The oral, multitargeted tyrosine kinase inhibitor pazopanib (Votrient) is active and safe in patients with renal cell carcinoma and other neoplasms caused by von Hippel-Lindau disease, a phase 2 trial has found.
Eric Jonasch, MD, and his coinvestigators at the University of Texas MD Anderson Cancer Center, Houston, conducted the single-arm trial among 31 adult patients with clinical manifestations of von Hippel-Lindau disease, an autosomal dominant disorder that currently has no approved treatment.
All patients were treated with open-label pazopanib (800 mg daily with dose reductions permitted) for 24 weeks, with an option to continue thereafter. Pazopanib derives its antiangiogenic and antineoplastic activity from its selective inhibition of vascular endothelial growth factor receptors (VEGFR)–1, –2, and –3; c-KIT; and platelet-derived growth factor receptor (PDGFR). It is currently approved by the FDA for treatment of advanced renal cell carcinoma and advanced soft-tissue sarcoma.
The trial was stopped before attaining planned enrollment because accrual slowed and it met a prespecified toxicity stopping threshold, according to results reported in Lancet Oncology.
At a median follow-up of 12 months, 42% of patients overall had an objective response to pazopanib. By site, response was seen in 52% of 59 renal cell carcinomas, 53% of 17 pancreatic lesions (mainly serous cystadenomas), and 4% of 49 CNS hemangioblastomas; the median reduction in tumor size was 40.5%, 30.5%, and 13%, respectively.
Slightly more than half of patients, 52%, opted to stay on pazopanib after 24 weeks, with the longest duration being 60 months at data cutoff.
Some 13% of patients withdrew from the study because of grade 3 or 4 transaminitis, and 10% stopped treatment because of general intolerance related to multiple grade 1 and 2 toxicities. There were three treatment-related serious adverse events: one case of appendicitis, one case of gastritis, and one case of fatal CNS bleeding after a fall.
“Pazopanib was associated with encouraging preliminary activity in von Hippel-Lindau disease, with a side effect profile consistent with that seen in previous trials,” the investigators concluded. “Pazopanib could be considered as a treatment choice for patients with von Hippel-Lindau disease and growing lesions, or to reduce the size of unresectable lesions in these patients.”
Dr. Jonasch disclosed that he receives research support and honoraria from Novartis. The study was funded by Novartis and by a National Institutes of Health National Cancer Institute core grant.
SOURCE: Jonasch E et al. Lancet Oncol. 2018 Sep 17. doi: 10.1016/S1470-2045(18)30487-X,