Mandrekar, Sumithra J.

Abstract The cyclooxygenase (COX)-2 enzyme appears to be an important target for cancer chemoprevention. Given the recent emergence of potentially serious cardiovascular toxicity associated with selective COX-2 inhibitors, nonsteroidal antiinflammatory drugs (NSAIDs), which inhibit both COX-1 and COX-2, have received renewed attention as candidate chemoprevention agents. Sulindac has shown consistent chemopreventive potential in preclinical studies as well as in a limited number of clinical trials reported to date. For the current pharmacokinetic study, sulindac capsules were prepared to facilitate ample agent supplies for future intervention studies. Encapsulation of the parent compound (sulindac sulfoxide) can be readily accomplished, but the effects of alternate formulations on bioavailability have not been rigorously examined. In the present single-dose, two-period crossover trial, we conducted pharmacokinetic analyses of sulindac in capsule (test) versus tablet (reference) formulations. Overall, bioavailability appeared to be higher for the capsule compared with the tablet formulation based on test-to-reference pharmacokinetic variable ratios for the parent compound alone. However, additional analyses based on the sulfide and sulfone metabolites of sulindac with the same pharmacokinetic variables indicated similar chemopreventive exposures between the capsule and tablet formulations. These data support the use of sulindac capsules, which can be readily prepared with matching placebos, in future blinded chemoprevention trials. (Cancer Epidemiol Biomarkers Prev 2008;17(3):674–9)

AbstractPurpose: To evaluate the combination of sorafenib and gefitinib in patients with advanced non–small cell lung cancer.Experimental Design: In this dose-escalation trial, patients received oral sorafenib (200-400 mg) twice daily with gefitinib (250 mg orally) once daily to identify the recommended dose for phase II trials (RDP; part A). The pharmacokinetics of the RDP were characterized further in additional patients (part B) receiving single-agent gefitinib or sorafenib for 21 days followed by a 7-day washout with crossover to the other agent for an additional 21 days. Patients then received the combination of sorafenib plus gefitinib in 28-day cycles. Safety, pharmacokinetics, and antitumor efficacy were evaluated. Potential drug-drug interactions and the relationship between pharmacokinetics and toxicity were also assessed.Results: Thirty-one patients were treated (n = 12, part A; n = 19, part B). Most adverse events were grade 1/2. The most frequent grade 3/4 events included diarrhea and elevated alanine aminotransferase (both 9.7%). One dose-limiting toxicity occurred (part A: elevated alanine aminotransferase at 400 mg twice daily). Gefitinib had no effect on sorafenib pharmacokinetics. However, gefitinib Cmax (26%) and area under the curve (38%) were reduced by concomitant sorafenib. One patient had a partial response; 20 (65%; n = 8, part A; n = 12, part B) had stable disease ≥4 months. The RDP was sorafenib 400 mg twice daily with gefitinib 250 mg once daily.Conclusions: Sorafenib combined with gefitinib is well tolerated, with promising efficacy in patients with advanced non–small cell lung cancer. Studies to further investigate the significance of the reduction in gefitinib exposure by sorafenib are warranted.

Abstract Purpose: To determine the maximum tolerated dose (MTD), dose-limiting toxicity, and pharmacokinetics of 17-allylamino-demethoxy-geldanamycin (17-AAG) administered on days 1, 4, 8, and 11 every 21 days and to examine the effect of 17-AAG on the levels of chaperone and client proteins. Experimental Design: A phase I dose escalating trial in patients with advanced solid tumors was done. Toxicity and tumor responses were evaluated by standard criteria. Pharmacokinetics were done and level of target proteins was measured at various points during cycle one. Results: Thirteen patients were enrolled in the study. MTD was defined as 220 mg/m2. Dose-limiting toxicities were as follows: dehydration, diarrhea, hyperglycemia, and liver toxicity. At the MTD, the mean clearance of 17-AAG was 18.7 L/h/m2. There was a significant decrease in integrin-linked kinase at 6 hours after infusion on day 1 but not at 25 hours in peripheral blood mononuclear cells. Treatment with 17-AAG on day 1 significantly increased pretreatment levels of heat shock protein (HSP) 70 on day 4, which is consistent with the induction of a stress response. In vitro induction of a stress response and up-regulation of HSP70 resulted in an increased resistance to HSP90-targeted therapy in A549 cells. Conclusions: The MTD of 17-AAG on a twice-weekly schedule was 220 mg/m2. Treatment at this dose level resulted in significant changes of target proteins and also resulted in a prolonged increase in HSP70. This raises the possibility that HSP70 induction as part of the stress response may contribute to resistance to 17-AAG.

Abstract Purpose: To define the toxicities, pharmacodynamics, and clinical activity of the proteasome inhibitor, PS-341 (bortezomib), in patients with advanced malignancies. Patients and Methods: Twenty-eight patients (14 male and 14 female) received PS-341 twice weekly for 4 of 6 weeks (schedule I). Because toxicity necessitated dose omissions on this schedule, 16 additional patients (12 male and 4 female) received PS-341 twice weekly for 2 of every 3 weeks (schedule II). A total of 73 courses of treatment was given (median, 2; range, 1-4). Inhibition of 20S proteasome activity in peripheral blood mononuclear cells (PBMC) and accumulation of proteasome-targeted polypeptides in tumor tissue were evaluated as pharmacodynamic markers of PS-341 activity. Results: The most common toxicity was thrombocytopenia, which was dose limiting at 1.7 mg/m2 (schedule I) and 1.6 mg/m2 (schedule II), respectively. Sensory neuropathy was dose-limiting in a patient in schedule I. Grade ≥3 toxicities for schedule I were constipation, fatigue, myalgia, and sensory neuropathy. Grade ≥3 toxicities for schedule II were dehydration resulting from diarrhea, nausea and vomiting, fatigue, hypoglycemia, and hypotension. The maximum tolerated dose was 1.5 mg/m2 for both schedules. Reversible dose-dependent decreases in 20S proteasome activity in PBMCs were observed, with 36% inhibition at 0.5 mg/m2, 52% at 0.9 mg/m2, and 75% at 1.25 mg/m2. Accumulation of proteasome-targeted polypeptides was detected in tumor samples after treatment with PS-341. A patient with multiple myeloma had a partial response. Conclusion: PS-341 given 1.5 mg/m2 twice weekly for 2 of every 3 weeks is well tolerated and should be further studied.

Abstract Purpose: This phase I study was conducted to determine the toxicities, pharmacokinetics, and pharmacodynamics of BMS-214662, a farnesyl transferase inhibitor, in combination with paclitaxel and carboplatin, in patients with advanced solid tumors. Experimental Design: Patients with solid tumors received one of six escalating dose levels of BMS-214662 infused over 1 hour given following paclitaxel and carboplatin on the first day of a 21-day cycle. Toxicities were graded by the National Cancer Institute common toxicity criteria and recorded as maximum grade per patient for each treatment cycle. Inhibition of farnesyl transferase activity in peripheral blood mononuclear cells (PBMCs) was evaluated. Accumulation of unfarnesylated HDJ-2 in PBMCs of patients was evaluated as a marker of farnesyl transferase inhibition by BMS-214662. Results: Thirty patients received 141 cycles of treatment through six dose levels. Dose-limiting toxicities were neutropenia, thrombocytopenia, nausea, and vomiting. There was no pharmacokinetic interaction between BMS-214662 and paclitaxel. The maximum tolerated dose was established as BMS-214662 (160 mg/m2), paclitaxel (225 mg/m2) and carboplatin (area under the curve = 6 on day 1), every 21 days. Inhibition of HDJ-2 farnesylation in PBMCs of patients was shown. One measurable partial response was observed in a patient with taxane-resistant esophageal cancer. There was partial regression of evaluable disease in two other patients (endometrial and ovarian cancer). Stable disease (> 4 cycles) occurred in eight other patients. Conclusions: The combination of BMS-214662 with paclitaxel and carboplatin was well tolerated, with broad activity in solid tumors. There was no correlation between dose level and accumulation of unfarnesylated HDJ-2 in PBMCs nor tumor response.

Purpose A randomized three-arm phase II study was undertaken to evaluate the optimum administration schedule of pemetrexed and gemcitabine in chemotherapy-naïve patients with non–small-cell lung cancer. Patients and Methods Patients were randomly assigned to three schedules of pemetrexed 500 mg/m2 plus gemcitabine 1,250 mg/m2, separated by a 90-minute interval, on a 21-day cycle as follows: schedule A, pemetrexed followed by gemcitabine on day 1 and gemcitabine on day 8; schedule B, gemcitabine followed by pemetrexed on day 1 and gemcitabine on day 8; and schedule C, gemcitabine on day 1 and pemetrexed followed by gemcitabine on day 8. Results One hundred fifty-two eligible patients (schedule A, n = 59; schedule B, n = 31, and schedule C, n = 62) received a median of five (schedule A), two (schedule B), and four (schedule C) treatment cycles. Overall, 66% of patients experienced grade 3 or 4 neutropenia. Common grade 3 and 4 nonhematologic toxicities were dyspnea (11%), fatigue (16%), and transaminase elevation (9%). Schedule A seemed less toxic compared with schedule C (grade 3 or 4 events: 86% v 94%, respectively; P = .19; grade 4 events: 39% v 48%, respectively; P = .30). Schedule B was closed at interim analysis for inferior efficacy. Schedule A, with a confirmed response rate of 31% (95% CI, 20% to 45%), met the protocol-defined efficacy criteria, whereas schedule C, with a confirmed response rate of 16.1% (95% CI, 11% to 34%), did not. Median survival time and time to progression were 11.4 and 4.4 months, respectively, with no observable difference between the arms. Conclusion Pemetrexed and gemcitabine administered as outlined for schedule A met the protocol-defined efficacy criteria, was less toxic compared with the other treatment schedules, and should be further evaluated.

Purpose To describe the prevalence, clinical characteristics, and pattern of use of complementary and alternative medicine (CAM) in patients enrolled onto phase I trials. Patients and Methods Questionnaires were administered to 108 patients with advanced malignancies enrolled onto phase I chemotherapy trials at the Mayo Clinic Comprehensive Cancer Center (Rochester, MN). CAM was classified into two modalities, pharmacologic and nonpharmacologic. Clinical and demographic data, including age, sex, and prior cancer treatment, were subsequently obtained from patient charts and examined for any correlation with CAM use, using χ2 analysis. Results One hundred two survey forms were returned. Among respondents, 88.2% (90 of 102) had used at least one CAM modality; 93.3% (84 of 90) and 53.3% (48 of 90) had used pharmacologic and nonpharmacologic CAM, respectively; and 46.7% (42 of 90) used both modalities. Vitamin and mineral preparations constituted 89.3% (75 of 84) of all pharmacologic CAM used. Intake was highest for vitamins E (48.8% [41 of 84]) and C (38.1% [32 of 84]), and 71.4% (60 of 84) of respondents took nonvitamin/mineral agents. Green tea (29.8% [25 of 84]), echinacea (13.1% [11 of 84]), and essiac (9.5% [8 of 84]) were the most popular. Prayer and spiritual practices were the most commonly used nonpharmacologic CAM, accounting for 52.1% (25 of 48). Chiropractors, the most frequently visited nontraditional medicine practitioners, were consulted by only 10% (9 of 90) of those who practiced CAM. Both CAM modalities were used more frequently by women (53.5% [23 of 43]) than men (40.4% [19 of 47]). Conclusion CAM use is common among patients in phase I trials and should be ascertained by investigators, because some of the agents used may interact with investigational agents and affect adverse effects and/or efficacy.

Skewness indicates a lack of symmetry in a distribution. Knowing the symmetry of the underlying data is essential for parametric analysis, fitting distributions or doing transformations to the data. The coefficient of skewness is the commonly used measure to identify a lack of symmetry in the underlying data, although graphical procedures can also be effective. We discuss three different methods to assess skewness: traditional coefficient of skewness index, skewness index based on the L-moments discussed by Hosking and the asymptotic test of symmetry developed by Randles et al. With this work, we provide easy-to-implement S-PLUS functions as well as discuss the advantages and shortcomings of each technique.