Nobuyuki Mizunuma

Randomized Trial of TAS-102 for Refractory Metastatic Colorectal Cancer

BACKGROUND Early clinical trials conducted primarily in Japan have shown that TAS-102, an oral agent that combines trifluridine and tipiracil hydrochloride, was effective in the treatment of refractory colorectal cancer. We conducted a phase 3 trial to further assess the efficacy and safety of TAS-102 in a global population of such patients. METHODS In this double-blind study, we randomly assigned 800 patients, in a 2:1 ratio, to receive TAS-102 or placebo. The primary end point was overall survival. RESULTS The median overall survival improved from 5.3 months with placebo to 7.1 months with TAS-102, and the hazard ratio for death in the TAS-102 group versus the placebo group was 0.68 (95% confidence interval [CI], 0.58 to 0.81; P<0.001). The most frequently observed clinically significant adverse events associated with TAS-102 were neutropenia, which occurred in 38% of those treated, and leukopenia, which occurred in 21%; 4% of the patients who received TAS-102 had febrile neutropenia, and one death related to TAS-102 was reported. The median time to worsening performance status (a change in Eastern Cooperative Oncology Group performance status [on a scale of 0 to 5, with 0 indicating no symptoms and higher numbers indicating increasing degrees of disability] from 0 or 1 to 2 or more) was 5.7 months with TAS-102 versus 4.0 months with placebo (hazard ratio, 0.66; 95% CI, 0.56 to 0.78; P<0.001). CONCLUSIONS In patients with refractory colorectal cancer, TAS-102, as compared with placebo, was associated with a significant improvement in overall survival. (Funded by Taiho Oncology-Taiho Pharmaceutical; RECOURSE ClinicalTrials.gov number, NCT01607957.).

Dlk-1, a cell surface antigen on foetal hepatic stem/progenitor cells, is expressed in hepatocellular, colon, pancreas and breast carcinomas at a high frequency.

Delta-like 1 protein (Dlk-1), also known as preadipocyte factor 1 (Pref-1), is a transmembrane and secreted protein with epidermal growth factor (EGF)-like repeats. Dlk-1 is known to be expressed in foetal liver, but absent in neonatal and adult liver in mice and rats. Dlk-1 is also expressed in a subpopulation of hepatic oval cells, which are considered as stem/progenitor cells in rat adult liver. In this study, we generated monoclonal antibodies against human Dlk-1 (hDlk-1) and investigated hDlk-1 expression in human liver and hepatocellular carcinoma (HCC). Like rodent livers, hDlk-1 was detected in foetal liver, but not in adult liver. In HCC, hDlk-1 was positive for 20.5% of the cases examined and was localized in both cytoplasm and cell membrane, whereas hDlk-1 was undetected in viral hepatitis, nodular cirrhosis. Interestingly, hDlk-1 positive HCC was found more frequently in younger patients and its expression was correlated with alpha-fetoprotein expression. Furthermore, hDlk-1 was also detected frequently in colon adenocarcinomas (58%), pancreatic islet carcinoma (50%), and small cell lung carcinoma (50%). Thus, hDlk-1 is a cell surface protein expressed in many carcinomas including HCC and may be a potential target for monoclonal antibody therapy for carcinomas.

Circulating tumor cells as a surrogate marker for determining response to chemotherapy in patients with advanced gastric cancer

The purpose of this study was to quantify circulating tumor cells (CTCs) in advanced gastric cancer (AGC) patients, and to demonstrate the role of CTCs in cancer therapy. This study investigates the hypothesis that CTCs can predict clinical outcomes in patients with AGC. From November 2007 to June 2009, 52 patients with AGC were enrolled into a prospective study. The chemotherapy regimen was an S‐1‐based regimen (S‐1 with or without cisplatin) or paclitaxel. CTCs of whole blood at baseline, 2 weeks, and 4 weeks after initiation of chemotherapy, were isolated and enumerated using immunomagnetics. Patients with ≥4 CTCs at 2‐week points and 4‐week points had a shorter median progression‐free survival (PFS) (1.4, 1.4 months, respectively) than those with the median PFS of <4 CTCs (4.9, 5.0 months, respectively) (log‐rank test; P < 0.001, P < 0.001, respectively). Patients with ≥4 CTCs at 2‐week points and 4‐week points had shorter median overall survival (OS) (3.5, 4.0 months, respectively) than those with the median PFS of <4 CTCs (11.7, 11.4 months, respectively) (log‐rank test; P < 0.001, P = 0.001, respectively). In conclusion, this study demonstrates that CTC measurement may be useful as a surrogate marker for determining response to S‐1‐based or paclitaxel regimens in AGC.

Blockade of bulky lymphoma‐associated CD55 expression by RNA interference overcomes resistance to complement‐dependent cytotoxicity with rituximab

Recently, anti‐CD20 (rituximab) and anti‐Her2/neu (trastuzumab) antibodies have been developed and applied to the treatment of malignant lymphoma and breast cancer, respectively. However, bulky lymphoma is known to be resistant to rituximab therapy, and this needs to be overcome. Fresh lymphoma cells were collected from 30 patients with non‐Hodgkins lymphoma, the expression of CD20 and CD55 was examined by flow cytometry, and complement‐dependent cytotoxicity (CDC) assays were carried out. Susceptibility to CDC with rituximab was decreased in a tumor size‐dependent manner (r = –0.895, P < 0.0001), but not in a CD20‐dependent manner (r = –0.076, P = 0.6807) using clinical samples. One complement‐inhibitory protein, CD55, contributed to bulky lymphoma‐related resistance to CDC with rituximab. A decrease in susceptibility to CDC with rituximab was statistically dependent on CD55 expression (r = –0.927, P < 0.0001) and the relationship between tumor size and CD55 expression showed a significant positive correlation (r = 0.921, P < 0.0001) using clinical samples. To overcome the resistance to rituximab by high expression of CD55 in bulky lymphoma masses, small interfering RNA (siRNA) was designed from the DNA sequence corresponding to nucleic acids 1–380 of the CD55 cDNA. Introduction of this siRNA decreased CD55 expression in the breast cancer cell line SK‐BR3 and in CD20‐positive cells of patients with recurrent lymphoma; resistance to CDC was also inhibited. This observation gives us a novel strategy to suppress bulky disease‐related resistance to monoclonal antibody treatment. (Cancer Sci 2006; 97: 72–79)

Circulating tumor cells as a surrogate marker for determining response to chemotherapy in Japanese patients with metastatic colorectal cancer

The purpose of this study was to investigate the potential of circulating tumor cells (CTC) as a surrogate marker of the clinical outcome in metastatic colorectal cancer (mCRC) patients in order to identify Japanese patients responsive to oxaliplatin‐based chemotherapy. Between January 2007 and April 2008, 64 patients with mCRC were enrolled in this prospective study. The treatment regimen was oxaliplatin‐based chemotherapy. Collection of CTC from whole blood was performed at baseline and at 2 and 8–12 weeks after initiation of chemotherapy. Isolation and enumeration of CTC was performed using immunomagnetics. Patients with ≥3 CTC at baseline and at 2 and 8–12 weeks had a shorter median progression‐free survival (8.5, 7.3 and 1.9 months, respectively) than those with <3 CTC (9.7, 10.4 and 9.1 months, respectively) (log‐rank test: P = 0.047, P < 0.001 and P < 0.001, respectively). Patients with ≥3 CTC at 2 and 8–12 weeks had a shorter median overall survival (10.2 and 4.1 months, respectively) than those with <3 CTC (29.1 and 29.1 months, respectively) (P < 0.001 and P = 0.001, respectively). A spurious early rise in carcinoembryonic antigen level was observed in 11 patients showing a partial response. In contrast, no rise in early CTC level was observed among responders. Our data support the clinical utility of CTC enumeration in improving our ability to accurately assess treatment benefit and in expediting the identification of effective treatment regimens for individual Japanese patients. (Cancer Sci 2011; 102: 1188–1192)

Phase I/II study of capecitabine plus oxaliplatin (XELOX) plus bevacizumab as first-line therapy in Japanese patients with metastatic colorectal cancer.

Objective The addition of bevacizumab to fluoropyrimidine-based combination chemotherapy as first-line therapy for metastatic colorectal cancer results in clinically significant improvements in patient outcome. However, clinical trials have been conducted primarily in Caucasian patients with only a small proportion of Asian patients. This Phase I/II study was designed to evaluate the efficacy and safety of XELOX (capecitabine plus oxaliplatin) plus bevacizumab in Japanese patients with metastatic colorectal cancer. Methods Patients with previously untreated, measurable metastatic colorectal cancer received bevacizumab 7.5 mg/kg and oxaliplatin 130 mg/m2 on day 1, plus capecitabine 1000 mg/m2 twice daily on days 1–14, every 3 weeks. A three-step design evaluated in: step 1, initial safety of XELOX in six patients; step 2, initial safety of XELOX plus bevacizumab in six patients; and step 3, efficacy and safety in a further 48 patients. The primary study endpoints were safety and response rate. Results No dose-limiting toxicity occurred during Steps 1 and 2. Fifty-eight patients were enrolled in Steps 2 and 3 and received XELOX plus bevacizumab. In the 57 patients assessed for response, the overall response rate was 72% (95% confidence interval, 58.5–83.0). Median progression-free survival was 11.0 months (95% confidence interval, 9.6–12.5) and median overall survival was 27.4 months (95% confidence interval, 22.0–not calculated). Eight patients (14%) underwent surgery with curative intent. The most common grade 3/4 adverse events were neurosensory toxicity (17%) and neutropenia (16%). Conclusions XELOX plus bevacizumab is effective and has a manageable tolerability profile when given to Japanese patients with metastatic colorectal cancer.

Irinotecan plus cisplatin for therapy of small-cell carcinoma of the esophagus: report of 12 cases from single institution experience.

BACKGROUND Esophageal small-cell cancer is a rare disease, and standard therapy has not yet been established. METHODS A total of 12 esophageal small-cell carcinoma patients were treated with CPT-11 (70 mg/m(2)) on Days 1 and 15 and CPT-11 plus CDDP (80 mg/m(2)) on Day 1 with each cycle repeated every 4 weeks at our institution. RESULTS A total of 46 chemotherapy courses were given (median, 3.5). There were two complete responses and eight partial responses. The median survival time was 417 (97-1626) days, and three patients were still alive for >40 months. Grade 4 neutropenia was observed in two patients, Grade 4 anemia in one patient, Grade 3-4 diarrhea in three patients and Grade 3-4 hyponatremia in three patients. Other adverse reactions seen were mild with no treatment-related deaths observed. CONCLUSIONS To our knowledge, this is the first report of the series of more than 10 patients with small-cell carcinoma of the esophagus treated with the same chemotherapy regimen. The combination of CPT-11 and CDDP appears to be effective therapy of this disease with acceptable toxicity profile. We believe that this regimen is one of the options to be considered for treatment of esophageal small-cell carcinoma.

Circulating endothelial progenitors and CXCR4‐positive circulating endothelial cells are predictive markers for bevacizumab

Bevacizumab plus chemotherapy is a standard option in the treatment of metastatic colorectal cancer (mCRC). The aim of this study was to investigate the potential of circulating endothelial cell progenitors (CEPs) and phenotypical circulating endothelial cells (CECs) as surrogate markers of clinical outcome in mCRC patients to identify responders to bevacizumab in combination with chemotherapy.

PACLITAXEL ADMINISTERED WEEKLY IN PATIENTS WITH DOCETAXEL- RESISTANT METASTATIC BREAST CANCER: A SINGLE-CENTER STUDY

Aims and background We evaluated retrospectively the efficacy and toxicity of paclitaxel in patients with docetaxel-resistant metastatic breast cancer. Study design Paclitaxel (80 mg/m2) was administered weekly to 44 patients who had previously received chemotherapy regimens for metastatic breast cancer. All patients had progressive disease in spite of having received docetaxel therapy. Results Treatment was repeated until there was evidence of disease progression. Objective responses were obtained in 14 of 44 assessable patients (31.8%; 95% confidence interval, 17.5–46.1). Fourteen patients had partial responses; none responded completely. Seven of 14 responders had primary resistance to docetaxel therapy. The median duration of response was 6.1 months (range, 2.1–12.7). The median time to progression was 5.0 months. Clinically severe adverse events (grade 3 or 4) included neutropenia (27.2%), leukopenia (25.0%), neuropathy-sensory (13.6%), febrile neutropenia (6.8%), anemia (2.2%), constipation (2.2%), and edema (2.2%). Treatment was generally well tolerated and could be continued on an out-patient basis. Conclusions Weekly paclitaxel is effective in patients with docetaxel-resistant metastatic breast cancer. This observation suggests partial cross-resistance between paclitaxel and docetaxel. There was no evidence for additive cumulative toxic effects of the two taxanes.

Efficacy and safety of trastuzumab as a single agent in heavily pretreated patients with HER-2/neu-overexpressing metastatic breast cancer.

Aims and background The human epidermal growth factor receptor 2 (HER2) protein is a unique and useful target for antibody therapy against breast cancers that overexpress the HER-2/neu gene. The recombinant humanized anti-HER2 monoclonal antibody, trastuzumab, was approved for clinical use in the United States in 1998. It became available in Japan in June 2001. This study focuses on the efficacy and safety of trastuzumab as a single agent in second-third line treatment of HER2/neu-overexpressing metastatic breast cancer. Study design Between June 2001 and May 2002, we treated 62 patients with trastuzumab, as a single agent or in combination chemotherapy, for second-third line treatment of HER2-overexpressing metastatic breast cancer. Twenty-seven of 62 patients were treated with trastuzumab as a single agent. We reviewed retrospectively the efficacy and safety of the drug given as a single agent. The expression of HER2 was determined by immunohistochemical staining. All patients received a standard loading dose of 4 mg/kg followed by 2 mg/kg weekly. Results Patients received a median of 16.7 weekly infusions (range, 1–66 infusions). Trastuzumab therapy was generally well tolerated. Clinically severe adverse events (grade 3 or 4) included hypotension (7.4%), and hypoxia (3.7%). Grade 1 to 2 toxicity included fever (11.1%) and diarrhea (3.7%). Infusion-related reactions were infrequent, as were serious hematologic complications. Cardiotoxicity did not occur in the study. Three patients had a complete and 3 a partial response, 3 had no change, 17 had progressive disease, and one was not evaluated. The overall response rate in the 26 patients with available data was 23.1% (95% confidence interval, 5.7–40.4). The median duration of response was 6.4 months (range, 2.5–14.0). The median time to progression was 3.1 months (range, 0.2–16.7). Response rates differed by metastatic site as follows: lung 0% (0/12), bone 10.0% (1/10), liver 0% (0/8), skin 50.0% (4/8), lymph nodes 42.9% (3/7), brain 0% (0/2). Conclusions Molecular target therapy with trastuzumab appears safe and is generally well tolerated. For treatment of metastatic breast cancer, single agent therapy produces a durable response in some patients but lacks sufficient efficacy. Single agent use of trastuzumab is a viable option for treatment in cases with non-life-threatening disease without visceral metastasis.