Background: Octreotide has been used for decades in the United States (US) and Europe to treat patients with advanced neuroendocrine tumors (NETs). Lanreotide was approved in 2014 to improve progression-free survival (PFS) in patients with unresectable, well- or moderately-differentiated, locally advanced or metastatic gastroenteropancreatic NETs. Therefore, clinicians and patients may consider sequencing therapy from octreotide to lanreotide. However, current real-world outcomes data on patients who have made this transition is limited.
Methods: We conducted a multicenter, noninterventional, retrospective medical record review of patients with locally advanced or metastatic gastroenteropancreatic NETs (NCT03112694). Included patients had been treated with long-acting octreotide monotherapy for ≥90 days before transitioning to lanreotide monotherapy and continued on lanreotide for ≥90 days. Abstractors entered patient demographic and clinical data into a customized, web-based case report form. We assessed clinically defined PFS and other tumor-related outcomes while patients were treated with lanreotide. Outcomes were analyzed according to level of response at the time of transition from octreotide to lanreotide: progressive disease, nonprogressive disease, or unknown. Statistical analyses were descriptive. Clinically defined PFS and duration of treatment with lanreotide were estimated using the Kaplan-Meier method.
Results: Data were abstracted for 91 patients with gastroenteropancreatic NETs who received long-acting octreotide followed by lanreotide at six US based sites. At initial diagnosis, 71.4% of patients had stage IV disease. Small intestine (63.7%) and pancreas (14.3%) were the most common primary tumor sites. Mean [standard deviation (SD)] duration of follow-up from diagnosis was 70.6 (41.3) months. Patients received long-acting octreotide for a mean (SD) of 38.4 (32.8) months. When patients transitioned to lanreotide, 57.1% had nonprogressive disease on octreotide, 30.8% had progressive disease, and the remainder had unknown disease status. The most common reasons for switching from octreotide to lanreotide were progressive disease (22.0%), formulary change (15.4%), and patient preference (9.9%). Patients received lanreotide for a median (95% CI) duration of 24.7 (16.7-59.9) months. At the end of follow-up, 74% of patients remained on lanreotide monotherapy. Progression occurred in 24.2% of patients during lanreotide treatment. Overall median (95% CI) clinician-defined PFS following the transition to lanreotide was estimated to be 23.7 months [20.2 months-NE (not estimable)]. Patients with nonprogressive disease when they transitioned to lanreotide experienced a median clinician-defined PFS of 24.7 (17.0-NE) months. Among patients reported to have progressive disease when they transitioned to lanreotide, median (95% CI) clinician-defined PFS was estimated to be 15.2 (11.4-NE) months. There were no material differences in adverse events recorded during the long-acting octreotide and lanreotide treatment periods.
Conclusions: Our study suggests that lanreotide monotherapy is well tolerated and may contribute to stabilization of disease in a subset of patients with locally advanced or metastatic gastroenteropancreatic NETs previously treated with long-acting octreotide.
Keywords: Neuroendocrine tumors/drug therapy; disease-free survival; lanreotide; octreotide; somatostatin/aa.