Economic Impact of Post-Progression Treatment in Gastroenteropancreatic Neuroendocrine Tumor (GEP-NET) Patients Previously Treated with Octreotide Monotherapy.

e18366 Background: For unresectable, well-differentiated, advanced GEP-NET patients somatostatin analogs octreotide LAR (OCT) and lanreotide depot (LAN) are recommended as first-line systemic therapy. Recent evidence suggests that GEP-NET patients may benefit from LAN after OCT prior to modifying treatment class. The goal of this analysis is to quantify treatment escalation costs among patients who progress on OCT. Methods: A decision-tree model was used to assess the cost of treating GEP-NET patients over a 6-month time horizon after they progress on OCT. Drug acquisition (Wholesale Acquisition Costs), administration, grade 3/4 adverse event (AE) management, and patient monitoring costs were considered. Patients could utilize either OCT escalation (30 mg every 3 weeks or 40 or 60 mg every 4 weeks), OCT + peptide receptor radionuclide therapy (PRRT), OCT + liver directed therapy (e.g. transarterial chemoembolization (TACE)), everolimus, or LAN 120mg every 4 weeks. Administration and monitoring test costs were based on CMS physician and laboratory fee schedules, respectively. AE management costs were determined from the CMS Inpatient prospective payment system based on reimbursements corresponding to the associated DRG codes. Results: LAN ($44,462) was found to be cost-saving versus alternatives when used post-OCT. OCT escalations to 30mg every 3 weeks, 40mg every 4 weeks, and its use with liver directed therapy were 2nd, 3rd, and 4th lowest cost treatment options ($52,873, $53,041, and $72,152, respectively); all three had higher drug acquisition and AE management costs. Drug acquisition costs for everolimus were more than twice those of LAN and for PRRT + OCT nearly 4 times that amount. GA-68 Dotatate PET/CT imaging greatly increased the monitoring costs of PRRT + OCT, which were $3,682 higher than the nearest alternative. Conclusions: LAN was the lowest cost treatment option over a 6-month interval for GEP-NET patients who progressed on OCT, however clinical appropriateness must be considered when transitioning patients. Evidence for the appropriate clinical strategy of sequencing of patients is still needed.