A Budget Impact Model of the Addition of Telotristat Ethyl Treatment to the Standard of Care in Patients with Uncontrolled Carcinoid Syndrome

Background Carcinoid syndrome, a rare condition in patients with neuroendocrine tumours, characterised by flushing and diarrhoea, severely affects patients’ quality of life. The current carcinoid syndrome standard of care includes somatostatin analogues, but some patients experience uncontrolled symptoms despite somatostatin analogue therapy. Telotristat ethyl is a novel treatment approved by the European Medicines Agency (EMA) and US FDA that significantly reduces bowel movement frequency in patients with uncontrolled carcinoid syndrome. Objective We developed a model to evaluate the 5-year budget impact of introducing telotristat ethyl to standard care in Swedish patients with uncontrolled carcinoid syndrome. Methods Treatment response in the 12-week phase III TELESTAR trial (NCT01677910) informed telotristat ethyl efficacy; subsequently, health states were captured by a Markov model using 4-week cycles. TELESTAR open-label extension data informed telotristat ethyl discontinuation. The number of treatment-eligible patients was estimated from literature reviews reporting the prevalence, incidence and mortality of carcinoid syndrome. A Swedish database study informed real-world costs related to carcinoid syndrome and carcinoid heart disease costs. Telotristat ethyl market share was assumed to increase annually from 24% (year 1) to 70% (year 5). Results Over the 5-year model horizon, 44 patients were expected to initiate telotristat ethyl treatment. The cumulative net budget impact of adding telotristat ethyl to current standard of care was €172,346; per-year costs decreased from €66,495 (year 1) to €29,818 (year 5). Increased drug costs from adding telotristat ethyl were offset by reduced costs elsewhere. Conclusions The expected budget impact of adding telotristat ethyl to the standard of care in Sweden was relatively low, largely because of the rarity of carcinoid syndrome.