6561 POSTER Updated Survival and Safety Data From RADIANT-3 – a Randomized, Double-blind, Placebo-controlled, Multicenter, Phase III Trial of Everolimus in Patients With Advanced Pancreatic Neuroendocrine Tumours (pNET)

Everolimus, lutetium-177 DOTATATE and sunitinib for advanced, unresectable or metastatic neuroendocrine tumours with disease progression: a systematic review and cost-effectiveness analysis

BACKGROUND

Neuroendocrine tumours (NETs) are a group of heterogeneous cancers that develop in cells in the diffuse neuroendocrine system.

OBJECTIVES

To estimate the clinical effectiveness of three interventions [everolimus (Afinitor^®; Novartis International AG, Basel, Switzerland), lutetium-177 DOTATATE (177Lu-DOTATATE) (Lutathera^®; Imaging Equipment Ltd, Radstock, UK) and sunitinib (Sutent^®; Pfizer Inc., New York, NY, USA)] for treating unresectable or metastatic NETs with disease progression and establish the cost-effectiveness of these interventions.

DATA SOURCES

The following databases were searched from inception to May 2016: MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, MEDLINE Daily, Epub Ahead of Print, EMBASE, Cochrane Central Register of Controlled Trials and Web of Science.

REVIEW METHODS

We systematically reviewed the clinical effectiveness and cost-effectiveness literature on everolimus, 177Lu-DOTATATE and sunitinib for treating advanced, unresectable or metastatic progressive NETs. The following NET locations were considered separately: pancreas, gastrointestinal (GI) tract and lung, and GI tract (midgut only). We wrote a survival partition cohort-based economic evaluation in Microsoft Excel^® 2013 (Microsoft Corporation, Redmond, WA, USA) from the UK NHS and Personal Social Services perspective. This comprised three health states: (1) progression-free survival (PFS), (2) progressed disease and (3) death.

RESULTS

Three randomised controlled trials (RCTs), RADIANT-3 [RAD001 in Advanced Neuroendocrine Tumors, Third Trial; pancreatic NETs (pNETs): everolimus vs. best supportive care (BSC)], A6181111 (pNETs: sunitinib vs. BSC) and RADIANT-4 (RAD001 in Advanced Neuroendocrine Tumors, Fourth Trial; GI and lung NETs: everolimus vs. BSC), met the inclusion criteria for the clinical effectiveness systematic review. The risk of bias was low. Although the NETTER-1 (Neuroendocrine Tumors Therapy) RCT, of 177Lu-DOTATATE plus 30 mg of octreotide (Sandostatin^®, Novartis) compared with 60 mg of octreotide, was excluded from the review, we nonetheless present the results of this trial, as it informs our estimate of the cost-effectiveness of 177Lu-DOTATATE. The pNETs trials consistently found that the interventions improved PFS and overall survival (OS) compared with BSC. Our indirect comparison found no significant difference in PFS between everolimus and sunitinib. Estimates of OS gain were confounded because of high rates of treatment switching. After adjustment, our indirect comparison suggested a lower, but non-significant, hazard of death for sunitinib compared with everolimus. In GI and lung NETs, everolimus significantly improved PFS compared with BSC and showed a non-significant trend towards improved OS compared with BSC. Adverse events were more commonly reported following treatment with targeted interventions than after treatment with BSC. In the base case for pNETs, assuming list prices, we estimated incremental cost-effectiveness ratios (ICERs) for everolimus compared with BSC of £45,493 per quality-adjusted life-year (QALY) and for sunitinib compared with BSC of £20,717 per QALY. These ICERs increased substantially without the adjustment for treatment switching. For GI and lung NETs, we estimated an ICER for everolimus compared with BSC of £44,557 per QALY. For GI (midgut) NETs, the ICERs were £199,233 per QALY for everolimus compared with BSC and £62,158 per QALY for a scenario analysis comparing 177Lu-DOTATATE with BSC. We judge that no treatment meets the National Institute for Health and Care Excellence's (NICE) end-of-life criteria, although we cannot rule out that sunitinib in the A6181111 trial does.

LIMITATIONS

A RCT with included comparators was not identified for 177Lu-DOTATATE. The indirect treatment comparison that our economic analysis was based on was of a simple Bucher type, unadjusted for any differences in the baseline characteristics across the two trials.

CONCLUSIONS

Given NICE's current stated range of £20,000-30,000 per QALY for the cost-effectiveness threshold, based on list prices, only sunitinib might be considered good value for money in England and Wales.

FUTURE WORK

Further analysis of individual patient data from RADIANT-3 would allow assessment of the robustness of our findings. The data were not made available to us by the company sponsoring the trial.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016041303.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Everolimus in advanced pancreatic neuroendocrine tumors: the clinical experience

The incidence of neuroendocrine tumors (NET) has increased dramatically in the past 30 years. This information has revitalized basic and clinical research into the molecular biology of NET and has resulted in the recent approval of new therapies for pancreatic NET (pNET), including the oral inhibitor of the mTOR everolimus. Everolimus significantly improved progression-free survival among patients with pNET in the phase III RADIANT-3 study. Here, we review the clinical studies showing the efficacy of everolimus in pNET and summarize the translational science from these studies. To understand the mechanisms of resistance and cause of treatment failure, we compared the type of progression events observed in the everolimus and placebo arms of the RADIANT-3 study. Comparison of the everolimus arm to the placebo arm indicated the fractions of progression events due to new metastasis only (21% vs. 22%), growth of preexisting lesions only (54% vs. 49%), and new metastasis along with growth of preexisting lesions (24% vs. 27%) were similar. These results suggest that although everolimus delays disease progression in patients with pNET, patients who experience disease progression while on everolimus do not appear to have a more aggressive metastatic phenotype than those whose disease progresses while on placebo.