Updated Efficacy and Safety Outcomes for Patients with Well-Differentiated Pancreatic Neuroendocrine Tumors Treated with Sunitinib

BACKGROUND

Sunitinib prolonged progression-free survival (PFS) versus placebo in patients with metastatic pancreatic neuroendocrine tumors (panNETs) in a phase III trial. The efficacy and safety of sunitinib in patients with panNETs were confirmed in an open-label phase IV trial.

OBJECTIVE

To assess the clinical benefit with sunitinib using the combined data from these trials.

PATIENTS AND METHODS

An updated overall survival (OS) in patients with panNETs for the phase IV trial was provided, and an analysis of results from the sunitinib-treated combined cohort from the phase III and IV trials (combined cohort) was conducted to assess PFS, OS, and objective response rate (ORR).

RESULTS

The updated median OS for the phase IV trial was 54.1 months (95% CI 37.9-not reached). Investigator-assessed median PFS for the combined cohort (n = 102) was 12.9 months (95% CI 7.4-16.7) with a significant benefit versus placebo in the phase III trial (n = 35) (HR 0.429; 95% CI 0.245-0.752; p = 0.001). Median OS could not be calculated for the combined cohort or placebo group due to the high number of patients censored; however, the estimated HR of 0.303 (CI 0.100-0.921; p = 0.013) favored sunitinib. ORR for the combined cohort was 16.7% (95% CI 10.0-25.3). Sunitinib was well tolerated in both trials with a safety profile similar to previously seen in other studies.

CONCLUSIONS

The combined analysis of these studies confirms the objective tumor responses and improvements in PFS observed in the initial phase III trial, providing further support for the clinical benefit of sunitinib in patients with advanced panNETs. CLINICALTRIALS.

GOV IDENTIFIERS

NCT00428597 and NCT01525550.

Intratumoural immunotherapies in oncology

Although immune checkpoint inhibitors have become the standard of care for many tumours, the majority of patients fail to achieve sustained benefit, often owing to the lack of a T-cell inflamed tumour microenvironment (TME). Directly injected intratumoural therapies present a potential strategy to induce T-cell inflammation and convert a 'cold' immune-inert TME into a 'hot' immune-inflamed TME. Various approaches including chemoablation, oncolytic viral therapy, cytokines and agents targeting innate immunity such as Toll-like receptor agonists and stimulator of interferon genes agonists are in clinical development. Thus far, melanoma has led the way in intratumoural drug development owing to its relative immunogenicity and propensity for cutaneous metastasis easily amenable to injections. However, intratumoural therapies are moving to other tumour types and advances in endoscopic and interventional radiological techniques are allowing these agents to be injected into visceral lesions. This review provides an overview of the current status of intratumoural therapies in oncology, as well as future directions regarding therapeutic niches and appropriate trial design for intratumoural agents.