Dose-escalating study of capecitabine plus gemcitabine combination therapy in patients with advanced cancer.

PURPOSE: The goals of this phase I study were to determine the maximum-tolerated doses of capecitabine and gemcitabine in patients with advanced cancer and to describe the dose-limiting toxicities (DLT) and safety profile of this combination. PATIENTS AND METHODS: Eligible patients had advanced solid tumors that had failed to respond to standard therapy or for which no standard therapy was available, measurable or assessable disease, Karnofsky performance status > or = 70%, and acceptable organ function. Capecitabine was administered twice daily by mouth each day for 21 consecutive days followed by a 1-week break. Gemcitabine was administered as a 30-minute intravenous infusion weekly for 3 weeks followed by a 1-week break. RESULTS: Forty patients were enrolled onto the study, and 33 are fully assessable for toxicity. The most common toxicities during the first cycle of chemotherapy were neutropenia and mucositis. Only one patient treated at gemcitabine and capecitabine doses of 800 and 2000 mg/m(2), respectively, met protocol-specified DLT criteria; however, at these doses 65% of successive cycles required dose reduction or delay for toxicity. No episodes of DLT were observed at gemcitabine and capecitabine doses of 1,000 and 1,660 mg/m(2), respectively, and 70% of cycles of therapy were delivered without dose reduction or delay. Therefore, these doses are recommended for further study. Tumor responses were observed in patients with metastatic colorectal and pancreatic cancer. CONCLUSION: Gemcitabine and capecitabine can be combined with acceptable toxicity at nearly full doses. Antitumor activity of the combination merits further investigation in phase II studies.

Phase I study of an oral formulation of ZD9331 administered daily for 28 days.

PURPOSE: To define the maximum-tolerated dose and dose-limiting toxicities (DLTs) of an oral formulation of ZD9331, a novel thymidylate synthase inhibitor that is not a substrate for folylpolyglutamate synthase. PATIENTS AND METHODS: Patients had Cancer and Leukemia Group B performance status < or = 2 and refractory solid tumors. Initially, patients received ZD9331 daily for 2 weeks, with the duration of treatment escalated to a maximum of 4 weeks, followed by a 2-week rest period. Once the maximum-tolerated duration of treatment was determined, the dose of ZD9331 was increased until DLT occurred. RESULTS: Fifty-five patients were enrolled at eight dose levels. The DLTs were thrombocytopenia and neutropenia. At 3 mg/d, two of 19 patients developed DLT; one patient had grade 3 thrombocytopenia and grade 4 neutropenia, and the other patient had grade 3 thrombocytopenia only. Anemia was common, with a median hemoglobin nadir of 75% of baseline, before recovery or transfusion. The apparent oral clearance of ZD9931 was 11.6 +/- 6.3 mL/min. Dose-limiting myelosuppression was associated with both an increased 24-hour ZD9931 concentration and blood urea nitrogen. CONCLUSION: The recommended phase II dose on this schedule is 3 mg/d for 4 weeks, followed by a 2-week rest period. ZD9331 seems to have a manageable toxicity profile, although it should be used with caution in patients with renal impairment.

Determination of the optimal modulatory dose of O6-benzylguanine in patients with surgically resectable tumors.

PURPOSE: O6-benzylguanine (BG) provides a means to effectively inactivate the DNA repair protein O6-alkylguanine-DNA alkyltransferase (AGT) and increase the chemotherapeutic effectiveness of chloroethylating and methylating agents in preclinical and clinical studies. Two different doses of BG have been reported as the optimal biochemical modulatory dose for patients (i.e., 100 and 120 mg/m2). The objective of our study was to compare these doses by measuring AGT in surgically removed specimens after treatment with BG. EXPERIMENTAL DESIGN: BG was administered to patients as an i.v. infusion 16 +/- 4 h before surgical resection of their systemic tumor. AGT activity was measured in the tumor using a methylated DNA substrate. The target end point was defined as > or =11 of 13 patients with undetectable tumor AGT levels (<10 fmol/mg protein). RESULTS: Of the 28 patients enrolled, 25 of whom were analyzed for AGT activity, the most common primary sites of cancer included the colon (n = 11), bladder (n = 3), rectum (n = 4), and stomach (n = 3). Positive (DaOY cells) and negative (Chinese hamster ovary cells) control cell lines were included in each assay. Seven of the 12 patients treated with 100 mg/m2 BG had AGT activity of >10 fmol/mg protein (15-147 fmol/mg protein). Only 2 of the 13 patients treated with 120 mg/m2 BG had AGT activity of >10 fmol/mg protein (11 and 12 fmol/mg protein). CONCLUSIONS: From our surgically removed tissue data, a dose of 120 mg/m2 BG is recommended to deplete systemic tumors of AGT activity.

Adult stem cells from bone marrow stroma differentiate into airway epithelial cells: potential therapy for cystic fibrosis.

Cystic fibrosis (CF), the most prevalent, fatal genetic disorder in the Caucasian population, is caused by mutations of CF transmembrane conductance regulator (CFTR). The mutations of this chloride channel alter the transport of chloride and associated liquid and thereby impair lung defenses. Patients typically succumb to chronic bacterial infections and respiratory failure. Restoration of the abnormal CFTR function to CF airway epithelium is considered the most direct way to treat the disease. In this report, we explore the potential of adult stem cells from bone marrow, referred to as mesenchymal or marrow stromal stem cells (MSCs), to provide a therapy for CF. We found that MSCs possess the capacity of differentiating into airway epithelia. MSCs from CF patients are amenable to CFTR gene correction, and expression of CFTR does not influence the pluripotency of MSCs. Moreover, the CFTR-corrected MSCs from CF patients are able to contribute to apical Cl(-) secretion in response to cAMP agonist stimulation, suggesting the possibility of developing cell-based therapy for CF. The ex vivo coculture system established in this report offers an invaluable approach for selection of stem-cell populations that may have greater potency in lung differentiation.

Transcriptome analysis of Pseudomonas aeruginosa after interaction with human airway epithelial cells.

The transcriptional profile of Pseudomonas aeruginosa after interactions with primary normal human airway epithelial cells was determined using Affymetrix GeneChip technology. Gene expression profiles indicated that various genes involved in phosphate acquisition and iron scavenging were differentially regulated.