Cost-effectiveness analysis of abiraterone and sipuleucel-T in asymptomatic metastatic castration-resistant prostate cancer.

Of patients diagnosed with prostate cancer, 0% to 20% experience disease progression to metastatic castration-resistant prostate cancer (mCRPC). Recently, 4 novel therapies have been introduced for the treatment of mCRPC; of these, abiraterone and sipuleucel-T have been studied in the asymptomatic, pre-docetaxel population. Both have shown clinical benefits compared with placebo. This study evaluated the cost-effectiveness of abiraterone acetate and sipuleucel-T compared with prednisone in asymptomatic, pre-docetaxel mCRPC from a US societal perspective. A Markov model was constructed to simulate stable disease, progressed disease, and death. Survival and event rates were derived from published clinical trial data. Costs were derived from the literature and government reimbursement schedules. Outcomes were measured as average cost-effectiveness ratios (ACERs), incremental cost-effectiveness ratios (ICERs), and net monetary benefits (NMBs). One-way and probabilistic sensitivity analyses were conducted to test the robustness of the model. The base-case ACER was $114K/quality-adjusted life-years (QALY) for abiraterone, $85K/QALY for sipuleucel-T, and $31K/QALY for prednisone. The base-case ICER was $389K/QALY for abiraterone and $547K/QALY for sipuleucel-T. Prednisone dominates both abiraterone and sipuleucel-T in terms of NMB at willingness-to-pay (WTP) thresholds of $400K or less. One-way sensitivity analyses revealed that the model was most sensitive to overall survival and utility inputs. Probabilistic sensitivity analyses showed abiraterone to be cost-effective 50% or more of the time at a WTP of greater than $400K, whereas sipuleucel-T was cost-effective 50% or more of the time at a WTP of greater than $270K. Neither abiraterone nor sipuleucel-T was found to be cost-effective compared with prednisone in the treatment of asymptomatic, pre-docetaxel mCRPC.