ABSTRACT
Sitravatinib (MGCD516) is an orally available, small molecule, tyrosine kinase inhibitor that has been evaluated in patients with advanced solid tumors. Concentration-corrected QT interval (QTc; C-QTc) modeling was undertaken, using 767 matched concentration-ECG observations from 187 patients across two clinical studies in patients with advanced solid malignancies, across a dose range of 10-200 mg, via a linear mixed-effects (LME) model. The effect on heart rate (HR)-corrected QT interval via Fridericia's correction method (QTcF) at the steady-state maximum concentration (Cmax,ss) for the sitravatinib proposed therapeutic dosing regimen (100 mg malate once daily [q.d.]) without and with relevant intrinsic and extrinsic factors were predicted. No significant changes in HR from baseline were observed. Hysteresis between sitravatinib plasma concentration and change in QTcF from baseline (ΔQTcF) was not observed. There was no significant relationship between sitravatinib plasma concentration and ΔQTcF. The final C-QTc model predicted a mean (90% confidence interval [CI]) ΔQTcF of 3.92 (1.95-5.89) ms and 2.94 (0.23-6.10) ms at the proposed therapeutic dosing regimen in patients with normal organ function (best case scenario) and patients with hepatic impairment (worst-case scenario), respectively. The upper bounds of the 90% CIs were below the regulatory threshold of concern of 10 ms. The results of the described C-QTc analysis, along with corroborating results from nonclinical safety pharmacology studies, indicate that sitravatinib has a low risk of QTc interval prolongation at the proposed therapeutic dose of 100 mg malate q.d.
Subject(s)
Electrocardiography , Heart Rate , Neoplasms , Humans , Neoplasms/drug therapy , Heart Rate/drug effects , Male , Female , Middle Aged , Aged , Adult , Dose-Response Relationship, Drug , Long QT Syndrome/chemically induced , Long QT Syndrome/diagnosis , Models, Biological , Aged, 80 and over , Protein Kinase Inhibitors/adverse effects , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/pharmacokinetics , Young Adult , Antineoplastic Agents/adverse effects , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/pharmacokineticsABSTRACT
BACKGROUND AND OBJECTIVE: Checkpoint inhibitor therapy (CPI) has demonstrated survival benefits in urothelial carcinoma (UC); however, not all patients benefit from CPI due to resistance. Combining sitravatinib, a multitargeted receptor tyrosine kinase inhibitor of TYRO3, AXL, and MERTK (TAM) receptors and VEGFR2, with CPI may improve antitumor responses. Our objective was to assess the efficacy and safety of sitravatinib plus nivolumab in patients with advanced/metastatic UC. METHODS: The 516-003 trial (NCT03606174) is an open-label, multicohort phase 2 study evaluating sitravatinib plus nivolumab in patients with advanced/metastatic UC enrolled in eight cohorts depending on prior treatment with CPI, platinum-based chemotherapy (PBC), or antibody-drug conjugate (ADC). Overall, 244 patients were enrolled and treated with sitravatinib plus nivolumab (median follow-up 14.1-38.2 mo). Sitravatinib (free-base capsules 120 mg once daily [QD] or malate capsule 100 mg QD) plus nivolumab (240 mg every 2 wk/480 mg every 4 wk intravenously). KEY FINDINGS AND LIMITATIONS: The primary endpoint was objective response rate (ORR; RECIST v1.1). The secondary endpoints included progression-free survival (PFS) and safety. The Predictive probability design and confidence interval methods were used. Among patients previously treated with PBC, ORR, and median PFS were 32.1% and 3.9 mo in CPI-naïve patients (n = 53), 14.9% and 3.9 mo in CPI-refractory patients (n = 67), and 5.4% and 3.7 mo in CPI- and ADC-refractory patients (n = 56), respectively. Across all cohorts, grade 3 treatment-related adverse events (TRAEs) occurred in 51.2% patients and grade 4 in 3.3%, with one treatment-related death (cardiac failure). Immune-related adverse events occurred in 50.4% patients. TRAEs led to sitravatinib/nivolumab discontinuation in 6.1% patients. CONCLUSIONS AND CLINICAL IMPLICATIONS: Sitravatinib plus nivolumab demonstrated a manageable safety profile but did not result in clinically meaningful ORRs in patients with advanced/metastatic UC in the eight cohorts studied. PATIENT SUMMARY: In this study, the combination of two anticancer drugs, sitravatinib and nivolumab, resulted in manageable side effects but no meaningful responses in patients with bladder cancer.