Crossover is not associated with faster trial accrual

ACTION: a randomized phase 3 study of ONC201 (dordaviprone) in patients with newly diagnosed H3 K27M-mutant diffuse glioma

BACKGROUND

H3 K27M-mutant diffuse glioma primarily affects children and young adults, is associated with a poor prognosis, and no effective systemic therapy is currently available. ONC201 (dordaviprone) has previously demonstrated efficacy in patients with recurrent disease. This phase 3 trial evaluates ONC201 in patients with newly diagnosed H3 K27M-mutant glioma.

METHODS

ACTION (NCT05580562) is a randomized, double-blind, placebo-controlled, parallel-group, international phase 3 study of ONC201 in newly diagnosed H3 K27M-mutant diffuse glioma. Patients who have completed standard frontline radiotherapy are randomized 1:1:1 to receive placebo, once-weekly dordaviprone, or twice-weekly dordaviprone on 2 consecutive days. Primary efficacy endpoints are overall survival (OS) and progression-free survival (PFS); PFS is assessed by response assessment in neuro-oncology high-grade glioma criteria (RANO-HGG) by blind independent central review. Secondary objectives include safety, additional efficacy endpoints, clinical benefit, and quality of life. Eligible patients have histologically confirmed H3 K27M-mutant diffuse glioma, a Karnofsky/Lansky performance status ≥70, and completed first-line radiotherapy. Eligibility is not restricted by age; however, patients must be ≥10 kg at time of randomization. Patients with a primary spinal tumor, diffuse intrinsic pontine glioma, leptomeningeal disease, or cerebrospinal fluid dissemination are not eligible. ACTION is currently enrolling in multiple international sites.

What drives cancer clinical trial accrual? An empirical analysis of studies leading to FDA authorisation (2015-2020)

OBJECTIVE

To examine factors associated with accrual rate in industry sponsored clinical trials supporting US Food and Drug Administration (FDA) cancer drug approvals from 2015 to 2020.

DESIGN, SETTING AND PARTICIPANTS

Retrospective cross-sectional study included 194 pivotal trials supporting cancer drug approvals by the US FDA from 2015 to 2020.

INTERVENTIONS

Clinical trials were analysed for the type of blinding, primary endpoint, whether crossover was specified in the publication, study phase, line of therapy, response rate, investigational sites, manufacturer and randomisation ratio.

MAIN OUTCOME MEASURES

The main outcome was the rate of accrual, which is the number of patients accrued in the study per open month of enrolment.

RESULTS

The study consisted of 133 randomised (68%) and 61 (32%) non-randomised clinical trials. In randomised studies, we found the accrual rate was higher in trials investigating first and second line drugs (adjusted rate ratios (aRR): 1.55, 95% CI 1.18 to 2.09), phase III trials (aRR: 2.13, 95% CI 1.48 to 2.99), and for studies sponsored by Merck (aRR: 1.47, 95% CI 1.18 to 2.37), adjusting for other covariates. In contrast, the primary endpoint of a study, presence of crossover, single agent response rate, the number of investigational sites, population disease burden and skewed randomisation ratios were not associated with the rate of accrual. In the non-randomised adjusted model, the accrual rate was 2.03 higher (95% CI 1.10 to 3.92) for clinical trials sponsored by manufacturer, specifically Merck. Primary endpoint, crossover, trial phase, response rate, the number of investigational sites, disease burden or line of therapy were not associated with the rate of accrual.

CONCLUSION

In this cross-sectional study, line of therapy, study phase and manufacturer were the only factors associated with accrual rate. These findings suggest many proffered factors for speedy trial accrual are not associated with greater enrolment rates.

Limitations in Clinical Trials Leading to Anticancer Drug Approvals by the US Food and Drug Administration

IMPORTANCE

While there have been multiple assessments of clinical trials leading to anticancer drug approvals by the US Food and Drug Administration (FDA), the cumulative percentage of approvals based on trials with a limitation remains uncertain.

OBJECTIVE

To assess the percentage of clinical trials with limitations in 4 domains-lack of randomization, lack of significant overall survival advantage, inappropriate use of crossover, and use of suboptimal control arms-that led to FDA approvals from June 30, 2014, to July 31, 2019.

DESIGN, SETTING, AND PARTICIPANTS

This observational analysis included all anticancer drug indications approved by the FDA from June 30, 2014, through July 31, 2019. All indications were investigated, and each clinical trial was evaluated for design, enrollment period, primary end points, and presence of a limitation in the domains of interest. The standard-of-care therapy was determined by evaluating the literature and published guidelines 1 year prior to the start of clinical trial enrollment. Crossover was examined and evaluated for optimal use. The percentage of approvals based on clinical trials with any or all limitations of interest was then calculated.

MAIN OUTCOMES AND MEASURES

Estimated percentage of clinical trials with limitations of interest that led to an anticancer drug marketing authorization by the FDA.

RESULTS

A total of 187 trials leading to 176 approvals for 75 distinct novel anticancer drugs by the FDA were evaluated. Sixty-four (34%) were single-arm clinical trials, and 123 (63%) were randomized clinical trials. A total of 125 (67%) had at least 1 limitation in the domains of interest; 60 of the 125 trials (48%) were randomized clinical trials. Of all 123 randomized clinical trials, 37 (30%) lacked overall survival benefit, 31 (25%) had a suboptimal control, and 17 (14%) used crossover inappropriately.

CONCLUSIONS AND RELEVANCE

Two-thirds of cancer drugs are approved based on clinical trials with limitations in at least 1 of 4 essential domains. Efforts to minimize these limitations at the time of clinical trial design are essential to ensure that new anticancer drugs truly improve patient outcomes over current standards.