Potential Survival Advantage Observed for 177Lu-Dotatate in Midgut Neuroendocrine Tumors

CHICAGO — NETTER-1 trial results of the somatostatin analogue peptide, ¹⁷⁷Lu-DOTA⁰-Tyr³-octreotate (¹⁷⁷Lu-Dotatate), suggest a potential survival benefit in patients with advanced midgut neuroendocrine tumors (NETs), attendees at the American Society of Clinical Oncology (ASCO) 2016 Annual Meeting were told.¹

The agent results in clinically meaningful and statistically significant increases in progression-free survival and objective radiographic response rates, with a favorable safety profile, said Jonathan R. Strosberg, MD, Moffitt Cancer Center, Tampa, Florida.

Currently, therapeutic options for patients with advanced midgut NETs who progress on first-line somatostatin analog therapy are limited.

The study randomly assigned 230 patients with grade 1-2 metastatic midgut NETs to ¹⁷⁷Lu-Dotatat 7.4 GBq every 8 weeks (x 4 administrations) vs octreotide LAR 60 mg every 4 weeks.

In the intent-to-treat population, median progression-free survival, the primary end point, was not reached for ¹⁷⁷Lu-Dotatate and was 8.4 months in the control arm (HR, 0.21; 95% CI, 0.13-0.33; P < .0001).

Dr. Strosberg reported that there were 23 centrally confirmed disease progressions or deaths in the ¹⁷⁷Lu-DOTA⁰-Tyr³-Octreotate arm and 67 in the Octreotide LAR 60 mg arm.

Objective radiographic response rate was 18% with ¹⁷⁷Lu-Dotatate and 3% with the control (P = .0008).

Interim overall survival analysis revealed 14 deaths in ¹⁷⁷Lu-Dotatate arm and 26 in the control arm (HR, 0.398; 95% CI, 0.21-0.77; P = .043), which suggests increased overall survival, which will be confirmed by final analysis.

Six patients (5%) experienced dose modifying toxicity with ¹⁷⁷Lu-Dotatate. Grade 3 or 4 neutropenia (1%), thrombocytopenia (2%), and lymphopenia (9%) occurred in the ¹⁷⁷Lu-Dotatate arm compared with 0% in the control arm.

Reference

1. Strosberg JR, Wolin EM, Chasen, B et al. NETTER-1 phase III: Efficacy and safety results in patients with midgut neuroendocrine tumors treated with ¹⁷⁷Lu-DOTATATE. Oral presentation at: ASCO 2016 Annual Meeting; June 3-7, 2016; Chicago, IL.