Reporting practices of pharmacodynamic studies involving invasive research procedures in cancer trials

Critical importance of correctly defining and reporting secondary endpoints when assessing the ethics of research biopsies

This article reviews the implementation challenges to the American Society of Clinical Oncology's ethical framework for including research biopsies in oncology clinical trials. The primary challenges to implementation relate to the definitions of secondary endpoints, the scientific and regulatory framework, and the incentive structure that encourages inclusion of biopsies. Principles of research stewardship require that the clinical trials community correctly articulate the scientific goals of any research biopsies, especially those that are required for the patient to enroll on a trial and receive an investigational agent. Furthermore, it is important to sufficiently justify the characterization of secondary (as distinguished from exploratory) endpoints, protect the interest of research participants, and report accurate and complete information to ClinicalTrials.gov and the published literature.

Variability in biopsy quality informs translational research applications in hepatocellular carcinoma

In the era of precision medicine, biopsies are playing an increasingly central role in cancer research and treatment paradigms; however, patient outcomes and analyses of biopsy quality, as well as impact on downstream clinical and research applications, remain underreported. Herein, we report biopsy safety and quality outcomes for percutaneous core biopsies of hepatocellular carcinoma (HCC) performed as part of a prospective clinical trial. Patients with a clinical diagnosis of HCC were enrolled in a prospective cohort study for the genetic, proteomic, and metabolomic profiling of HCC at two academic medical centers from April 2016 to July 2020. Under image guidance, 18G core biopsies were obtained using coaxial technique at the time of locoregional therapy. The primary outcome was biopsy quality, defined as tumor fraction in the core biopsy. 56 HCC lesions from 50 patients underwent 60 biopsy events with a median of 8 core biopsies per procedure (interquartile range, IQR, 7–10). Malignancy was identified in 45/56 (80.4%, 4 without pathology) biopsy events, including HCC (40/56, 71.4%) and cholangiocarcinoma (CCA) or combined HCC-CCA (5/56, 8.9%). Biopsy quality was highly variable with a median of 40% tumor in each biopsy core (IQR 10–75). Only 43/56 (76.8%) and 23/56 (41.1%) samples met quality thresholds for genomic or metabolomic/proteomic profiling, respectively, requiring expansion of the clinical trial. Overall and major complication rates were 5/60 (8.3%) and 3/60 (5.0%), respectively. Despite uniform biopsy protocol, biopsy quality varied widely with up to 59% of samples to be inadequate for intended purpose. This finding has important consequences for clinical trial design and highlights the need for quality control prior to applications in which the presence of benign cell types may substantially alter findings.

Ethical Framework for Including Research Biopsies in Oncology Clinical Trials: American Society of Clinical Oncology Research Statement

In contrast to clinical biopsies, where tissue is collected to inform patient care, research biopsies are performed for scientific purposes to potentially enhance understanding of the biologic bases of cancer and drug action, thereby improving diagnosis and treatment, but they may offer no direct benefit to participants and have known risks. The widespread use of research biopsies that do not have the potential to directly benefit participants has come under scrutiny, with critics raising ethical concerns related to the adequacy of participant protections, informed consent, and participant understanding of the risks and benefits, as well as the scientific impact of research biopsies on drug development and treatment. This manuscript presents the American Society of Clinical Oncology’s (ASCO’s) ethical framework for incorporation of research biopsies in trials. The framework provides guidance on the circumstances to include optional and mandatory biopsies, as well as provides recommendations to stakeholders on necessary steps for improving the conduct of research biopsies overall.

What concentration of tranexamic acid is needed to inhibit fibrinolysis? A systematic review of pharmacodynamics studies

: Intravenous tranexamic acid (TXA) reduces death because of bleeding in patients with trauma and postpartum haemorrhage. However, in some settings intravenous injection is not feasible. To find different routes of administration, we first need to determine the minimal concentration of TXA in the blood that is required to inhibit fibrinolysis.We conducted a systematic review of in-vitro and in-vivo pharmacodynamics studies. We searched MEDLINE, EMBASE, OviSP, and ISI Web of Science from database inception to November 2017 for all in-vitro (including simulated clotting models) or in-vivo studies reporting the relationship between the TXA concentration in blood or plasma and any reliable measure of fibrinolysis.We found 21 studies of which 20 were in vitro and one was in vivo. Most in-vitro studies stimulated fibrinolysis with tissue plasminogen activator and measured fibrinolysis using viscoelastic, optical density, or immunological assays. TXA concentrations between 10 and 15 mg/l resulted in substantial inhibition of fibrinolysis, although concentrations between 5 and 10 mg/l were partly inhibitory.TXA concentrations of 10-15 mg/l may be suitable targets for pharmacokinetic studies, although TXA concentrations above 5 mg/l may also be effective.

Underreporting of Research Biopsies from Clinical Trials in Oncology

Purpose: Research biopsies are frequently incorporated within clinical trials in oncology and are often a mandatory requirement for trial enrollment. However, limited information is available regarding the extent and completeness of research biopsy reporting.Experimental Design: We identified a cohort of therapeutic clinical trials where research biopsies were performed between January 2005 and October 2010 from an IR database at our institution. Clinical trial protocols were compared with the highest level of corresponding publication as a manuscript or registry report.Results: A total of 866 research biopsies were performed across 46 clinical trials, with a median of 8 patients biopsied/trial and 19 biopsies collected/trial. After a median follow-up time of 4.3 years from trial completion, 36 of 46 trials (78%) reported trial results: published manuscripts (n = 35), or registry report (n = 1). A total of 635 conducted biopsies were reported in 18 of the 46 trials (39%). Six (33%) of these 18 trials underreported the number of biopsies performed. Of 33 trials with mandatory research biopsies, 13 (39%) trials reported on these biopsies. Biopsy complications occurred in 8 trials [n = 39 patients, 6 grade 3/4 adverse events (AE)] but only 1 trial reported these. Factors associated with biopsy reporting included a larger number of biopsies (P ≤ 0.001) and serial biopsies (P < 0.001). Twelve of 16 (75%) trials with >12 biopsies performed reported on these biopsies compared with only 20% (6/30) that performed ≤12 biopsies.Conclusions: Despite ethical obligations to report research biopsies, the majority (61%) of trials do not report results from research biopsies. Complications are rarely reported in these studies. Improved reporting of results and AEs from research biopsies is needed. Clin Cancer Res; 23(21); 6450-7. ©2017 AACR.

Burdensome Research Procedures in Trials: Why Less Is More

A large volume of trials involve invasive, nontherapeutic research procedures, like organ biopsy or sham surgeries, that can pose risks comparable with the experimental treatment itself but that have no direct benefit for volunteers. Though such procedures can enhance the value of clinical investigations, recent studies suggest that many studies involving invasive, nontherapeutic research procedures are not well planned and reported; some studies suggest that their results are often not utilized in the planning of new investigations. This commentary offers recommendations for how investigators, sponsors, and ethics committees might improve evaluation and implementation of studies involving invasive nontherapeutic procedures. We conclude by urging more demanding scientific standards for the rationale, design, and reporting of burdensome, nontherapeutic research procedures-particularly where they involve risk of serious complications.

Safety and utility of image-guided research biopsies in relapsed high-grade serous ovarian carcinoma-experience of the BriTROC consortium

BACKGROUND

Investigating tumour evolution and acquired chemotherapy resistance requires analysis of sequential tumour material. We describe the feasibility of obtaining research biopsies in women with relapsed ovarian high-grade serous carcinoma (HGSC).

METHODS

Women with relapsed ovarian HGSC underwent either image-guided biopsy or intra-operative biopsy during secondary debulking, and samples were fixed in methanol-based fixative. Tagged-amplicon sequencing was performed on biopsy DNA.

RESULTS

We screened 519 patients in order to enrol 220. Two hundred and two patients underwent successful biopsy, 118 of which were image-guided. There were 22 study-related adverse events (AE) in the image-guided biopsies, all grades 1 and 2; pain was the commonest AE. There were pre-specified significant AE in 3/118 biopsies (2.5%). 87% biopsies were fit-for-purpose for genomic analyses. Median DNA yield was 2.87 μg, and was higher in biopsies utilising 14 G or 16 G needles compared to 18 G. TP53 mutations were identified in 94.4% patients.

CONCLUSIONS

Obtaining tumour biopsies for research in relapsed HGSC is safe and feasible. Adverse events are rare. The large majority of biopsies yield sufficient DNA for genomic analyses-we recommend use of larger gauge needles and methanol fixation for such biopsies, as DNA yields are higher but with no increase in AEs.

Analysis of Impact of Post-Treatment Biopsies in Phase I Clinical Trials

PURPOSE

The use of biopsy-derived pharmacodynamic biomarkers is increasing in early-phase clinical trials. It remains unknown whether drug development is accelerated or enhanced by their use. We examined the impact of biopsy-derived pharmacodynamic biomarkers on subsequent drug development through a comprehensive analysis of phase I oncology studies from 2003 to 2010 and subsequent publications citing the original trials.

METHODS

We conducted a search to identify and examine publications of phase I oncology studies including the use of biopsy-derived pharmacodynamic biomarkers between 2003 and 2010. Characteristics of those studies were extracted and analyzed, along with outcomes from the biomarker data. We then compiled and reviewed publications of subsequent phase II and III trials citing the original phase I biomarker studies to determine the impact on drug development.

RESULTS

We identified 4,840 phase I oncology publications between 2003 and 2010. Seventy-two studies included a biopsy-derived pharmacodynamic biomarker. The proportion of biomarker studies including nondiagnostic biopsies increased over time (P = .002). A minimum of 1,873 tumor biopsies were documented in the 72 studies, 12 of which reported a statistically significant biomarker result. Thirty-three percent of studies (n = 24) were referenced by subsequent publications specifically with regard to the biomarkers. Only five positive biomarker studies were cited subsequently, and maximum tolerated dose was used for subsequent drug development in all cases.

CONCLUSION

Despite their increased use, the impact of biopsy-derived pharmacodynamic biomarkers in phase I oncology studies on subsequent drug development remains uncertain. No impact on subsequent dose or schedule was demonstrated. This issue requires further evaluation, given the risk and cost of such studies.

Ethics of Cancer Gene Transfer Clinical Research

Translation of cancer gene transfer confronts many familiar-and some distinctive-ethical challenges. In what follows, I survey three major ethical dimensions of cancer gene transfer development. Subheading 1 centers on the ethics of planning, designing, and reporting animal studies. Subheading 2 describes basic elements of human subjects protection as pertaining to cancer gene transfer. In Subheading 3, I describe how cancer gene transfer researchers have obligations to downstream consumers of the evidence they produce.