Critical analysis of contemporary clinical research in muscle-invasive and metastatic urothelial cancer: a report from the Bladder Cancer Advocacy Network Clinical Trials Working Group.

BACKGROUND: There have been no improvements in the treatment of metastatic urothelial cancer in the past several decades. A census of contemporary clinical research in this disease was performed to identify potential barriers and opportunities. METHODS: These authors performed a search for clinical trials exploring interventions in muscle-invasive and metastatic urothelial cancer, using the ClinicalTrials.gov registry. Data extracted from the registry included title, recruitment status, interventions, sponsor, phase, enrollment, study design, and study sites. RESULTS: Among 120 eligible trials exploring interventions in muscle-invasive and metastatic urothelial cancer, 73% were phase 2 and 73% were nonrandomized. The majority (63%) involved treatment in the metastatic disease state. The median planned enrollment size per trial was 45 patients (interquartile range, 47 patients). The majority of trials (55%) involved ≤ 3 study sites. Trials most commonly explored interventions in the first-line metastatic (30%) or second-line metastatic (37%) settings. Targeted therapeutics were studied in 58% of the trials. Among 56 trials that completed enrollment, the median time to complete accrual was 50 months (range, 10-109 months), and these trials enrolled a median of 40 patients per trial (interquartile range, 44 patients). CONCLUSIONS: The majority of contemporary clinical trials in muscle-invasive and metastatic urothelial cancer are small, nonrandomized, phase 2 trials involving 1 to 3 study sites. Enhanced communication and collaboration among the urothelial cancer community, and other stakeholders, is needed to facilitate the design and conduct of trials capable of expediting progress in this disease.

The landscape of precision cancer medicine clinical trials in the United States.

PURPOSE: Advances in tumor biology and multiplex genomic analysis have ushered in the era of precision cancer medicine. Little is currently known, however, about the landscape of prospective "precision cancer medicine" clinical trials in the U.S. METHODS: We identified all adult interventional cancer trials registered on ClinicalTrials.gov between September 2005 and May 2013. Trials were classified as "precision cancer medicine" if a genomic alteration in a predefined set of 88 genes was required for enrollment. Baseline characteristics were ascertained for each trial. RESULTS: Of the initial 18,797 trials identified, 9094 (48%) were eligible for inclusion: 684 (8%) were classified as precision cancer medicine trials and 8410 (92%) were non-precision cancer medicine trials. Compared with non-precision cancer medicine trials, precision cancer medicine trials were significantly more likely to be phase II [RR 1.19 (1.10-1.29), p<0.001], multi-center [RR 1.18 (1.11-1.26), p<0.001], open-label [RR 1.04 (1.02-1.07), p=0.005] and involve breast [RR 4.03 (3.49-4.52), p<0.001], colorectal [RR 1.62 (1.22-2.14), p=0.002] and skin [RR 1.98 (1.55-2.54), p<0.001] cancers. Precision medicine trials required 38 unique genomic alterations for enrollment. The proportion of precision cancer medicine trials compared to the total number of trials increased from 3% in 2006 to 16% in 2013. CONCLUSION: The proportion of adult cancer clinical trials in the U.S. requiring a genomic alteration for enrollment has increased substantially over the past several years. However, such trials still represent a small minority of studies performed within the cancer clinical trials enterprise and include a small subset of putatively "actionable" alterations.

Adult cancer clinical trials that fail to complete: an epidemic?

The number and diversity of cancer therapeutics in the pipeline has increased over the past decade due to an enhanced understanding of cancer biology and the identification of novel therapeutic targets. At the same time, the cost of bringing new drugs to market and the regulatory burdens associated with clinical drug development have progressively increased. The finite number of eligible patients and limited financial resources available to evaluate promising new therapeutics represent rate-limiting factors in the effort to translate preclinical discoveries into the next generation of standard therapeutic approaches. Optimal use of resources requires understanding and ultimately addressing inefficiencies in the cancer clinical trials system. Prior analyses have demonstrated that a large proportion of trials initiated by the National Cancer Institute (NCI) Cooperative Group system are never completed. While NCI Cooperative Group trials are important, they represent only a small proportion of all cancer clinical trials performed. Herein, we explore the problem of cancer clinical trials that fail to complete within the broader cancer clinical trials enterprise. Among 7776 phase II-III adult cancer clinical trials initiated between 2005-2011, we found a seven-year cumulative incidence of failure to complete of approximately 20% (95% confidence interval = 18% to 22%). Nearly 48000 patients were enrolled in trials that failed to complete. These trials likely contribute little to the scientific knowledge base, divert resources and patients from answering other critical questions, and represent a barrier to progress.

Association of the Charlson comorbidity index and hypertension with survival in men with metastatic castration-resistant prostate cancer.

OBJECTIVES: The independent prognostic effect of comorbidities on outcomes in men with metastatic castration-resistant prostate cancer (mCRPC) is unclear. We sought to determine whether the Charlson comorbidity index (CCI) and hypertension (HTN) are associated with overall survival (OS) independent of known clinical prognostic factors in mCRPC. PATIENTS AND METHODS: A retrospective analysis was conducted on 221 patients with mCRPC treated with docetaxel plus prednisone combined with AT-101 (bcl-2 antagonist) or placebo on a prospective randomized phase II trial. The Cox regression analysis was performed to identify whether the CCI or HTN or both (by medical history) independently predicted OS after adjusting for baseline variables known to be associated with OS. The Wilcoxon rank sum test and the Fisher exact test were used to compare data by comorbidity groups (CCI as a continuous variable, CCI = 6 vs. CCI ≥ 7 and HTN vs. no HTN). RESULTS: The CCI was 6 in 116 patients (52.7%), 7 in 70 (31.8%), 8 in 23 (10.5%), 9 in 4 (1.8%), and 10 in 7 patients (3.2%). HTN was present in 107 (48.6%) patients. Patients with CCI of ≥ 7 were older and exhibited worse performance status and anemia than patients with CCI of 6 (P<0.05). The CCI was not independently predictive of OS on univariable and multivariable analyses. HTN alone or in combination with the CCI was borderline significantly associated with OS (P ~ 0.09) on both univariable and multivariable analyses. CONCLUSIONS: The CCI did not predict OS independent of known prognostic factors in mCRPC. Age, performance status, and anemia may adequately capture comorbidities in the context of mCRPC, given their association with higher CCI. Further prospective study of comorbidities in a larger data set may be warranted. The study of HTN in a larger data set may also be warranted given its borderline-independent association with OS.

Dynamic Stokes shift of the time-resolved phosphorescence spectrum of Zn(II)-substituted cytochrome c.

The dynamic phosphorescence Stokes shift (PSS) response of Zn(II)-substituted cytochrome c (ZnCytc) was detected using the time-resolved phosphorescence spectrum of the intrinsic Zn(II)-porphyrin chromophore, which senses the motions of the surrounding protein and hydration shell. The phosphorescence spectrum of ZnCytc exhibits resolved vibronic structure arising from in-plane deformations of the porphyrin macrocycle, as is also observed in the absorption and fluorescence spectra. As the emission time increases, the phosphorescence spectrum shifts to the red without incurring a significant change in vibronic structure or line shape, so the shift arises from dynamic solvation, the reorganizational motions of the protein and solvent that occur in response to formation of the first excited triplet state. A correlation time of 294 ± 14 µs was obtained from a single-exponential fit to the time dependence of the mean emission frequency of the T(0,0) peak in the phosphorescence spectrum. This time scale is consistent with a diffusive sampling of the native structure's minimum due to global or collective conformational fluctuations. We suggest that studies of the PSS response sensed in proteins by an intrinsic probe will be informative of protein and hydration-shell dynamics over the microsecond-millisecond time regimes associated with biological function.