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

Amplifying the Patient's Voice in Oncology Early-Phase Clinical Trials: Solutions to Burdens and Barriers

Dose-finding oncology trials (DFOTs) provide early access to novel compounds of potential therapeutic benefit in addition to providing critical safety and dosing information. While access to trials for which a patient is eligible remains the largest barrier to enrollment on clinical trials, additional direct and indirect barriers unique to enrollment on DFOTs are often overlooked but worthy of consideration. Direct barriers including financial costs of care, travel and time investments, and logical challenges including correlative study designs are important to bear in mind when developing strategies to facilitate the patient experience on DFOTs. Indirect barriers such as strict eligibility criteria, washout periods, and concomitant medication restrictions should be accounted for during DFOT design to maintain the fidelity of the trial without being overly exclusionary. Involving patients and advocates and incorporating patient-reported outcomes (PROs) throughout the process, from initial DFOT design, through patient recruitment and participation, is critical to informing strategies to minimize identified barriers to offer the benefit of DFOTs to all patients.

Realizing the promise of Project Optimus: Challenges and emerging opportunities for dose optimization in oncology drug development

Project Optimus is a US Food and Drug Administration Oncology Center of Excellence initiative aimed at reforming the dose selection and optimization paradigm in oncology drug development. This project seeks to bring together pharmaceutical companies, international regulatory agencies, academic institutions, patient advocates, and other stakeholders. Although there is much promise in this initiative, there are several challenges that need to be addressed, including multidimensionality of the dose optimization problem in oncology, the heterogeneity of cancer and patients, importance of evaluating long-term tolerability beyond dose-limiting toxicities, and the lack of reliable biomarkers for long-term efficacy. Through the lens of Totality of Evidence and with the mindset of model-informed drug development, we offer insights into dose optimization by building a quantitative knowledge base integrating diverse sources of data and leveraging quantitative modeling tools to build evidence for drug dosage considering exposure, disease biology, efficacy, toxicity, and patient factors. We believe that rational dose optimization can be achieved in oncology drug development, improving patient outcomes by maximizing therapeutic benefit while minimizing toxicity.

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.

Oncology phase I trial design and conduct: time for a change - MDICT Guidelines 2022

In 2021, the Food and Drug Administration Oncology Center of Excellence announced Project Optimus focusing on dose optimization for oncology drugs. The Methodology for the Development of Innovative Cancer Therapies (MDICT) Taskforce met to review and discuss the optimization of dosage for oncology trials and to develop a practical guide for oncology phase I trials. Defining a single recommended phase II dose based on toxicity may define doses that are neither the most effective nor the best tolerated. MDICT recommendations address the need for robust non-clinical data which are needed to inform trial design, as well as an expert team including statisticians and pharmacologists. The protocol must be flexible and adaptive, with clear definition of all endpoints. Health authorities should be consulted early and regularly. Strategies such as randomization, intrapatient dose escalation, and real-world eligibility criteria are encouraged whereas serial tumor sampling is discouraged in the absence of a strong rationale and appropriately validated assay. Endpoints should include consideration of all longitudinal toxicity. The phase I dose escalation trial should define the recommended dose range for later testing in randomized phase II trials, rather than a single recommended phase II dose, and consider scenarios where different populations may require different dosages. The adoption of these recommendations will improve dosage selection in early clinical trials of new anticancer treatments and ultimately, outcomes for patients.

Impact of pharmacodynamic biomarkers in immuno-oncology phase 1 clinical trials

BACKGROUND

Phase 1 immuno-oncology (IO) trials frequently involve pharmacodynamic (PD) biomarker assessments involving tumour biopsies and/or blood collection, with increasing use of molecular imaging. PD biomarkers are set to play a fundamental role in early drug development of immuno-oncology (IO) agents. In the IO era, the impact of PD biomarkers for confirmation of biologic activity and their role in subsequent drug development have not been investigated.

METHODS

Phase 1 studies published between January 2014 and December 2020 were reviewed. Studies that reported on-treatment PD biomarkers [tissue-derived (tissue-PD), blood-based (blood-PD) and imaging-based (imaging-PD)] were analysed. PD biomarker results and their correlation with clinical activity endpoints were evaluated. Authors' statements on the influence of PD biomarkers on further drug development decisions, and subsequent citations of PD biomarker study results were recorded.

RESULTS

Among 386 trials, the most frequent IO agent classes evaluated were vaccines (32%) and PD-(L)1 inhibitors (25%). No PD biomarker assessments were reported in 100 trials (26%). Of the remaining 286, blood-PD, tissue-PD, and imaging-PD data were reported in 270 (94%), 94 (33%), and 12 (4%) trials, respectively. Assessments of more than one PD biomarker type were reported in 82 studies (29%). Similar proportions of blood-PD (9%), tissue-PD (7%), and imaging-PD studies (8%) had positive results that correlated with clinical activity. Results of 22 PD biomarker studies (8%) were referenced in subsequent clinical trials.

CONCLUSIONS

Most phase 1 IO studies performed PD biomarker assessments. Overall, positive PD biomarker results were infrequently correlated with clinical activity or cited in subsequent trials, suggesting a limited impact on subsequent drug development. With emerging health regulatory emphasis on optimal dose selection based on PD activity, more informative and integrative multiplexed assays that capture the complexity of tumour-host immunity interactions are warranted to improve phase 1 IO trial methodology.

Analyses of the Rationale and Implementation of Research Biopsies in Oncology Clinical Trials at a Tertiary Cancer Center

BACKGROUND

Biomarkers in clinical trials have led to massive incorporation of research biopsies, with potentially risks and no direct benefit for patients. In 2018, the American Society of Clinical Oncology (ASCO) released an ethical framework to provide guidance on incorporating research biopsies in cancer clinical trials.

MATERIALS AND METHODS

We collected biopsy requirements of cancer clinical trials conducted at Institut Jules Bordet (IJB) between 2015 and 2019 to examine adherence with the ASCO Ethical Framework. We used logistic regression models to test the association between the request for biopsy, the request for tissue, and the adherence to the ASCO framework as well as some trial characteristics.

RESULTS

Between January 2015 and December 2019, 178 oncological studies were conducted at IJB. Of these, 138 (78%) were sponsored by industry, 132 (74%) were phase II and III studies, and 141 (79%) concerned metastatic disease. Tissue was required for inclusion for 119 (67%) studies, among which 59 required at least one new biopsy. Adherence to ASCO's Ethical Framework was 67% for studies requiring tissue and went down to 39% for studies requiring at least one new biopsy. In multivariate analysis, requests for tissue or new biopsies increased in early-phase studies (p < .001, p < .001, respectively) and in studies investigating innovative treatments (immunotherapy or targeted therapies; p < .01, p = .02). Compliance to the ASCO framework significantly decreased with time (p < .001) and in early-phase studies (p < .001).

CONCLUSION

Numerous studies required tissue or new biopsies for exploratory objectives of unknown clinical utility. Requests for tissue increased over the years, whereas compliance to ASCO's Ethical Framework decreased.

IMPLICATIONS FOR PRACTICE

In 2019, the American Society of Clinical Oncology (ASCO) developed an ethical framework to provide guidance on incorporating research biopsies in clinical trials. This study underlines the growing request for tissue in clinical trials with potentially no impact on drug development and no benefit to actual or future patients. Adherence to ASCO's Ethical Framework decreases through time. These results highlight the importance of improving the ethics of research biopsies. ASCO's Ethical Framework offers an opportunity to improve quality of care in clinical research by maximizing scientific utility and allowing for clinically meaningful correlative science and safe access to innovative treatments for a maximum number of patients.

The value of interventional radiology in clinical trial teams: experience from the BATTLE lung cancer trials

AIM

To report on the multidisciplinary approach, focusing specifically on the role of the interventional radiologist (IR), used to support the Biomarker-integrated Approaches of Targeted Therapy for Lung Cancer Elimination (BATTLE) and BATTLE-2 trials.

MATERIALS AND METHODS

Patients who underwent percutaneous image-guided biopsy for the BATTLE and BATTLE-2 trials were reviewed. A radiology-based, three-point, lesion-scoring system was developed and used by two IRs. Lesions were given a score of 3 (most likely to yield sufficient material for biomarker analysis) if they met the following criteria: size >2 cm, solid mass, demonstrated imaging evidence of viability, and were technically easy to sample. Lesions not meeting all four criteria were scored 2 with the missing criteria noted as negative factors. Lesions considered to have risks that outweighed potential benefits receive a score of 1 and were not biopsied. Univariate and multivariate analyses were performed to evaluate the score's ability to predict successful yield for biomarker adequacy.

RESULTS

A total of 555 biopsies were performed. The overall yield for analysis of the required biomarkers was 86.1% (478/555), and 84% (268/319) and 88.9% (210/236) for BATTLE and BATTLE-2, respectively (p=0.09). Lesions receiving a score of 3 were adequate for biomarker analysis in 89% of cases. Lesions receiving a score of 2 with more than two negative factors were adequate for molecular analysis in 69.2% (IR1, p=0.03) and 74% (IR2, p=0.04) of cases. The two IRs scored 78.4% of the lesions the same indicating moderate agreement (kappa=0.55; 95% confidence interval [CI]: 0.48, 0.61).

CONCLUSIONS

IRs add value to clinical trial teams by optimising lesions selected for biopsy and biomarker analysis.

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.

Strategies for clinical development of monoclonal antibodies beyond first-in-human trials: tested doses and rationale for dose selection

BACKGROUND

Our previous survey on first-in-human trials (FIHT) of monoclonal antibodies (mAbs) showed that, due to their limited toxicity, the recommended phase II dose (RP2D) was only tentatively defined.

METHODS

We identified, by MEDLINE search, articles on single-agent trials of mAbs with an FIHT included in our previous survey. For each mAb, we examined tested dose(s) and dose selection rationale in non-FIHTs (NFIHTs). We also assessed the correlation between doses tested in the registration trials (RTs) of all FDA-approved mAbs and the corresponding FIHT results.

RESULTS

In the 37 dose-escalation NFIHTs, the RP2D indication was still poorly defined. In phase II-III NFIHTs (n=103 on 37 mAbs), the FIHT RP2D was the only dose tested for five mAbs. For 16 mAbs, only doses different from the FIHT RP2D or the maximum administered dose (MAD) were tested and the dose selection rationale infrequently indicated. In the 60 RTs on 27 FDA-approved mAbs with available FIHT, the FIHT RP2D was tested only for two mAbs, and RT doses were much lower than the FIHT MAD.

CONCLUSIONS

The rationale beyond dose selection in phase II and III trials of mAbs is often unclear in published articles and not based on FIHT data.

The changing face of clinical trials in the personalized medicine and immuno-oncology era: report from the international congress on clinical trials in Oncology & Hemato-Oncology (ICTO 2017)

In the past decade, the oncology community has witnessed major advances in the understanding of cancer biology and major breakthroughs in several different therapeutic areas, from solid tumors to hematological malignancies; moreover, the advent of effective immunotherapy approaches, such as immune-checkpoint blockade, is revolutionizing treatment algorithms in almost all oncology disease areas. As knowledge evolves and new weapons emerge in the “war against cancer”, clinical and translational research need to adapt to a rapidly changing environment to effectively translate novel concepts into sustainable and accessible therapeutic options for cancer patients.

With this in mind, translational cancer researchers, oncology professionals, treatment experts, CRO and industry leaders, as well as patient representatives gathered in London, 16-17 March 2017, for The International Congress on Clinical Trials in Oncology and Hemato-Oncology (ICTO2017), to discuss the changing face of oncology clinical trials in the new era of personalized medicine and immuno-oncology. A wide range of topics, including clinical trial design in immuno-oncology, biomarker-oriented drug development paths, statistical design and endpoint selection, challenges in the design and conduct of personalized medicine clinical trials, risk-based monitoring, financing and reimbursement, as well as best operational practices, were discussed in an open, highly interactive format, favoring networking among all relevant stakeholders. The most relevant data, approaches and issues emerged and discussed during the conference are summarized in this report.

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.

High-Content Biopsies Facilitate Molecular Analyses and Do Not Increase Complication Rates in Patients With Advanced Solid Tumors

Purpose

Precision oncology relies on frequent pathologic, molecular, and genomic assessments of tumor tissue to guide treatment selection, evaluate pharmacodynamic effects of novel agents, and determine drug resistance mechanisms. Newer forms of analyses such as drug screens in cell lines and patient-derived xenografts demand increasing amounts of tissue material. It remains unknown how the need for serial biopsies with large numbers of tumor cores relates to tissue yields and biopsy complication rates.

Materials and Methods

In this study, we performed a retrospective analysis of 199 focal liver biopsies performed in 143 patients in the setting of oncologic research protocols (research biopsy group) over a 4-year period at a single-intervention oncology service. Practice patterns and complication rates were compared with those related to 1,522 consecutive biopsies performed in 1,154 patients in whom two cores were obtained for standard clinical management of patients (standard biopsy).

Results

In the research biopsy group, 1,100 tissue cores (average, 5.5 cores per procedure) were harvested and distributed to trial sponsors, internal research laboratories, and pathology services. The complication rate in this cohort was 0.5% for major complications (one of 199) and 1.0% for minor complications managed conservatively (two of 199). In the standard biopsy control group, major complications were observed in 1.4% of procedures (22 of 1,522) and minor complications in 0.2% (three of 1,522). These complication rates were not statistically different.

Conclusion

Harvesting extra tissue cores through coaxial needles during focal liver biopsies does not increase complication rates and yields valuable tissue for additional experimental testing.

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.

Prospective Feasibility Study for Using Cell-Free Circulating Tumor DNA-Guided Therapy in Refractory Metastatic Solid Cancers: An Interim Analysis

Purpose

Retrospective studies have demonstrated that cell-free circulating tumor DNA (ctDNA) hotspot testing predicts matched therapy response to first- and second-line therapies in patients with advanced non–small-cell lung cancer (NSCLC). However, no prospective outcomes studies have evaluated ctDNA-guided matched therapy decision making on the basis of comprehensive plasma genomic testing including all four major classes of alterations. Here, we report the clinical utility of this approach in advanced solid tumor cancers.

Patients and Methods

We conducted a multiple parallel cohort, open-label, clinical trial using ctDNA-guided matched therapy when tissue was insufficient or unobtainable for next-generation sequencing. Plasma-based digital sequencing identified point mutations in 70 genes and indels, fusions, and copy number amplifications in selected genes. Patients with prespecified targetable alterations in metastatic NSCLC, gastric cancer (GC), and other cancers were matched to several independent targeted agent trials at a tertiary academic center.

Results

Somatic alterations were detected in 59 patients with GC (78%), and 25 patients (33%) had targetable alterations (ERBB2, n = 11; MET, n = 5; FGFR2, n = 3; PIK3CA, n = 6). In NSCLC, 62 patients (85%) had somatic alterations, and 34 (47%) had targetable alterations (EGFR, n = 29; ALK, n = 2; RET, n = 1; ERBB2, n = 2). After confirmation of ctDNA findings on tissue (to meet trial eligibility criteria), 10 patients with GC and 17 patients with NSCLC received molecularly matched therapy. Response rate and disease control rate were 67% and 100%, respectively, in GC and 87% and 100%, respectively, in NSCLC. Response was independent of targeted alteration variant allele fraction in NSCLC (P = .63).

Conclusion

To our knowledge, this is the first prospective feasibility study of comprehensive ctDNA-guided treatment in advanced GC and lung cancers. Response rates in this interim analysis are similar to those in tissue-based targeted therapy studies.

Mechanistic and pharmacologic insights on immune checkpoint inhibitors

The concept of augmenting the immune system to eradicate cancer dates back at least a century. A major resurgence in cancer immunotherapy has occurred over the past decade since the identification and targeting of negative regulators with antibody therapies to augment the anti-tumor immune response. Unprecedented responses across a broad array of cancer types elevated this class of therapies to the forefront of cancer treatment. The most successful drugs to date target the cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and programmed cell death-1 (PD-1) pathways. The immune biology of these pathways was illuminated through thoughtful pre-clinical experiments over the past 20 years. The characterization of these negative immune regulators, also known as immune checkpoints, subsequently led to the successful clinical development four drugs in six different cancer types to date, and progress continues. Despite these successes, significant challenges remain including the development of predictive biomarkers, recognition and management of immune related toxicities, and elucidating and reversing mechanisms of primary and secondary resistance. Ongoing work is expected to build upon recent accomplishments and allow more patients to benefit from this class of therapies.

Enhancing value of clinical pharmacodynamics in oncology drug development: An alliance between quantitative pharmacology and translational science

Clinical pharmacodynamic evaluation is a key component of the "pharmacologic audit trail" in oncology drug development. We posit that its value can and should be greatly enhanced via application of a robust quantitative pharmacology framework informed by biologically mechanistic considerations. Herein, we illustrate examples of intersectional blindspots across the disciplines of quantitative pharmacology and translational science and offer a roadmap aimed at enhancing the caliber of clinical pharmacodynamic research in the development of oncology therapeutics.

Implementation of a Multicenter Biobanking Collaboration for Next-Generation Sequencing-Based Biomarker Discovery Based on Fresh Frozen Pretreatment Tumor Tissue Biopsies

BACKGROUND

The discovery of novel biomarkers that predict treatment response in advanced cancer patients requires acquisition of high-quality tumor samples. As cancer evolves over time, tissue is ideally obtained before the start of each treatment. Preferably, samples are freshly frozen to allow analysis by next-generation DNA/RNA sequencing (NGS) but also for making other emerging systematic techniques such as proteomics and metabolomics possible. Here, we describe the first 469 image-guided biopsies collected in a large collaboration in The Netherlands (Center for Personalized Cancer Treatment) and show the utility of these specimens for NGS analysis.

PATIENTS AND METHODS

Image-guided tumor biopsies were performed in advanced cancer patients. Samples were fresh frozen, vital tumor cellularity was estimated, and DNA was isolated after macrodissection of tumor-rich areas. Safety of the image-guided biopsy procedures was assessed by reporting of serious adverse events within 14 days after the biopsy procedure.

RESULTS

Biopsy procedures were generally well tolerated. Major complications occurred in 2.1%, most frequently consisting of pain. In 7.3% of the percutaneous lung biopsies, pneumothorax requiring drainage occurred. The majority of samples (81%) contained a vital tumor percentage of at least 30%, from which at least 500 ng DNA could be isolated in 91%. Given our preset criteria, 74% of samples were of sufficient quality for biomarker discovery. The NGS results in this cohort were in line with those in other groups.

CONCLUSION

Image-guided biopsy procedures for biomarker discovery to enable personalized cancer treatment are safe and feasible and yield a highly valuable biobank. The Oncologist 2017;22:33-40Implications for Practice: This study shows that it is safe to perform image-guided biopsy procedures to obtain fresh frozen tumor samples and that it is feasible to use these biopsies for biomarker discovery purposes in a Dutch multicenter collaboration. From the majority of the samples, sufficient DNA could be yielded to perform next-generation sequencing. These results indicate that the way is paved for consortia to prospectively collect fresh frozen tumor tissue.

Pharmacodynamic endpoints as clinical trial objectives to answer important questions in oncology drug development

Analyzing the molecular interplay between malignancies and therapeutic agents is rarely a straightforward process, but we hope that this special issue of Seminars has highlighted the clinical value of such endeavors as well as the relevant theoretical and practical considerations. Here, we conclude with both an overview of the various high-value applications of clinical pharmacodynamics (PD) in developmental therapeutics and an outline of the framework for incorporating PD analyses into the design of clinical trials. Given the increasingly recognized importance of determining and administering the biologically effective dose (BED) and schedule of targeted agents, we explain how clinical PD biomarkers specific to the agent mechanism of action (MOA) can be used for the development of pharmacodynamics-guided biologically effective dosage regimens (PD-BEDR) to maximize the efficacy and minimize the toxicity of targeted therapies. In addition, we discuss how MOA-based PD biomarker analyses can be used both as patient selection diagnostic tools and for designing novel drug combinations targeting the specific mutational signature of a given malignancy. We also describe the role of PD analyses in clinical trials, including for MOA confirmation and dosage regimen optimization during phase 0 trials as well as for correlating molecular changes with clinical efficacy when establishing proof-of-concept in phase I/II trials. Finally, we outline the critical technological developments that are needed to enhance the quality and quantity of future clinical PD data collection, broaden the types of molecular questions that can be answered in the clinic, and, ultimately, improve patient outcomes.

Theory and practice of clinical pharmacodynamics in oncology drug development

The clinical development of molecularly targeted cancer therapies is enhanced by proof of mechanism of action as well as proof of concept, which relate molecular pharmacodynamics to efficacy via changes in cancer cell biology and physiology resulting from drug action on its intended target. Here, we present an introduction to the field of clinical pharmacodynamics, its medical and laboratory aspects, and its practical incorporation into clinical trials. We also describe key success factors that are useful for judging the quality of clinical pharmacodynamic studies, including biopsy quality and suitability, specimen handling, assay fitness-for-purpose, and reagent quality control. This introduction provides not only context for the following articles in this issue, but also an appreciation of the role of well-conducted clinical pharmacodynamic studies in oncology drug development.

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.