staining), which were not observed in later durations (56 and 80 days) with TP+PZ. Long-term TP+PZ therapy also increased the levels of HIF-1 alpha, VEGF and Oct-4 within the tumor tissue. Conclusion: This study indicates that even though prolonged TP+PZ therapy demonstrates sustained antiangiogenic activity, it encounters resistance in NB, potentially mediated by pericyte coverage. Long-term TP+PZ therapy may also increase tumor stemness. Citation Format: Sushil Kumar, Reza Bayat Mokhtari, Syed Islam, Herman Yeger, Sylvain Baruchel. Prolonged antiangiogenic therapy with oral metronomic topotecan and pazopanib in pediatric solid tumor mouse model. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 962. doi:10.1158/1538-7445.AM2013-962

Abstract 5499: Lurbinectedin (PM01183) synergizes with topoisomerase I inhibitors in vitro and in vivo.

Abstract Background: Lurbinectedin (PM01183), a new synthetic tetrahydroisoquinoline alkaloid, is a minor groove specific DNA binder that interacts directly with specific factors involved in DNA repair and transcription pathways. In living cells, PM01183-DNA adducts stall replication and transcription giving rise to double strand breaks, inducing accumulation of cells in the S-phase of the cell cycle and triggering apoptosis. In both the ongoing phase II trials (pancreas and platinum-resistant ovarian cancer) the first stage was concluded with positive results in clinical activity, ensuring the continuity of the trials. Also, phase I trials in combination with doxorubicin and gemcitabine as well as in advanced acute leukemia are ongoing. The in vitro and in vivo synergism of PM01183+ topoisomerase I inhibitors is presented here. Material and Methods: In vitro: PM01183+topotecan synergism was tested in a panel of 12 tumor cell lines. In vivo: Athymic mice were implanted with SW1990 (pancreas), HT29 (colon) or H460 (NSCLC) cancer cells. Mice bearing HT29 or H460 tumors (ca. 150 mm3) were allocated to 13 groups (N=6-8/group): placebo; PM01183 at MTD (0.180 mg/kg [0.54 mg/m2]), 0.75MTD, 0.5MTD and 0.25MTD; irinotecan at MTD (50 mg/kg [150 mg/m2]), 0.75MTD, 0.5MTD and 0.25MTD; and, PM01183+irinotecan at (1+1), (0.75+0.75), (0.50+0.50) and (0.25+0.25) MTDs. Animals bearing SW1990 tumors received treatments (single or combination) at the MTD levels. Treatments were given intravenously once per week (PM01183) or every 4 days (irinotecan) during the placebo-treated survival time. The combination index (CI) was determined by the CI-isobol method. Results: The combination of PM01183 plus topotecan in NSCLC (A549), melanoma (SK-MEL-2), hepatocarcinoma (HepG2), colon (HT29), pancreas (PANC-1) and glioma (U87MG) cells was considered synergistic. In vivo, a synergistic antitumor effect (CI&amp;lt;1.0) was seen after the treatment with PM01183+irinotecan in the HT29 (CI=0.93) and H460 (CI=0.30) experimental models. Also, in SW1990 tumor bearing animals, the treatment with the combination of PM01183 and irinotecan produced more antitumor effect (P&amp;lt;0.05) than the more active single agent in this experiment (irinotecan at MTD level). Conclusion: PM01183 synergizes the in vitro effect of topotecan in several tumor cell lines including NSCLC, melanoma, hepatocarcinoma, colon, pancreas and glioma. In agreement with the in vitro results, the treatment of mice xenografted with colon, NSCLC or pancreas tumors with PM01183 combined with a topoisomerase I inhibitor (irinotecan) resulted in synergistic antitumor activity. Citation Format: Carlos Galmarini, Maria José Guillen, Victoria Moneo, Luis Francisco Garcia, Mandy Palomares, Oscar Cataluña, Carmen Cuevas, Pablo Avilés. Lurbinectedin (PM01183) synergizes with topoisomerase I inhibitors in vitro and in vivo. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5499. doi:10.1158/1538-7445.AM2013-5499

Multicenter phase II trial of topotecan, cisplatin and bevacizumab for recurrent or persistent cervical cancer

ObjectiveWe evaluated the activity and safety of the combination of topotecan, cisplatin and bevacizumab in patients with recurrent or persistent carcinoma of the cervix. MethodsEligible patients had persistent or recurrent cervical cancer not amenable to curative intent treatment. No prior chemotherapy for recurrence was allowed. Treatment consisted of cisplatin 50mg/m2 day 1, topotecan 0.75mg/m2 days 1, 2 and 3 and bevacizumab 15mg/kgday 1 every 21days until disease progression or limiting toxicity. The primary endpoint was progression free survival at 6months. We explored PET/CT as a potential early indicator of response to therapy. ResultsTwenty-seven eligible patients received a median of 3 treatment cycles (range, 1–19). Median follow-up was 10months (range, 1.7–33.4). The 6-month PFS was 59% (80% CI: 46–70%). In 26 evaluable patients, we observed 1 CR (4%; 80% CI: 0.4–14%) and 8 PR (31%; 80% CI: 19–45%) lasting a median of 4.4months. Ten patients had SD (39%; 80% CI: 25–53%) with median duration of 2.2months. Median PFS was 7.1months (80% CI: 4.7–10.1) and median OS was 13.2months (80% CI: 8.0–15.4). All patients were evaluated for toxicity. Grade 3–4 hematologic toxicity was common (thrombocytopenia 82% leukopenia 74%, anemia 63%, neutropenia 56%). Most patients (78%) required unanticipated hospital admissions for supportive care and/or management of toxicities. ConclusionThe addition of bevacizumab to topotecan and cisplatin results in an active but highly toxic regimen. Future efforts should focus on identification of predictive biomarkers of prolonged response and regimen modifications to minimize toxicity.

Escalating Topotecan in Combination with Treosulfan has Acceptable Toxicity in Advanced Pediatric Sarcomas

Patients with advanced pediatric sarcomas have a poor prognosis and novel combination therapies are needed to improve the response rates. Hematological and organ related toxicities have been observed when administering topotecan in combination with, e.g., high dose thiotepa. This study evaluates the toxicity of escalating doses of topotecan alone or in combination with thiotepa or treosulfan. We compared the toxicity including death of complication (DOC) of topotecan alone or in combination with thiotepa or treosulfan in advanced pediatric sarcomas (n = 12). Ten of 12 patients (0.83) suffered from advanced tumors of the Ewing family (i.e., bone or marrow metastases or relapse <24 month after diagnosis, including one neuroepithelial tumor of the kidney) and two from alveolar rhabdomyosarcoma stage IV (0.17). Median age was 15 years (range 5–28). Ratio of female to male was 1:1. Two patients received topotecan alone (1.25 mg/m2 q 5d and 1.5 mg/m2 q 5d), three patients received four courses of topotecan (2 mg/m2 q d 1–5) in combination with thiotepa (100 mg/m2 q d 1–5), and seven patients received topotecan (2 mg/m2 q d 1–5) in combination with treosulfan (10g/m2 q d 3–5). Overall toxicity was not different between all three groups; mean scores were 1.6, 1.8, and 1.7 according to WHO grading (Scale 0–4). Organ related toxicity ranged between 0 and 4 and was not different as well. DOC was 0/2, 1/3, and 0/7 patients respectively. Escalating therapy with topotecan in combination with treosulfan has acceptable toxicity and warrants further investigation in advanced pediatric sarcomas.

A Modified Protocol with Vincristine, Topotecan, and Cyclophosphamide for Recurrent/Progressive Ewing Sarcoma Family Tumors

Purpose: Topotecan has recently been used in the treatment of pediatric cancer. We evaluated our experience with the modified combination of vincristine, topotecan, and cyclophosphamide (VTC) given in 3 days, in children with recurrent Ewing sarcoma. Method: Children received vincristine (1.5 mg/m2/1st day), cyclophosphamide (600 mg/m2/day × 2 days) + mesna, and topotecan (1 mg/m2/day × 3 days) every 21 days. Result: A total of 118 courses of VTC were given to 13 patients. One patient received VTC both at first and at second relapse. Thus, 14 relapse episodes in 13 patients were evaluated. After three courses of VTC chemotherapy (CT), two achieved complete response (CR), five achieved partial response, thus an objective response was attained in 7/14 (50%) episodes. Two patients had stable disease and two patients progressed. In three episodes, CR was achieved by surgery before CT. One of them had a second relapse and attained CR with VTC. Median time from diagnosis to relapse was 23 months (5–45 months). Site of relapse was local in four patients, and metastatic in 10 episodes of nine patients. Seven patients are alive, three with no evidence of disease and four alive with disease; six have died of disease. Local treatment was used in 11 episodes. The toxicity of the VTC combination was limited mainly to the hematopoietic system. Conclusion: In conclusion, the modified VTC protocol in 3 days every 3 weeks seems to be effective and tolerable in children and adolescents with recurrent/progressive Ewing sarcoma.

Topotecan and Doxorubicin Combination to Treat Recurrent Ovarian Cancer: The Influence of Drug Exposure Time and Delivery Systems to Achieve Optimum Therapeutic Activity

To provide proof-of-concept data to support use of Doxil-liposomal topotecan (Topophore C) combinations to treat ovarian cancer. ES-2, OVCAR-3, and SKOV-3 ovarian cancer cell lines were treated with doxorubicin-topotecan combinations by exposing the cells to drugs from 1 to 72 hours. Pharmacokinetic analysis was conducted following administration of liposomal formulations of these drugs alone and in combination. Efficacy assessments were completed in ES-2 and SKOV-3 ovarian cancer models. On the basis of drug doses capable of achieving 50% reduction in cell viability over 72 hours, doxorubicin-topotecan combinations were additive in SKOV-3 but highly synergistic in ES-2 and OVCAR-3 cells. Favorable drug-drug interactions increased with increased drug exposure time. Topophore C pharmacokinetic remained unaffected when co-administered with Doxil. In the ES-2 model, Doxil at maximum tolerated dose (MTD 7.5 mg/kg) in combination with free topotecan (MTD 15 mg/kg) did not enhance median survival time (MST) over that achieved with topotecan alone. In contrast, MST was increased to 52 days with combination of Topophore C (MTD 2.5 mg/kg) and Doxil (7.5 mg/kg) compared with untreated animals (MST 18 days) or those treated with Topophore C alone (MTD 5 mg/kg, MST 40 days). In the SKOV-3 model, combination treatments showed better therapeutic efficacy than the individual drugs. Topotecan-doxorubicin combinations produced additive or synergistic effects which were best achieved when the tumor cells were exposed to drugs over extended time. Doxil-Topophore C combinations are therapeutically superior as judged in two ovarian cancer models. Clin Cancer Res; 19(4); 865-77. ©2012 AACR.

Synergistic Anticancer Activity of Topotecan— Cyclin-Dependent Kinase Inhibitor Combinations against Drug-Resistant Small Cell Lung Cancer (SCLC) Cell Lines

Extended-stage small cell lung cancer (SCLC) responds to platinum/vepeside-based first-line chemotherapy but relapses rapidly as drug-resistant tumor. Topotecan (TPT) is the single chemotherapeutic agent approved for second-line treatment of SCLC. However, the response to TPT is short-lived and novel treatment modalities need to be developed. Sequential treatment of cytotoxic drugs and inhibitors of cyclin-dependent kinases (CDKs) showed promising preclinical anticancer activity and, in the present work, combinations of TPT with CDK inhibitors olomoucine, roscovitine and CDK4I are shown to exhibit synergistic cytotoxic activity against SCLC cell lines. Highest activity was found against TPT-resistant NCI-H417 and DMS153 cell lines and moderate chemosensitizing effects against a primary SCLC cell line and sensitive GLC19 cells at levels of CDK inhibitors which exerted low toxicity. A combination of 0.6 μM TPT with 0.6 μM roscovitine, exhibiting no significant cytotoxicity as single agents, reduced viability of the TPT-resistant NCI-H417 line (IC50 > 10 μM) by 50%. In the TPT resistant cell lines olomoucine and roscovitine, targeting CDK1,2,5,7, were highly effective, whereas in the more sensitive cell lines CDK4I, inhibiting mainly CDK4/6, showed activity. In NCI-417 cells, preincubation with roscovitine for one day proved synergistic with TPT. Thus, in good accordance with previous findings, CDK inhibitors are able to convert SCLC cancer cells which are cell-cycle arrested by a blockade of topoisomerase I by TPT to apoptotic cells. Since nowadays several CDK inhibitors are at various phases of clinical testing their combination with TPT seems to constitute a promising approach to improve second-line chemotherapy in SCLC.