Citations 33

Historical Controls for Metastatic Pancreatic Cancer: Benchmarks for Planning and Analyzing Single-Arm Phase II Trials

Clinical Cancer Research | June 10, 2014 | Volume: 20 | Issue: 16 | Pages: 4176-4185

10.1158/1078-0432.ccr-13-2024 | PMID 24914040

AbstractWe compiled and analyzed a database of cooperative group trials in advanced pancreatic cancer to develop historical benchmarks for overall survival (OS) and progression-free survival (PFS). Such benchmarks are essential for evaluating new therapies in a single-arm setting. The analysis included patients with untreated metastatic pancreatic cancer receiving regimens that included gemcitabine, between 1995 and 2005. Prognostic baseline factors were selected by their significance in Cox regression analysis. Outlier trial arms were identified by comparing individual 6-month OS and PFS rates against the entire group. The dataset selected for the generation of OS and PFS benchmarks was then tested for intertrial arm variability using a logistic-normal model with the selected baseline prognostic factors as fixed effects and the individual trial arm as a random effect. A total of 1,132 cases from eight trials qualified. Performance status and sex were independently significant for OS, and performance status was prognostic for PFS. Outcomes for one trial (NCCTG-034A) were significantly different from the other trial arms. When this trial was excluded, the remaining trial arms were homogeneous for OS and PFS outcomes after adjusting for performance status and sex. Benchmark values for 6-month OS and PFS are reported along with a method for using these values in future study design and analysis. The benchmark survival values were generated from a dataset that was homogeneous between trials. The benchmarks can be used to enable single-arm phase II trials using a gemcitabine platform, especially under certain circumstances. Such circumstances might be when a randomized control arm is not practically feasible, an early signal of activity of an experimental agent is being explored such as in expansion cohorts of phase I studies, and in patients who are not candidates for combination cytotoxic therapy. Clin Cancer Res; 20(16); 4176–85. ©2014 AACR.
Genetic polymorphisms in oxidative stress‐related genes are associated with outcomes following treatment for aggressive B‐cell non‐Hodgkin lymphoma

American Journal of Hematology | March 14, 2014 | Volume: 89 | Issue: 6 | Pages: 639-645

10.1002/ajh.23709 | PMID 24633940

Variable survival outcomes are seen following treatment for aggressive non‐Hodgkin lymphoma (NHL). This study examined whether outcomes for aggressive B‐cell NHL are associated with single nucleotide polymorphisms (SNPs) in oxidative stress‐related genes, which can alter drug metabolism and immune responses. Genotypes for 53 SNPs in 29 genes were determined for 337 patients given anthracycline‐based therapies. Their associations with progression‐free survival (PFS) and overall survival (OS) were estimated by Cox proportional hazard regression; associations with hematologic toxicity were estimated by logistic regression. To validate the findings, the top three SNPs were tested in an independent cohort of 572 DLBCL patients. The top SNPs associated with PFS in the discovery cohort were the rare homozygotes for MPO rs2243828 (hazard ratio [HR] = 1.87, 95% confidence interval [CI] = 1.14–3.06, P = 0.013), AKR1C3 rs10508293 (HR = 2.09, 95% CI = 1.28–3.41, P = 0.0032) and NCF4 rs1883112 (HR = 0.66, 95% CI = 0.43–1.02, P = 0.06). The association of the NCF4 SNP with PFS was replicated in the validation dataset (HR = 0.66, 95% CI = 0.44–1.01, P = 0.05) and the meta‐analysis was significant (HR = 0.66, 95% CI = 0.49–0.89, P < 0.01). The association of the MPO SNP was attenuated in the validation dataset, while the meta‐analysis remained significant (HR = 1.64, 95% CI = 1.12–2.41). These two SNPs showed similar trends with OS in the meta‐analysis (for NCF4, HR = 0.72, 95% CI = 0.51–1.02, P = 0.07 and for MPO, HR = 2.06, 95% CI = 1.36–3.12, P < 0.01). In addition, patients with the rare homozygote of the NCF4 SNP had an increased risk of hematologic toxicity. We concluded that genetic variations in NCF4 may contribute to treatment outcomes for patients with aggressive NHL. Am. J. Hematol. 89:639–645, 2014. © 2014 Wiley Periodicals, Inc.
Randomized Phase II Designs

Clinical Cancer Research | March 11, 2009 | Volume: 15 | Issue: 6 | Pages: 1883-1890

10.1158/1078-0432.ccr-08-2031 | PMID 19276275

Abstract As the use of molecularly targeted agents, which are anticipated to increase overall survival (OS)and progression-free survival (PFS) but not necessarily tumor response, has increased in oncology, there has been a corresponding increase in the recommendation and use of randomized phase II designs. Such designs reduce the potential for bias, existent in comparisons with historical controls, but also substantially increase the sample size requirements. We review the principal statistical designs for historically controlled and randomized phase II trials, along with their advantages, disadvantages, and statistical design considerations. We review the arguments for and against the use of randomization in phase II studies, the situations in which the use of historical controls is preferred, and the situations in which the use of randomized designs is preferred. We review methods used to calculate predicted OS or PFS values from historical controls, adjusted so as to be appropriate for an experimental sample with particular prognostic characteristics. We show how adjustment of the type I and type II error bounds for randomized studies can facilitate the detection of appropriate target increases in median PFS or OS with sample sizes appropriate for phase II studies. Although there continue to be differences among investigators concerning the use of randomization versus historical controls in phase II trials, there is agreement that each approach will continue to be appropriate, and the optimal approach will depend upon the circumstances of the individual trial.