Second-line pazopanib in patients with relapsed and refractory small-cell lung cancer: a multicentre phase II study of the Hellenic Oncology Research Group.

BACKGROUND: Pazopanib is a tyrosine kinase inhibitor with antiangiogenic activity. Vascular endothelial growth factor expression is increased in SCLC and is correlated with poor prognosis. The efficacy and tolerance of second-line pazopanib in SCLC was evaluated. PATIENTS AND METHODS: Patients with platinum-sensitive (cohort A; n=39) and -resistant/refractory (cohort B; n=19) SCLC were enrolled in a multicentre phase II study. The primary end point was the progression-free survival rate (PFS-R) at week 8 in each cohort. Pazopanib (800 mg per day per os) was administered until progressive disease (PD). Circulating tumour cells (CTCs) were enumerated using the Cellsearch assay. RESULTS: All patients were evaluable for response and toxicity. In the intention-to-treat analysis, eight (13.8%) patients achieved partial response (PR) (95% confidence interval (CI): 5.0-22.7), 20 (34.5%) stable disease (SD) and 30 (51.7%) PD. Accrual in cohort B was halted because the hard-stop rule was met; in cohort A, the PFS-R was 59% (95% CI: 43.5-74.4; PR=7, SD=16). Nine (23.1%) patients received pazopanib for >6 months and 3 of them for >12 months. One pazopanib cycle resulted to a significant decrease to the number of patients with ⩾5 CTCs/7.5 ml of blood (20%) compared with baseline (50%). The median PFS and OS for all patients was 2.5 months (95% CI: 1.9-3.1 months) and 6.0 months (95% CI: 3.8-8.2 months), respectively (cohort A: PFS=3.7 months and OS=8.0 months). No unexpected toxicity was observed. CONCLUSIONS: Second-line treatment with pazopanib in platinum-sensitive SCLC is well tolerated and resulted in promising objective responses and disease control; CTC enumeration might serve as a reliable surrogate biomarker of response.

Heterogeneity of circulating tumor cells (CTCs) in patients with recurrent small cell lung cancer (SCLC) treated with pazopanib.

OBJECTIVES: To investigate the effect of pazopanib on different CTCs subpopulations in patients with recurrent SCLC and evaluate their clinical relevance. METHODS: Peripheral blood was obtained before the administration of pazopanib (n=56 patients), after the first cycle (n=35 patients) and at disease progression (n=45 patients). CTCs were detected by CellSearch and double immunofluorescent staining using antibodies against the cytokeratins (CK), TTF-1, CD56 and VEGFR2. RESULTS: Before treatment, CTCs could be detected in 50% of patients by CellSearch; phenotypic characterization of CTCs demonstrated that 50%, 46.6% and 27.6% of patients had CD45-/TTF1+, CD45-/CD56+ and TTF-1+/CD56+ CTCs, respectively. Additionally, 59% of CTCs were TTF-1+/VEGFR2+ and 53% CK+/VEGFR2+. One pazopanib cycle resulted to a significant decrease of the number of CTCs (CellSearch: p=0.043) and CK+/VEGFR2+ cells (p=0.027). At the time of PD, both the total number of CTCs (p=0.027) and the number of the different subpopulations were significantly increased compared to post-1st cycle values; this increased CTCs number was associated with a significant increase of TTF-1+/VEGFR2+ (p=0.028) and CK+/VEGFR2+ CTCs (p=0.018). In multivariate analysis, only the number of CTCs as assessed by CellSearch after one treatment cycle was significantly associated with OS (HR: 0.21; p=0.005). CONCLUSIONS: Pazopanib has a significant effect on different subpopulations of CTCs in patients with relapsed SCLC; the detection of VEGFR2+ CTCs during treatment could be a surrogate marker associated with resistance to pazopanib.

A multicentre phase II trial of cabazitaxel in patients with advanced non-small-cell lung cancer progressing after docetaxel-based chemotherapy.

BACKGROUND: Cabazitaxel, a semisynthetic microtubule inhibitor, has shown antitumour activity in models resistant to paclitaxel and docetaxel, and it has been approved for the treatment of docetaxel-resistant prostate cancer. We investigated its activity in patients with advanced non-small-cell lung cancer (NSCLC) progressing under or after docetaxel-based regimens. METHODS: Patients with locally advanced unresectable or metastatic NSCLC, with an Eastern Cooperative Oncology Group performance status of 0-2, were enrolled; patients had to have received up to two prior chemotherapy regimens for the treatment of advanced disease, including one docetaxel-containing regimen. Treatment consisted of cabazitaxel (25 mg m(-2) intravenously, every 21 days) until disease progression. The primary end point was the overall response rate. RESULTS: Among the 46 evaluable patients, 28.3% had squamous cell carcinoma and 54.3% had adenocarcinoma. Eight (17.4%) patients had received one and 38 (82.6%) two prior chemotherapy regimens. Treatment compliance was 95%; 26 (16%) cycles were delayed because of toxicity, (n=13) and dose reduction was required in 6 (13%) patients because of haematologic toxicity. Six (13%) patients achieved a partial response and 17 (37.0%) stable disease. The median progression-free survival and overall survival were 2.1 (95% confidence interval (CI): 1.0-3.2) and 7.4 (95% CI: 5.2-9.6) months, respectively. Grade 4 adverse events included neutropenia (n=8; 17%), febrile neutropenia (n=6; 13%) and thrombocytopenia (n=3; 6.5%). There was one treatment-related death. CONCLUSIONS: Cabazitaxel exhibits activity in NSCLC patients pre-treated with docetaxel-based chemotherapy with a substantial but manageable toxicity profile. The drug merits further evaluation in this indication.

Phase I trial of intravenous cisplatin-topotecan chemotherapy for three consecutive days in patients with advanced solid tumors: parallel topotecan escalation in two fixed platinum dosing schemes.

PURPOSE: We performed a phase I study of two fixed dosing schemes of cisplatin, a DNA cross-linker, with intravenous escalating topotecan, a DNA-topoisomerase I inhibitor. EXPERIMENTAL DESIGN: 40 patients with advanced solid tumors received intravenous cisplatin at a fixed dose of either 25 mg/m2 (schedule A) or 20 mg/m2 (schedule B) daily for 3 days with standard hydration. Topotecan escalation proceeded in 0.75, 0.90, 1.0, 1.15 mg/m2 cohorts in schedule A and 1.0, 1.1, 1.2, 1.3 mg/m2 cohorts in schedule B, administered intravenously at the end of cisplatin infusion daily for 3 days, repeated every 3 weeks. Dose-limiting toxicity (DLT) consisted of protracted grade IV neutropenia, febrile neutropenia, grade IV thrombocytopenia and any grade III/IV non-hematological toxicity. Epoetin and granulocyte colony-stimulating factor support was allowed on severe myeloablation. Endpoints were the identification of maximal tolerated dose (MTD), DLT and other toxicity. RESULTS: The MTD was reached in cohort 25/1.15 mg/m2 in schedule A and 20/1.2 mg/m2 in schedule B. All DLT seen consisted of three episodes of febrile neutropenia and two of grade IV thrombocytopenia in schedule A, with three episodes of febrile neutropenia and one of protracted neutropenia in schedule B. Myelosuppression was substantial in all cohorts despite granulocyte colony-stimulating factor and epoetin support, peaked on the third week of treatment and resulted in administration of chemotherapy at a median of every 4 weeks. Non-hematologic toxicity was mild. The response rate was 51% with seven complete responses occurring in patients with ovarian cancer, small cell and non-small cell lung cancer and cancer of unknown primary. The recommended dose was 20/ 1.1 mg/m2 for cisplatin and topotecan on schedule B, as the number of responses and administered topotecan dose were higher in schedule B recommended dose with lower cisplatin dose, minimizing problems of nephrotoxicity and vomiting. CONCLUSIONS: The schedule B daily cisplatin-topotecan x 3 combination with secondary cytokine support is associated with promising activity and schedule convenience. However, substantial myelosuppression undermines its applicability in the palliative setting, stressing the need for less toxic regimens.