Cost-effectiveness analysis of trastuzumab emtansine for second-line treatment of HER2+ advanced breast cancer in Singapore.

Objective: To evaluate the cost-effectiveness of trastuzumab emtansine (T-DM1) compared to both lapatinib plus capecitabine (lapcap) and trastuzumab plus capecitabine (trascap) for treating human epidermal growth factor 2-positive advanced breast cancer patients, who have received prior treatment with trastuzumab and a taxane, in Singapore.

Research Design And Methods: A three-state partitioned survival model was used to evaluate the cost-effectiveness from the local healthcare system perspective. Key effectiveness data, including progression-free survival and overall survival from the pivotal EMILIA trial, were used alongside local clinician inputs. Health state utilities (in quality-adjusted life years [QALYs]) were obtained from the literature and direct medical costs obtained from the public health institutions in Singapore. Scenario, one-way, and probabilistic sensitivity analyses were conducted to explore the impact of uncertainties on cost-effectiveness.

Results: The base-case incremental cost-effectiveness ratios (ICERs) for T-DM1, compared to lapcap and trascap, were S$472,600 and S$495,200 per QALY gained, respectively. Sensitivity and scenario analyses showed high ICERs, with a 50% price reduction for T-DM1 resulting in an ICER above S$200,000.

Conclusion: At current prices, T-DM1 is unlikely to be a cost-effective use of Singapore's limited healthcare budget. These findings can help inform policymakers, alongside other considerations, on funding decisions.