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Electrocardiograms (ECGs) in phase I anticancer drug development: the MD Anderson Cancer Center experience with 8518
A Naing1, H Veasey-Rodrigues1, D S Hong1
1Departments of Investigational Cancer Therapeutics.
Background:
Cardiac sequelae from oncologic drugs are important in early cancer drug development. Prolongation of the corrected QT interval (QTc) by noncardiac drugs is the most common cause of drug development delays, nonapprovals and postmarketing withdrawals by the US Food and Drug Administration.
Patients And Methods:
We analyzed 8518 electrocardiograms (ECGs) in 525 consecutive cancer patients enrolled in 22 industry-sponsored phase I clinical trials, starting 1 January 2006.
Results:
Seventy-four patients [14%, 95% confidence interval (CI) 11% to 17%] with normal QTc at baseline had QTc intervals above upper limit of normal after treatment initiation; 33 (6%, 95% CI 4% to 9%) had prolonged QTc intervals at baseline, and only one (3%, 95% CI 0% to 16%) worsened after dosing. Seven of 33 patients (21%, 95% CI 9% to 39%) with prolonged baseline QTc had normalization of QTc intervals after dosing. All QTc prolongations were clinically insignificant; study drugs were continued uneventfully. Two of 525 patients (0.4%, 95% CI 0% to 1%) experienced cardiac serious adverse events (myocardial infarction possibly related to drug and unstable atrial flutter related to metastatic disease). Both cardiac events were detected by clinical assessment, not surveillance ECGs.
Conclusion:
Frequent ECG monitoring provided no clinically significant information in 525 patients in early phase trials.
Insights
Frequent electrocardiogram (ECG) monitoring in early phase cancer trials did not yield clinically significant information. While some patients showed corrected QT interval (QTc) changes, these were insignificant and did not impact drug continuation.
Area of Science:
- Cardiology
- Oncology
- Clinical Pharmacology
Background:
- Cardiac sequelae are a significant concern in early cancer drug development.
- Corrected QT interval (QTc) prolongation by noncardiac drugs frequently causes drug development delays and regulatory actions.
Purpose of the Study:
- To evaluate the clinical significance of electrocardiogram (ECG) monitoring, specifically corrected QT interval (QTc) assessments, in cancer patients undergoing early phase clinical trials.
Main Methods:
- Analysis of 8518 ECGs from 525 cancer patients in 22 industry-sponsored phase I trials.
- Assessment of QTc intervals at baseline and post-treatment initiation.
Main Results:
- 14% of patients with normal baseline QTc had post-treatment QTc above the upper limit of normal; 6% had prolonged baseline QTc.
- All identified QTc prolongations were clinically insignificant, allowing uninterrupted study drug continuation.
- Only two patients (0.4%) experienced cardiac serious adverse events, detected by clinical assessment, not ECG surveillance.
Conclusions:
- Routine ECG monitoring in this cohort of early phase cancer trials provided no clinically significant information.
- Clinical assessment was more effective in detecting adverse cardiac events than surveillance ECGs.
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