Urothelial carcinoma (UC) is the most common subtype of bladder cancer. The randomized phase 3 KEYNOTE-045 trial showed that pembrolizumab, used as second-line therapy significantly prolonged overall survival with fewer treatment-related adverse events than chemotherapy for advanced UC. Pembrolizumab has been approved by the European Medicines Agency for the treatment of locally advanced or metastatic UC in adults who have received platinum-containing chemotherapy. Many European countries use cost-effectiveness analysis to inform reimbursement decisions.

To assess the cost-effectiveness of pembrolizumab as second-line therapy for the treatment of advanced UC from a Swedish health care perspective.

We developed a partitioned-survival model to assess the costs and effectiveness of pembrolizumab compared with vinflunine (base case), paclitaxel, or docetaxel monotherapy in patients with advanced UC over a 15-yr time horizon. We obtained Kaplan-Meier estimates for survival endpoints, adverse events, and utility data from KEYNOTE-045.

We performed parametric extrapolations to estimate overall and progression-free survival beyond the clinical trial period. Swedish costs and utility weights were used to estimate total costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs). We performed deterministic and probabilistic sensitivity analyses to assess the robustness of the model results.

In the base-case analysis, pembrolizumab resulted in a mean survival gain of 1.66 years (1.38 QALYs) at an incremental cost of €69852 and an ICER of €50529/QALY gained versus vinflunine monotherapy. ICERs for other chemotherapies were €81356/QALY for pembrolizumab versus paclitaxel or docetaxel monotherapy, and €71924/QALY for pembrolizumab versus paclitaxel, docetaxel, or vinflunine monotherapy. Long-term follow-up from KEYNOTE-045 and real-world data are needed to validate the extrapolations.

The results indicate that pembrolizumab improves survival, increases QALYs, and is cost-effective as second-line therapy at a willingness-to-pay threshold of €100000/QALY for the treatment of advanced UC.

To date, pembrolizumab is the only treatment associated with a significant overall survival benefit compared with chemotherapy in a randomized controlled trial as second-line therapy for advanced urothelial carcinoma. Our trial-based cost-effectiveness analysis suggests that pembrolizumab is a cost-effective option over chemotherapy in patients with advanced urothelial carcinoma after platinum-based therapy in Sweden.

European urology oncology. 2018 Nov 20 [Epub ahead of print]

Tushar Srivastava, Vimalanand S Prabhu, Haojie Li, Ruifeng Xu, Natalie Zarabi, Yichen Zhong, James M Pellissier, Rodolfo F Perini, Ronald de Wit, Ronac Mamtani

Complete HEOR Solutions, North Wales, PA, USA., Merck & Co, Inc., Kenilworth, NJ, USA., Merck Sharp & Dohme, Stockholm, Sweden., Merck & Co, Inc., Kenilworth, NJ, USA. Electronic address: ., Erasmus MC Cancer Institute, Rotterdam, The Netherlands., Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA, USA.