A phase I dose-escalation study of the polyamine analog PG-11047 in patients with advanced solid tumors.

PURPOSE: Polyamines are essential for the sustained proliferation and biomass required by tumor cells. Bis-alkylated polyamine analogs are nonfunctional competitors of natural polyamines. Of these, PG-11047, a second-generation unsaturated analog of the polyamine spermine, has demonstrated anticancer activity in cell lines and animal models of multiple cancer types. This report describes the first phase I clinical trial to investigate PG-11047 in patients with advanced refractory metastatic solid tumors. METHODS: Forty-six patients were treated with 60-min intravenous infusions of PG-11047 using a 28-day dosing cycle with treatments on days 1, 8, and 15. Doses ranged from 50 to 750 mg. The treatment period consisted of at least two cycles. RESULTS: The maximum tolerated dose of PG-11047 administered at this dosing schedule was 610 mg. Dose-limiting toxicities (DLT) were mainly gastrointestinal, including oral/anal mucositis and diarrhea; other DLTs included one case each of angioedema and a grade 3 alanine aminotransferase (ALT) increase. The most common adverse effects were fatigue and anorexia. Stable disease was documented in 30% of patients. CONCLUSION: Results of this phase I trial suggest that PG-11047 can be safely administered to patients on the once weekly dosing schedule described. The manageable toxicity profile and high MTD determination provide a safety profile for further clinical studies, including those in combination with current chemotherapeutic agents.

Robotic Ventral Hernia Repair and Endoscopic Component Separation: Outcomes.

BACKGROUND AND OBJECTIVES: Robot-assisted hernia repair, combined with endoscopic component separation, has reduced recurrence and complication rates and allowed immediate intervention in obese patients. We sought to study surgical outcomes in this high-risk group of patients in a community hospital. METHODS: We conducted a retrospective chart review of ventral, incisional, and umbilical hernia repairs performed at a small community hospital by a single surgeon from March 2014 through November 2016, with statistical analysis of the surgical outcomes. Patients included were those who underwent hernia repair during the study period and had a body mass index (BMI) >30. Patients were followed up for a minimum of 6 months (range, 6-37). RESULTS: Forty-seven hernia repairs were performed, including 33 combined and 14 control cases. The demographics of each group were comparable when comparing sex, age, BMI, and ASA classification. Mean follow-up was 19.39 months in the study group and 28.64 months in the control group. There were no significant differences in total operative time, estimated blood loss, conversion rates, or hospital length of stay. Two complications occurred in each of the study and control groups, with no recurrences in the study group and 3 in the control group and no mortalities. CONCLUSION: Robotic laparoscopic repair of abdominal wall defects offers significant advantages, including easier primary defect closure. Our analyses showed that combining robot-assisted hernia repair with mesh and endoscopic component separation is an effective intervention in obese patients.

Sorafenib for treatment of renal cell carcinoma: Final efficacy and safety results of the phase III treatment approaches in renal cancer global evaluation trial.

PURPOSE: Mature survival data and evaluation of vascular endothelial growth factor (VEGF) as a prognostic biomarker from the Treatment Approaches in Renal Cancer Global Evaluation Trial (TARGET) study in patients with renal cell carcinoma (RCC) are reported. PATIENTS AND METHODS: Nine hundred three previously treated patients were randomly assigned to receive sorafenib versus placebo. On demonstration of progression-free survival (PFS) benefit with sorafenib, patients assigned to placebo were offered sorafenib. Overall survival (OS) was determined at two planned interim analyses and one final analysis, with a secondary OS analysis conducted by censoring placebo patients who crossed over to sorafenib. The relationships between baseline VEGF level and prognosis and efficacy were evaluated. RESULTS: The final OS of patients receiving sorafenib was comparable with that of patients receiving placebo (17.8 v 15.2 months, respectively; hazard ratio [HR] = 0.88; P = .146); however, when post-cross-over placebo survival data were censored, the difference became significant (17.8 v 14.3 months, respectively; HR = 0.78; P = .029). Adverse events at 16 months after cross over were similar to those previously reported. Baseline VEGF levels correlated with Eastern Cooperative Oncology Group performance status (P < .0001), Memorial Sloan-Kettering Cancer Center score (P < .0001), and PFS and OS in univariate (PFS, P = .0013; OS, P = .0009) and multivariate (PFS, P = .0231; OS, P = .0416) analyses of placebo patients and with short OS by multivariate analysis of patients receiving sorafenib (P = .0145). Both high-VEGF (P < .01) and low-VEGF (P < .01) groups benefited from sorafenib. CONCLUSION: Although an OS benefit was not seen on a primary intent-to-treat analysis, results of a secondary OS analysis censoring placebo patients demonstrated a survival advantage for those receiving sorafenib, suggesting an important cross-over effect. VEGF levels are prognostic for PFS and OS in RCC. The results of TARGET establish the efficacy and safety of sorafenib in advanced RCC.

Phase I and pharmacokinetic study of sorafenib in patients with hepatic or renal dysfunction: CALGB 60301.

PURPOSE: We sought to characterize the pharmacokinetics (PK) and determine a tolerable dose of oral sorafenib in patients with hepatic or renal dysfunction. PATIENTS AND METHODS: Patients were assigned to one of nine cohorts: cohort 1, bilirubin < or = upper limit of normal (ULN) and AST < or = ULN and creatinine clearance (CC) > or = 60 mL/min; cohort 2, bilirubin more than ULN but < or = 1.5x ULN and/or AST more than ULN; cohort 3, CC between 40 and 59 mL/min; cohort 4, bilirubin more than 1.5x ULN to < or = 3x ULN (any AST); cohort 5, CC between 20 and 39 mL/min; cohort 6, bilirubin more than 3x ULN to 10x ULN (any AST); cohort 7, CC less than 20 mL/min; cohort 8, albumin less than 2.5 mg/dL (any bilirubin/AST); and cohort 9, hemodialysis. Sorafenib was administered as a 400-mg dose on day 1 for PK, and continuous daily dosing started on day 8. RESULTS: Of 150 registered patients, 138 patients were treated. With the exception of cohorts 6 and 7, at least 12 patients per cohort were assessable, and the dose level with prospectively defined dose-limiting toxicity in less than one third of patients by day 29 was considered tolerable. No significant associations between the sorafenib PK and cohort were found. CONCLUSION: We recommend the following empiric sorafenib starting doses by cohort: cohort 1, 400 mg twice a day; cohort 2, 400 mg twice a day; cohort 3, 400 mg twice a day; cohort 4, 200 mg twice a day; cohort 5, 200 mg twice a day; cohort 6, not even 200 mg every third day tolerable; cohort 7, not defined; cohort 8, 200 mg each day; and cohort 9, 200 mg each day.

A phase I trial to determine the safety, tolerability, and maximum tolerated dose of deforolimus in patients with advanced malignancies.

PURPOSE: This was a phase I trial to determine the maximum tolerated dose and toxicity of deforolimus (AP23573, MK-8669), an inhibitor of mammalian target of rapamycin (mTOR). The pharmacokinetics, pharmacodynamics, and antineoplastic effects were also studied. EXPERIMENTAL DESIGN: Deforolimus was administered intravenously over 30 min every 7 days according to a flat dosing schedule. Dose was escalated according to an accelerated titration design. Patients remained on study until disease progression as long as they tolerated the drug without significant toxicities. RESULTS: Forty-six patients were enrolled on the study. Common side effects included fatigue, anorexia, and mucositis. The maximum tolerated dose was 75 mg and mucositis was the dose-limiting toxicity. Similar to other mTOR inhibitors, deforolimus exhibited nonlinear pharmacokinetics and a prolonged half-life. Among 34 patients evaluable for response, 1 patient had a partial response, 21 patients had stable disease, and 12 had progressed. Percent change in tumor size was significantly associated with AUC (P=0.015). A significant association was also detected for maximum change in cholesterol within the first two cycles of therapy and change in tumor size (r=-0.38; P=0.029). CONCLUSIONS: Deforolimus was well tolerated on the schedule tested in this trial with toxicity and pharmacokinetic profiles that were similar to that of other mTOR inhibitors. Additional phase II studies are needed to determine if deforolimus is superior to other mTOR inhibitors in terms of efficacy. The change in serum cholesterol as a potential biomarker of activity should be studied further.

A phase I and pharmacokinetic study of the quinoxaline antitumour Agent R(+)XK469 in patients with advanced solid tumours.

PURPOSE: To investigate the safety and pharmacokinetics of R(+)XK469, a quinoxaline analogue, in patients with advanced refractory solid tumours. Preclinical studies suggested that efficacy was independent of schedule but that toxicity was decreased by dividing the dose. METHODS: R(+)XK469 was initially administered as a 30 min intravenous infusion on days 1-5 of a 21-d cycle. Based on the demonstration of a long half-life, the dosing schedule was subsequently amended to infusion on days 1, 3 and 5 of a 21-d cycle. An alternate single-dose schedule of once every 21 d was also explored. Blood samples were collected for pharmacokinetic studies. RESULTS: Dose-limiting toxicity (DLT) was neutropaenia. There was significant interindividual variability in clearance as evidenced by a coefficient of variation of 46%. A flat-dosing scheme (not based on body surface area) was justified by the absence of correlation between clearance and body surface area. A partial response was observed in a patient with nasopharyngeal carcinoma. CONCLUSIONS: The recommended phase II doses are 850-1100 mg/d on days 1, 3 and 5 of a 21-d cycle and 2500 mg on day 1 of a 21-d cycle. The observed interpatient pharmacokinetic variability should prompt investigation into the presence of genetic polymorphism in relevant metabolizing enzymes.

Pharmacogenomic and pharmacokinetic determinants of erlotinib toxicity.

PURPOSE: To assess the pharmacogenomic and pharmacokinetic determinants of skin rash and diarrhea, the two primary dose-limiting toxicities of the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib. PATIENTS AND METHODS: A prospective clinical study of 80 patients with non-small-cell lung cancer, head and neck cancer, and ovarian cancer was performed. Detailed pharmacokinetics and toxicity of erlotinib were assessed. Polymorphic loci in EGFR, ABCG2, CYP3A4, and CYP3A5 were genotyped, and their effects on pharmacokinetics and toxicities were evaluated. RESULTS: A novel diplotype of two polymorphic loci in the ABCG2 promoter involving -15622C/T and 1143C/T was identified, with alleles conferring lower ABCG2 levels associated with higher erlotinib pharmacokinetic parameters, including area under the curve (P = .019) and maximum concentration (P = .006). Variability in skin rash was best explained by a multivariate logistic regression model incorporating the trough erlotinib plasma concentration (P = .034) and the EGFR intron 1 polymorphism (P = .044). Variability in diarrhea was associated with the two linked polymorphisms in the EGFR promoter (P < .01), but not with erlotinib concentration. CONCLUSION: Although exploratory in nature, this combined pharmacogenomic and pharmacokinetic model helps to define and differentiate the primary determinants of skin and gastrointestinal toxicity of erlotinib. The findings may be of use both in designing trials targeting a particular severity of rash and in considering dose and schedule modifications in patients experiencing dose-limiting toxicities of erlotinib or similarly targeted agents. Further studies of the relationship between germline polymorphisms in EGFR and the toxicity and efficacy of EGFR inhibitors are warranted.

A Phase I/II study of GTI-2040 and capecitabine in patients with renal cell carcinoma.

BACKGROUND: Fluoropyrimidine based therapy has modest activity in patients with metastatic renal carcinoma and inhibition of ribonucleotide reductase is synergistic in model systems. GTI-2040 is a 20-mer phosphorothioate oligonucleotide complimentary to the R2 component of ribonucleotide reductase that has activity in renal cancer models. METHODS: Metastatic renal carcinoma patients without prior fluoropyrimidine therapy and normal organ function were treated with oral capecitabine 880 mg/m(2) twice daily along with continuous infusion GTI-2040 starting at 148 mg/m(2)/day for 21 days, for each 28-day cycle. After completion of the phase I portion, the phase II study portion sought to rule out a null hypothesized 10% response rate versus an alternative 25% response rate utilizing alpha and beta errors of 0.05 and 0.2, respectively. GTI-2040 pharmacokinetics and effects on ribonucleotide reductase expression in peripheral mononuclear cells were evaluated in a subset of patients. RESULTS: Based on one dose limiting toxicity in nine patients in the phase I portion, the phase II portion was conducted using the previously recommended 185 mg/m(2)/day dose of GTI-2040. Twenty-six patients were enrolled in the phase II portion to obtain 18 fully evaluable for response. Only one patient, treated at a GTI 2040 dose of 185 mg/m(2)/day in the phase I portion of the protocol, responded. Toxicities and GTI-2040 pharmacokinetics were consistent with previously reported results. R2 expression in peripheral mononuclear cells was too variable for accurate interpretation. CONCLUSION: Further study of GTI-2040 and capecitabine in metastatic renal cancer at this dose and schedule is not indicated. Further study is necessary to determine whether lack of activity is due to inadequate target inhibition or inadequate effect of appropriate targeting.

Phase 2 study of ABT-510 in patients with previously untreated advanced renal cell carcinoma.

PURPOSE: Angiogenesis is a characteristic of renal cell carcinoma. ABT-510 is an angiogenesis inhibitor that mimics the antiangiogenic properties of thrombospondin-1. This study was designed to assess the safety and efficacy of ABT-510 in patients with advanced renal cell carcinoma. EXPERIMENTAL DESIGN: Patients with previously untreated metastatic or unresectable renal cell carcinoma were randomized to treatment with one of two doses of ABT-510, self-administered s.c. twice daily in 28-day treatment periods without intervening rest periods. End points were progression-free survival (PFS), objective response rate, overall survival, and toxicity. RESULTS: The objective response rate was 4% in the 10 mg twice daily group, and there were two unconfirmed PRs in the 100 mg twice daily group. Respective median PFS was 4.2 and 3.3 months, with a 6-month PFS of 39% and 32%. Median overall survival was 27.8 months (10 mg twice daily) and 26.1 months (100 mg twice daily). The most frequent adverse events were injection site reactions (84%), fatigue (50%), headache (20%), and nausea (19%). The incidence of treatment-related, grade 3/4 adverse events was low and included three bleeding episodes (gastrointestinal hemorrhage, intracranial hemorrhage, and hemoptysis) and one thrombotic event (deep vein thrombosis). No deaths were attributed to ABT-510. CONCLUSIONS: There was little evidence of clinical activity for ABT-510, and further evaluation as a single agent for treating advanced renal cell carcinoma is not warranted. The evidence of a favorable safety profile may justify further evaluation in combination therapy.

Pharmacokinetic modulation of oral etoposide by ketoconazole in patients with advanced cancer.

PURPOSE: Etoposide is a widely used cytotoxic drug that is commercially available in both intravenous and oral formulations. High interpatient pharmacokinetic variability has been associated with oral etoposide administration. Various strategies used in the past to reduce such variability have not been successful. Hence, this study was designed to evaluate if pharmacokinetic modulation of oral etoposide with ketoconazole could lead to a favorable alteration of etoposide pharmacokinetics, and to assess the feasibility and safety of this approach. METHODS: Thirty-two patients were treated with ketoconazole 200 mg daily with an escalating dose of oral etoposide starting at a dose of 50 mg every other day. Pharmacokinetic samples were obtained during the first treatment cycle after the administration of an oral etoposide and ketoconazole dose. Additional baseline pharmacokinetic studies of etoposide alone were performed 4 days prior to the first treatment cycle. RESULTS: Dose limiting toxicities were neutropenia and fatigue. Ketoconazole increased the area under the plasma concentration-time curve (AUC) of oral etoposide by a median of 20% (p < 0.005). Ketoconazole did not reduce the interpatient variability in etoposide pharmacokinetics. Pretreatment bilirubin levels correlated with etoposide clearance (Spearman's r = -0.48, p = 0.008). The maximum tolerated dose was etoposide administered at 50 mg daily and ketoconazole 200 mg qd for 3 of 5 weeks. CONCLUSIONS: Ketoconazole reduces the apparent clearance of oral etoposide, does not alter its toxicity profile and does not reduce interpatient pharmacokinetic variability. Other methods to reduce the pharmacokinetic variability of oral etoposide are needed.

Sorafenib in advanced clear-cell renal-cell carcinoma.

BACKGROUND: We conducted a phase 3, randomized, double-blind, placebo-controlled trial of sorafenib, a multikinase inhibitor of tumor-cell proliferation and angiogenesis, in patients with advanced clear-cell renal-cell carcinoma. METHODS: From November 2003 to March 2005, we randomly assigned 903 patients with renal-cell carcinoma that was resistant to standard therapy to receive either continuous treatment with oral sorafenib (at a dose of 400 mg twice daily) or placebo; 451 patients received sorafenib and 452 received placebo. The primary end point was overall survival. A single planned analysis of progression-free survival in January 2005 showed a statistically significant benefit of sorafenib over placebo. Consequently, crossover was permitted from placebo to sorafenib, beginning in May 2005. RESULTS: At the January 2005 cutoff, the median progression-free survival was 5.5 months in the sorafenib group and 2.8 months in the placebo group (hazard ratio for disease progression in the sorafenib group, 0.44; 95% confidence interval [CI], 0.35 to 0.55; P<0.01). The first interim analysis of overall survival in May 2005 showed that sorafenib reduced the risk of death, as compared with placebo (hazard ratio, 0.72; 95% CI, 0.54 to 0.94; P=0.02), although this benefit was not statistically significant according to the O'Brien-Fleming threshold. Partial responses were reported as the best response in 10% of patients receiving sorafenib and in 2% of those receiving placebo (P<0.001). Diarrhea, rash, fatigue, and hand-foot skin reactions were the most common adverse events associated with sorafenib. Hypertension and cardiac ischemia were rare serious adverse events that were more common in patients receiving sorafenib than in those receiving placebo. CONCLUSIONS: As compared with placebo, treatment with sorafenib prolongs progression-free survival in patients with advanced clear-cell renal-cell carcinoma in whom previous therapy has failed; however, treatment is associated with increased toxic effects. (ClinicalTrials.gov number, NCT00073307 [ClinicalTrials.gov].).

Diffuse alveolar damage after a single dose of topotecan in a patient with pulmonary fibrosis and small cell lung cancer.

Drug-induced pulmonary toxicities of anticancer agents have been well described, but the pathophysiology of agents typically used in advanced disease has not been well studied. Symptoms of pulmonary drug toxicity in advanced lung cancer patients may frequently be attributed to disease progression, pulmonary embolism, or infection. In patients with pre-existing interstitial pulmonary fibrosis even less is known. This report describes an unfortunate patient with pre-existing pulmonary fibrosis and progressive extensive stage small cell lung cancer. After receiving a single intravenous dose of topotecan, the patient developed sub-acute respiratory failure, and died 15 days later with pathology findings of organizing, reparative phase, diffuse alveolar damage. To our knowledge this is the first pathology confirmation of diffuse alveolar damage in a patient developing dyspnea following topotecan therapy. The frequency with which camptothecin-related dyspnea is associated with diffuse alveolar damage might be underestimated and is of special concern in patients with limited pulmonary reserve.

Combination therapy of imatinib mesylate and interferon-alpha demonstrates minimal activity and significant toxicity in metastatic renal cell carcinoma: results of a single- institution phase II trial.

BACKGROUND: Renal cell carcinoma (RCC) is characterized by increased expression of vascular endothelial growth factor and platelet-derived growth factor (PDGF)-beta, both of which contribute to its angiogenic phenotype. Interferon-alpha (IFN-alpha) improves survival in patients with metastatic RCC, perhaps partly because of its antiangiogenic properties. Imatinib mesylate inhibits PDGF-mediated signal transduction and might thus have antiangiogenic activity as well. PATIENTS AND METHODS: Patients with metastatic RCC were treated with IFN-alpha (9 million IU subcutaneously 3 times weekly) and oral imatinib mesylate (600 mg daily starting on day 8). Therapy was continuous, and response was evaluated at 8-week intervals using the Response Evaluation Criteria in Solid Tumors. Baseline plasma PDGF-AA, PDGF-AB, and PDGF-BB levels were obtained. RESULTS: Between January 2003 and January 2005, 17 patients were treated. One patient (6%) had a partial response, 4 (24%) had stable disease, 7 (41%) had progressive disease, and 5 (29%) were unevaluable because of early withdrawal secondary to toxicity. Median time to progression (TTP) using the Kaplan-Meier method was 8 weeks, and median overall survival was 17.8 months. Six patients (35%) withdrew from therapy because of toxicity, and 9 patients (53%) experienced > or = 1 grade 3/4 toxicity. Platelet-derived growth factor AA, AB, and BB plasma levels did not correlate with TTP or overall survival. CONCLUSION: Based on a response rate of only 6%, a median TTP of 2 months, and significant toxicities, further study of IFN-alpha in combination with imatinib mesylate is not recommended in patients with metastatic RCC.

Phase II placebo-controlled randomized discontinuation trial of sorafenib in patients with metastatic renal cell carcinoma.

PURPOSE: This phase II randomized discontinuation trial evaluated the effects of sorafenib (BAY 43-9006), an oral multikinase inhibitor targeting the tumor and vasculature, on tumor growth in patients with metastatic renal cell carcinoma. PATIENTS AND METHODS: Patients initially received oral sorafenib 400 mg twice daily during the initial run-in period. After 12 weeks, patients with changes in bidimensional tumor measurements that were less than 25% from baseline were randomly assigned to sorafenib or placebo for an additional 12 weeks; patients with > or = 25% tumor shrinkage continued open-label sorafenib; patients with > or = 25% tumor growth discontinued treatment. The primary end point was the percentage of randomly assigned patients remaining progression free at 24 weeks after the initiation of sorafenib. RESULTS: Of 202 patients treated during the run-in period, 73 patients had tumor shrinkage of > or = 25%. Sixty-five patients with stable disease at 12 weeks were randomly assigned to sorafenib (n = 32) or placebo (n = 33). At 24 weeks, 50% of the sorafenib-treated patients were progression free versus 18% of the placebo-treated patients (P = .0077). Median progression-free survival (PFS) from randomization was significantly longer with sorafenib (24 weeks) than placebo (6 weeks; P = .0087). Median overall PFS was 29 weeks for the entire renal cell carcinoma population (n = 202). Sorafenib was readministered in 28 patients whose disease progressed on placebo; these patients continued on sorafenib until further progression, for a median of 24 weeks. Common adverse events were skin rash/desquamation, hand-foot skin reaction, and fatigue; 9% of patients discontinued therapy, and no patients died from toxicity. CONCLUSION: Sorafenib has significant disease-stabilizing activity in metastatic renal cell carcinoma and is tolerable with chronic daily therapy.

Novel kinase inhibitors in renal cell carcinoma: progressive development of static agents.

The rapidly expanding knowledge regarding neoplastic diseases is providing a plethora of new targets for drug discovery and development as exemplified by recent data in renal cell carcinoma. The initial experience with molecularly "targeted" agents has demonstrated that development of the newer non-cytotoxic agents will provide unique challenges requiring modification of many traditional drug development concepts and methods. We discuss recently reported data from a few renal cell carcinoma trials with putative cytostatic agents and highlight issues that need to be addressed for efficient development of cytostatic agents during various phases of clinical development.

Modulation of irinotecan with cyclosporine: a phase II trial in advanced colorectal cancer.

INTRODUCTION: Despite the extensive clinical experience with irinotecan, significant concerns remain regarding its toxicity. In a phase I trial, we modulated irinotecan pharmacokinetics by inhibiting biliary excretion of SN-38, the active metabolite of irinotecan, using cyclosporine. The modulation appeared to decrease the gastrointestinal toxicity of irinotecan and suggested that irinotecan activity might also be retained. Hence, we conducted this phase II trial in patients with colorectal cancer (CRC) to further evaluate the toxicity and activity of irinotecan modulated with cyclosporine. PATIENTS AND METHODS: Sixteen patients with 5-fluorouracil refractory CRC were treated. Cyclosporine (5 mg/kg) was administered as a 6-h infusion and irinotecan (60 mg/m2/day, 90-min infusion) was started 3 h after initiation of the Cyclosporine. Both agents were given weekly for 4 weeks, every 6 weeks. Responses were assessed every 12 weeks, and toxicity was monitored weekly. RESULTS: Sixteen patients were evaluable for toxicity and 11 for response. There was 1 partial response (6%). Five patients had SD lasting a median of 12 weeks. Grade 3/4 diarrhea was observed in only 13% of the patients. CONCLUSION: Pharmacokinetic modulation of irinotecan using parenteral cyclosporine appears to decrease the incidence of diarrhea in CRC patients. Given the modest activity of irinotecan monotherapy, a larger study would be required to assess if the modulation improves the toxicity without compromising this activity. The available clinical data suggest that pharmacokinetic modulation of irinotecan should be evaluated further to define its optimal clinical utility.

Haplotypes of variants in the UDP-glucuronosyltransferase1A9 and 1A1 genes.

OBJECTIVES: Nine different functional UGT1A enzymes are generated from a single UGT1A gene by alternative splicing, with each enzyme having a unique exon 1. SN-38, the active metabolite of the anticancer agent irinotecan, is metabolized by both UGT1A1 and UGT1A9. We aim to characterize the UGT1A9-UGT1A1 haplotypes in Asians and Caucasians and gain insights on their functional consequences. METHODS: Asian and Caucasian individuals were genotyped for UGT1A1 and UGT1A9 variants. RESULTS: A higher frequency of the UGT1A9 -118T10 allele was observed in Asians compared to Caucasians, while the -275T>A and -2152C>T variants were relatively uncommon in Caucasians and not found in Asians. The strongest linkage disequilibrium (LD) was observed between the UGT1A1 -53 and -3156 and between the UGT1A9 -275 and -2152 loci. Lower LD was observed between the -118 UGT1A9 variant and the UGT1A1 variants. Fourteen UGT1A9-UGT1A1 haplotypes were found in Asians, seven of them found to be shared by both populations. Common UGT1A9-UGT1A1 diplotypes were defined, and a difference was observed across the SN-38 glucuronidation rates in Caucasian livers stratified by diplotypes. CONCLUSION: This study for the first time described common UGT1A9-UGT1A1 haplotypes, highlighting important ethnic differences between Asians and Caucasians. If the functional effect of these haplotypes can be confirmed, this haplotypic information would be applicable to the correct design of prospective clinical studies of irinotecan, as well as of other drugs primarily metabolized by both UGT1A1 and UGT1A9.

Novel kinase inhibitors in renal cell carcinoma: progressive development of static agents.

The rapidly expanding knowledge regarding neoplastic diseases is providing a plethora of new targets for drug discovery and development as exemplified by recent data in renal cell carcinoma. The initial experience with molecularly "targeted" agents has demonstrated that development of the newer non-cytotoxic agents will provide unique challenges requiring modification of many traditional drug development concepts and methods. We discuss recently reported data from a few renal cell carcinoma trials with putative cytostatic agents and highlight issues that need to be addressed for efficient development of cytostatic agents during various phases of clinical development.