Impact and perceptions of mandatory tumor biopsies for correlative studies in clinical trials of novel anticancer agents

Overlooking evolution: a systematic analysis of cancer relapse and therapeutic resistance research

Cancer therapy selects for cancer cells resistant to treatment, a process that is fundamentally evolutionary. To what extent, however, is the evolutionary perspective employed in research on therapeutic resistance and relapse? We analyzed 6,228 papers on therapeutic resistance and/or relapse in cancers and found that the use of evolution terms in abstracts has remained at about 1% since the 1980s. However, detailed coding of 22 recent papers revealed a higher proportion of papers using evolutionary methods or evolutionary theory, although this number is still less than 10%. Despite the fact that relapse and therapeutic resistance is essentially an evolutionary process, it appears that this framework has not permeated research. This represents an unrealized opportunity for advances in research on therapeutic resistance.

Outcomes of research biopsies in phase I clinical trials: the MD anderson cancer center experience

BACKGROUND

Research biopsies are crucial for exploring the impact of novel agents on putative targets. The current study assesses the safety and success rate associated with performing such biopsies.

METHODS

We reviewed the medical records of 155 consecutive patients who had one or more research biopsies as part of a phase I trial from September 2004 to October 2009.

RESULTS

Of 281 research biopsies performed, 118 were paired before and after treatment biopsies (total = 236 biopsies). The most common sites of biopsy were superficial lymph node (19.9%), followed by liver (16.4%), and then soft tissue (15.7%). Ultrasound-guided biopsies were the most frequent type (53.7%). Among 142 patients who consented for mandatory biopsy, 86.6% had the biopsy performed, compared with 4.4% of 911 patients offered a biopsy on an optional basis (p < .0001). Biopsy was obtained most frequently on industry-sponsored trials; lack of funding on nonindustry trials was the most common reason that biopsies were not obtained. Of 281 single biopsies, only 4 (1.4%) had complications: pneumothorax requiring chest tube placement (n = 2), infection requiring admission (n = 1), and arrhythmia with hypotension (n = 1). All but one biopsy was successful in obtaining tissue. No deaths were attributable to biopsy.

CONCLUSIONS

Our experience demonstrates that research biopsies in early phase clinical trials are safe (1.4% risk of serious complications), and a higher percentage of patients underwent mandatory biopsies (86.6%) compared with that of the patients with optional biopsies (4.4%).

The ethical use of mandatory research biopsies

Increasingly, clinical trials incorporate translational research questions aimed at identifying biomarkers of response or resistance to agents under investigation. Biomarker assays can require tissue samples to be collected through a research biopsy before therapy, during treatment, or at the time of tumor progression. Such biopsy samples will generally not provide a direct benefit to the patient and, given the risks associated with any surgical procedure, ethical concerns have been raised when the participant's enrollment on a clinical trial depends on their consent to undergo a research biopsy. In this Perspectives article, we present the rationale for mandatory research biopsies and offer suggestions for standardization to ensure that high-quality, patient-centered, clinical trials continue to be designed with scientific and ethical rigor.

Patient willingness to undergo pharmacodynamic and pharmacokinetic tests in early phase oncology trials

BACKGROUND

Increasingly, early phase clinical trials involve pharmacodynamic (PD) and pharmacokinetic (PK) assays as well as frequent imaging studies. The authors conducted a prospective study examining patients' willingness to undergo such tests and the number of tests the patients would tolerate.

METHODS

A prospective, correlative study was conducted using a self-reported questionnaire to measure patients' willingness on a scale from 1 (not willing) to 10 (very willing) to undergo various procedures (eg, tumor and skin biopsies, blood tests) and imaging studies (eg, magnetic resonance imaging, echocardiogram). In addition, correlations were assessed between the number and type of tests and demographics, previous test experience, inconvenience, and insurance coverage. Sixty-one patients (22 women and 39 men) with advanced malignancies were enrolled. Descriptive, nonparametric, and parametric inferential statistics were used.

RESULTS

Overall willingness to undergo study-required tests was very high. Patients were most willing to undergo urine, blood, ultrasound, x-rays, echocardiogram, and computed tomography studies and were least willing to undergo tumor and skin biopsies and magnetic resonance imaging (all P ≤ .01). Significant inverse relations were observed between the frequency of a particular test and patient's willingness to undergo such tests. Inconvenience and prior negative experiences for more invasive tests (eg, skin biopsies) modestly affected willingness to undergo these tests again. College education, insurance coverage, and the requirement of tests for enrollment were correlated positively with willingness to undergo tests.

CONCLUSIONS

The current findings provide the first prospectively collected data on patients' willingness to undergo PK/PD tests and imaging studies associated with early stage oncology drug trials and can serve as basis for further exploration toward the design of patient-friendly, biomarker-driven clinical studies in oncology.

Phase I safety, pharmacokinetic, and biomarker study of BIBF 1120, an oral triple tyrosine kinase inhibitor in patients with advanced solid tumors

BIBF 1120 is an oral multitargeted tyrosine kinase inhibitor that blocks the activity of vascular endothelial growth factor (VEGF) and other growth factor receptors. We have done a phase I study to evaluate the safety, pharmacokinetics, and pharmacodynamic biomarkers of BIBF 1120. Patients with advanced refractory solid tumors were treated with BIBF 1120 at oral doses of 150 to 250 mg twice daily. Drug safety and pharmacokinetics were evaluated, as were baseline and post-treatment levels of circulating CD117-positive bone marrow-derived progenitor cells and plasma soluble VEGF receptor 2 as potential biomarkers for BIBF 1120. Twenty-one patients were treated at BIBF 1120 doses of 150 (n = 3), 200 (n = 12), or 250 mg twice daily (n = 6). Dose-limiting toxicities of reversible grade 3 or 4 elevations of liver enzymes occurred in 3 of 12 patients at 200 mg twice daily and 3 of 6 patients at 250 mg twice daily. Stable disease was achieved in 16 (76.2%) patients, and median progression-free survival was 113 days (95% confidence interval, 77-119 d). Pharmacokinetic analysis indicated that the maximum plasma concentration and area under the curve for BIBF 1120 increased with the dose within the dose range tested. Levels of CD117-positive bone marrow-derived progenitors and soluble VEGF receptor 2 decreased significantly during treatment over all BIBF 1120 dose cohorts. In conclusion, the maximum tolerated dose of BIBF 1120 in the current study was determined to be 200 mg twice daily, and our biomarker analysis indicated that this angiokinase inhibitor is biologically active.

Reasons for participation in optional pharmacokinetic studies in children with cancer: a Children's Oncology Group phase 1 consortium study

PURPOSE

Pharmacokinetic (PK) studies provide critical information about the disposition of anticancer drugs in children. In the Children's Oncology Group (COG) Phase 1 Consortium, pharmacokinetic studies are usually optional. We surveyed the attitudes towards PK studies among subjects in phase 1 trials at COG institutions.

METHODS

Subjects were eligible if they participated in a phase 1 anticancer drug study with optional PK studies within the 4 weeks, regardless of whether they agreed to participate in the PK studies. Staff provided demographics; subjects/parents completed a questionnaire.

RESULTS

Fifty eligible subjects enrolled. Thirty-six (72%) of the 50 eligible subjects consented to participate in PK studies; 14 (25%) declined. The most common reasons for participating were "the results might help researchers learn more about the drug" and "results from the pharmacokinetic studies might help other children." The most common reasons for not participating were "having the samples drawn would mean spending extra time in the hospital," and "my child might have needed a separate IV catheter in order to participate."

CONCLUSIONS

The majority of subjects identified altruistic motives for participation in PK studies. Subjects who did not participate in PK studies identified extra time and need for an extra IV as important concerns. Simple interventions like sending staff to the subjects' home to draw PK samples or drawing samples from existing catheters could increase the number of subjects who are willing to participate in PK studies.

Ethics of mandatory research biopsy for correlative end points within clinical trials in oncology

Clinical investigators in oncology are increasingly interested in using molecular analysis of cancer tissue to understand the biologic bases of response or resistance to novel interventions and to develop prognostic and predictive biomarkers that will guide clinical decision making. Some scientific questions of this nature can only be addressed, or may best be addressed, through the conduct of a clinical trial in which research biopsies are obtained from all participants. However, trial designs with mandatory research biopsies have raised ethical concerns related to the risk of harm to participants, the adequacy of voluntary informed consent, and the potential for misunderstanding among research participants when access to an experimental intervention is linked to the requirement to undergo a research biopsy. In consideration of the ethical and scientific issues at stake in this debate, the Cancer and Leukemia Group B Ethics Committee proposes guidelines for clinical trials involving mandatory research biopsies. Any cancer clinical trial that requires research biopsies of participants must be well designed to address the scientific question, obtain the biopsy in a way that minimizes risk, and ensure that research participants are fully informed of the risks, rationale, and requirements of the study, as well as of treatment alternatives. Further guidelines and discussions of this issue are specified in this position paper. We feel that if these principles are respected, an informed adult with cancer can both understand and voluntarily consent to participation in a clinical trial involving mandatory research biopsy for scientific end points.

Informed consent in genomics and genetic research

There are several features of genetic and genomic research that challenge established norms of informed consent. In this paper, we discuss these challenges, explore specific elements of informed consent for genetic and genomic research conducted in the United States, and consider alternative consent models that have been proposed. All of these models attempt to balance the obligation to respect and protect research participants with the larger social interest in advancing beneficial research as quickly as possible.

Does confirmatory tumor biopsy alter the management of breast cancer patients with distant metastases?

BACKGROUND

Decisions about systemic treatment of women with metastatic breast cancer are often based on estrogen receptor (ER), progesterone receptor (PgR), and Her2 status of the primary tumor. This study prospectively investigated concordance in receptor status between primary tumor and distant metastases and assessed the impact of any discordance on patient management.

MATERIALS AND METHODS

Biopsies of suspected metastatic lesions were obtained from patients and analyzed for ER/PgR and Her2. Receptor status was compared for metastases and primary tumors. Questionnaires were completed by the oncologist before and after biopsy to determine whether the biopsy results changed the treatment plan.

RESULTS

Forty women were enrolled; 35 of them underwent biopsy, yielding 29 samples sufficient for analysis; 3/29 biopsies (10%) showed benign disease. Changes in hormone receptor status were observed in 40% (P = 0.003) and in Her2 status in 8% of women. Biopsy results led to a change of management in 20% of patients (P = 0.002).

CONCLUSIONS

This prospective study demonstrates the presence of substantial discordance in receptor status between primary tumor and metastases, which led to altered management in 20% of cases. Tissue confirmation should be considered in patients with clinical or radiological suspicion of metastatic recurrence.

Are we HER-ting for innovation in neoadjuvant breast cancer trial design?

Through the use of surrogate markers of efficacy, neoadjuvant studies may facilitate the implementation of new treatments into clinical practice. However, disease-free survival is the current standard outcome endpoint for registration of a novel treatment. The coupling of smaller neoadjuvant 'proof of principle' studies with larger adjuvant registration trials offers the promise of speeding up the time to market of new therapies. Clever new designs, such as the 'biological window' and 'learn on the way', can provide valuable insight regarding mechanisms of action and resistance of these novel drugs by identifying patients who are most likely to respond to a novel therapy early in the drug development process. Using the ongoing neoadjuvant trials with HER2 (human epidermal growth factor receptor 2)-directed therapy as a paradigm, this article discusses recent innovations in study design and the challenges of conducting translational research in the neoadjuvant setting.

Ethics of cancer gene transfer clinical research

Cancer gene transfer is a relatively novel intervention strategy. In part because of this novelty, trials often present greater uncertainties than those investigating more conventional approaches. In the following review, I examine how this greater uncertainty might affect how clinical studies are designed, when they are initiated, their degree of risk, and whether such risk can be justified in terms of therapeutic benefit. The review also discusses two other ethical issues presented by gene transfer clinical research: fairness in subject selection and communications with the public. I conclude with a series of recommendations directed toward researchers, policymakers, and ethics committee members.

Clinical biomarkers of angiogenesis inhibition

INTRODUCTION

An expanding understanding of the importance of angiogenesis in oncology and the development of numerous angiogenesis inhibitors are driving the search for biomarkers of angiogenesis. We review currently available candidate biomarkers and surrogate markers of anti-angiogenic agent effect.

DISCUSSION

A number of invasive, minimally invasive, and non-invasive tools are described with their potential benefits and limitations. Diverse markers can evaluate tumor tissue or biological fluids, or specialized imaging modalities.

CONCLUSIONS

The inclusion of these markers into clinical trials may provide insight into appropriate dosing for desired biological effects, appropriate timing of additional therapy, prediction of individual response to an agent, insight into the interaction of chemotherapy and radiation following exposure to these agents, and perhaps most importantly, a better understanding of the complex nature of angiogenesis in human tumors. While many markers have potential for clinical use, it is not yet clear which marker or combination of markers will prove most useful.

Phase 0 clinical trials: conceptions and misconceptions

Phase 0 clinical trials, developed in response to the United States Food and Drug Administration (FDA)'s recent exploratory Investigational New Drug (IND) guidance, are intended to expedite the clinical evaluation of new molecular entities. The exploratory IND supports the performance of first-in-human testing of new investigational agents at subtherapeutic doses based on reduced manufacturing and toxicologic requirements, allowing the demonstration of drug-target effects and assessment of pharmacokinetic-pharmacodynamic relationships in humans earlier in clinical development. The objectives of a phase 0 cancer clinical trial are to establish at the very earliest opportunity-before large numbers of patients have been accrued and exposed to potential drug-associated toxicity-whether an agent is modulating its target in a tumor, and consequently whether further clinical development is warranted. We review here the fundamental requirements of clinical studies conducted under an exploratory IND and address some common misconceptions regarding oncologic phase 0 trials.

Performing nondiagnostic research biopsies in irradiated tissue: a review of scientific, clinical, and ethical considerations

PURPOSE

Recent development of drugs that target specific pathways in tumors has increased scientific interest in studying drug effects on tumor tissue. As a result, biopsies have become an important part of many early-phase clinical trials. Performing nondiagnostic tumor biopsies raises technical and ethical concerns mostly related to the use of a potentially harmful procedure with no potential benefit to the patient. This issue is complicated by uncertainty about whether performing biopsies in irradiated fields adds significant risk. This article reviews the clinical, scientific, and ethical considerations involved in performing nondiagnostic tumor biopsies in competent adults for research purposes, with a focus on biopsies performed in the setting of therapeutic irradiation.

METHODS

Clinical trials that performed biopsies during or within 4 months of the completion of radiotherapy were identified with a literature review.

RESULTS

Twenty-nine studies with 2,160 patients were identified. Sixteen of 29 studies reported adverse events (AEs) but did not report active evaluation for biopsy complications. Ten studies did not mention AEs within the study report. At least three studies actively evaluated patients for biopsy complications. Taking this into consideration, 17 (>1%) of 2,160 patients were reported to have biopsy complications, although reporting of AEs was suboptimal in most studies.

CONCLUSION

Limited data suggest that biopsies can be performed in irradiated tissues without clinically significant excess risk. Ongoing and future trials including nondiagnostic research biopsies should record and report AEs related to this procedure to provide additional data on safety and toxicity.

The clinical significance of radiologically detected silent pulmonary nodules in early breast cancer

BACKGROUND

Increasing numbers of patients with early cancer undergo routine staging using computerized tomography (CT). Those in whom indeterminate pulmonary nodules are visualized without the presence of other metastatic lesions represent a clinical dilemma regarding their management as early breast cancer or metastatic disease.

PATIENTS AND METHODS

Medical records of breast cancer patients who underwent thoracic CT scans between the years 2002 and 2008 were analyzed. Those with obvious metastatic disease were excluded. Patients were identified via the radiology database by searching for the terms: 'suspicious lung metastases' and 'indeterminate nodules'.

RESULTS

Out of 1578 new patients assessed from 2002 to 2008, we carried out 802 staging CT scans. Thirty-four cases (4.2%) with indeterminate pulmonary nodules were identified. We categorized cases by size and number of nodules. At a median follow-up of 18 months, there were no changes in lesion size in 86% of patients with a solitary nodule <1 cm and 89% with multiple subcentimeter nodules. In contrast, in 100% of cases with pulmonary nodules >1 cm, the nodules had progressed at follow-up (chi(2), P = 0.004).

CONCLUSIONS

Breast cancer cases with subcentimeter indeterminate pulmonary lesions and no evidence of metastases elsewhere are unlikely to represent metastatic disease. Treatment with curative intent or entry into clinical trials should not be excluded.

Nomograms to predict serious adverse events in phase II clinical trials of molecularly targeted agents

PURPOSE

A tool that quantifies the risk of treatment-related toxicity based on individual patient characteristics can augment the informed consent process and safety monitoring in the setting of phase II cancer treatment trials of molecularly targeted agents (MTAs).

METHODS

A regression model was constructed to predict the risk of a serious adverse event (SAE) with an MTA and presented as a nomogram. Estimation of risk can be performed by integrating risk estimates from the nomogram and from a reference or average patient. Internal validation was performed using bootstrapping techniques.

RESULTS

A total of 578 patients were treated with one of 14 MTAs given alone or in combination on one of 27 clinical trials performed by the Princess Margaret Hospital Drug Development Program between 2001 and 2006. Approximately 50% and 24% of patients experienced an SAE and an attributable SAE (SAEatt) during cycle 1, respectively. Albumin, lactate dehydrogenase (LDH), number of target lesions, prior radiotherapy, Charlson score, age, and performance status were included in the optimal model as predictors of a cycle 1 SAE, whereas the number of prior chemotherapy regimens, baseline creatinine, LDH, prior radiotherapy, Charlson score, body-surface area, and performance status were included as predictors of an SAEatt. Moderate-good internal validity was demonstrated, with area under the curve estimates ranging from 56.7% to 86.1% for all SAEs and 63.0% to 89.7% for SAEatts.

CONCLUSION

A regression model was constructed that predicts the SAE and SAEatt risk for an individual patient during cycle 1 of phase II trial treatment with moderate to good internal validity. External validation is still required.

Malignancies of the head and neck: the role for molecular targeted agents

Although cancers arising in the head and neck region are a diverse group of malignancies, a unifying thread remains a poor overall survival for patients with advanced, recurrent or metastatic disease. Treatment strategies need to evolve and improve upon established therapeutic practices. As the process of cancer evolution is understood to be derived from aberrations in genetic and epigenetic processes, molecularly targeted agents offer attractive therapeutic options by restoring normal control of oncogenic processes. The direct role for the treatment of squamous cell carcinoma of the head and neck, nasopharynx and salivary gland carcinomas with these novel, molecularly targeted agents are reviewed and their potential to improve on the existing standard of care is further explored.

Ethics at phase 0: clarifying the issues

The Food and Drug Administration (FDA) and the European Agency for the Evaluation of Medicinal Products (EMEA) recently issued documents encouraging sponsors to consider microdose testing before launching Phase I trials, and many commentators predict that such methodologies will be applied more routinely in drug development. However, exploratory testing has provoked several ethical criticisms. Skeptics question the value and validity of microdose trials, and whether they present a reasonable balance of risks and benefits for subjects. Another major criticism is that such studies serve mainly commercial ends. The present article explores these and other ethical concerns for studies conducted in the oncology setting. It concludes that microdosing is not inconsistent with prevailing practices in Phase I research, and that in principle, such studies could strengthen the ethical basis for Phase I trials by providing them better evidentiary justification.