Sunitinib in pancreatic neuroendocrine tumors: updated progression-free survival and final overall survival from a phase III randomized study.

BACKGROUND: In a phase III trial in patients with advanced, well-differentiated, progressive pancreatic neuroendocrine tumors, sunitinib 37.5 mg/day improved investigator-assessed progression-free survival (PFS) versus placebo (11.4 versus 5.5 months; HR, 0.42; P < 0.001). Here, we present PFS using retrospective blinded independent central review (BICR) and final median overall survival (OS), including an assessment highlighting the impact of patient crossover from placebo to sunitinib. PATIENTS AND METHODS: In this randomized, double-blind, placebo-controlled study, cross-sectional imaging from patients was evaluated retrospectively by blinded third-party radiologists using a two-reader, two-time-point lock, followed by a sequential locked-read, batch-mode paradigm. OS was summarized using the Kaplan-Meier method and Cox proportional hazards model. Crossover-adjusted OS effect was derived using rank-preserving structural failure time (RPSFT) analyses. RESULTS: Of 171 randomized patients (sunitinib, n = 86; placebo, n = 85), 160 (94%) had complete scan sets/time points. By BICR, median (95% confidence interval [CI]) PFS was 12.6 (11.1-20.6) months for sunitinib and 5.8 (3.8-7.2) months for placebo (HR, 0.32; 95% CI 0.18-0.55; P = 0.000015). Five years after study closure, median (95% CI) OS was 38.6 (25.6-56.4) months for sunitinib and 29.1 (16.4-36.8) months for placebo (HR, 0.73; 95% CI 0.50-1.06; P = 0.094), with 69% of placebo patients having crossed over to sunitinib. RPSFT analysis confirmed an OS benefit for sunitinib. CONCLUSIONS: BICR confirmed the doubling of PFS with sunitinib compared with placebo. Although the observed median OS improved by nearly 10 months, the effect estimate did not reach statistical significance, potentially due to crossover from placebo to sunitinib. TRIAL REGISTRATION NUMBER: NCT00428597.

Sunitinib in combination with gemcitabine for advanced solid tumours: a phase I dose-finding study.

BACKGROUND: This phase I, dose-finding study determined the maximum tolerated dose (MTD), safety, and pharmacokinetics of sunitinib plus gemcitabine in patients with advanced solid tumours. METHODS: Two schedules with sunitinib (25-50 mg per day) and IV gemcitabine (750-1250 mg m(-2)) in escalating doses were studied. First, patients received sunitinib on a 4-weeks-on-2-weeks-off schedule (Schedule 4/2) plus gemcitabine on days 1, 8, 22, and 29. Second, patients received sunitinib on a 2-weeks-on-1-week-off schedule (Schedule 2/1) plus gemcitabine on days 1 and 8. The primary endpoint was determination of MTD and tolerability. RESULTS: Forty-four patients received the combination (Schedule 4/2, n=8; Schedule 2/1, n=36). With no dose-limiting toxicities (DLTs) at maximum dose levels on Schedule 2/1, MTD was not reached. Grade 4 treatment-related AEs and laboratory abnormalities included cerebrovascular accident, hypertension, and pulmonary embolism (n=1 each), and neutropenia (n=3), thrombocytopenia and increased uric acid (both n=2), and lymphopenia (n=1). There were no clinically significant drug-drug interactions. Antitumor activity occurred across dose levels and tumour types. In poor-risk and/or high-grade renal cell carcinoma patients (n=12), 5 had partial responses and 7 stable disease ≥ 6 weeks. CONCLUSION: Sunitinib plus gemcitabine on Schedule 2/1 with growth factor support was well tolerated and safely administered at maximum doses of each drug, without significant drug-drug interactions.

Sunitinib, a receptor tyrosine kinase inhibitor, increases blood pressure in rats without associated changes in cardiac structure and function.

BACKGROUND: Sunitinib, a multi-tyrosine kinase inhibitor has demonstrated clinical activity in advanced renal cell carcinoma and imatinib-resistant/intolerant gastrointestinal stromal tumor. It has been associated with manageable hypertension and other unique toxicities. AIMS: Two nonclinical studies were conducted to determine if sunitinib has direct/indirect effects on cardiac structure/function that may be related to hypertension at clinically relevant exposures. MATERIALS & METHODS: Rats received once-daily vehicle or sunitinib 1 or 10 mg/kg/day (n = 10/group) orally for 4 weeks, followed by 2 weeks off treatment then a 2-week rechallenge. Blood pressure (BP) and heart rate (HR) were continuously acquired and echocardiograms were obtained weekly. Effects of sunitinib and its metabolite (0.003-0.3 µM) were also evaluated in guinea pig isolated Langendorff-perfused hearts (n = 4-6 hearts/group). RESULTS: Sunitinib 10 mg/kg/day produced significant (P < 0.05) hemodynamic changes: 24 h average BP increased during initial dosing/rechallenge, with rebound hypotension during the off-treatment period; 24 h average HR increased during the off-treatment period, and decreased during rechallenge; no changes in cardiac structure/function were observed. In guinea pig isolated hearts, neither sunitinib nor its metabolite had direct effects on contractility, HR or left ventricular pressure. DISCUSSION & CONCLUSION: These studies demonstrate that sunitinib/metabolite had no direct effects on cardiac function ex vivo, and that therapeutically relevant concentrations of sunitinib dosed on a "clinical schedule" increased BP in rats without adverse changes in cardiac structure/function.

Evaluation of the safety and pharmacokinetics of the multi-targeted receptor tyrosine kinase inhibitor sunitinib during embryo-fetal development in rats and rabbits.

BACKGROUND: Angiogenesis plays a key role in embryo-fetal development and, based on nonclinical safety data, the majority of vascular endothelial growth factor (VEGF)-targeted antiangiogenic agents used in cancer therapy are not recommended during pregnancy. We investigated the effects of sunitinib (an oral inhibitor of multiple receptor tyrosine kinases [RTKs] including VEGF-receptors) on embryo-fetal development. METHODS: Presumed-pregnant Sprague-Dawley rats and New Zealand White rabbits received repeated daily oral doses of sunitinib (0-30 mg/kg/day), during the major period of organogenesis. Clinical/physical examinations were performed throughout the gestation phase, and blood samples were collected to determine systemic exposure. Necropsy (including uterine examination) was performed on all animals and fetal morphology was examined. RESULTS: The no-observed-adverse-effect level was 1-5 mg/kg/day for maternal toxicity and 3 mg/kg/day for developmental toxicity in rats; 1 and 0.5 mg/kg/day, respectively, in rabbits. Embryo-fetal toxicity included decreases in the number of live fetuses and increases in the numbers of resorptions and post-implantation/complete litter losses; these were observed at doses of > or =5 mg/kg/day in rats and 5 mg/kg/day in rabbits. Malformations included fetal skeletal malformations (generally thoracic/lumbar vertebral alterations) in rats and cleft lip/palate in rabbits. These developmental effects were observed at approximately 5.5- (rats) and approximately 0.3-times (rabbits) the human systemic exposure at the approved sunitinib dose (50 mg/day). CONCLUSIONS: Similar effects have been reported with the prototype monoclonal antibody bevacizumab. As is typically observed for potent inhibitors of RTKs involved in angiogenesis, sunitinib was associated with embryo-fetal developmental toxicity in rats and rabbits at clinically relevant dose levels.