QTc interval prolongation with vascular endothelial growth factor receptor tyrosine kinase inhibitors.

BACKGROUND: Multi-targeted vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKIs) are known to cause cardiac toxicity, but the relative risk (RR) of QTc interval prolongation and serious arrhythmias associated with them are not reported. METHODS: We conducted a trial-level meta-analysis of randomised phase II and III trials comparing arms with and without a US Food and Drug Administration-approved VEGFR TKI (sunitinib, sorafenib, pazopanib, axitinib, vandetanib, cabozantinib, ponatinib and regorafenib). A total of 6548 patients from 18 trials were selected. Statistical analyses were conducted to calculate the summary incidence, RR and 95% CIs. RESULTS: The RR for all-grade and high-grade QTc prolongation for the TKI vs no TKI arms was 8.66 (95% CI 4.92-15.2, P<0.001) and 2.69 (95% CI 1.33-5.44, P=0.006), respectively, with most of the events being asymptomatic QTc prolongation. Respectively, 4.4% and 0.83% of patients exposed to VEGFR TKI had all-grade and high-grade QTc prolongation. On subgroup analysis, only sunitinib and vandetanib were associated with a statistically significant risk of QTc prolongation, with higher doses of vandetanib associated with a greater risk. The rate of serious arrhythmias including torsades de pointes did not seem to be higher with high-grade QTc prolongation. The risk of QTc prolongation was independent of the duration of therapy. CONCLUSIONS: In the largest study to date, we show that VEGFR TKI can be associated with QTc prolongation. Although most cases were of low clinical significance, it is unclear whether the same applies to patients treated off clinical trials.

Risk of infections in renal cell carcinoma (RCC) and non-RCC patients treated with mammalian target of rapamycin inhibitors.

BACKGROUND: Mammalian target of rapamycin (mTOR) inhibitors are used in a variety of malignancies. Infections have been reported with these drugs. We performed an up-to-date meta-analysis to further characterise the risk of infections in cancer patients treated with these agents. METHODS: Pubmed and oncology conferences' proceedings were searched for studies from January 1966 to June 2012. Studies were limited to phase II and III randomised controlled trials (RCTs) of everolimus or temsirolimus reporting on cancer patients with adequate safety profiles. Summary incidences, relative risks (RRs), and 95% confidence intervals (CIs) were calculated. RESULTS: A total of 3180 patients were included. The incidence of all-grade and high-grade infections due to mTOR inhibitors was 33.1% (95% CI, 24.5-43.0%) and 5.6% (95% CI, 3.8-8.3%), respectively. Compared with controls, the RR of all-grade and high-grade infections due to mTOR inhibitors was 2.00 (95% CI, 1.76-2.28, P<0.001) and 2.60 (95% CI, 1.54-4.41, P<0.001), respectively. Subgroup analysis found no difference in incidences or risks between everolimus and temsirolimus or between different tumour types (renal cell carcinoma (RCC) vs non-RCC). Infections included respiratory tract (61.7%), genitourinary (29.4%), skin/soft tissue (4.2%), and others (4.9%). CONCLUSION: Treatment with mTOR inhibitors is associated with a significant increase in risk of infections. Close monitoring for any signs of infections is warranted.

Incidence and risk of treatment-related mortality in cancer patients treated with the mammalian target of rapamycin inhibitors.

BACKGROUND: Inhibition of the mammalian target of rapamycin (mTOR) is an established treatment for multiple malignancies. We carried out an up-to-date meta-analysis to determine the risk of fatal adverse events (FAEs) in cancer patients treated with mTOR inhibitors. PATIENTS AND METHODS: PubMed, conferences and clinicaltrials.gov databases were searched for articles reported from January 1966 to June 2012. Eligible studies were limited to approved mTOR inhibitors (everolimus and temsirolimus) and reported on patients with cancer, randomized design and adequate safety profiles. Data extraction was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. RESULTS: In all, 3193 patients from eight randomized, controlled trials (RCTs) were included, 2236 from everolimus trials and 957 from temsirolimus trials. The relative risk (RR) of FAEs related to mTOR inhibitors use was 2.20 (95% CI, 1.25-3.90; P = 0.006) compared with control patients. On subgroup analysis, no difference in the rate of FAEs was found between everolimus and temsirolimus or between tumor types [renal cell carcinoma (RCC) versus non-RCC]. No evidence of publication bias was observed. CONCLUSION: The use of mTOR inhibitors is associated with a small but higher risk of FAEs compared to control patients. In the appropriate clinical scenario, the use of these drugs remains justified in their approved indications.