Tumor burden in serotonin secreting pancreatic neuroendocrine tumors after initiating telotristat ethyl.

Abstract

367 Background: Pancreatic neuroendocrine tumors (pNETs) characterized by high serotonin levels and carcinoid syndrome (CS) are rare. We evaluated tumor burden in a subgroup of patients with pNETS from the real-world TELEACE study before and after initiating telotristat ethyl (TE) in US clinical practice. Methods: Detailed methods of the TELEACE study have been reported previously. This was a retrospective, single arm, pre-post physician panel-based chart review of patients who received TE for at least 6 months. Descriptive statistics analyzed demographic, clinical, laboratory and radiological data extracted from medical charts of TELEACE patients with pNETS. Results: Fifty-two patients with pNETS initiating TE were eligible for this analysis. The average age at the time of TE initiation was 60+10.4 years; 64% were males. The majority of patients had well-differentiated (60%) tumors and low-grade (54%) tumor status. Patients received TE for an average of 11.5+7.84 months, and 21% were still receiving TE at the time of data extraction. Diarrhea and flushing were the most common CS symptoms recorded at the time of TE initiation. Urinary 5-HIAA levels were reported for 9 patients before and for 2 patients after TE initiation. Mean (median) 5-HIAA levels before and after TE initiation were 693 (211) and 22 (22) µmol/24h, respectively. Significant mean reduction in tumor size of 0.67 cm after TE initiation (P = 0.017) was observed. Conclusions: This subgroup analysis of the TELEACE study population showed that the addition of TE to somatostatin analog treatment may positively impact tumor burden for patients with functional pNETs.