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

A phase I/II trial of irinotecan plus amrubicin supported with G-CSF for extended small-cell lung cancer

OBJECTIVE

This study reports the findings of a Phase I/II, cohort, dose-escalation trial of amrubicin and irinotecan with the support of granulocyte colony-stimulation factor. This study aimed to determine the dose-limiting toxicity of the combination and to define the maximum-tolerated dose, as a recommended dose for Phase II trials. We also sought to obtain preliminary data on the efficacy of this combination as a frontline therapy for extensive-disease small-cell lung cancer.

METHODS

We included 23 chemo-naïve patients with extensive-disease small-cell lung cancer in the trial. The amrubicin dose was escalated from 35 to 40 mg/m(2) (Levels 1 and 2, respectively) to determine the dose-limiting toxicity, with an unchanged dose of irinotecan at 50 mg/m(2).

RESULTS

Of nine patients, three experienced dose-limiting toxicities at Level 1 of prolonged Grade 4 neutropenia, Grade 3 febrile neutropenia and Grade 3 febrile neutropenia with Grade 3 diarrhea. At Level 2, two patients experienced dose-limiting toxicities of Grade 4 neutropenia and Grade 3 neutropenia with Grade 4 diarrhea. The maximum-tolerated doses and recommended doses for amrubicin and irinotecan were therefore determined to be 35 and 50 mg/m(2), respectively. The Level 1 trial was then expanded to 21 patients, 14 (70%) of whom showed partial responses to the recommended dose. The median progression-free and overall survival times were 6.37 and 15.21 months, respectively.

CONCLUSIONS

The combination of amrubicin and irinotecan with the support of granulocyte colony-stimulation factor produced a potent effect in chemo-naïve extensive-disease small-cell lung cancer patients. The use of biomarkers for this regimen may identify patients who are likely to suffer from treatment-ending severe adverse effects.

A phase I study of amrubicin and fixed dose of irinotecan (CPT-11) in relapsed small cell lung cancer: Japan multinational trial organization LC0303

PURPOSE

To determine the maximum tolerated dose of amrubicin (AMR) with a fixed dose of irinotecan (CPT-11).

METHODS

Patients having pathologically proven small cell lung cancer (SCLC) relapsed after one or two chemotherapies, and Eastern Cooperative Oncology Group performance status of 0 to 2 were eligible for the study. CPT-11 was delivered as 50 mg/m2 on days 1 and 8, every 21 days. AMR was delivered on day 1. Doses of AMR were level 1: 80 mg/m2, level 2: 90 mg/m2, and level 3: 100 mg/m2. Dose elevation was determined using the modified continuous reassessment method. Tolerability was assessed after the first cycle. Another two cycles were conducted when disease progression or unacceptable toxicities were not observed.

RESULTS

Eighteen patients (mean age: 66.3 years) were enrolled. A total of 40 courses were conducted. Grade 3/4 toxicities of the first cycle were leukocytopenia: 11 (61%, grade 3/4: 8/3); neutropenia: 15 (83%, grade 3/4: 6/9); and thrombocytopenia: three (17%, grade 3/4: 2/1). Other grade 3 toxicities observed were febrile neutropenia, one; infection, three; diarrhea, one; and dyspnea, one. Dose-limiting toxicity was observed in two of six patients at level 2 (neutropenia and febrile neutropenia) and in one of six at level 3 (thrombocytopenia and infection). The maximum tolerated dose was level 3, and so, the recommended dose for phase II trials was judged to be 90 mg/m2. Objective response was obtained in four of eight patients who were able to evaluate responses. Median survival time was 13 months, with 68% at 1-year survival rate.

CONCLUSIONS

This combination was well tolerated and showed encouraging activities in SCLC. Randomized phase II trials are being planned in chemonaive SCLC.

Review of the management of relapsed small-cell lung cancer with amrubicin hydrochloride

Lung cancer is the leading cause of cancer death, and approximately 15% of all lung cancer patients have small-cell lung cancer (SCLC). Although second-line chemotherapy can produce tumor regression, the prognosis is poor. Amrubicin hydrochloride (AMR) is a synthetic anthracycline anticancer agent and a potent topoisomerase II inhibitor. Here, we discuss the features of SCLC, the chemistry, pharmacokinetics, and pharmacodynamics of AMR, the results of in vitro and in vivo studies, and the efficacy and safety of AMR monotherapy and combination therapy in clinical trials. With its predictable and manageable toxicities, AMR is one of the most attractive agents for the treatment of chemotherapy-sensitive and -refractory relapsed SCLC. Numerous studies are ongoing to define the applicability of AMR therapy for patients with SCLC. These clinical trials, including phase III studies, will clarify the status of AMR in the treatment of SCLC.

Efficacy of combination treatment and influence of schedule with irinotecan and amrubicin in human lung carcinoma cells in vivo and in vitro

The aim of this study was to elucidate the efficacy of combination therapy with irinotecan and amrubicin for lung cancer and the influence of administration schedule in a xenograft mouse model and human cancer cell culture. We investigated the antitumor activity of irinotecan and amrubicin on human small cell lung cancer cell line LX-1 inoculated in mice in vivo and the cytotoxic effect of SN-38 and amrubicinol on human lung cancer cell lines A549 and PC-6 in vitro. Combined administration of irinotecan and amrubicin in divided doses inhibited tumor growth by approximately 90%, with complete recovery observed in one case. Furthermore, combined administration in divided doses induced little loss of body weight. Combination index analysis revealed that the cell growth inhibitory effect of SN-38 combined with amrubicinol was additive, regardless of schedule or cell line. The effect of combination treatment with SN-38 and amrubicinol on cell cycle was investigated. Cell cycle showed arrest at both the S and G2/M phases. The results indicate that combination therapy with irinotecan and amrubicin can be expected to yield improved outcomes, including less toxicity, especially with divided administration.

Amrubicin for the treatment of advanced lung cancer

Although the advancement of the chemotherapy of non-small cell lung cancer and small cell lung cancer is remarkable in recent years, it is still unsatisfactory. Therefore, some new agents or a new treatment strategy for lung cancer is required. Amrubicin is a totally synthetic anthracycline anticancer drug that acts as a potent topoisomerase II inhibitor. Recently, amrubicin has been approved in Japan for the treatment of small- and non-small cell lung cancers and some clinical trials about amrubicin were conducted in Japan, and promising results have been reported for the treatment of small cell lung cancer in particular. The preclinical, pharmacology and clinical data of amrubicin for the treatment of advanced lung cancer are reviewed.

Plasma concentration of amrubicinol in plateau phase in patients treated for 3 days with amrubicin is correlated with hematological toxicities

Amrubicinol (AMR-OH) is an active metabolite of amrubicin (AMR), a novel synthetic 9-aminoanthracycline derivative. The time-concentration profile of AMR-OH exhibits a continuous long plateau slope in the terminal phase. To determine the relationships between the steady-state plasma concentration of AMR-OH and treatment effects and toxicities associated with AMR therapy, we carried out a pharmacokinetic/pharmacodynamic study in patients treated with AMR alone or the combination of AMR+cisplatin (CDDP). AMR was given at a dose of 30 or 40 mg/m(2) on days 1-3. Plasma samples were collected 24 h after the third injection (day 4). Plasma concentrations of AMR-OH or total CDDP were determined by a high-performance liquid chromatography or an atomic absorption spectrometry. Percent change in neutrophil count (dANC) and the plasma concentration of AMR-OH were evaluated using a sigmoid E(max) model. A total of 35 patients were enrolled. Significant relationships were observed between AMR-OH on day 4 and the toxicity grades of leukopenia, neutropenia, and anemia (P=0.018, P=0.012, and P=0.025, respectively). Thrombocytopenia grade exhibited a tendency toward relationship with AMR-OH on day 4 (P=0.081). The plasma concentration of AMR-OH on day 4 was positively correlated with dANC in the group of all patients, as well as in patients treated with AMR alone and in patients coadministered with CDDP. In conclusion, the plasma concentration of AMR-OH on day 4 was correlated with hematological toxicities in patients treated with AMR. The assessment of plasma concentration of AMR-OH at one timepoint might enable the prediction of hematological toxicities.

Long-term disease-free survivor of metastatic large-cell neuroendocrine carcinoma of the lung treated with amrubicin and irinotecan

Large-cell neuroendocrine carcinoma (LCNEC) is a relatively uncommon variant of non-small cell lung cancer. Since the biological characteristics of LCNEC are similar to those of small cell lung cancer, LCNEC is usually treated with chemotherapy regimens used for small cell lung cancer. However, the outcomes are usually dismal. Here, we report a patient with LCNEC (a metastasis to the brain). After whole brain irradiation, he received a combination of amrubicin and irinotecan chemotherapy, and has been relapse-free for two years. This treatment regimen may be beneficial for patients with advanced LCNEC.

Simple and sensitive HPLC method for determination of amrubicin and amrubicinol in human plasma: application to a clinical pharmacokinetic study

A simple and sensitive high-performance liquid chromatographic (HPLC) method was developed for determination of amrubicin and its metabolite amrubicinol in human plasma. After protein precipitation with methanol without evaporation procedure, large volume samples were injected and separated by two monolithic columns with a guard column. The mobile phase consisted of tetrahydrofuran-dioxane-water (containing 2.3 mM acetic acid and 4 mM sodium 1-octanesulfonate; 2:6:15, v/v/v). Wavelengths of fluorescence detection were set at 480 nm for excitation and 550 nm for detection. Under these conditions, linearity was confirmed in the 2.5-5000 ng/mL concentration range of both compounds. The intra- and inter-day precision and intra- and inter-day accuracy for both compounds were less than 10%. The method was successfully applied to a clinical pharmacokinetic study of amrubicin and amrubicinol in cancer patients.

Amrubicin for non-small-cell lung cancer and small-cell lung cancer

Amrubicin is a totally synthetic anthracycline anticancer drug and a potent topoisomerase II inhibitor. Recently, amrubicin was approved in Japan for the treatment of small- and non-small-cell lung cancers (SCLC and NSCLC). Here, we review the efficacy and toxicities of amrubicin monotherapy and amrubicin in combination with cisplatin for extensive-disease SCLC (ED-SCLC), and of amrubicin monotherapy for advanced NSCLC, as observed in the clinical trials. Recommended dosage for previously untreated advanced NCSLC was 45 mg/m2/day by intravenous administration for 3 days. Dose-limiting toxicities were leucopenia, thrombocytopenia, and gastrointestinal disturbance. Response rate was 27.9% for advanced NSCLC, and 75.8% for ED-SCLC with a median survival time (MST) of 11.7 months. Recommended dosage of amrubicin was 40 mg/m2/day in combination with cisplatin at 60 mg/m2/day, with MST of 13.6 months and 1-year survival rate of 56.1%. In sensitive or refractory relapsed SCLC, response rate was 52 and 50%, progression-free survival was 4.2 and 2.6 months, overall survival was 11.6 and 10.3 months, and 1-year survival rate was 46 and 40%, respectively. These results are promising for the treatment of both NSCLC and SCLC. Further clinical trials will clarify the status of amrubicin in the treatment of lung cancer.