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.

QT Prolongation in Cancer Patients

Background: QT prolongation and torsades de pointes pose a major concern for cardiologists and oncologists. Although cancer patients are suspected to have prolonged QT intervals, this has not been investigated in a large population. The purpose of this study was to analyze the QT interval distribution in a cancer population and compare it to a non-cancer population in the same institution. Methods: The study was a retrospective review of 82,410 ECGs performed in cancer patients (51.8% women and 48.2% men) and 775 ECGs performed in normal stem cell donors (47.9% women and 52.1% men) from January 2009 to December 2013 at the University of Texas MD Anderson Cancer Center. Pharmacy prescription data was also collected and analyzed during the same time period. Correction of the QT interval for the heart rate was performed using the Bazett and Fridericia formulas. Results: After QT correction for heart rate by the Fridericia formula (QTcF), the mean and 99% percentile QTc for cancer patients were 414 and 473 ms, respectively. These were significantly longer than the normal stem cell donors, 407 and 458 ms, p < 0.001, respectively. Among the cancer patients, the QTc was longer in the inpatient setting when compared to both outpatient and emergency center areas. The most commonly prescribed QT prolonging medications identified were ondansetron and methadone. Conclusion: Our study demonstrates significantly longer QTc intervals in cancer patients, especially in the inpatient setting. Frequently prescribed QT prolonging medications such as antiemetics and analgesics may have a causative role in QT prolongation seen in our cancer hospital.

Effect of small angiokinase inhibitor nintedanib (BIBF 1120) on QT interval in patients with previously untreated, advanced renal cell cancer in an open-label, phase II study

PURPOSE

Some targeted anticancer agents are associated with serious ventricular tachyarrhythmias, which may be predicted by electrocardiographic evaluation of drug-related QT prolongation. We studied the effects of nintedanib (BIBF 1120; an oral, triple angiokinase inhibitor targeting vascular endothelial growth factor, fibroblast growth factor, and platelet-derived growth factor receptors) on the QT interval in patients with renal cell carcinoma (RCC) participating in an open-label phase II trial.

METHODS

Treatment-naïve, adult patients with unresectable/metastatic, clear cell RCC received nintedanib 200 mg twice daily. QT intervals were evaluated at baseline (day -1), on day 1 (after the first dose), and on day 15 (steady state) by 12-lead electrocardiograms (ECGs) performed in triplicate. Pharmacokinetic sampling was also undertaken.

RESULTS

Among 64 evaluable patients, the upper limits of the 2-sided 90 % confidence intervals for the adjusted mean time-matched changes in QTcF interval (corrected for heart rate by Fridericia's method) from baseline to day 1 and 15 (primary ECG endpoint) were well below the regulatory threshold of 10 ms at all times. No relationship between nintedanib exposure and change from baseline in QTcF was seen. Nintedanib was generally well tolerated with no drug-related cardiovascular adverse events.

CONCLUSION

Nintedanib administered at 200 mg twice daily was not associated with clinically relevant QT prolongation.