Citations

BACKGROUNDChemotherapy‐induced peripheral neuropathy (CIPN) is a significant side effect of taxane and platinum‐based chemotherapy. Several studies have supported the potential benefit of glutathione for the prevention of platinum‐induced CIPN. The current trial was designed to determine whether glutathione would prevent CIPN as a result of carboplatin/paclitaxel therapy.METHODSIn total, 185 patients who received treatment with paclitaxel and carboplatin were accrued between December 4, 2009 and December 19, 2011. Patients were randomized to receive either placebo (n = 91) or 1.5 g/m2 glutathione (n = 94) over 15 minutes immediately before chemotherapy. CIPN was assessed using the European Organization for Research and Treatment of Cancer Quality‐of‐Life (EORTC‐QLQ) 20‐item, CIPN‐specific (CIPN20) sensory subscale and the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE), version 4.0.RESULTSThere were no statistically significant differences between the 2 study arms with regard to: 1) peripheral neurotoxicity, as assessed using both the EORTC‐QLQ‐CIPN20 (P = .21) and the CTCAE scales (P = .449 for grade ≥2 neurotoxicity; P = .039 for time to development of grade ≥2 neuropathy, in favor of the placebo); 2) the degree of paclitaxel acute pain syndrome (P = .30 for patients who received paclitaxel every 3‐4 weeks and P = .002, in favor of the placebo, for patients who received weekly paclitaxel); 3) the time to disease progression (P = .63); or 4) apparent toxicities. Subgroup analyses did not reveal any evidence of benefit in any particular subgroup.CONCLUSIONSThe results from this study do not support the use of glutathione for the prevention of paclitaxel/carboplatin‐induced CIPN. Cancer 2014;120:1890–1897. © 2014 American Cancer Society.

Purpose Cumulative neurotoxicity is a prominent toxicity of oxaliplatin-based therapy. Intravenous calcium and magnesium have been extensively used to reduce oxaliplatin-induced neurotoxicity. This trial was designed to definitively test whether calcium/magnesium decreases oxaliplatin-related neurotoxicity. Patients and Methods In all, 353 patients with colon cancer undergoing adjuvant therapy with FOLFOX (fluorouracil, leucovorin, and oxaliplatin) were randomly assigned to intravenous calcium/magnesium before and after oxaliplatin, a placebo before and after, or calcium/magnesium before and placebo after. The primary end point was cumulative neurotoxicity measured by the sensory scale of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Chemotherapy-Induced Peripheral Neuropathy 20 tool. Results There were no statistically significant neuropathy differences among the study arms as measured by the primary end point or additional measures of neuropathy, including clinician-determined measurement of the time to grade 2 neuropathy by using the National Cancer Institute Common Terminology Criteria for Adverse Events scale or an oxaliplatin-specific neuropathy scale. In addition, calcium/magnesium did not substantially decrease oxaliplatin-induced acute neuropathy. Conclusion This study does not support using calcium/magnesium to protect against oxaliplatin-induced neurotoxicity.

The aim of a phase I oncology trial is to identify a dose with an acceptable safety profile. Most phase I designs use the dose‐limiting toxicity, a binary endpoint, to assess the unacceptable level of toxicity. The dose‐limiting toxicity might be incomplete for investigating molecularly targeted therapies as much useful toxicity information is discarded. In this work, we propose a quasi‐continuous toxicity score, the total toxicity profile (TTP), to measure quantitatively and comprehensively the overall severity of multiple toxicities. We define the TTP as the Euclidean norm of the weights of toxicities experienced by a patient, where the weights reflect the relative clinical importance of each grade and toxicity type. We propose a dose‐finding design, the quasi‐likelihood continual reassessment method (CRM), incorporating the TTP score into the CRM, with a logistic model for the dose–toxicity relationship in a frequentist framework. Using simulations, we compared our design with three existing designs for quasi‐continuous toxicity score (the Bayesian quasi‐CRM with an empiric model and two nonparametric designs), all using the TTP score, under eight different scenarios. All designs using the TTP score to identify the recommended dose had good performance characteristics for most scenarios, with good overdosing control. For a sample size of 36, the percentage of correct selection for the quasi‐likelihood CRM ranged from 80% to 90%, with similar results for the quasi‐CRM design. These designs with TTP score present an appealing alternative to the conventional dose‐finding designs, especially in the context of molecularly targeted agents. Copyright © 2013 John Wiley & Sons, Ltd.

Recent therapeutic advances for managing advanced prostate cancer include the successful targeting of the androgen-AR axis with several new drugs in castrate resistant prostate cancer including abiraterone acetate and enzalutamide (MDV3100). This translational progress from “bench to bed-side” has resulted in an enlarging repertoire of novel and traditional drug choices now available for use in advanced prostate cancer therapeutics, which has had a positive clinical impact in prolonging longevity and quality of life of advanced prostate cancer patients. In order to further the clinical utility of these drugs, development of predictive biomarkers guiding individual therapeutic choices remains an ongoing challenge. This paper will summarize the potential in developing predictive biomarkers based on the pathophysiology of the androgen-AR axis in tumor tissue from patients with advanced prostate cancer as well as inherited variation in the patient’s genome. Specific examples of rational clinical trial designs incorporating potential predictive biomarkers from these pathways will illustrate several aspects of pharmacogenetic and pharmacogenomic predictive biomarker development in advanced prostate cancer therapeutics.

Abstract Purpose: Novel therapies are challenging current drug development standards. Agents with specific biologic targets, unknown dose-efficacy curves, limited toxicity profiles, and in combination therapy require novel statistical designs. We compared the operating characteristics of three model based designs incorporating both toxicity and a measure of efficacy to identify the optimal dose region for combination therapies. Methods: Three designs were considered: continuation ratio model with a trinary outcome, bivariate logistic model treating toxicity and efficacy as independent outcomes, and bivariate probit model allowing for dependent toxicity and efficacy outcomes. All designs utilized a model-based methodology to adaptively determine dose escalation/de-escalation, based on the data observed to date in the trial. The model parameters were estimated using Markov chain Monte Carlo approach in a Bayesian framework. The target threshold for toxicity was set at 33%; the minimum and maximum sample sizes were set at 30 and 45, respectively, for the simulated trials; and the cohort size was 3 with at least nine patients needed to be treated at the proposed combination dose level. The performance of the designs was evaluated in simulation studies under six clinically relevant scenarios. Results: As expected, the ability to correctly identify an optimal dose region was sensitive to the changes in the toxicity and/or efficacy across the dose level combinations. Considering 50% as a benchmark for the recommendation rate for the optimal dose or region (dose levels within 10% of the maximum efficacious dose level), at least one of the three models performed well in recommending the optimal dose region except when the dose-efficacy surface was non-monotone or the dose-toxicity surface was close to the target rate of 33%. All three models worked well in not recommending any dose combination when the starting dose level combination was too toxic. The median sample size across all scenarios ranged from 27–33. Conclusions: Despite favorable operating characteristics, the implementation of these new designs in practice is challenging for a variety of reasons. Adoption of novel designs require a multi-pronged approach that provides a) clinically obvious advantages, b) practical design framework with a transparent decision making process, c) timely access to both toxicity and preliminary efficacy data, and d) portable user-friendly software, or very attentive statisticians. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C53.

Abstract Src transduces activated HER tyrosine kinase and phosphorylates HER to further increase its activity. Src also is involved in osteoclast differentiation. We hypothesized that combining a HER tyrosine kinase inhibitor with a Src inhibitor would result in increased therapeutic activity. To address this hypothesis we performed a phase I trial of D and L to: 1)determine the maximally tolerated dose (MTD) of D combined with L; 2)describe the toxicities associated with this combination; 3)assess the pharmacokinetic (PK) interaction of L and D; 4) assess the effect of the L and D combination on circulating tumor cells (CTC) and on osteoclast precursor activation; 5)study the association of toxicity and/or tumor response with PK, and/or pharmacodynamic parameters; and 6)describe the responses of this combination. Eligibility criteria included ≥ 18 years of age, incurable solid tumors not amenable to other therapies, ANC ≥ 1500/ L, PLT ≥ 100,000/ L, total bilirubin ≤ ULN, AST ≤ 3 × ULN or AST ≤5 × ULN if liver involvement, creatinine ≤ 1.5 × ULN, Hgb ≥ 9.0 g/dL, K+ and Mg++ WNL, life expectancy ≥ 12 weeks, ejection fraction > 50%, ECOG PS 0–2, and able to swallow pills whole. In addition to standard phase I exclusion criteria patients could not have received erlotinib, sunitinib, sorafenib, gefitinib, imatinib ≤ 4 weeks prior to registration. Each agent was administered once daily on a 28 day schedule. At the MTD patients were treated with D day 1, and day 9–28 and L day 2–28 to assess PK interaction. Dose levels (mg) were #1 D 70, L 1000, #2 D 100, L 1000, #3 D 140, L 1000. 12 patients were entered on the dose escalation portion of the trial and 15 were entered at the MTD. 5 patients entered at the MTD are too early to be fully evaluable. Characteristics of evaluable patients were: median age, 63; 46% female; PS 0 (64%) 1 (27%), 1 (9%); ≥ 3 prior chemotherapies (59%). DLT was seen in 2 patients at # 3 (1 patient, grade 3 hypermagnesemia, 1, grade 3 rash) and 1 patient at # 2 (grade 3 dyspnea). The MTD was determined to be # 2. No grade 4 or 5 events have been observed in this study. 6 patients had stable disease in the dose escalation cohort. 1 (RCC) was stable disease for 6 cycles, 2 (colorectal) were stable for 5 cycles, 1 (esophagus) was stable for 3 cycles, and 2 (GIST & leiomyosarcoma) were stable for 2 cycles. Analysis of drug levels, CTCs and circulating osteoclast precursors is ongoing. There was a consistent increase in the percentage of CD11b (monocyte/macrophage/osteoclast lineage marker) positive cells in circulation as treatment progressed. However, the late osteoclast lineage marker c-Fms was not similarly increased, suggesting that the elevated CD11b reflects an inflammatory response and not activation of osteoclastogenesis. D and L is a tolerable combination at nearly full doses of each drug. Funded by a grant from Glaxo Smith Kline and Bristol Myers Squibb. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B56.

Abstract SR13668, an orally active Akt pathway inhibitor, has demonstrated cancer chemopreventive potential in preclinical studies. To accelerate the clinical development of this promising agent, we designed and conducted the first-ever phase 0 chemoprevention trial to evaluate and compare the effects of food and formulation on SR13668 bioavailability. Healthy adult volunteers were randomly assigned to receive a single, 38-mg oral dose of SR13668 in one of five different formulations, with or without food. On the basis of existing animal data, SR13668 in a PEG400/Labrasol oral solution was defined as the reference formulation. Blood samples were obtained pre- and post-agent administration for pharmacokinetic analyses. Area under the plasma concentration–time curve (AUC0–∞) was defined as the primary endpoint. Data were analyzed and compared using established statistical methods for phase 0 trials with a limited sample size. Participants (n = 20) were rapidly accrued over a 5-month period. Complete pharmacokinetic data were available for 18 randomized participants. AUC0–∞ values were highest in the fed state (range = 122–439 ng/mL × hours) and were statistically significantly different across formulations (P = 0.007), with Solutol HS15 providing the highest bioavailability. SR13668 time to peak plasma concentration (3 hours; range, 2–6 hours) and half-life were (11.2 ± 3.1 hours) were not formulation-dependent. Using a novel, highly efficient study design, we rapidly identified a lead formulation of SR13668 for further clinical testing. Our findings support application of the phase 0 trial paradigm to accelerate chemoprevention agent development. Cancer Prev Res; 4(3); 347–53. ©2011 AACR.