Challenges of characterizing proarrhythmic risk due to QTc prolongation induced by nonadjuvant anticancer agents

Cardiovascular safety of pimitespib in patients with advanced solid tumors: An open-label, nonrandomized, phase 1 study

BACKGROUND

Pimitespib (TAS-116), a first-in-class, oral, selective heat-shock protein 90 inhibitor, is approved as fourth-line treatment for gastrointestinal stromal tumors in Japan. This phase 1 study evaluated the cardiac safety of pimitespib.

METHODS

In this open-label, nonrandomized, multicenter study, Japanese patients (aged ≥20 years) with refractory, advanced solid tumors received placebo on day -1, then pimitespib 160 mg daily on days 1-5 of the cardiac safety evaluation period. Electrocardiograms were conducted at baseline, and on days -2, -1, 1, and 5; and blood samples were collected on days 1 and 5. Patients then received once-daily pimitespib for 5 days every 3 weeks. The primary end point was the time-matched difference in QT interval corrected for heart rate using the Fridericia correction (QTcF) between pimitespib and placebo. Pharmacokinetics, safety, and preliminary efficacy were also assessed.

RESULTS

Of the 22 patients in the cardiac safety-evaluable population, no clinically relevant QTc prolongation was observed; the upper bound of the one-sided 95% confidence interval for the time-matched difference in change from baseline in QTcF was <20 msec at all time points on days 1 and 5. Pimitespib pharmacokinetic parameters were consistent with previous data, and the time-matched difference in change from baseline in QTcF showed no marked increase as plasma concentrations increased. The safety profile was acceptable; 40% of patients experienced grade 3 or greater adverse drug reactions, mostly diarrhea (20%). The median progression-free survival was 3.1 months.

CONCLUSIONS

In Japanese patients with refractory, advanced solid tumors, pimitespib was not associated with clinically relevant QTc prolongation, and there were no cardiovascular safety concerns.

PLAIN LANGUAGE SUMMARY

Pimitespib is a new anticancer drug that is being used to treat cancer in the stomach or intestines (gastrointestinal stromal tumors). This study demonstrated that pimitespib had no marked effect on heart rhythm or negative effects on the heart or blood vessels and had promising anticancer effects in Japanese patients with advanced solid tumors who were unable to tolerate or benefit from standard treatment.

Drug-induced QT prolongation and torsade de pointes: a real-world pharmacovigilance study using the FDA Adverse Event Reporting System database

Introduction: Drug-induced QT prolongation and (or) Torsade de Pointes (TdP) is a well-known serious adverse reaction (ADR) for some drugs, but the widely recognized comprehensive landscape of culprit-drug of QT prolongation and TdP is currently lacking. Aim: To identify the top drugs reported in association with QT prolongation and TdP and provide information for clinical practice. Method: We reviewed the reports related to QT prolongation and TdP in the FDA Adverse Event Reporting System (FAERS) database from January 1, 2004 to December 31, 2022, and summarized a potential causative drug list accordingly. Based on this drug list, the most frequently reported causative drugs and drug classes of QT prolongation and TdP were counted, and the disproportionality analysis for all the drugs was conducted to in detect ADR signal. Furthermore, according to the positive-negative distribution of ADR signal, we integrated the risk characteristic of QT prolongation and TdP in different drugs and drug class. Results: A total of 42,713 reports in FAERS database were considered to be associated with QT prolongation and TdP from 2004 to 2022, in which 1,088 drugs were reported as potential culprit-drugs, and the largest number of drugs belonged to antineoplastics. On the whole, furosemide was the most frequently reported drugs followed by acetylsalicylic acid, quetiapine, citalopram, metoprolol. In terms of drug classes, psycholeptics was the most frequently reported drug classes followed by psychoanaleptics, analgesics, beta blocking agents, drugs for acid related disorders. In disproportionality analysis, 612 drugs showed at least one positive ADR signals, while citalopram, ondansetron, escitalopram, loperamide, and promethazine were the drug with the maximum number of positive ADR signals. However, the positive-negative distribution of ADR signals between different drug classes showed great differences, representing the overall risk difference of different drug classes. Conclusion: Our study provided a real-world overview of QT prolongation and TdP to drugs, and the presentation of the potential culprit-drug list, the proportion of reports, the detection results of ADR signals, and the distribution characteristics of ADR signals may help understand the safety profile of drugs and optimize clinical practice.

Dostarlimab, an anti-programmed death-1 monoclonal antibody, does not cause QT prolongation in patients with solid tumours: A concentration-QT analysis

AIMS

Patients with solid tumours were treated with the anti-PD-1 antibody dostarlimab in the Phase I GARNET trial. This study aimed to examine dostarlimab's effect on corrected QT (QTc) interval and the systemic concentration-QTc interval relationship.

METHODS

In GARNET Part 2B, patients received 500 mg dostarlimab every 3 weeks (Q3W) for four cycles, then 1000 mg Q6W. Triplicate 12-lead ECGs were recorded and time-matched pharmacokinetic (PK) samples collected at screening, on Day 1 of Cycles 1, 4, 5, 8, 12 (pre-dose and 0.5 h after infusion end), and at treatment end. Concentration-change from baseline QTcF (ΔQTcF) analysis using a linear mixed effects model, summary statistics, incidence of clinically noteworthy ECG values and rhythm abnormalities were evaluated.

RESULTS

A total of 377 patients were considered for evaluation (n = 15 excluded from concentration-ΔQTcF). There was a non-significant concentration-ΔQTcF relationship (0.001589 ms/μg/mL; P = .5906). Mean ΔQTcF increase was <6 ms (upper-bound two-sided 90% confidence interval [CI], <10 ms at all post-dose timepoints). Highest geometric mean concentration was 414.1 μg/mL (Cycle 5 Day 1, 0.5 h) with predicted mean ∆QTcF of 3.064 ms (upper-bound two-sided 90% CI: 5.071). Mean QTcF prolongation (all concentrations) was 2.4 ms. QTcF prolongation ≥500 ms occurred in five patients (1.3%); 51 (13.6%) and nine patients (2.4%) had ΔQTcF ≥30 ms and ≥60 ms, respectively. Ten patients (2.7%) reported rhythm abnormalities. No U-wave abnormalities, torsades de pointes, ventricular tachycardia or ventricular fibrillation/flutter were observed.

CONCLUSIONS

Dostarlimab does not cause clinically significant QTcF prolongation exceeding the regulatory concern threshold.

Effect of Pevonedistat, an Investigational NEDD8-Activating Enzyme Inhibitor, on the QTc Interval in Patients With Advanced Solid Tumors

The purpose of this study was to assess the effect of pevonedistat, a neural precursor cell expressed, developmentally down-regulated protein 8 (NEDD8)-activating enzyme inhibitor, on the heart rate-corrected QT (QTc) interval in cancer patients. Patients were randomized 1:1 to receive pevonedistat 25 or 50 mg/m² on day 1 and the alternate dose on day 8. Triplicate electrocardiograms were collected at intervals over 0-11 hours and at 24 hours via Holter recorders on days -1 (baseline), 1, and 8. Changes from time-matched baseline values were calculated for QTc by Fridericia (QTcF), PR, and QRS intervals. Serial time-matched blood samples for analysis of pevonedistat plasma pharmacokinetics were collected and a concentration-QTc analysis conducted. Safety was assessed by monitoring vital signs, physical examinations, and clinical laboratory tests. Forty-four patients were included in the QTc analysis. Maximum least square (LS) mean increase from time-matched baseline in QTcF was 3.2 milliseconds at 1 hour postdose for pevonedistat at 25 mg/m² , while the LSs mean change from baseline in QTcF was -1.7 milliseconds 1 hour postdose at 50 mg/m² . The maximum 2-sided 90% upper confidence bound was 6.7 and 2.9 milliseconds for pevonedistat at 25 and 50 mg/m² , respectively. Pevonedistat did not result in clinically relevant effects on heart rate, nor on PR or QRS intervals. Results from pevonedistat concentration-QTc analysis were consistent with these findings. Administration of pevonedistat to cancer patients at a dose of up to 50 mg/m² showed no evidence of QT prolongation, indicative of the lack of clinically meaningful effects on cardiac repolarization. ClinicalTrials.gov identifier: NCT03330106 (first registered on November 6, 2017).

Concentration QTc analysis of giredestrant: Overcoming QT/heart rate confounding in the presence of drug-induced heart rate changes

Concentration-QTc (C-QTc) analysis has become a common approach for evaluating proarrhythmic risk and delayed cardiac repolarization of oncology drug candidates. Significant heart rate (HR) change has been associated with certain classes of oncology drugs and can result in over- or underestimation of the true QT prolongation risk. Because oncology early clinical trials typically lack a placebo control arm or time-matched, treatment-free baseline electrocardiogram collection, significant HR change brings additional challenges to C-QTc analysis in the oncology setting. In this work, a spline-based correction method (QTcSPL) was explored to mitigate the impact of HR changes in giredestrant C-QTc analysis. Giredestrant is a selective estrogen receptor degrader being developed for the treatment of patients with estrogen receptor-positive (ER+) breast cancer. A dose-related HR decrease has been observed in patients under giredestrant treatment, with significant reductions (>10 bpm) observed at supratherapeutic doses. The QTcSPL method demonstrated superior functionality to reduce the correlation between QTc and HR as compared with the Fridericia correction (QTcF). The effect of giredestrant exposure on QTc was evaluated at the clinical dose of 30 mg and supratherapeutic dose of 100 mg based on a prespecified linear mixed effect model. The upper 90% confidence interval of ΔQTcSPL and ΔQTcF were below the 10 ms at both clinical and supratherapeutic exposures, suggesting giredestrant has a low risk of QT prolongation at clinically relevant concentrations. This work demonstrated the use case of QTcSPL to address HR confounding challenges in the context of oncology drug development for the first time.

Clinical Pharmacokinetics and Pharmacodynamics of Rucaparib

Rucaparib is an oral small-molecule poly(ADP-ribose) polymerase inhibitor indicated for patients with recurrent ovarian cancer in the maintenance and treatment settings and for patients with metastatic castration-resistant prostate cancer associated with a deleterious BRCA1 or BRCA2 mutation. Rucaparib has a manageable safety profile; the most common adverse events reported were fatigue and nausea in both indications. Accumulation in plasma exposure occurred after repeated administration of the approved 600-mg twice-daily dosage. Steady state was achieved after continuous twice-daily dosing for a week. Rucaparib has moderate oral bioavailability and can be dosed with or without food. Although a high-fat meal weakly increased maximum concentration and area under the curve, the effect was not clinically significant. A mass balance analysis indicated almost a complete dose recovery of rucaparib over 12 days, with metabolism, renal, and hepatic excretion as the elimination routes. A population pharmacokinetic analysis of rucaparib revealed no effect of age, sex, race, or body weight. No starting dose adjustments were necessary for patients with mild-to-moderate hepatic or renal impairment; the effect of severe organ impairment on rucaparib exposure has not been evaluated. In patients, rucaparib moderately inhibited cytochrome P450 (CYP) 1A2 and weakly inhibited CYP3As, CYP2C9, and CYP2C19. Rucaparib weakly increased systemic exposures of oral contraceptives and oral rosuvastatin and marginally increased the exposure of oral digoxin (a P-glycoprotein substrate). In vitro studies suggested that rucaparib inhibits transporters MATE1, MATE2-K, OCT1, and OCT2. No clinically meaningful drug interactions with rucaparib as a perpetrator were observed. An exposure-response analysis revealed dose-dependent changes in selected clinical efficacy and safety endpoints. Overall, this article provides a comprehensive review of the clinical pharmacokinetics, pharmacodynamics, drug-drug interactions, effects of intrinsic and extrinsic factors, and exposure-response relationships of rucaparib.

False Negative ECG Device Results May Increase the Risk of Adverse Events in Clinical Oncology Trials

Background

Sites participating in clinical trials may not have the expertise and infrastructure to accurately measure cardiac intervals on 12-lead ECGs and rely heavily on the automated ECG device generated results for clinical decision-making.

Methods

Using a dataset of over 260,000 ECGs collected in clinical oncology studies, we investigated the mean difference and the rate of false negative results between the digital ECG machine QTc and QRS measurements compared to those obtained by a centralized ECG core lab.

Results

The mean differences between the core lab and the automated algorithm QTcF and QRS measurements were + 1.8 ± 16.0 ms and − 1.0 ± 8.8 ms, respectively. Among the ECGs with a centralized QTcF value > 450 or > 470 ms, 39.5% and 47.8% respectively had a device reported QTcF value ≤ 450 ms or ≤ 470 ms. Among the ECGs with a centrally measured QTcF > 500 ms, 55.8% had a device reported value ≤ 500 ms. Automated QTcF measurements failed to detect a QTcF increase > 60 ms for 53.9% of the ECGs identified by the core lab. Automated measurements also failed to detect QRS prolongation, though to a lesser extent than failures to detect QTc prolongation. Among the ECGs with a centrally measured QRS > 110 or 120 ms, 7.9% and 7.3% respectively had a device reported QRS value ≤ 110 ms or ≤ 120 ms.

Conclusion

Relying on automated measurements from ECG devices for patient inclusion and treatment (dis)continuation decisions poses a potential risk to patients participating in oncology studies.

Update on glasdegib in acute myeloid leukemia - broadening horizons of Hedgehog pathway inhibitors

Numerous new emerging therapies, including oral targeted chemotherapies, have recently entered the therapeutic arsenal against acute myeloid leukemia (AML). The significant shift toward the use of these novel therapeutics, administered either alone or in combination with intensive or low-intensity chemotherapy, changes the prospects for the control of this disease, especially for elderly patients. Glasdegib, an oral Hedgehog pathway inhibitor, showed satisfactory response rates associated with moderate toxicity and less early mortality than standard induction regimens in this population. It was approved in November 2018 by the FDA and in June 2020 by the EMA for use in combination with low-dose cytarabine as a treatment of newly-diagnosed AML in patients aged ≥ 75 and/or unfit for intensive induction chemotherapy. The current paper proposes an extensive, up-to-date review of the preclinical and clinical development of glasdegib. Elements of its routine clinical use and the landscape of ongoing clinical trials are also stated.

Concentration-QT modelling in early clinical oncology settings: Simulation evaluation of performance

AIMS

Concentration-QT modelling (C-QTc) of first-in-human data has been rapidly adopted as the primary evaluation of QTc interval prolongation risk. Here, we evaluate the performance of C-QTc in early oncology settings (i.e., patients, no placebo or supratherapeutic dose, 3 + 3 designs).

METHODS

C-QTc performance was evaluated across three oncology scenarios using a simulation-estimation approach: (scen1) typical dose-escalation testing six dose levels (n = 21); (scen2) small dose-escalation testing two dose levels (n = 9); (scen3) expansion cohorts at one dose level (n = 6-140). True ΔΔQTc effects ranged from 3 ms ("no effect") to 20 ms ("large effect"). Performance was assessed based on the upper limit of the ΔQTc two-sided 90% CI against a threshold of 10 or 20 ms.

RESULTS

The performance against the 10 ms threshold was limited based on C-QTc data from typical dose escalation (scen1) and acceptable performance was observed only for relatively large expansions (n ≥ 45; scen3). Performance against the 20 ms threshold was acceptable based on C-QTc data from a typical dose escalation (scen1) or dose expansion cohort n > 10 (scen3). In general, pooling C-QTc data from dose escalation and expansion cohorts substantially improved the performance and reduced the ΔQTc 90% CI width.

CONCLUSION

C-QTc performance appeared limited using a 10 ms threshold, but acceptable against a 20 ms threshold. Selection of threshold may be informed by the benefit-risk balance in a specific disease area. Acceptable precision (i.e., confidence intervals) of the estimated ΔQTc, regardless of its magnitude, can be facilitated by pooling data from dose escalation and expansion cohorts.

Population exposure-efficacy and exposure-safety analyses for rucaparib in patients with recurrent ovarian carcinoma from Study 10 and ARIEL2

OBJECTIVE

To evaluate correlations between rucaparib exposure and selected efficacy and safety endpoints in patients with recurrent ovarian carcinoma using pooled data from Study 10 and ARIEL2.

METHODS

Efficacy analyses were limited to patients with carcinomas harboring a deleterious BRCA1 or BRCA2 mutation who had received ≥2 prior lines of chemotherapy. Safety was evaluated in all patients who received ≥1 rucaparib dose. Steady-state daily area under the concentration-time curve (AUCss) and maximum concentration (Cmax,ss) for rucaparib were calculated for each patient and averaged by actual dose received over time (AUCavg,ss and Cmax,avg,ss) using a previously developed population pharmacokinetic model.

RESULTS

Rucaparib exposure was dose-proportional and not associated with baseline patient weight. In the exposure-efficacy analyses (n = 121), AUCavg,ss was positively associated with independent radiology review-assessed RECIST response in the subgroup of patients with platinum-sensitive recurrent disease (n = 75, p = 0.017). In the exposure-safety analyses (n = 393, 40 mg once daily to 840 mg twice daily [BID] starting doses), most patients received a 600 mg BID rucaparib starting dose, with 27% and 21% receiving 1 or ≥2 dose reductions, respectively. Cmax,ss was significantly correlated with grade ≥2 serum creatinine increase, grade ≥3 alanine transaminase/aspartate transaminase increase, platelet decrease, fatigue/asthenia, and maximal hemoglobin decrease (p < 0.05).

CONCLUSION

The exposure-response analyses provide support for the approved starting dose of rucaparib 600 mg BID for maximum clinical benefit with subsequent dose modification only following the occurrence of a treatment-emergent adverse event in patients with BRCA-mutated recurrent ovarian carcinoma.

Exposure-response modeling of the effect of glasdegib on cardiac repolarization in patients with cancer

PURPOSE

To characterize the effect of glasdegib on cardiac repolarization (QTc) in patients with advanced cancer.

METHODS

A concentration-QTc model was developed using data from two glasdegib single-agent, dose-escalation trials. Triplicate electrocardiogram was performed at pre-specified timepoints paired with pharmacokinetic blood collections after a single dose and at steady-state. Changes in QTc from baseline were predicted by model-based simulations at the clinical dose (100 mg QD) and in a supratherapeutic setting.

RESULTS

Glasdegib did not affect the heart rate, but had a positive effect on the corrected QT interval, described by a linear mixed-effects model with ΔQTcF (QTc using Fridericia's formula) as the dependent variable with glasdegib plasma concentrations from doses of 5-640 mg QD. The predicted mean QTcF change (upper bound of the 95% CI) was 5.30 (6.24) msec for the therapeutic 100-mg QD dose; at supratherapeutic concentrations (40% and 100% increase over the therapeutic C_max), it was 7.42 (8.74) and 12.09 (14.25) msec, respectively.

CONCLUSIONS

The relationship of glasdegib exposure and QTc was well characterized by the model. The effect of glasdegib on the QTc interval did not cross the threshold of clinical concern for an oncology drug.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT01286467 and NCT00953758.

QT Prolongation Risk Assessment in Oncology: Lessons Learned From Small-Molecule New Drug Applications Approved During 2011-2019

The International Conference on Harmonisation (ICH) E14 guidance provides recommendations to assess the potential of a drug to delay cardiac repolarization (QT prolongation), including general guidelines for cases in which a conventional thorough QT study (TQT) might not be feasible. These guidelines have been updated through the ICH question-and-answer process, with the last revision in 2015. We conducted a comprehensive analysis of QT prolongation evaluation of small-molecule new drug applications (NDAs) approved in oncology between 2011 and 2019 to extract learning experience. The following information was analysed: (1) methods to assess QT prolongation, (2) electrocardiogram data collection, (3) QT-related label language, and (4) postmarketing requirements. Overall, every NDA included a QT assessment. The concentration-QTc modeling approach (studies in which QT was not the primary objective) was the most common approach (59%), followed by the TQT and the dedicated QT studies (20% and 21%, respectively). The quality and quantity of the QT assessments were different across NDAs, which suggested relatively large flexibility in the designs and approaches to characterizing QT liability. The QT-related label language reflected the QT results, but also the safety events and the study design limitations because of the oncology settings. There was no delay in approval because of less robust QTc studies as long as the benefit-to-risk ratio of the drug was acceptable, and the implications were reflected in the label. This work offers a structured understanding of the QT evaluation criteria by the Food and Drug Administration and can assist in planning QT prolongation assessments in oncology settings.

Evaluation of Cardiac Repolarization in the Randomized Phase 2 Study of Intermediate- or High-Risk Smoldering Multiple Myeloma Patients Treated with Daratumumab Monotherapy

Introduction

Daratumumab is a CD38-targeting monoclonal antibody that has demonstrated clinical benefit for multiple myeloma. Daratumumab inhibition of CD38, which is expressed on immune cell populations and cardiomyocytes, could potentially affect cardiac function. This QTc substudy of the phase 2 CENTAURUS study investigated the potential effect of intravenous daratumumab monotherapy on QTc prolongation and other electrocardiogram (ECG) parameters, including concentration-QTc effect modeling.

Methods

Patients had intermediate- or high-risk smoldering multiple myeloma. Patients with QT interval corrected by Fridericia’s formula (QTcF) > 470 ms, QRS interval ≥ 110 ms, or PR interval ≥ 200 ms were excluded. Triplicate ECGs were collected at screening, Dose 1, and Dose 8. Analyses of on-treatment ECGs were conducted with a time-matched baseline (primary analysis). By time-point, pharmacokinetic-pharmacodynamic (PK/PD), and outlier analyses were conducted.

Results

Of 123 patients in CENTAURUS, 31 were enrolled in the QTc substudy. Daratumumab produced a small increase in heart rate (5–12 beats per minute) of unclear significance. There was a small but clinically insignificant effect on QTc, as measured by both time-matched time-point and PK/PD analyses. The primary analysis demonstrated a maximum mean increase in QTcF of 9.1 ms (90% 2-sided upper confidence interval [CI], 14.1 ms). The primary PK/PD analysis predicted a maximum QTcF increase of 8.5 ms (90% 2-sided upper CI, 13.5 ms). No patient had an abnormal U wave, a new QTcF > 500 ms, or > 60 ms change from baseline for QTcF.

Conclusion

Analysis of ECG intervals and concentration-QTc relationships showed a small but clinically insignificant effect of daratumumab.

Trial Registration

ClinicalTrials.gov Identifier: NCT02316106.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-020-01601-w.

Clinical and Model-Based Evaluation of the Effect of Glasdegib on Cardiac Repolarization From a Randomized Thorough QT Study

Glasdegib is a potent, selective oral inhibitor of the Hedgehog signaling pathway. This phase 1 double‐blind thorough QT study (NCT03162900) evaluated the effects of glasdegib on QTc interval. The study enrolled 36 healthy volunteers to receive a single dose of 150 mg glasdegib (representing a therapeutic dose), 300 mg glasdegib (representing a supratherapeutic dose), 400 mg moxifloxacin (positive control), or placebo under fasted conditions. The study demonstrated that therapeutic and supratherapeutic doses of glasdegib had no significant effect on QTc interval; the upper bound of the 2‐sided 90% confidence intervals (CIs) for all time‐matched least‐squares mean differences in QT interval corrected using Fridericia's formula (QTcF) between glasdegib and placebo was below the prespecified criterion of 20 milliseconds (Food and Drug Administration correspondence reviewed and accepted). Based on an exposure–response analysis, glasdegib was determined not to have a meaningful effect on heart rate (change in RR interval). The mean (90%CI) model‐derived baseline and placebo‐adjusted QTcF at the average maximum observed concentration values corresponding to therapeutic and supratherapeutic glasdegib doses was 7.3 milliseconds (6.5‐8.2 milliseconds) and 13.7 milliseconds (12.0‐15.5 milliseconds), respectively. Together these results demonstrated that following therapeutic and supratherapeutic glasdegib dosing, the change in QTc from baseline was well below the 20‐millisecond threshold of clinical concern in oncology.

Phase 1 Study to Evaluate the Effect of the Investigational Anticancer Agent Sapanisertib on the QTc Interval in Patients With Advanced Solid Tumors

The aim of this phase 1 study was to determine the effects of sapanisertib on the heart rate–corrected QT (QTc) interval in patients with advanced solid tumors. Adult patients with advanced solid tumors were enrolled to receive a single sapanisertib 40‐mg dose. Blood samples for pharmacokinetic analysis were collected and electrocardiogram readings were recorded at baseline and up to 48 hours after dosing. Patients could continue to receive sapanisertib 30 mg once weekly in 28‐day cycles for up to 12 months. The primary objective was to characterize the effect of a single dose of sapanisertib (40 mg) on the QT interval. Secondary objectives were to evaluate safety, tolerability, and pharmacokinetics. Following a single sapanisertib 40‐mg dose in 44 patients, the maximum least squares mean (upper bound of 1‐sided 95% confidence interval) changes from time‐matched baseline were 7.1 milliseconds (11.4 milliseconds) for individual rate‐corrected QT interval at 24 hours after dosing, and 1.8 milliseconds (5.6 milliseconds) for Fridericia‐corrected QTc at 1 hour post‐dose. There was no sapanisertib plasma concentration‐dependent increase in the change from time‐matched baseline individual rate‐corrected QTc interval or Fridericia‐corrected QTc. The most common adverse events following sapanisertib 30 mg once‐weekly dosing were nausea (80%), fatigue (61%), vomiting (57%), and decreased appetite (45%). A single sapanisertib 40 mg dose did not produce clinically relevant effects on QTc interval in patients with advanced solid tumors. The safety profile of sapanisertib 30 mg once weekly was favorable, and no new safety signals were observed (NCT02197572, clinicaltrials.gov).

Assessment of the effect of erdafitinib on cardiac safety: analysis of ECGs and exposure-QTc in patients with advanced or refractory solid tumors

PURPOSE

To characterize the effect of erdafitinib on electrocardiogram (ECG) parameters and the relationship between erdafitinib plasma concentrations and QTc interval changes in patients with advanced or refractory solid tumors.

METHODS

Triplicate ECGs and continuous 12-lead Holter data were collected in the dose escalation part (Part 1) of the first-in-human study, with doses ranging from 0.5 to 12 mg. Triplicate ECG monitoring continued in Parts 2-4 where 2 dose regimens selected from Part 1 were expanded in prespecified tumor types. Analyses of ECG data included central tendency analyses, identification of categorical outliers and morphological assessment. A concentration-QTc analysis was conducted using a linear mixed-effect model based on extracted time matching Holter data.

RESULTS

Central tendency, categorical outlier, and ECG morphologic analyses from 187 patients revealed no clinically significant effect of erdafitinib on heart rate, atrioventricular conduction or cardiac depolarization (PR and QRS), and no effect on cardiac repolarization (QTc). Concentration-QTc analysis from 62 patients indicated that the slopes of relationship between total and free erdafitinib plasma concentrations and QTcI (mean exponent of 0.395) were estimated as - 0.00269 ms/(ng/mL) and - 1.138 ms/(ng/mL), respectively. The predicted change in QTcI at the observed geometric mean of total and free concentration at the highest therapeutic erdafitinib dose (9 mg daily) was < 10 ms at the upper bound of the two-sided 90% confidence interval.

CONCLUSIONS

ECG data and the concentration-QTc relationships demonstrate that erdafitinib does not prolong QTc interval and has no effects on cardiac repolarization or other ECG parameters. Clinical trial registration numbers NCT01703481, EudraCT: 2012-000697-34.

Model-Informed Drug Development for Ixazomib, an Oral Proteasome Inhibitor

Model-informed drug development (MIDD) was central to the development of the oral proteasome inhibitor ixazomib, facilitating internal decisions (switch from body surface area (BSA)-based to fixed dosing, inclusive phase III trials, portfolio prioritization of ixazomib-based combinations, phase III dose for maintenance treatment), regulatory review (model-informed QT analysis, benefit-risk of 4 mg dose), and product labeling (absolute bioavailability and intrinsic/extrinsic factors). This review discusses the impact of MIDD in enabling patient-centric therapeutic optimization during the development of ixazomib.

An open-label, multicenter, phase Ib study investigating the effect of apalutamide on ventricular repolarization in men with castration-resistant prostate cancer

PURPOSE

Phase Ib study evaluating the effect of apalutamide, at therapeutic exposure, on ventricular repolarization by applying time-matched pharmacokinetics and electrocardiography (ECG) in patients with castration-resistant prostate cancer. Safety of daily apalutamide was also assessed.

METHODS

Patients received 240 mg oral apalutamide daily. Time-matched ECGs were collected via continuous 12-lead Holter recording before apalutamide (Day - 1) and on Days 1 and 57 (Cycle 3 Day 1). Pharmacokinetics of apalutamide were assessed on Days 1 and 57 at matched time points of ECG collection. QT interval was corrected for heart rate using Fridericia correction (QTcF). The primary endpoint was the maximum mean change in QTcF (ΔQTcF) from baseline to Cycle 3 Day 1 (steady state). Secondary endpoints were the effect of apalutamide on other ECG parameters, pharmacokinetics of apalutamide and its active metabolite, relationship between plasma concentrations of apalutamide and QTcF, and safety.

RESULTS

Forty-five men were enrolled; 82% received treatment for ≥ 3 months. At steady state, the maximum ΔQTcF was 12.4 ms and the upper bound of its associated 90% CI was 16.0 ms. No clinically meaningful effects of apalutamide were reported for heart rate or other ECG parameters. A concentration-dependent increase in QTcF was observed for apalutamide. Most adverse events (AEs) (73%) were grade 1-2 in severity. No patients discontinued due to QTc prolongation or AEs.

CONCLUSION

The effect of apalutamide on QTc prolongation was modest and does not produce a clinically meaningful effect on ventricular repolarization. The AE profile was consistent with other studies of apalutamide.

Strategic and Statistical Considerations on the QT Assessment of Volasertib

Volasertib is a selective cell cycle kinase inhibitor that induces mitotic arrest and apoptosis by targeting Polo-like kinase (Plk). A potential for prolonged QT intervals was indicated with volasertib in preclinical studies and preliminary clinical data. As a result, electrocardiograms (ECGs) have been collected in all volasertib clinical trials to monitor potential cardiac effects. This article describes strategic and statistical methods prospectively planned to perform an integrated analysis of ECG data from available trials to evaluate volasertib's effect on cardiac repolarization, as reflected by changes in the duration of QT interval and other ECG-related endpoints. Methods to effectively cope with heterogeneity between trials (ie, differences in study designs) are discussed. These strategies may be useful for other investigational drugs for which QT risk assessment is required, but a thorough QT/QTc trial is not feasible, resulting in the need for an alternative approach. Volasertib therapy relevantly prolonged adjusted mean QTcF change from administration baseline following the first and subsequent infusions. The integrated analysis revealed that the volasertib effects on the mean QTc changes from baseline were transient and had resolved at 24 hours after start of the first infusion. There was no evidence for a long-term impact on the QTcF interval following multiple infusions with volasertib.

Effect of ulixertinib, a novel ERK1/2 inhibitor, on the QT/QTc interval in patients with advanced solid tumor malignancies

PURPOSE

The aim of this analysis was to investigate the potential for ulixertinib (BVD-523) to prolong cardiac repolarization. The mean prolongation of the corrected QT (QTc) interval was predicted at the mean maximum drug concentrations of the recommended phase 2 dose (RP2D; 600 mg BID) and of higher concentrations. In addition, the effect of ulixertinib on other quantitative ECG parameters was assessed.

METHODS

In a two-part, phase 1, open-label study in adults with advanced solid tumors, 105 patients [24 in Part 1 (dose escalation) and 81 in Part 2 (cohort expansion)] were included in a QT prolongation analysis. Electrocardiograms (ECGs) extracted from 12-lead Holter monitors, along with time-matched pharmacokinetic blood samples, were collected over 12 h on cycle 1 day 1 and cycle 1 day 15 and analyzed by a core ECG laboratory.

RESULTS

A small increase in heart rate was observed on both study days (up to 5.6 bpm on day 1 and up to 7 bpm on day 15). The estimated mean changes from baseline in the study-specific QTc interval (QTcSS), at the ulixertinib Cmax, were - 0.529 ms (90% CI - 6.621, 5.562) on day 1 and - 9.202 ms (90% CI - 22.505, 4.101) on day 15. The concentration: QTc regression slopes were mildly positive but not statistically significant [0.53 (90% CI - 1.343, 2.412) and 1.16 (90% CI - 1.732, 4.042) ms per µg/mL for days 1 and 15, respectively]. Ulixertinib had no meaningful effect on PR or QRS intervals.

CONCLUSIONS

Ulixertinib administered to patients with solid tumors at clinically relevant doses has a low risk for QT/QTc prolongation or any other effects on ECG parameters.

REGISTRATION

The study is registered at Clinicaltrials.gov (NCT01781429) and was sponsored by BioMed Valley Discoveries.

Effect of alisertib, an investigational aurora a kinase inhibitor on the QTc interval in patients with advanced malignancies

Aims A primary objective of this study was to investigate the effect of single and multiple doses of alisertib, an investigational Aurora A kinase inhibitor, on the QTc interval in patients with advanced malignancies. The dose regimen used was the maximum tolerated dose which was also the recommended phase 3 dose (50 mg twice daily [BID] for 7 days in 21-day cycles). Methods Patients received a single dose of alisertib (50 mg) on Day 1, and multiple doses of alisertib (50 mg BID) on Days 4 through to the morning of Day 10 of the first cycle of treatment. Triplicate ECGs were collected at intervals over 10 to 24 h via Holter recorders on Days −1 (baseline), 1 and 10. Changes from time-matched baseline values were calculated for various ECG parameters including QTc, heart rate, PR and QRS intervals. Alisertib pharmacokinetics were also assessed during the study, and an exposure-QTc analysis was conducted. Results Fifty patients were included in the QTc analysis. The upper bounds of the 95% confidence intervals for changes from time-matched baseline QTcF and QTcI values were <5 ms across all study days, time points and correction methods. Alisertib did not produce clinically relevant effects on heart rate, PR or QRS intervals. There was no evidence of a concentration-QTc effect relationship. Conclusions Alisertib does not cause QTc prolongation and can be concluded to not have any clinically relevant effects on cardiac repolarization or ECG parameters at the single agent maximum tolerated dose of 50 mg BID.

Phase 1 study of cardiac safety of TAS-102 in patients with advanced solid tumors

Purpose

TAS-102 is a novel oral agent combining the antineoplastic thymidine-based nucleoside analogue, trifluridine, and the thymidine phosphorylase inhibitor, tipiracil (molar ratio 1:0.5). TAS-102 has shown good activity in refractory metastatic colorectal cancer with acceptable safety. No QT prolongation was seen in clinical studies. This study aimed to investigate TAS-102 cardiac safety for regulatory requirements.

Methods

This was a phase 1, non-randomized study in adults with advanced solid tumors. Intensive QT assessments were conducted at baseline, placebo, and following single and multiple doses of TAS-102 during a 28-day cycle.

Results

Following single- and multiple-dose administration (N = 30), the upper bounds of the one-sided 95 % confidence intervals for the difference between TAS-102 and placebo in time-matched baseline-subtracted 12-lead Holter QT intervals did not exceed 20 ms at any prespecified time point. One patient had a change from baseline in QTcI interval ≥60 ms, and one patient had a QTcI interval >500 ms following multiple-dose TAS-102 administration. No patient had an uncorrected QT, QTcF, or QTcB interval >500 ms. Based on the exposure-response analysis between TAS-102 plasma concentrations and the placebo-adjusted QTc intervals, none of the upper bounds of the one-sided 95 % prediction intervals exceeded 20 ms. There were no significant morphological changes for T or U waves. No cardiovascular AEs were reported in cycle 1. Across all cycles, no patient experienced an AE of ventricular tachycardia, ventricular fibrillation, syncope, or seizure.

Conclusions

There was no clinically relevant relationship between TAS-102 plasma concentrations and QTc interval; TAS-102 had no clinically relevant effects on cardiac repolarization.

Clinical trials

ClinicalTrials.gov study number: NCT01867879.

PK/PD Modelling of the QT Interval: a Step Towards Defining the Translational Relationship Between In Vitro, Awake Beagle Dogs, and Humans

Inhibiting the human ether-a-go-go-related gene (hERG)-encoded potassium ion channel is positively correlated with QT-interval prolongation in vivo, which is considered a risk factor for the occurrence of Torsades de Pointes (TdP). A pharmacokinetic/pharmacodynamic model was developed for four compounds that reached the clinic, to relate drug-induced QT-interval change in awake dogs and humans and to derive a translational scaling factor a 1. Overall, dogs were more sensitive than humans to QT-interval change, an a 1 of 1.5 was found, and a 10% current inhibition in vitro produced a higher percent QT-interval change in dogs as compared to humans. The QT-interval changes in dogs were predictive for humans. In vitro and in vivo information could reliably describe the effects in humans. Robust translational knowledge is likely to reduce the need for expensive thorough QT studies; therefore, expanding this work to more compounds is recommended.

Electrocardiographic effects of class 1 selective histone deacetylase inhibitor romidepsin

Romidepsin is a histone deacetylase inhibitor approved by the FDA for the treatment of patients with cutaneous or peripheral T-cell lymphoma who have received prior systemic therapy. The objective of this analysis was to evaluate the potential QTc effects of romidepsin. Patients with advanced malignancy received 4-h infusions of 14 mg/m² romidepsin on days 1, 8, and 15 of a 28-day cycle. In cycle 2, a subset of patients received 1-h infusions of 8–12 mg/m² romidepsin. Patients were administered antiemetics before each romidepsin dose and electrolyte supplementation as needed. Electrocardiogram readings were performed prior to antiemetic administration, prior to romidepsin administration, and at specified time points over the subsequent 24 h. Romidepsin exposure and heart rate were also assessed. In the electrocardiogram-evaluable population, 26 patients received romidepsin at 14 mg/m² over 4 h. The maximum mean increases from the preantiemetic baseline for QTcF and heart rate were 10.1 msec (upper 90% CI, 14.5 msec) and 18.2 beats per minute, respectively. No patient in this study had an absolute QTcF value >450 msec and only one patient had an increase from the preantiemetic baseline of >60 msec. There was a mild reduction in the PR interval and no meaningful changes in the QRS interval. Despite the use of QT-prolonging antiemetics, treatment with romidepsin did not markedly prolong the QTc interval through 24 h. Increases in calculated QTc may have been exaggerated as a consequence of transient increases in heart rate.

Effect of axitinib on the QT interval in healthy volunteers

PURPOSE

Axitinib is a potent and selective inhibitor of vascular endothelial growth factor receptors 1-3, approved for second-line treatment of advanced renal cell carcinoma (RCC). Preclinical studies did not indicate potential for axitinib-induced delayed cardiac repolarization.

METHODS

The effect of axitinib on corrected QT (QTc) prolongation was evaluated with one-stage concentration-QTc response modeling using data from a definitive randomized crossover QT phase I study in healthy volunteers administered one single 5-mg axitinib dose alone or in the presence of steady-state ketoconazole (400 mg once daily).

RESULTS

Axitinib and ketoconazole had opposite effects on heart rate: Axitinib lowered it, ketoconazole raised it. The final analysis showed a flat relationship between QTc and axitinib concentration (slope -0.0314 ms·mL/ng) for axitinib alone. Mean highest placebo-matched change from baseline in QTc was -3.0 [90 % confidence interval (CI) -5.4, -0.6] ms. At supratherapeutic axitinib exposures achieved with potent cytochrome P450 3A4/5 inhibition by ketoconazole, the model predicted mean QTc change of 6.5 (90 % CI 4.4-8.5) ms. The slope population mean estimate was -0.331 (95 % CI -0.860, 0.198) ms·mL/µg for ketoconazole alone and 0.0725 (0.0445-0.1005) ms·mL/ng for axitinib in the presence of ketoconazole. The results were then compared with those obtained based on more widely used Fridericia's, Bazett's, and study-specific correction methods.

CONCLUSIONS

Since axitinib plasma concentrations observed in this study exceeded the range of concentrations observed in patients with RCC at the highest approved clinical dose (10 mg twice daily), axitinib was not associated with clinically significant QTc prolongation in target populations.

Clinical ECG Assessment

With the adoption of the ICH E14 guidance, the thorough QT/QTc (TQT) study has become the focus of clinical assessment of an NCE's effects on ECG parameters. The TQT study is used as a guide to the liability of a drug to cause proarrhythmias on the basis of delayed cardiac repolarization. Around 300 TQT studies have been performed since 2005 and through interactions between sponsors and regulators, especially FDA's Interdisciplinary Review Team (IRT) for QT studies. These studies can today be performed more effectively and with great confidence in the generated data. This chapter will discuss technical features and the design and analysis of TQT studies, how assay sensitivity is demonstrated, and examples from recently conducted studies. ECG assessment for drugs that cannot be safely given to healthy volunteers is also addressed, and examples from studies in cancer patients and in healthy volunteers with tyrosine kinase inhibitors are discussed. The TQT study is resource intensive and designed to solely evaluate whether an NCE prolongs the QTc interval. If data with similar confidence can be generated from other studies that are routinely performed as part of the clinical development, this would represent a more optimal use of human resources. Methods and approaches to increase the confidence in ECG data derived from "early QT assessment" in single-ascending/multiple-ascending dose studies are therefore discussed, and a path toward replacing the TQT study using these approaches will be outlined.

Evaluation of Assay Sensitivity and the Concentration-Effect Relationship of Moxifloxacin in a QT/QTc Study in Japan

To investigate the potential for a QT/QTc study in Japan, a randomized, single-blind, crossover study was conducted using moxifloxacin in 64 healthy Japanese male volunteers. A 12-lead Holter electrocardiogram was used to test a relatively small population at each of 4 incorporated clinical research units to confirm the assay sensitivity and efficiency. Moxifloxacin (400 mg) significantly prolonged QT intervals, as previously reported, with small variations in this study. In addition, the placebo-adjusted mean QTcF changes from predose baseline showed that the lower bounds of the 1-sided 95% confidence interval exceeded 5 milliseconds at all of the clinical research units. The data also indicated statistically significant concentration-QT relationships in 3 of the 4 research units by separate analysis. These findings and the small amount of variability in this study suggest the feasibility of conducting a high-quality QT/QTc study in Japan.

Optimizing oncology therapeutics through quantitative translational and clinical pharmacology: challenges and opportunities

Despite advances in biomedical research that have deepened our understanding of cancer hallmarks, resulting in the discovery and development of targeted therapies, the success rates of oncology drug development remain low. Opportunities remain for objective dose selection informed by exposure-response understanding to optimize the benefit-risk balance of novel therapies for cancer patients. This review article discusses the principles and applications of modeling and simulation approaches across the lifecycle of development of oncology therapeutics. Illustrative examples are used to convey the value gained from integration of quantitative clinical pharmacology strategies from the preclinical-translational phase through confirmatory clinical evaluation of efficacy and safety.

Trastuzumab, in combination with carboplatin and docetaxel, does not prolong the QT interval of patients with HER2-positive metastatic or locally advanced inoperable solid tumors: results from a phase Ib study

Purpose

This study evaluated the potential effect of trastuzumab on the electrocardiogram (ECG) QT interval and assessed the potential pharmacokinetic interaction between trastuzumab and carboplatin. Here, we report the QT and safety results.

Methods

Patients with metastatic or inoperable HER2-positive solid tumors received docetaxel and carboplatin on Day 1 of each 3-week (q3w) cycle. Trastuzumab was administered intravenously, as an accelerated loading dose regimen, on Cycle 1, Day 2 and Cycle 1, Day 8, and then on Day 1 of each subsequent q3w cycle. ECG assessments were performed pre- and posttrastuzumab infusion in the first two cycles. Fridericia’s correction was applied to QT intervals (QTcF). Baseline-adjusted QTcF intervals (the change from baseline) and their 90 % confidence intervals (CIs) were calculated.

Results

The study enrolled 59 patients. At all time points, the 90 % CI upper bound for the mean baseline-adjusted QTcF was <10 ms. At steady-state serum trastuzumab concentrations, the mean baseline-adjusted QTcF interval was −8.4 ms (90 % CI −11.1, −5.7). No patient exhibited an absolute QTcF interval of >480 ms. No relationship was observed between trastuzumab concentration and baseline-adjusted QTcF interval. At data cutoff, 84.5 % of patients had experienced grade ≥3 adverse events, the most common of which were hematologic and as expected. Left ventricular ejection fraction remained ≥45 % in all patients during the study.

Conclusions

The results suggest that trastuzumab had no clinically relevant effect on QTcF interval. The safety profile of trastuzumab in combination with carboplatin and docetaxel was consistent with the known safety profile of this combination.

Electronic supplementary material

The online version of this article (doi:10.1007/s00280-014-2603-9) contains supplementary material, which is available to authorized users.

An open-label study to investigate the cardiac safety profile of cabazitaxel in patients with advanced solid tumors

PURPOSE

This study assessed the cardiovascular safety of cabazitaxel, based on thorough evaluation of QT and non-QT variables, and the relationship between pharmacokinetic and pharmacodynamic electrocardiographic (ECG) profiles and the occurrence of Grade ≥3 cardiovascular adverse events.

METHODS

Patients with advanced solid tumors were treated with cabazitaxel 25 mg/m(2) every 3 weeks. Digital ECG recordings were obtained during Cycle 1 over 24 h after dosing. The primary end point was effect of cabazitaxel on QT interval corrected by the Fridericia formula (QTcF). Secondary end points were additional ECG parameters (QT, PR and QRS intervals, and heart rate), plasma pharmacokinetics of cabazitaxel and overall clinical safety.

RESULTS

The pharmacodynamic (ECG) population included 94 patients. In 63 patients with a full 24-h ECG evaluation, the maximum upper bound of 90 % confidence interval (CI) for mean QTcF change from baseline was 7.46 ms (mean 4.8 ms), occurring at 1 h 30 min post-infusion. The slope of QTcF change from baseline versus cabazitaxel concentration was slightly negative (-0.012 [95 % CI -0.017; -0.008], equivalent to a 1.2 ms decrease per 100 ng/mL increase in cabazitaxel concentration). For non-QT variables, no effect was noted. No Grade ≥3 cardiac adverse events were observed; Grade ≥3 hypotension and lymphocele occurred in two patients and one patient, respectively.

CONCLUSION

These results suggest that cabazitaxel has no clinically significant cardiovascular adverse effects in patients with advanced solid tumors.

A randomized, double-blind, placebo-controlled study to assess QTc interval prolongation of standard dose aflibercept in cancer patients treated with docetaxel

: The effect of repeated doses of aflibercept on ventricular repolarization in cancer patients was evaluated in an intensive electrocardiogram trial. This randomized, placebo-controlled, double-blind trial was conducted in 87 treated solid tumor patients. Treatment was with 6 mg/kg aflibercept, 1-hour intravenous (n = 43), or placebo (n = 44), combined with ≤75 mg/m docetaxel, every 3 weeks. Electrocardiograms were collected for 6 hours posttreatment using digital 12-lead Holter recorders, at day 1, in cycles 1 and 3. Free and vascular endothelial growth factor-bound aflibercept concentrations were assessed at similar time points. Eighty-four patients (43 placebo and 41 aflibercept) were evaluable for QT interval, Fridericia correction (QTcF) at cycle 1 and 59 (31 placebo and 28 aflibercept) at cycle 3. During cycle 3, from 30 minutes to 6 hours after the start of aflibercept, the maximum observed upper limit of the QTcF 90% confidence interval was 16 ms, for a mean of 8.4 ms. QTcF prolongation above 480 ms and 60 ms above baseline was observed in 1 aflibercept patient (2%). The slope of the relationship between free aflibercept concentration and QTcF was 0.048 (95% confidence interval, 0.013-0.082), corresponding to a 5-ms increase per 100 µg/mL increase in concentration. These results exclude a clinically important effect of aflibercept on ventricular repolarization.

Daily dosing of vismodegib to steady state does not prolong the QTc interval in healthy volunteers

INTRODUCTION

Vismodegib was assessed as being of low risk for QT interval prolongation based on prior nonclinical and clinical experience. A dedicated study was conducted to further assess the potential for vismodegib to prolong the QTc interval.

METHODS AND RESULTS

Given the nonlinear pharmacokinetics of vismodegib, a thorough QTc study as is typically designed was not possible, and an innovative design was employed. This dedicated QTc study was powered to exclude a 20-millisecond change from the baseline QTc interval. The subjects were administered daily oral 150 mg of vismodegib for 7 days, or a single dose of 400 mg of moxifloxacin, with corresponding matching placebos. The upper limits of the 90% confidence intervals for the difference in ΔQTcF between vismodegib and placebo at steady state were <20 milliseconds at all timepoints with a maximum of 10 milliseconds at 12 hours postdose. Exposure-response analysis yielded an estimated slope equal to 0.11 ms/μM, which was not statistically significant. After a single dose of moxifloxacin was administered, the lower limits of the 90% confidence interval of the difference in ΔQTcF between moxifloxacin and placebo were >5 milliseconds from 1-12 hours postdose, thereby establishing assay sensitivity.

CONCLUSIONS

There was no effect of vismodegib on the QTc interval when dosed daily at 150 mg to steady state.

Effects of Trastuzumab Emtansine (T-DM1) on QT Interval and Safety of Pertuzumab Plus T-DM1 in Patients With Previously Treated Human Epidermal Growth Factor Receptor 2-Positive Metastatic Breast Cancer

Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate in development for human epidermal growth factor receptor 2 (HER2)-positive cancer. Drugs in development are generally tested for their effects on QT interval, prolongation of which is associated with the potentially fatal arrhythmia torsades de pointes. In addition, an association between left ventricular dysfunction and other HER2-directed agents has been documented. This multicenter, phase 2 study, TDM4688g, assessed the safety and pharmacokinetic characteristics of T-DM1 (3.6 mg/kg every 3 weeks) in patients with previously treated HER2-positive metastatic breast cancer, and the safety of pertuzumab plus T-DM1, an anti-HER2 extracellular domain antibody, in patients with early disease progression on T-DM1 alone. The primary end point was the change in QTc interval from baseline to each postbaseline time point, adjusted for heart rate using Fridericia's correction. T-DM1 had no clinically relevant effect on QTc interval. The observed upper limit of the one-sided 95% confidence interval was below the 10-millisecond threshold of safety concern. The safety and efficacy of single-agent T-DM1 was consistent with that observed in previous studies. Pertuzumab plus T-DM1 was generally well tolerated with no new safety signals. These results support further investigation of T-DM1 as a single agent and with pertuzumab.

Electrocardiographic assessment for therapeutic proteins--scientific discussion

Electrocardiographic monitoring is an integral component of the clinical assessment of cardiac safety of all compounds in development. The International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use E14 guideline recommends a dedicated study to evaluate drug-induced effects on cardiac repolarization ("thorough QT/QTc study"). There has been limited published information on QT interval changes secondary to therapeutic proteins; however, in theory, biologic therapies may affect cardiac electrical activity either directly or indirectly. This article summarizes scientific discussions of members of the Cardiac Safety Research Consortium and includes possible approaches to consider for the clinical evaluation of drug-induced QT prolongation in development programs of therapeutic proteins.

Prolonged QTc interval in cancer therapeutic drug development: defining arrhythmic risk in malignancy

Anticancer therapy drug development is an arduous task, taking 10 to 15 years to complete, requiring approximately 1 billion dollars, and rarely leads to Food and Drug Administration approval. Methods to predict unacceptable drug-induced toxicity, such as a prolonged QTc interval/risk of torsade de pointes, should be highly informative to quickly and accurately determine if further resources should be allocated in the continued development of an agent. Expert consensus has established guidelines to ascertain the ability of a new drug to prolong the QTc interval. Although QTc measurement is the best way to assess arrhythmic risk, it is imprecise for a variety of reasons. In addition, oncology patients have multiple risk factors for QTc prolongation at baseline. Competing interests involved in assessing arrhythmic risk of a new oncology agent include inability to precisely follow published guidelines for QTc assessment, patients' concomitant medical problems interfering with drug assessment and therefore clinical trial enrollment, patient safety concerns, general public safety concerns regarding toxicity assessment, need for discovery of more curative drug therapies, and individual patient perception of therapeutic risk vs benefit. Oncology patients are concerned about access to experimental agents, as well as early abandonment of a potentially beneficial agent because of a low estimated risk of toxicity, even if the event is catastrophic. We review the issues involved in evaluating the QTc interval-prolonging risk in new anticancer agents.

The thorough QT/QTc study 4 years after the implementation of the ICH E14 guidance

The ICH E14 guidance on how to clinically assess a new drug's liability to prolong the QT interval was adopted in May 2005. A centre-piece of the guidance was the establishment of one single trial, the 'thorough QT/QTc study', intended to confidently identify drugs that may cause QT prolongation. Initially perceived as a great challenge, this study has rapidly become a standard component of all clinical development programs for new molecular entities. The study is normally conducted in healthy volunteers, includes both a positive and a negative (placebo) control and is stringently powered to exclude an effect on the QTc interval exceeding 10 ms. The E14 guidance was intentionally not very prescriptive and allowed sponsors and service providers to explore new methodologies. This has allowed for a rapid development of new methods during the first years after the guidance's implementation, such as computer-assisted algorithms for QT measurements. Regulators have worked in close collaboration with pharmaceutical industry to set standards for the design and conduct of the 'thorough QT/QTc study', which therefore has evolved as a key component of cardiac safety assessment of new drugs. This paper summarizes the requirements on the 'thorough QT/QTc study' with emphasis on the standard that has evolved based on interactions between regulators and sponsors and the experience from a large number of completed studies.

Evaluation and management of cardiac safety using the electrocardiogram in oncology clinical trials: focus on cardiac repolarization (QTc interval)

Non-antiarrhythmic drugs have been reported to prolong the QTc interval and induce potentially fatal ventricular tachyarrhythmias. An increasing number of drugs that are used for treating malignancies are no exception. Therefore, both oncologists and regulators expect sponsors of oncology drugs to evaluate, during the development of the drugs, their effects on the electrocardiogram (ECG), particularly on the QTc interval. In the case of agents that cannot be administered to healthy volunteers, the primary approach is to carry out an intense ECG evaluation, employing robust ECG recordings, during early-phase clinical trials, together with characterization of the concentration-QTc interval relationship, and follow this up with an appropriate intensity of ECG monitoring in the later phases of development. This article describes the broad principles of these approaches, including recommendations for exclusion criteria (relative to baseline QTc interval and to cardiac comorbidity); it also describes methods for conducting ECG monitoring and a proposed scheme for the management of any QTc-related effects that may emerge.

Update on the evaluation of a new drug for effects on cardiac repolarization in humans: issues in early drug development

Following reports of death from cardiac arrhythmias with drugs like terfenadine and cisapride, the International Conference for Harmonization formulated a guidance (E14) document. This specifies that all new drugs must undergo a 'thorough QT/QTc' (TQT) study to detect drug-induced QT prolongation, a surrogate marker of ventricular tachycardia, especially torsades de pointes (TdPs). With better understanding of data from several completed TQT studies, regulatory requirements have undergone some changes since the E14 guidance was implemented in October 2005. This article reviews the implications of the E14 guidance and the changes in its interpretation including choice of baseline QT, demonstration of assay sensitivity, statistical analysis of the effect of new drug and positive control, and PK-PD modelling. Some issues like use of automated QT measurements remain unresolved. Pharmaceutical companies too are modifying Phase 1 studies to detect QTc liability early in order to save time and resources. After the E14 guidance, development of several drugs that prolong QTc by >5 ms is being abandoned by sponsors. However, all drugs that prolong the QT interval do not increase risk of TdP. Researchers in regulatory agencies, academia and industry are working to find better biomarkers of drug-induced TdP which could prevent many useful drugs from being prematurely abandoned. Drug-induced TdP is a rare occurrence. With fewer drugs that prolong QT interval reaching the licensing stage, knowing which of these drugs are torsadogenic is proving to be elusive. Thus, paradoxically, the effectiveness of the E14 guidance itself has made prospective validation of new biomarkers difficult.