A dose escalation/expansion study evaluating dose, safety, and efficacy of the novel tyrosine kinase inhibitor surufatinib, which inhibits VEGFR 1, 2, & 3, FGFR 1, and CSF1R, in US patients with neuroendocrine tumors

Surufatinib, is a potent inhibitor of vascular endothelial growth factor receptors 1-3; fibroblast growth factor receptor-1; colony-stimulating factor 1 receptor. This Phase 1/1b escalation/expansion study in US patients with solid tumors evaluated 5 once daily (QD) surufatinib doses (3 + 3 design) to identify maximum tolerated dose (MTD), recommended Phase 2 dose (RP2D), and evaluate safety and efficacy at the RP2D in 4 disease-specific expansion cohorts including pancreatic neuroendocrine tumors [pNET] and extrapancreatic NETs [epNET]. MTD and RP2D were 300 mg QD (escalation [n = 35]); 5 patients (15.6%) (Dose Limiting Toxicity [DLT] Evaluable Set [n = 32]) had DLTs. Pharmacokinetics were dose proportional. Estimated progression-free survival (PFS) rates at 11 months were 57.4% (95% confidence interval [CI]: 28.7, 78.2) and 51.1% (95% CI: 12.8, 80.3) for pNET and epNET expansion cohorts, respectively. Median PFS was 15.2 (95% CI: 5.2, not evaluable) and 11.5 (95% CI: 6.5,11.5) months. Response rates were 18.8% and 6.3%. The most frequent treatment-emergent adverse events (both cohorts) were fatigue (46.9%), hypertension (43.8%), proteinuria (37.5%), diarrhea (34.4%). Pharmacokinetics, safety, and antitumor efficacy of 300 mg QD oral surufatinib in US patients with pNETs and epNETs are consistent with previously reported studies in China and may support applicability of earlier surufatinib studies in US patients. Clinical trial registration: Clinicaltrials.gov NCT02549937.

Surufatinib for the treatment of advanced extrapancreatic neuroendocrine tumors

Introduction: Surufatinib (also known as HMPL-012, sulfatinib) is a novel oral tyrosine kinase inhibitor (TKI), which has the dual activity of anti-angiogenesis and immune regulation. In December 2020, surufatinib was approved as a monotherapy for unresectable locally advanced or metastatic, progressive nonfunctioning, well differentiated (grade 1 or 2) extrapancreatic neuroendocrine tumors (epNETs) in China.Areas covered: In this paper, the chemical properties, mechanism of action, pharmacokinetics, clinical efficacy, safety, and tolerability of surufatinib for treatment of advanced extrapancreatic NETs are introduced in detail. We performed a systematic review of the literature in PubMed and the following keywords were used: 'surufatinib,' 'sulfatinib' and 'HMPL-012.'Expert opinion: Surufatinib is a potent, selective, and small-molecule TKI that targets vascular endothelial growth factor receptor (VEGFR), fibroblast growth factor receptor 1 (FGFR1) and colony stimulating factor 1 receptor (CSF1R). Surufatinib showed an acceptable safety profile and encouraging antitumor activity in patients with advanced epNETs. The most frequently observed adverse events (AEs) were hypertension and proteinuria. Surufatinib provides a new treatment option for patients with advanced epNETs. More clinical trials of surufatinib are ongoing to develop a combination of therapy strategies and new indications for malignancies.

Efficacy and Safety of Everolimus in Extrapancreatic Neuroendocrine Tumor: A Comprehensive Review of Literature

BACKGROUND

Everolimus, an oral mTOR (mammalian target of rapamycin) inhibitor, is currently approved for the treatment of progressive pancreatic neuroendocrine tumors (NETs). Although promising, only scattered data, often from nondedicated studies, are available for extrapancreatic NETs.

PATIENTS AND METHODS

A systematic review of the published data was performed concerning the use of everolimus in extrapancreatic NET, with the aim of summarizing the current knowledge on its efficacy and tolerability. Moreover, the usefulness of everolimus was evaluated according to the different sites of the primary.

RESULTS

The present study included 22 different publications, including 874 patients and 456 extrapancreatic NETs treated with everolimus. Nine different primary sites of extrapancreatic NETs were found. The median progression-free survival ranged from 12.0 to 29.9 months. The median time to progression was not reached in a phase II prospective study, and the interval to progression ranged from 12 to 36 months in 5 clinical cases. Objective responses were observed in 7 prospective studies, 2 retrospective studies, and 2 case reports. Stabilization of the disease was obtained in a high rate of patients, ranging from 67.4% to 100%. The toxicity of everolimus in extrapancreatic NETs is consistent with the known safety profile of the drug. Most adverse events were either grade 1 or 2 and easy manageable with a dose reduction or temporary interruption and only rarely requiring discontinuation.

CONCLUSION

Treatment with everolimus in patients with extrapancreatic NETs appears to be a promising strategy that is safe and well tolerated. The use of this emerging opportunity needs to be validated with clinical trials specifically designed on this topic.

IMPLICATIONS FOR PRACTICE

The present study reviewed all the available published data concerning the use of everolimus in 456 extrapancreatic neuroendocrine tumors (NETs) and summarized the current knowledge on the efficacy and safety of this drug, not yet approved except for pancreatic NETs. The progression-free survival rates and some objective responses seem promising and support the extension of the use of this drug. The site-by-site analysis seems to suggest that some subtypes of NETs, such as colorectal, could be more sensitive to everolimus than other primary NETs. No severe adverse events were usually reported and discontinuation was rarely required; thus, everolimus should be considered a valid therapeutic option for extrapancreatic NETs.