BACKGROUND: Somatostatin analogs (SSA), such as OCT and LAN, are used to treat GEP-NETs. LAN is effective for carcinoid syndrome (CS) control in both SSA-experienced and -naïve patients (pts) with NETs. The study aim (NCT03112694) was to describe the clinical response to treatment among pts with locally advanced or metastatic GEP-NETs treated with LAN following treatment with OCT.
METHODS: A multicenter, retrospective medical record (MR) review of pts who had a confirmed diagnosis of locally advanced GEP-NET was conducted in adult pts who received ≥90 days OCT monotherapy followed by ≥90 days LAN monotherapy. MRs were reviewed to collect data including demographics, clinical characteristics, treatment responses, treatment duration, reason for change in these agents, and clinical progression. Clinically defined progressive disease (CDPD) and clinical progression free duration (CPFD) was based on radiological imaging, symptom control, biomarker(s) and/or clinical judgment.
RESULTS: The sample included data on 91 pts; male = 40.7%, age (mean) at initial diagnosis = 57.7 years (SD = 10.9). Median follow-up duration was 59.5 months (IQR: 41.4-94.9). Most pts (71.0%) presented with Stage IV disease with liver metastasis (71.4%). Most common primary tumor sites: small intestine (63.7%); pancreas (14.3%). Fifty-five pts (60.4%) had functional disease at initial diagnosis. Common reasons for transition to LAN included: CDPD (22.0%), formulary change (15.4%) and pt preference (9.9%). Data shows 30.8% of OCT pts had CDPD at the start of LAN treatment. After start of LAN treatment, 24.2% of pts had CDPD on LAN during the observed follow-up. The median treatment duration on OCT was 30.2 months (IQR: 13.8-54.1). CPFD on LAN (n = 91) was 23.7 months (95% CI: 20.2-NE). For CDPD OCT pts (n = 28) and clinically defined stable disease octreotide pts (n = 52), the CPFD was 15.2 months (95% CI: 11.4-NE) and 24.7 months (95% CI: 24.7-NE), respectively.
CONCLUSIONS: In addition to the phase III ELECT trial, these results suggest pts could transition from OCT to LAN in functioning and non-functioning GEP-NET. The CPFD observed under LAN in this SSA-pretreated population warrant further exploration.
