[A case of recurrent invasive thymic cancer showing a stable disease to carboplatin plus paclitaxel].

A 56-year-old man was admitted to our hospital because of increasing chest discomfort and abnormal chest shadow. Computed tomography (CT) of the chest revealed an anterior mediastinal mass, pleural dissemination and lung metastasis. Percutaneus needle biopsy guided by CT showed that the mass was advanced thymic cancer (stage IV b according to the classification proposed by Masaoka). After failure of combination chemotherapy of cisplatin, vincristine, doxorubicin and etoposide (CODE), he received 4 cycles of carboplatin plus paclitaxel and then achieved confirmed stable disease. In terms of toxicity profile, grade 4 anemia, grade 2 leucopenia and neutropenia were observed, and particularly non-severe toxicity was not observed in terms of non-hematologic toxicity. Carboplatin plus paclitaxel can be an active agent against pretreated thymic cancer.

Effect of gefitinib on warfarin antithrombotic activity.

BACKGROUND: Despite the literature indicating adverse interactions between warfarin and cytotoxic agents, whether such an interaction occurs when warfarin and gefitinib are used concomitantly is unknown. We analyzed the prevalence of the concomitant use of warfarin and gefitinib, and the incidence of prothrombin time-international normalized ratio (PT-INR) alterations or adverse interactions in concomitant users of warfarin and gefitinib. METHODS: We conducted a retrospective study of patients with non-small cell lung cancer treated at the Kitasato University Hospital who received concomitant warfarin and gefitinib between September 2002 and January 2007. Medical information, including the indication for warfarin use, warfarin dosing and dosing changes, and exposure to gefitinib were collected from computerized databases and medical records. RESULTS: Twelve (4.1%) of 296 patients treated with gefitinib received warfarin. PT-INR elevation occurred in 6 patients (50.0%). Two (16.7%) of the 12 patients had liver metastases. Liver dysfunction was associated with PT-INR elevation (P = 0.0100). CONCLUSION: As there is a possibility of PT-INR abnormalities occurring during the concomitant use of gefitinib and warfarin, clinicians should be aware of this interaction. Because of the potentially severe consequences of this interaction, close monitoring of PT-INR and warfarin dose adjustment are recommended for patients receiving warfarin and gefitinib, especially during the first 2 weeks in the beginning of warfarin therapy.

Metabolism of irinotecan and its active metabolite SN-38 by intestinal microflora in rats.

One of the dose-limiting toxicities of irinotecan (CPT-11) is delayed-onset diarrhea, which is the greatest barrier to treatment with CPT-11-containing regimens. CPT-11 is converted to its active metabolite, SN-38, which is conjugated by hepatic uridine diphosphate glucuronosyl transferase to SN-38 glucuronide (SN-38G). SN-38G, once excreted in the intestinal lumen via bile, is extensively deconjugated by bacterial beta-glucuronidase with the regeneration of SN-38 in the intestinal lumen, which may cause diarrhea. However, the metabolism of CPT-11 and its metabolites by intestinal microflora are yet to be reported. This study was carried out to investigate the microbial transformation of CPT-11 and SN-38 using an anaerobic mixed culture of rat cecal microorganisms. No reaction in the mixed cultures was observed when CPT-11 or SN-38 lactone was added to the culture medium. When CPT-11 was added to the culture broth, a significant amount of water-soluble CPT-11 was detected in the spent culture medium. In contrast, only a slight amount of SN-38 was found in the supernatant when SN-38 lactone was added to the broth. A significant quantity of SN-38 was found in the sediment. In conclusion, these results strongly suggest that SN-38 produced from SN-38G by the action of bacterial beta-glucuronidase is rapidly adsorbed by the intestinal bacterial cell walls in the sediment because of the hydrophobic and lipophilic nature of SN-38, and a small amount of SN-38 remains in the intestinal luminal fluid. Thus, we need to reconsider the role of SN-38 in the intestinal lumen in CPT-11-induced late-onset diarrhea.

Phase I and pharmacologic study of irinotecan and amrubicin in advanced non-small cell lung cancer.

PURPOSE: We conducted a Phase I trial of irinotecan (CPT-11), a topoisomerase I inhibitor, combined with amrubicin, a topoisomerase II inhibitor. The aim was to determine the maximum tolerated dose (MTD) of amrubicin combined with a fixed dose of CPT-11 as well as the dose-limiting toxicities (DLT) of this combination in patients with advanced non-small cell lung cancer. PATIENTS AND METHODS: Eleven patients with stage IIIB or IV disease were treated at 3-week intervals with amrubicin (5-min intravenous injection on days 1-3) plus 60 mg/m2 of CPT-11 (90-min intravenous infusion on days 1 and 8). The starting dose of amrubicin was 25 mg/m2, and it was escalated in 5 mg/m2 increments until the maximum tolerated dose was reached. RESULTS: The 30 mg/m2 of amrubicin dose was one dose level above the MTD, since three of the five patients experienced DLT during the first cycle of treatment at this dose level. Diarrhea and leukopenia were the DLT, while thrombocytopenia was only a moderate problem. Amrubicin did not affect the pharmacokinetics of CPT-11, SN-38 or SN-38 glucuronide. Except for one patient, the biliary index on day-1 correlated well with the percentage decrease of neutrophils in a sigmoid Emax model. There were five partial responses among 11 patients for an overall response rate of 45%. CONCLUSION: The combination of amrubicin and CPT-11 seems to be active against non-small cell lung cancer with acceptable toxicity. The recommended dose for Phase II studies is 60 mg/m2 of CPT-11 (days 1 and 8) and 25 mg/m2 of amrubicin (days 1-3) administered every 21 days.

Phase II trial of amrubicin for treatment of refractory or relapsed small-cell lung cancer: Thoracic Oncology Research Group Study 0301.

PURPOSE: This multicenter, phase II study was conducted to evaluate the activity of amrubicin, a topoisomerase II inhibitor, against refractory or relapsed small-cell lung cancer (SCLC). PATIENTS AND METHODS: SCLC patients with measurable disease who had been treated previously with at least one platinum-based chemotherapy regimen and had an Eastern Cooperative Oncology Group performance status of 0 to 2 were eligible. Two groups of patients were selected: patients who experienced first-line treatment failure less than 60 days from treatment discontinuation (refractory group), and patients who responded to first-line treatment and experienced disease progression > or = 60 days after treatment discontinuation (sensitive group). Amrubicin was administered as a 5-minute daily intravenous injection at a dose of 40 mg/m2 for 3 consecutive days, every 3 weeks. RESULTS: Between June 2003 and December 2004, 60 patients (16 refractory and 44 sensitive) were enrolled. The median number of treatment cycles was four (range, one to eight). Grade 3 or 4 hematologic toxicities comprised neutropenia (83%), thrombocytopenia (20%), and anemia (33%). Febrile neutropenia was observed in three patients (5%). Nonhematologic toxicities were mild. No treatment-related death was observed. The overall response rates were 50% (95% CI, 25% to 75%) in the refractory group, and 52% (95% CI, 37% to 68%) in the sensitive group. The progression-free survival, overall survival, and 1-year survival in the refractory group and the sensitive group were 2.6 and 4.2 months, 10.3 and 11.6 months, and 40% and 46%, respectively. CONCLUSION: Amrubicin exhibits significant activity against SCLC, with predictable and manageable toxicities; this agent deserves to be studied more extensively in additional trials.

Drug interaction between gefitinib and warfarin.

Gefitinib is a synthetic, oral anilinoquinazoline specifically designed to inhibit the epidermal growth factor receptor tyrosine kinase, and is the first targeted drug to demonstrate reproducible activity in non-small cell lung cancer patients who do not respond to platinum-based chemotherapy. In this report, we present two cases of an interaction between gefitinib and warfarin which has not been reported previously. Because of the potentially serious consequences of this interaction, close monitoring of the International Normalized Ratio and warfarin dosage adjustment are recommended for patients receiving warfarin together with gefitinib.