Background: There are limited data guiding providers and payers on the most cost-effective position for vedolizumab (VDZ) in current ulcerative colitis (UC) treatment algorithms.
Methods: We employed a Markov model to identify the most cost-effective position for VDZ in 4 different positions in a step-up treatment algorithm for UC (Figure 1): (A1) prior to initiating azathioprine (AZA), (A2) prior to combined infliximab (IFX)+AZA, (A3) prior to combined adalimumab (ADA)+AZA, and (A4) last-line prior to colectomy. With each therapy, individuals could enter clinical remission or response, or develop a complication including infection, lymphoma, or other adverse events. Transition probabilities were derived from published clinical trials including ACT, GEMINI, SUCCESS, and ULTRA-2, stratified by prior exposures. Utilities and costs were derived from published estimates, Medicare reimbursement rates, the Nationwide Inpatient Sample, and wholesale acquisition costs. Primary analyses consisted of first order Monte Carlo simulation of 100 trials of 100,000 individuals at 1 year. Additional models included initial ADA or IFX monotherapy, dose optimization (DO) for biologics, and time horizons of up to 7 years. All models assumed a willingness-to-pay (WTP) threshold of $100,000 per quality adjusted life year gained.
Results: In this model, VDZ use prior to ADA+AZA but after IFX+AZA (A3) was the most cost-effective strategy (Table 1). VDZ was also preferred before ADA when considering ADA as an initial anti-TNF. These results were consistent in sensitivity analyses assessing initial IFX use, DO, and longer time horizons. No alternative strategy met the WTP threshold (Table 1). All models were sensitive to VDZ and IFX pricing.
Conclusion: This model suggests that in moderate to severe UC, utilizing VDZ as the first biologic (prior to IFX+AZA) may be the most effective strategy, while utilizing VDZ after IFX+AZA but prior to ADA may be the most cost-effective strategy.
