Safety and Efficacy of Lanreotide Depot Versus Placebo in Neuroendocrine Tumor Patients With a History of Carcinoid Syndrome and Prior Octreotide Therapy

Abstract

Introduction: In the ELECT study, lanreotide depot, a long-acting somatostatin analog (SSA), was associated with significant improvement over placebo in the percentage of days with short-acting octreotide used as rescue medication for symptomatic control of carcinoid syndrome (CS) in neuroendocrine tumor patients. In this subanalysis, we assessed the safety, tolerability, and efficacy of lanreotide depot 120 mg SC q4W in patients who had prior octreotide use. Methods: ELECT consisted of 16-week double-blind, 32-week open-label, and long-term extension phases. Adults with a histopathologically-confirmed gastroenteropancreatic neuroendocrine tumor (GEP-NET) or GEP-NET of unknown location with liver metastases and history of CS (flushing and/or diarrhea) were included. Patients were SSA-naïve or were responsive to conventional doses of octreotide LAR (≤30 mg q4W) or short-acting octreotide (≤600 μg daily), and were randomized to lanreotide depot 120 mg or placebo. Results: 64 patients (n=33 lanreotide; n=31 placebo) were previously treated with octreotide LAR (n=56), short-acting octreotide (n=24), or both (n=6). Mean age was 58.8 years, 45% were male, and 84% had been diagnosed ≥1 year before the study. Most treatment-emergent adverse events (TEAEs) were mild to moderate in nature. One patient receiving lanreotide experienced serious TEAEs (small intestinal obstruction and urinary infection). Nineteen patients (58%) receiving lanreotide experienced a TEAE; the most common included headache (18%), abdominal pain (12%), and nausea (9%).Twentytwo (71%) patients receiving placebo experienced a TEAE; the most common included abdominal pain (16%), nausea (16%), and dyspnea (13%). 52% of lanreotide patients experienced complete treatment success (0 to ≤3 days of rescue short-acting octreotide medication between weeks 12 and 15), vs 26% of placebo patients (RR = 1.996 [95% CI: 1.009, 3.950], p = 0.0471). Conclusion: A transition to lanreotide depot 120 mg in GEP-NET patients previously treated with octreotide LAR and/or SC was well tolerated and resulted in no new safety signals. The relative chance for achieving complete treatment success was 2 times greater with lanreotide than placebo.