QTc Interval-Prolonging Medications Among Patients With Lung Cancer: Implications for Clinical Trial Eligibility and Clinical Care

Association of QT interval-prolonging drugs with clinical trial eligibility in patients with advanced cancer

Introduction

Drug-induced prolongation of the heart rate-corrected QT interval (QTc) is associated with increased risk for the potentially fatal arrhythmia torsades de pointes. Due to arrhythmia risk, clinical trials with cancer therapeutics often exclude patients based on thresholds for QTc prolongation. Our objective was to assess associations between prescriptions for QT-prolonging drugs and the odds of meeting cancer trial exclusionary QTc thresholds in a cohort of adults with advanced cancer.

Methods

Electronic health records were retrospectively reviewed for 271 patients seen at our institutional molecular solid tumor clinic. Collected data included demographics, QTc measurements, ventricular arrhythmia-related diagnoses, and all inpatient and outpatient prescriptions. Potential associations were assessed between demographic and clinical variables, including prescriptions for QT-prolonging drugs, and QTc measurements.

Results

Women had longer median QTc measurements than men (p = 0.030) and were prescribed more QT-prolonging drugs during the study (p = 0.010). In all patients, prescriptions for QT-prolonging drugs were associated with longer median and maximum QTc measurements at multiple assessed time points (i.e., for QT-prolonging drugs prescribed within 10, 30, 60, and 90 days of QTc measurements). Similarly, the number of QT-prolonging drugs prescribed was correlated with longer median and maximum QTc measurements at multiple time points. Common QTc-related exclusionary criteria were collected from a review of ClinicalTrials.gov for recent cancer clinical trials. Based on common exclusion criteria, prescriptions for QT-prolonging drugs increased the odds of trial exclusion.

Conclusion

This study demonstrates that prescriptions for QT-prolonging drugs were associated with longer QTc measurements and increased odds of being excluded from cancer clinical trials.

Enhancing access to and diversity in cancer clinical trials through a financial reimbursement program: Protocol to evaluate a novel program

As clinical trials have become more complex, with increasing numbers of required procedures and clinic visits, gaining access to promising new treatments has become even more challenging for many individuals. To address these barriers, we implemented a financial reimbursement and outreach program designed to increase the number and diversity of participants in cancer clinical trials at centers in Dallas, Houston, and Philadelphia. As endorsed by U.S. Food and Drug Administration (FDA) and the Texas and Pennsylvania State Legislatures, the program provides financial reimbursement for non-clinical costs (e.g., travel, lodging) to patients on cancer clinical trials with household income up to 700% the Federal poverty rate. The research study described here, centered at the Dallas site, evaluates program impact by assessing (1) numbers and diversity of patients enrolled to cancer clinical trials before and after program implementation; (2) characteristics of patients offered participation in the program who do versus do not enroll; (3) characteristics of patients enrolled in the program who do versus do not complete the reimbursement process. To evaluate perceived barriers and facilitators of program participation, we will conduct semi-structured interviews and administer the Comprehensive Score for Financial Toxicity Patient Reported Outcome Measure (COST PROM) and the Short Assessment of Health Literacy (SAHL). This program will examine how reimbursement of non-clinical costs can improve access to cancer clinical trials, with the eventual goal of increasing trial enrollment, diversity, representativeness, and generalizability.

A New Approach to Simplifying and Harmonizing Cancer Clinical Trials-Standardizing Eligibility Criteria

Importance

Clinical trial sponsors rely on eligibility criteria to control the characteristics of patients in their studies, promote the safety of participants, and optimize the interpretation of results. However, in recent years, complex and often overly restrictive inclusion and exclusion criteria have created substantial barriers to patient access to novel therapies, hindered trial recruitment and completion, and limited generalizability of trial results. A LUNGevity Foundation working group developed a framework for lung cancer clinical trial eligibility criteria. The goals of this framework are to (1) simplify eligibility criteria, (2) facilitate stakeholders' (patients, clinicians, and sponsors) search for appropriate trials, and (3) harmonize trial populations to support intertrial comparisons of treatment effects.

Observations

Clinicians and representatives from the pharmaceutical industry, the National Cancer Institute, the US Food and Drug Administration (FDA), the European Medicines Agency, and the LUNGevity Foundation undertook a process to identify and prioritize key items for inclusion in trial eligibility criteria. The group generated a prioritized library of terms to guide investigators and sponsors in the design of first-line, advanced non-small cell lung cancer clinical trials intended to support marketing application. These recommendations address disease stage and histologic features, enrollment biomarkers, performance status, organ function, brain metastases, and comorbidities. This effort forms the basis for a forthcoming FDA draft guidance for industry.

Conclusions and Relevance

As an initial step, the recommended cross-trial standardization of eligibility criteria may harmonize trial populations. Going forward, by connecting diverse stakeholders and providing formal opportunity for public input, the emerging FDA draft guidance may also provide an opportunity to revise and simplify long-standing approaches to trial eligibility. This work serves as a prototype for similar efforts now underway for other cancers.