Kenichi Chikamori

A prospective, phase II, open-label study (JO22903) of first-line erlotinib in Japanese patients with epidermal growth factor receptor (EGFR) mutation-positive advanced non-small-cell lung cancer (NSCLC)

INTRODUCTION The epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitor erlotinib is associated with survival benefits in patients with EGFR mutation-positive non-small-cell lung cancer (NSCLC). This phase II, single-arm study examined the efficacy and safety of first-line erlotinib in Japanese patients with EGFR mutation-positive NSCLC. METHODS Eligible patients received erlotinib 150 mg/day until disease progression or unacceptable toxicity. The primary endpoints were progression-free survival (PFS) and safety. RESULTS A high degree of concordance was observed between different mutation testing methodologies, suggesting feasibility of early, rapid detection of EGFR mutations. Median PFS was 11.8 months (95% confidence interval [CI]: 9.7-15.3) at data cut-off (1 June 2012) (n = 102). Exon 19 deletions seemed to be associated with longer PFS compared with L858R mutations; T790M mutations were tentatively linked with shorter PFS. The safety profile was as expected: rash (any grade; 83%) and diarrhea (any grade; 81%) were most common. Six interstitial lung disease (ILD)-like cases were reported, and 5 were confirmed as ILD-like events by the extramural committee. Two patients died of treatment-related pneumonitis (JAPIC Clinical Trials Information number: Japic CTI-101085). CONCLUSION Erlotinib should be considered for first-line treatment in this subset of Japanese patients, with close monitoring for ILD-like events.

Phase II Trial of Gefitinib in Combination with Bevacizumab as First-Line Therapy for Advanced Non–Small Cell Lung Cancer with Activating EGFR Gene Mutations: The Okayama Lung Cancer Study Group Trial 1001

Purpose: Whether bevacizumab enhances the effect of the epidermal growth factor receptor (EGFR) inhibitor gefitinib on EGFR mutant non–small cell lung cancers (NSCLCs) remains unknown. We conducted a phase II trial to investigate the efficacy and safety of gefitinib when combined with bevacizumab as first-line therapy in patients with advanced NSCLC harboring EGFR gene mutations. Methods: In this trial, 42 patients with a performance status of 0 to 2 received gefitinib (250 mg/d) and bevacizumab (15 mg/kg, every 3 weeks). The primary end point of this study was the 1-year progression-free survival (PFS) rate. We assumed that a 1-year PFS rate of 55% would indicate potential usefulness and that a 1-year PFS rate of 40% would constitute the lower limit of interest. Results: Forty-two patients were enrolled in the study with a median age of 73 (range 42–86) years. Activating EGFR gene mutations included exon 19 deletion (57%) and L858R point mutations in exon 21 (38%). The objective response rate was 73.8% and included two complete responses. The 1-year PFS rate and median PFS time were 56.7% (95% confidence interval [CI] 39.9–70.5) and 14.4 months (95% CI 10.1–19.2), respectively. The median PFS differed significantly between EGFR exon 19 deletion and the L858R point mutation (18.0 versus 9.4 months, respectively; p = 0.006). The median overall survival had not yet been reached. Severe adverse events included grade 3 skin rash (15%), hypertension (17%), aspartate transaminase/alanine aminotransferase elevation (17%), proteinuria (7%), intracranial hemorrhage (2%), and grade 4 perforation of the digestive tract (2%). There were no treatment-related deaths. Conclusion: Gefitinib in combination with bevacizumab as first-line therapy seems to be a favorable and well-tolerated treatment for patients with advanced NSCLC with activating EGFR gene mutations, especially those with EGFR exon 19 deletion mutations, although the primary end point was not met because the lower limit of the CI was less than 40%.

Characterization of non-small-cell lung cancer cell lines established before and after chemotherapy

We established several in vitro drug-resistant cell lines after continuous, long-term exposure of each drug to elucidate mechanisms of drug resistance. Whether drug resistance in these in vitro resistant cell lines reflects clinical drug resistance still remains unanswered. In this study, a pair of lung cancer cell lines was established from one patient with squamous cell carcinoma of the lung, with one line being established before and one line after combination chemotherapy (cisplatin/ifosfamide/vindesine). Combination chemotherapy selected resistant EBC-2/R cells, which showed cross-resistance to 4-hydroxyifosfamide (3.2-fold), cisplatin (2.3-fold), and methotrexate (3.7-fold) and collateral sensitivity to vindesine (0.77-fold) compared with parent EBC-2 cells. EBC-2/R cells showed decrease in intracellular accumulation of cisplatin, increase in intracellular concentration of glutathione (GSH), and overexpression of multidrug resistance-associated protein (MRP) 3 when compared with EBC-2 cells. A single cycle of chemotherapy was not sufficient to select other mechanisms of drug resistance, such as multidrug resistance-1/P-glycoprotein, MRPs 1, 2, 4, and 5, lung resistance-related protein, metallothionein IIa, glutathione S-transferase pi, gamma-glutamylcysteine synthetase (light and heavy chain), and excision repair cross complementing 1. Sequentially we established two cell lines, which cell lines showed the differences of the cisplatin resistance, expression level of MRP3, intracellular GSH level and intracellular accumulation of cisplatin. A pair of cell lines will be useful to elucidate resistant mechanisms of cisplatin in heterogeneous lung cancer cells.

Fractionated administration of irinotecan and cisplatin for treatment of lung cancer : a phase I study

SummaryA combination chemotherapy of irinotecan (CPT-11) and cisplatin (CDDP) has been reported to be active for lung cancer. In the previous trial, however, diarrhoea and leucopenia became the major obstacle for sufficient dose escalation of CPT-11 to improve the treatment outcome. We conducted a phase I study to investigate whether the fractionated administration of CDDP and CPT-11 at escalated dose was feasible and could improve the treatment outcome. Twenty-four previously untreated patients with unresectable non-small-cell lung cancer (NSCLC) or extensive disease of small-cell lung cancer (SCLC) were eligible. Both CDDP and CPT-11 were given on days 1 and 8, and repeated every 4 weeks. The dose of CDDP was fixed at 60 mg m–2 and given by 1-h infusion before CPT-11 administration. The starting dose of CPT-11 was 40 mg m–2, and the dose was escalated by an increase of 10 mg m–2. The maximally tolerated dose of CPT-11 was determined as 60 mg m–2 because grade 4 haematological or grade 3 or 4 non-haematological toxicities developed in six patients out of 11 patients evaluated. Diarrhoea became a dose-limiting toxicity. The objective response rates were 76% for NSCLC and 100% for SCLC. The recommended dose of CPT-11 and CDDP in a phase II study will be 50 mg m–2 and 60 mg m–2 respectively.

A phase I study of combination S-1 plus cisplatin chemotherapy with concurrent thoracic radiation for locally advanced non-small cell lung cancer

A combination of S-1, a newly developed oral 5-fluorouracil derivative, and cisplatin is reported to show anti-tumour activity against advanced non-small cell lung cancer (NSCLC). Because S-1 shows synergistic effects with radiation, we conducted a phase I study to evaluate the maximum tolerated doses (MTDs), recommended doses (RDs), and dose-limiting toxicities (DLTs) of cisplatin and S-1 when combined with concurrent thoracic radiation (total dose of 60 Gy with 2 Gy per daily fraction) in patients with locally advanced NSCLC. Chemotherapy consisted of two 4-week cycles of cisplatin administered on days 1 and 8, and S-1 administered on days 1-14. S-1/cisplatin dosages (mg/m(2)/day) were escalated as follows: 60/30, 60/40, 70/40, 80/40 and 80/50. Twenty-two previously untreated patients were enrolled. The MTDs and RDs for S-1/cisplatin were 80/50 and 80/40, respectively. DLTs included febrile neutropaenia, thrombocytopaenia, bacterial pneumonia and delayed second cycle of chemotherapy. No patient experienced radiation pneumonitis>grade 2 and only one patient experienced grade 3 radiation oesophagitis. The overall response rate was 86.4% with a median survival time of 24.4 months. These results indicate that combination cisplatin-S-1 chemotherapy with concurrent thoracic radiation would be a feasible treatment option and a phase II study is currently under way.

A phase II study of amrubicin and topotecan combination therapy in patients with relapsed or extensive-disease small-cell lung cancer: Okayama Lung Cancer Study Group Trial 0401

BACKGROUNDS Chemotherapy is a mainstay in the treatment of extensive-disease small-cell lung cancer (ED-SCLC), although the survival benefit remains modest. We conducted a phase II trial of amrubicin (a topoisomerase II inhibitor) and topotecan (a topoisomerase I inhibitor) in chemotherapy-naïve and relapsed SCLC patients. METHODS Amrubicin (35 mg/m(2)) and topotecan (0.75 mg/m(2)) were administered on days 3-5 and 1-5, respectively. The objective response rate (ORR) was set as the primary endpoint, which was assessed separately in chemotherapy-naïve and relapsed cases. RESULTS Fifty-nine patients were enrolled (chemotherapy-naïve 31, relapsed 28). The ORRs were 74% and 43% in the chemotherapy-naïve and relapsed cases, respectively. Survival data were also promising, with a median progression-free survival time and median survival time of 5.3 and 14.9 months and 4.7 and 10.2 months in the chemotherapy-naïve and relapsed cases, respectively. Even refractory-relapsed cases responded to the treatment favorably (27% ORR). The primary toxicity was myelosuppression with grades 3 or 4 neutropenia in 97% of the patients, which led to grades 3 or 4 febrile neutropenia in 41% of the patients and two toxic deaths. CONCLUSION This phase II study showed the favorable efficacy and moderate safety profiles of a topotecan and amrubicin two-drug combination especially in relapsed patients with ED-SCLC.

A Phase II Study of Trastuzumab Emtansine in HER2-Positive Non–Small Cell Lung Cancer

&NA; Trastuzumab emtansine (T‐DM1), an anti–erb‐b2 receptor tyrosine kinase 2 (HER2) antibody‐drug conjugate, has been shown to significantly improve survival in HER2‐positive breast cancer. We report a phase II trial of T‐DM1 monotherapy in relapsed NSCLC with documented HER2 positivity (an immunohistochemistry [IHC] score of 3+, both an IHC score of 2+ and fluorescence in situ hybridization positivity, or exon 20 mutation). This study was terminated early because of limited efficacy. The demographic characteristics in the 15 assessable patients were as follows: median age, 67 years; male sex, 47%; performance status of 0 to 1, 80%; HER2 status IHC 3+, 33%; HER status IHC 2+/fluorescence in situ hybridization–positive, 20%; and exon 20 mutation, 47%. The median number of delivered cycles was 3 (range 1–11). One patient achieved a partial response with an objective response rate of 6.7% (90% confidence interval: 0.2–32.0). With a median follow‐up time of 9.2 months, the median progression‐free survival time and median survival time were 2.0 and 10.9 months, respectively. Grade 3 or 4 adverse events included thrombocytopenia (40%) and hepatotoxicity (20%) without any treatment‐related deaths. T‐DM1 had a limited efficacy for HER2‐positive NSCLC in our cohort. Applying the concept of precision medicine to tumors appears challenging; thus, additional molecular approaches are warranted.

Tyrosine 656 in topoisomerase IIβ is important for the catalytic activity of the enzyme: Identification based on artifactual +80-Da modification at this site.

Topoisomerase (topo) II catalyzes topological changes in DNA. Although both human isozymes, topo IIα and β are phosphorylated, site‐specific phosphorylation of topo IIβ is poorly characterized. Using LC‐MS/MS analysis of topo IIβ, cleaved with trypsin, Arg C or cyanogen bromide (CNBr) plus trypsin, we detected four +80‐Da modified sites: tyr656, ser1395, thr1426 and ser1545. Phosphorylation at ser1395, thr1426 and ser1545 was established based on neutral loss of H3PO4 (−98 Da) in the CID spectra and on differences in 2‐D‐phosphopeptide maps of 32P‐labeled wild‐type (WT) and S1395A or T1426A/S1545A mutant topo IIβ. However, phosphorylation at tyr656 could not be verified by 2‐D‐phosphopeptide mapping of 32P‐labeled WT and Y656F mutant protein or by Western blotting with phosphotyrosine‐specific antibodies. Since the +80‐Da modification on tyr656 was observed exclusively during cleavage with CNBr and trypsin, this modification likely represented bromination, which occurred during CNBr cleavage. Re‐evaluation of the CID spectra identified +78/+80‐Da fragment ions in CID spectra of two peptides containing tyr656 and tyr711, confirming bromination. Interestingly, mutation of only tyr656, but not ser1395, thr1326 or ser1545, decreased topo IIβ activity, suggesting a functional role for tyr656. These results, while identifying an important tyrosine in topo IIβ, underscore the importance of careful interpretation of modifications having the same nominal mass.

Spontaneous regression of malignant pleural mesothelioma

We describe the spontaneous regression of a malignant pleural mesothelioma with left pleural effusion, chest pain, and a high fever (38° to 39°C) in a 37-year-old man. The patient was referred to us because multiple nodules were seen on his chest radiograph after he was successfully treated with thoracocentesis and conventional antibiotic therapy for pleural effusion. Our diagnosis was malignant pleural mesothelioma, based on histologic findings in a biopsy specimen obtained during thoracoscopy. Interestingly, the tumors markedly regressed without treatment, and the patient was doing well more than 5 months after the cancer was diagnosed. The spontaneous regression of malignant pleural mesothelioma is rare, and this may represent the first case report.

A phase II trial of carboplatin plus S-1 for elderly patients with advanced non-small-cell lung cancer with wild-type epidermal growth factor receptor: The Okayama Lung Cancer Study Group Trial 1202

INTRODUCTION S-1 is an oral fluoropyrimidine-based combination of tegafur, gimeracil, and oteracil potassium. Although the combination of S-1 with carboplatin is a first-line chemotherapy regimen for advanced non-small cell lung cancer (NSCLC), the efficacy and safety of the regimen in the elderly remain unknown. METHODS The patient inclusion criteria were previously untreated advanced NSCLC, wild-type epidermal growth factor receptor, aged 70 years or more, and a performance status (PS) of 0-2. The patients received oral S-1 (40mg/m2, twice daily) for 2 weeks and carboplatin (area under the curve: 5) on day 1 every 4 weeks as induction treatment. After four induction cycles, S-1 alone (40mg/m2, twice daily) was administered for 2 weeks every 4 weeks as a maintenance therapy until disease progression. The primary endpoint was the overall response rate (ORR), which was expected to exceed 20%, and the secondary endpoints included the disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and the toxicity profile. The associations between clinical outcomes and expression of genes such as thymidylate synthase and thymidine phosphorylase in the tumors were evaluated. RESULTS Thirty-three patients were enrolled between March 2013 and June 2015. The median age was 78 (range 70-89) years, and 51.5% had a PS of 0. The ORR was 30.3% (95% confidence interval (CI): 14.6-46.0) and the DCR 57.6% (95% CI: 40.7-74.4). Grade 3/4 toxicities included thrombocytopenia (42.4%), neutropenia (33.3%), and anemia (27.3%). There was one treatment-related death due to aspiration pneumonia following febrile neutropenia. The median PFS and OS were 134days (95% CI: 79-173) and 479days (95% CI: 250-571), respectively. Low thymidine phosphorylase expression was associated with the DCR (P<0.01). CONCLUSION This study met the predesigned primary endpoint, and the regimen seems to be a favorable treatment option.