A Markov model (considering three transition states: remission, clinical response, relapse) was constructed using the software R 3.3.1 markovchain-package to evaluate incremental cost-utility ratios (ICUR) of adalimumab (ADA), infliximab (IFX), infliximab biosimilar (IFX-B), golimumab (GOL) and vedolizumab (VED) treatments of patients over a 10-year time horizon from the perspective of the Italian (N) and Lombardy Region (R) healthcare system. Clinical parameters were derived from clinical trials. Costs (actualized by – 1.5 percent) were obtained from the National database and Regional public tender. Utility was expressed as QALY (Quality-Adjusted Life Years).
Costs per treatment were different from a N and R perspective (ADA -55 percent; IFX -16.7 percent; IFX-B -29.6 percent; GOL -9.6 percent; VED -10 percent). Direct healthcare costs (treatment cost, visits, laboratory tests, hospital admissions) were calculated over 10 years of treatment per patient: ADA (N: EUR114,227, R: EUR68,314, -40.2 percent), IFX (N: EUR130,595, R: EUR103,081, -21 percent), IFX-B (N: EUR110,438, R: EUR78,852, -28.6 percent), GOL (N: EUR118,602, R: EUR96,922, -18.3 percent), VED (N: EUR113,852, R: EUR102,932, -9.6 percent) with associated QALY respectively of 6.68, 6.66, 6.66, 6.70, 7.02. From a N perspective, IFX-B was dominating compared to all other treatments. The ICUR of VED/IFX-B was EUR9,483 for 10 years (willingness to pay EUR948/QALY). From a R perspective, ADA was dominating compared to all other treatments. The ICUR of VED/ADA was EUR101,818 for 10 years (Willingness to Pay, WTP EUR10,182/QALY).