Cost-effectiveness analysis of telotristat ethyl for treatment of carcinoid syndrome diarrhea inadequately controlled with somatostatin analogs

Aims: This study evaluated the cost-effectiveness of telotristat ethyl (TE) added to somatostatin analog octreotide (SSA + TE) compared to octreotide alone (SSA) in patients with carcinoid syndrome diarrhea (CSD) whose symptoms remain uncontrolled with SSA alone. Materials and methods: A deterministic Markov model evaluated the costs and quality-adjusted life-years (QALY) gained with SSA + TE vs SSA per a third-party US payer perspective. The model reflected clinical practice and resource use estimates based on current standards of care, with utility estimates based on similar symptoms from ulcerative colitis. Treatment efficacy was based on the phase III clinical trial of SSA + TE vs SSA alone [TELESTAR, NCT01677910]. According to TELESTAR, 44% of SSA + TE and 20% of SSA patients responded to therapy after 12 weeks. At each 4-week assessment period, SSA patients not adequately controlled received increasing doses of SSA and SSA + TE patients discontinued TE and moved to SSA only. Drug costs for adequately and not adequately controlled patients were $4,291.75 and $5,890.57 for SSA, respectively, and $9,456.07 and $5,890.57 for SSA + TE, respectively. Results: The base-case analysis demonstrated lifetime QALYs of 1.67 at a cost of $495,125 for the SSA cohort and 2.33 ($590,087) for SSA + TE with an incremental QALY for SSA + TE of 0.66 for an additional $94,962. The incremental cost per QALY gained was $142,545. Sensitivity analyses demonstrated high probability (>99%) of SSA + TE being cost-effective at thresholds for rare diseases and orphan drugs of $300,000-$450,000. Limitations: The recent availability of TE precluded the incorporation of clinical and economic inputs based on real-world practice patterns. The scarcity of epidemiology and utility information for this rare condition required the use of some proxy estimates. Conclusions: This analysis demonstrated TE is a cost-effective treatment option when used on top of standard of care in CSD patients.