Proportion of Patients in Phase I Oncology Trials Receiving Treatments That Are Ultimately Approved

Trends in phase 1 oncology clinical trials across Australia; Analysis of ClinicalTrials.gov 2012-2022

BACKGROUND

Phase 1 oncology trials provide access to new therapies and may improve cancer outcomes. Phase 1 trials conducted in the Asian-Pacific region are increasing at a faster rate than the global trend. This study aimed to describe the changing landscape of phase 1 oncology trials in Australia in the last decade.

METHODS

This cross-sectional study reviewed phase 1 oncology trials registered on ClinicalTrials.gov conducted in Australia. Phase 1 trials were included for analysis if they enrolled adults with solid organ malignancies, used at least one systemic agent, and were first registered between January 1, 2012, and December 31, 2022. The number of trials, site locations, sponsor type, and drug class were analyzed using descriptive statistics.

RESULTS

Over the 10-year period, ClinicalTrials.gov included 493 phase 1 clinical trials across 71 Australian sites. Most sites were in metropolitan locations; in Melbourne, trials were concentrated within selected sites, while in Sydney, trials were spread across a larger number of sites. The number of phase 1 trials per annum increased from 18 in 2012 to 75 in 2022. Since 2020, emerging biopharmaceutical companies have become the predominant sponsor type, a trend that is also seen globally. While most trial sponsors were North American (42%), there was increasing representation from Asian sponsors over the 10-year period (6% in 2012 to 39% in 2022). Immunomodulatory (45%) and targeted approaches (44%) accounted for most drug classes used alone or in combination.

CONCLUSIONS

There are an increasing number of phase 1 trials conducted within Australia. Sponsors of phase 1 trials are increasingly from Asian countries and are more likely to be emerging biopharmaceutical companies.

Ethics of gene and cell therapy development for neurologic disorders

In this chapter, I provide a condensed overview of nine recurring policy and ethical challenges encountered with the development of gene and cell therapies for neurologic disease. These include the question of when to initiate first-in-human trials, the ethics and policy of expanded/special access, the conduct of individualized therapy trials, subject selection in trials, designing trials for negative results, unintended effects of interventions on personal identity, comparator choice in randomized trials, consent and therapeutic misestimation, and cost and access for effective therapies. Broadly speaking, I argue that early in their development, the justification of risk in trials of gene and cell therapies derives from the social and scientific value of a trial and not the therapeutic value for trial participation. This generates strong imperatives to justify, design, and report trials appropriately and select patient populations that incur the least burden and opportunity cost for trial participation. Late in intervention development, policy makers must contend with the fact that proven effective interventions will almost certainly amplify strains in healthcare budgets as well as the ethical justifications standing behind reimbursement decisions.

Dose optimization during drug development: whether and when to optimize

The goal of dose optimization during drug development is to identify a dose that preserves clinical benefit with optimal tolerability. Traditionally, the maximum tolerated dose in a small phase I dose escalation study is used in the phase II trial assessing clinical activity of the agent. Although it is possible that this dose level could be altered in the phase II trial if an unexpected level of toxicity is seen, no formal dose optimization has routinely been incorporated into later stages of drug development. Recently it has been suggested that formal dose optimization (involving randomly assigning patients between 2 or more dose levels) be routinely performed early in drug development, even before it is known that the experimental therapy has any clinical activity at any dose level. We consider the relative merits of performing dose optimization earlier vs later in the drug development process and demonstrate that a considerable number of patients may be exposed to ineffective therapies unless dose optimization is delayed until after clinical activity or benefit of the new agent has been established. We conclude that patient and public health interests may be better served by conducting dose optimization after (or during) phase III evaluation, with some exceptions when dose optimization should be performed after activity shown in phase II evaluation.

Success rates for US and Canadian anticancer drug development efforts in pediatric oncology

BACKGROUND

Approximately 5% of adult cancer interventions put into clinical testing attain regulatory approval. Little is known about corresponding rates for pediatric cancer.

METHODS

Our primary outcomes were the proportion of interventions graduating to the next trial phase, randomized trials, and/or clinical practice. We created a saturation sample of clinical trials by searching ClinicalTrials.gov for all pediatric anticancer trials in the United States or Canada. Trial characteristics were extracted automatically from ClinicalTrials.gov records, and cancer indication/drug class categorization, biomarker enrichment, and Food and Drug Administration (FDA) approval status at time of recruitment were double-extracted from each record. Regulatory approval status and labeling modifications for each intervention were determined by searching Drugs@FDA and the New Pediatric Labeling Information Database.

RESULTS

Five hundred eighty-nine pediatric trials launched between 1987 and 2019 were captured. The overall probability of graduation was 17.0%; 18.9% of interventions graduated from phase 1 to phase 2 trials, and 1.6% of interventions graduated from phase 2 to phase 3 trials. The proportion of interventions advancing from phase 1 to FDA approval was 3.6%, and 1.9% of interventions tested in phase 1 advanced to a randomized phase 2 trial. Only biomarker enrichment was significantly predictive of graduation from phase 1 to phase 2 trials (p = .011).

CONCLUSION

The proportion of interventions advancing from phase 1 testing to FDA approval was similar to estimates for adult oncology. Our findings highlight the challenges for current paradigms of pediatric anticancer drug development.

Ethical Considerations for Phase I Trials in Oncology

Phase I trials often represent the first occasion where new cancer strategies are tested in patients. Various developments in cancer biology, methodology, regulation, and medical ethics have altered the ethical landscape of such trials. We provide a narrative review of contemporary ethical challenges in design, conduct, and reporting of phase I cancer trials and outline recommendations for addressing each. We organized our review around four topics, supplementing the first three with scoping reviews: (1) benefit/risk, (2) research biopsies, (3) therapeutic misconception and misestimation, and (4) reporting. The main ethical challenges of conducting phase I trials stem from three issues. First, phase I trials often involve higher research burden and scientific uncertainty compared with other cancer trials. Second, many patients arrive at phase I trials at a transitional point in their illness trajectory where they have exhausted standard survival-extending options. Third, phase I trial results play a major role in informing downstream drug development and regulatory decisions. Together, these issues create distinct pressures for study design, ethical review, informed consent, and reporting. Developments in methodology, regulation, cancer biology, and ethical awareness have helped mitigate some of these challenges, while introducing others. We conclude our review with a series of recommendations regarding trial design, ethical review, consent, and reporting. We also outline several unresolved questions that, if addressed, would strengthen the ethical foundation of phase I cancer trials.

Do the Potential Medical Benefits of Phase 1 Pediatric Oncology Trials Justify the Risks? Views of the United States Public

OBJECTIVES

To assess the US public's views on whether the potential medical benefits of phase 1 pediatric oncology trials justify the risks.

STUDY DESIGN

Online survey of a nationally representative sample of US adults. Participants were presented with a hypothetical scenario in which they have a 10-year-old child with advanced cancer. They were then offered the option of giving their child supportive care or trying one more potential treatment, in the research or clinical care setting, which has the same risks and potential medical benefits as the average phase 1 pediatric oncology trial. We assessed what percentage of respondents thought the potential medical benefits justify the risks.

RESULTS

In total, 1658 of the 2508 individuals who were sent the survey participated (response rate = 66.1%). Of those who passed all 3 test questions indicating understanding, 67.1% in the research scenario and 58.5% in the clinical care scenario regarded the potential medical benefits of an average phase 1 pediatric oncology trial as equal to or greater than the risks. In addition, 53.4% of respondents in the research scenario thought it was appropriate for researchers to conduct a study in children with these risks and potential medical benefits, and 46.9% stated they would enroll their own child in such a trial.

CONCLUSIONS

A majority of the US public regards the potential medical benefits of average phase 1 pediatric oncology trials as justifying the risks. This finding suggests that these trials are ethically appropriate and approvable in patients who have no more effective treatment options. At the same time, a significant minority thought the potential medical benefits do not justify the risks, suggesting these trials should be approved only when they have significant social value. Moreover, approximately one-half of respondents regarded the trials as inappropriate and would not enroll their own child, underscoring the need for a rigorous informed consent process that accurately educates parents regarding the risks, potential medical benefits, and alternatives, so they can decide whether to enroll their child based on their own preferences and goals.

Revisiting Risk and Benefit in Early Oncology Trials in the Era of Precision Medicine: A Systematic Review and Meta-Analysis of Phase I Trials of Targeted Single-Agent Anticancer Therapies

PURPOSE

Phase I trials are a crucial step in the evaluation of new cancer therapies. Historically, low rates of response (5%) and comparably high rates of death from toxicities (0.5%) have contributed to debates on the ethics and orientation of these trials. With the introduction of novel targeted therapies, a contemporary estimate is needed.

METHODS

We systematically searched PubMed, Embase, and ClinicalTrials.gov for reports of phase I oncology trials of single-agent targeted immunomodulators, molecularly targeted therapies, and antiangiogenic agents, published between January 2015 and July 2018. Adult and pediatric trials of solid and hematological malignancies were eligible. Treatment-related adverse events (grades 3, 4, and 5) and response rates (objective, complete, and partial) were extracted and analyzed.

RESULTS

One hundred and fifty-eight trial reports, covering 6,707 patients, were included. The rate of treatment-related deaths was 0.0% (95% CI, 0.0 to 0.1), while 13.2% of patients (9.5 to 17.3) experienced a grade 3 or 4 treatment-related toxicity. The combined objective response rate was 6.4% (4.6 to 8.5). Among trials using tumor biomarkers as eligibility criteria, the objective response rate was higher (12.0% [7.3 to 17.6] compared to 4.9% [2.5 to 5.7], P value < .01). The same was true of trials focusing on a single tumor type (13.4% [8.2 to 19.4]) compared to multiple tumor types (3.8% [2.5 to 5.3], P value < .01).

CONCLUSION

Reduced grade 5 risk and improved benefit appears to exist in modern phase I oncology trials, particularly in trials that target single tumor types and integrate biomarkers as eligibility criteria. These findings provide information to support informed consent discussions, highlight the need for improved reporting of phase I oncology trials, and provide direction for optimizing their design.

Individualized therapy trials: navigating patient care, research goals and ethics

'Individualized therapy' trials (sometimes called n-of-1 trials) use patients as their own controls to evaluate treatments. Here we divide such trials into three categories: multi-crossover trials aimed at individual patient management, multi-crossover trial series and pre-post trials. These trials all customize interventions for patients; however, the latter two categories also aim to inform medical practice and thus embody tensions between the goals of care and research that are typical of other types of clinical trials. In this Perspective, we discuss four domains where such tensions play out-clinical equipoise, informed consent, reporting and funding, and we provide recommendations for addressing each.

Patient Participation in Clinical Trials of Oncology Drugs and Biologics Preceding Approval by the US Food and Drug Administration

IMPORTANCE

Several studies have estimated the financial inputs for successful drug development. Such analyses do not capture the large investment that patient study participants commit to drug development.

OBJECTIVE

To estimate the volume of patients required to achieve a first US Food and Drug Administration (FDA) approval for a new anticancer drug or biologic therapy.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included a random sample of prelicense oncology drugs and biologics with a trial site in the United States that were launched into clinical efficacy testing between January 1, 2006, and December 31, 2010. Drugs and biologics were identified using ClinicalTrials.gov registration records. Total patient enrollment was captured over an 8-year span, and each intervention was classified based on whether it received FDA approval and was deemed as having intermediate or substantial value according to the American Society of Clinical Oncology Value Framework (ASCO-VF) score. Secondarily, the association between patient numbers and intervention characteristics was tested. Data were analyzed in February 2020.

MAIN OUTCOMES AND MEASURE

The prespecified primary outcome was the number of patients enrolled in prelicense trials per FDA approval.

RESULTS

A total of 120 drugs and biologics were included in our study, with 84 (70.0%) targeted agents, 20 (16.7%) immunotherapies, and 71 (59.2%) novel agents. A total of 13 drugs and biologics (10.8%; 95% CI, 5.3%-16.8%) in our sample gained FDA approval within 8 years, of which 1 (7.7%) was deemed of intermediate value and 3 (23.1%) were deemed of substantial value using ASCO-VF scoring. Overall, 158 810 patients were enrolled in 1335 trials testing these drugs and biologics, 47 913 (30.2%) in trials that led to FDA approval and 110 897 (69.8%) in trials that did not. An estimated 12 217 (95% CI, 7970-22 215) patient study participants contributed to prelicense trials per FDA approval. The estimated number of patients needed to produce a single FDA-approved drug or biologic of intermediate or substantial ASCO-VF clinical value was 39 703 (95% CI, 19 391-177 991).

CONCLUSIONS AND RELEVANCE

The results of this cohort study make visible the substantial patient investment required for prelicense oncology drug development. Such analyses can be used to devise policies that maximize the clinical impact of research on a per-patient basis.

Details of risk-benefit communication in informed consent documents for phase I/II trials

BACKGROUND

Informed consent documents for clinical studies should disclose all reasonably foreseeable risks and benefits. Little guidance exists on how to navigate the complexities of risk-benefit communication, especially in early clinical research. Practice-oriented development of such guidance should be informed by evidence on what and how details of risks and benefits are currently communicated.

METHOD

We surveyed the responsible parties of phase I/II trials registered in ClinicalTrials.gov that started 2007 or later and completed between 2012 and 2016 to sample informed consent documents from a broad spectrum of early phase clinical trials. Based on an assessment matrix, we qualitatively and quantitatively assessed the informed consent documents for details of risk-benefit communication.

RESULTS

The risk-benefit communication in the 172 informed consent documents differed substantially in several regards. The outcome, extent, and likelihood of health risks, for example, were described in 83%, 32%, and 63% of the informed consent documents. Only 45% of informed consent documents specified the outcome of mentioned health benefits, and the extent and likelihood of health benefits were never specified. From those informed consent documents reporting risk likelihoods, only 57% added frequency numbers to words such as "common" or "rare," and even in these cases, we found strong variations for presented frequency ranges. Substantial heterogeneity also exists for how informed consent documents communicate other risk and benefit types and related safeguards.

CONCLUSION

Our study points to several shortcomings and heterogeneities in how informed consent documents communicate risks and benefits to potential research participants. Health risks, for example, should be specified with frequency numbers, and health benefits should be specified at least by mentioning their outcomes. Further demand for research and policy development is needed to harmonize risk-benefit communication and to clarify ways to specify the likelihood of health benefits.