Cost-Effectiveness of Ivermectin 1% Cream in Adults with Papulopustular Rosacea in the United States

BACKGROUND: Papulopustular rosacea is a chronic skin disease involving central facial erythema in combination with papules and pustules. Papulopustular rosacea is treated with topical, systemic, or a combination of topical and systemic therapies. Currently approved topical therapies include azelaic acid gel/cream/foam twice daily (BID) and metronidazole cream/gel/lotion BID. Ivermectin 1% cream once daily (QD) is a new topical agent for the treatment of papulopustular rosacea that has been approved for the management of inflammatory lesions of rosacea and offers an alternative to current treatments. OBJECTIVE: To evaluate the cost-effectiveness of ivermectin 1% cream QD compared with current topical treatments in order to understand the cost of adding ivermectin as a treatment option that would bring additional clinical benefit for adults with papulopustular rosacea in the United States. METHODS: The cost-effectiveness of ivermectin 1% cream QD was compared with metronidazole 0.75% cream BID and azelaic acid 15% gel BID for adults in the United States with moderate-to-severe papulopustular rosacea using a Markov cohort state transition structure with 2 mutually exclusive health states (rosacea and no rosacea) and 5 phases. Patients could succeed or fail to respond to treatment and experience a relapse after treatment success. The model took a health care payer perspective (direct medical costs of topical and/or systemic therapy plus health care costs for physician and specialist visits) and used a 3-year time horizon. The model was run for a cohort of 1,000 patients. Costs (2014 U.S. dollars) and benefits (disease-free days and quality-adjusted life-years [QALYs]) were discounted at a rate of 3% per annum. Cost-effectiveness was determined by the incremental cost-effectiveness ratio (ICER) and measured in terms of incremental cost per QALY gained (estimated from health state utilities for patients with and without rosacea). Univariate and probabilistic sensitivity analyses (PSA) were conducted to assess the robustness of model outcomes. RESULTS: Compared with metronidazole 0.75% cream BID, ivermectin 1% cream QD was associated with higher costs but provided greater clinical benefit, with an ICER of $13,211 per QALY gained. For a cohort of 1,000 patients, ivermectin 1% cream QD provided an additional 72,922 disease-free days (200 years) over a 3-year period compared with metronidazole 0.75% cream BID, leading to a lower cost per disease-free day for ivermectin 1% cream QD ($4.54) compared with metronidazole 0.75% cream BID ($4.85). Ivermectin 1% cream QD was associated with lower total costs and greater clinical benefit compared with azelaic acid 15% gel BID at year 3 and dominated this treatment. After 3 years, ivermectin 1% cream QD was associated with the lowest health care costs ($62,767 compared with $73,284 for metronidazole 0.75% cream BID and $77,208 for azelaic acid 15% gel BID), reflecting a 15% reduction in physician visit costs, when compared with metronidazole 0.75% cream BID, and almost a 20% reduction, when compared with azelaic acid 15% gel BID. The univariate sensitivity analyses indicated that the results are sensitive to the time horizon selected: the longer the time horizon, the more beneficial the results for ivermectin 1% cream QD relative to the comparators, although even at 1 year, ivermectin 1% cream QD dominated azelaic acid 15% gel BID. The PSA suggested that ivermectin 1% cream QD was the most likely treatment to be cost-effective at a willingness-to-pay threshold of $15,000 and above. CONCLUSIONS: Ivermectin 1% cream QD had favorable incremental cost-effectiveness when compared with metronidazole 0.75% cream BID and dominated azelaic acid 15% gel BID in the treatment of papulopustular rosacea in the United States. Therefore, ivermectin 1% cream QD may be a good first-line treatment for papulopustular rosacea, providing additional clinical benefit at no or low additional cost.