Preferences for adjuvant immunotherapy in patients with resected stage III melanoma: A discrete choice experiment.

9558 Background: Adjuvant immunotherapy has revolutionized the management of resectable melanoma, substantially reducing the risk of recurrence but at the risk of immune-related adverse events (AE). This study aimed to quantify patients' preferences for adjuvant immunotherapy, the influence of varying levels of key attributes, and baseline characteristics associated with preferences. Methods: We performed a discrete choice experiment (DCE), including patients with resected stage III melanoma considering or having received adjuvant immunotherapy. Patients chose between twelve randomly presented choice tasks of two alternative options (adjuvant immunotherapy versus observation without adjuvant immunotherapy). The two options varied across two-three levels of six attributes: chance of 3-year melanoma recurrence, mild, permanent, or fatal AE, drug regimen, and out-of-pocket costs. We calculated the marginal rate of substitution (MRS, how much an individual was willing to trade one attribute for preferred levels of another) and willingness-to-pay (WTP, maximum price to trade their preferred attributes) per year. Results: One hundred and sixteen patients completed the DCE. Patients chose adjuvant immunotherapy over observation without adjuvant immunotherapy in 70% of choice tasks. Patients preferred adjuvant immunotherapy with reduced probabilities of recurrence (OR 0.76, 95% CI 0.70-0.83, p<0.001), fatal AE (OR 0.60, 95% CI 0.44-0.80, p=0.006), permanent AE (OR 0.94, 95% CI 0.89-0.99, p=0.046), and lowered out-of-pocket costs, for those with lower incomes (OR 0.63, 95% CI 0.47-0.85, p=0.003) and higher incomes (OR 0.84, 95% CI 0.15-4.86, p=0.064). Patients accepted an increase in their chance of mild AE from 1% to 37% (OR 2.06, 95% CI 1.13-3.78, p=0.019) in return for adjuvant immunotherapy. Willingness-to-pay was lower for patients with incomes that were lower rather than higher: US$595 (95% CI US-$555 to 1,305) and US$1,638 (95% CI US$ -1,235 to 3,419) per year for adjuvant immunotherapy with an absolute reduction of 1% in the 3-year risk of recurrence. Conclusions: Almost three-quarters of patients preferred adjuvant immunotherapy over observation without adjuvant immunotherapy. Patients were more likely to select immunotherapy if the risk of melanoma recurrence and the chance of fatal AE were reduced. Understanding patient preferences and acceptable trade-offs for adjuvant immunotherapy may allow better-informed decisions for individuals and assist policymakers in decisions about access and subsidization of effective and expensive treatments.