Wolin, Edward M.

Purpose Treatment options for neuroendocrine tumors (NETs) remain limited. This trial assessed the progression-free survival (PFS) of bevacizumab or interferon alfa-2b (IFN-α-2b) added to octreotide among patients with advanced NETs. Patients and Methods Southwest Oncology Group (SWOG) S0518, a phase III study conducted in a US cooperative group system, enrolled patients with advanced grades 1 and 2 NETs with progressive disease or other poor prognostic features. Patients were randomly assigned to treatment with octreotide LAR 20 mg every 21 days with either bevacizumab 15 mg/kg every 21 days or 5 million units of IFN-α-2b three times per week. The primary end point was centrally assessed PFS. This trial is registered with ClinicalTrials.gov as NCT00569127. Results A total of 427 patients was enrolled, of whom 214 were allocated to bevacizumab and 213 to IFN-α-2b. The median PFS by central review was 16.6 months (95% CI, 12.9 to 19.6 months) in the bevacizumab arm and was 15.4 months (95% CI, 9.6 to 18.6 months) in the IFN arm (hazard ratio [HR], 0.93; 95% CI, 0.73 to 1.18; P = .55). By site review, the median PFS times were 15.4 months (95% CI, 12.6 to 17.2 months) for bevacizumab and 10.6 months (95% CI, 8.5 to 14.4 months) for interferon (HR, 0.90; 95% CI, 0.72 to 1.12; P = .33). Time to treatment failure was longer with bevacizumab than with IFN (HR, 0.72; 95% CI, 0.58 to 0.89; P = .003). Confirmed radiologic response rates were 12% (95% CI, 8% to 18%) for bevacizumab and 4% (95% CI, 2% to 8%) for IFN. Common adverse events with bevacizumab and octreotide included hypertension (32%), proteinuria (9%), and fatigue (7%); with IFN and octreotide, they included fatigue (27%), neutropenia (12%), and nausea (6%). Conclusion No significant differences in PFS were observed between the bevacizumab and IFN arms, which suggests that these agents have similar antitumor activity among patients with advanced NETs.

348 Background: Neuroendocrine tumor progression is associated with decline in quality of life, both due to tumor and hormone-related symptoms. The Phase III NETTER-1 trial randomized patients with advanced, progressive midgut NETs to receive treatment with 177Lu-DOTATATE (177Lu; Lutathera) versus high-dose (60 mg) Octreotide LAR (Oct). EORTC questionnaires C30 and GINET21 were assessed during the trial in order to determine the impact of treatment on health-related quality of life (HRQoL). Methods: Patients completed EORTC QLQ-30 and QLQ-G.I.NET21 questionnaires at baseline and every 12 weeks thereafter until disease progression. Raw scores were converted to a 100-point scale and individual changes from baseline scores were assessed. Clinically relevant ( ≥ 10 point) deterioration/improvement was considered clinically significant. Results: Clinically and statistically significant improvements in QoL were observed in the 177Lu arm versus the Oct arm at certain time points in key domains of HRQoL including global health status and diarrhea. In mean, global health status improved in 28% of patients on 177Lu arm vs. 15% on Oct, and worsened in 18% of patients on 177Lu vs. 26% on Oct. Diarrhea improved in 39% of patients on 177Lu vs. 23% on Oct, and worsened in 19% of patients on 177Lu vs. 23% on Oct. There was a trend towards improvement in pain that was not statistically significant. Flushing appeared to improve compared to baseline in both arms of the study with no clear advantage to treatment with 177Lu vs. Oct. Conclusions: QoL analysis suggests benefit in important domains associated with 177Lu treatment compared to high-dose octreotide in patients with advanced midgut NETs, and confirms the treatment value of 177Lu on patient QoL, in addition to the meaningful increase in progression-free survival already reported. Clinical trial information: NCT01578239.

224 Background: In the phase 3 RADIANT-3 trial, everolimus (EVE) demonstrated significantly improved median progression-free survival (PFS) versus placebo (PBO) (11.0 vs 4.6 months; HR=0.35, p < 0.0001) in patients (pts) with pancreatic neuroendocrine tumors (pNET) (Yao et al, NEJM, 2011). Here we present a planned exploratory analysis by prior chemotherapy (chemo) use. Methods: Pts with progressive low- or intermediate-grade pNET were prospectively stratified by prior chemo use and randomized (1:1) to EVE 10 mg/d (n = 207) or PBO (n = 203) plus best supportive care. Results: Of the 410 pts, 206 (50%) had received prior chemo and 204 (50%) were chemo naive. Baseline characteristics (age, sex, race, tumor type, histologic grade) and baseline tumor biomarker levels were similar for pts with/without prior chemo. More chemo-naive pts were newly diagnosed (time since initial diagnosis ≤ 6 mo: 50 [25%] vs. 7 [3%] pts with prior chemo). A lower proportion of chemo-naive pts received prior somatostatin therapy (45% vs. 54% prior chemo). EVE significantly prolonged median PFS regardless of prior chemo use (with prior chemo: 11.0 vs. 3.2 months; HR = 0.35, 95% CI 0.25-0.49, p < 0.001; chemo naive: 11.4 vs. 5.4 months; HR = 0.42, 95% CI 0.29-0.60; p < 0.001). Stable disease was the best overall response in 73% of EVE-treated pts irrespective of prior chemo use. The benefit from EVE irrespective of prior chemo was further demonstrated by disease stabilization or minor tumor shrinkage and in the lower incidence of progressive disease in waterfall plots. Safety of EVE was consistent regardless of prior chemo use. The most common drug-related adverse events (chemo vs chemo naive) included rash (53% vs. 52%), stomatitis (52% vs. 56%), diarrhea (41% vs. 52%), and fatigue (37% vs. 51%). Conclusions: This planned subgroup analysis demonstrated the beneficial effects of EVE in pts with pNET regardless of prior chemo use. These findings support the possible first-line use of EVE for pts with pNET.

194 Background: Currently, there are limited therapeutic options for patients with advanced midgut neuroendocrine tumors progressing on first-line somatostatin analog therapy. Methods: NETTER-1 is the first Phase III multicentric, randomized, controlled trial evaluating 177Lu-DOTA0-Tyr3-Octreotate (Lutathera) in patients with inoperable, progressive, somatostatin receptor positive midgut NETs. 230 patients with Grade 1-2 metastatic midgut NETs were randomized to receive Lutathera 7.4 GBq every 8 weeks (x4 administrations) versus Octreotide LAR 60 mg every 4-weeks. The primary endpoint was PFS per RECIST 1.1 criteria, with objective tumor assessment performed by an independent reading center every 12 weeks. Secondary objectives included objective response rate, overall survival, toxicity, and health-related quality of life. Results: Enrolment was completed in February 2015, with a target of 230 patients randomized (1:1) in 36 European and 15 sites in the United States. At the time of statistical analysis, the number of centrally confirmed disease progressions or deaths was 23 in the Lutathera group and 67 in the Octreotide LAR 60 mg group. The median PFS was not reached for Lutathera and was 8.4 months with 60 mg Octreotide LAR [95% CI: 5.8-11.0 months], p < 0.0001, with a hazard ratio of 0.21 [95% CI: 0.13-0.34]. Within the current evaluable patient dataset for tumor responses (n = 201), the number of CR+PR was 19 (18.8%) in the Lutathera group and 3 (3.0%) in the Octreotide LAR 60 mg group (p < 0.0004). Although the OS data were not mature enough for a definitive analysis, the number of deaths was 13 in the Lutathera group and 22 in the Octreotide LAR 60 mg group (p < 0.019 at interim analysis) which suggests an improvement in overall survival. Conclusions: The Phase III NETTER-1 trial provides evidence for a clinically meaningful and statistically significant increase in PFS and ORR, and also suggests a survival benefit in patients with advanced midgut NETs treated with Lutathera. Clinical trial information: NCT01578239.

158 Background: There is an unmet medical need for effective treatments for patients with advanced pNET. Systemic therapies for advanced pNET are limited both by toxicity and efficacy. Everolimus, an oral mTOR inhibitor, has shown promising antitumor activity in 2 phase II studies, leading to further investigation in the largest phase III randomized controlled trial completed in pNET patients. Methods: Patients with advanced low- or intermediate-grade pNET were randomly assigned to everolimus 10 mg/d orally + best supportive care (BSC; n = 207) or placebo + BSC (n = 203). Long-acting somatostatin analogs (SSAs) were permitted as BSC during the study. The primary endpoint was progression free survival (PFS). At progression (RECIST), patients could be unblinded and those randomly assigned to placebo were offered open-label everolimus. Results: Compared with placebo, everolimus reduced the risk of progression by 65% and increased median PFS by more than 6 months, from 4.6 to 11.0 months (HR = 0.35; 95% CI: 0.27-0.45; p < 0.0001), by investigator review (primary endpoint). Median PFS by central review was consistent (HR = 0.34; 95% CI: 0.26 to 0.44; p < 0.001] in favor of everolimus. Eighteen-month PFS estimates were 34% for everolimus (95% CI: 26-43) vs 9% (95% CI: 4-16) for placebo. Everolimus demonstrated a significant PFS benefit across all patient subgroups according to baseline characteristics and prior SSA use. Prior SSA use was 49% in the everolimus arm and 50% in the placebo arm. Updated analyses of the impact of concomitant SSA will be reported. The most common drug-related adverse events were stomatitis, rash, diarrhea, fatigue, and infections (primarily upper respiratory); most were grade 1 or 2. Stomatitis (6.9% vs 0%), anemia (6% vs 0%), and hyperglycemia (5% vs 2%) were the most common grade 3-4 events. Conclusions: Everolimus significantly prolonged PFS compared with placebo in patients with advanced pNET in this large phase III clinical trial. This benefit was seen across all patient subgroups. Treatment resulted in a significant 6.4-month prolongation in median PFS. Everolimus had an acceptable and predictable safety profile. [Table: see text]