Cost-effectiveness of pertuzumab and trastuzumab biosimilar combination therapy as initial treatment for HER2-positive metastatic breast cancer in Singapore.

BACKGROUND: This study evaluates the cost-effectiveness of pertuzumab with trastuzumab biosimilar and docetaxel as initial treatment for HER2-positive metastatic breast cancer (MBC) in Singapore. METHODS: A partitioned survival model with three health states was developed to evaluate the cost-effectiveness of trastuzumab biosimilar and docetaxel with or without pertuzumab from a healthcare system perspective over a 15-year time horizon for patients with HER2-positive MBC. Key clinical inputs were derived from the CLEOPATRA trial. Health state utilities were derived from the literature and direct medical costs were obtained from local public healthcare institutions. RESULTS: The base-case resulted in an incremental cost-effectiveness ratio (ICER) of SGD366,658 (USD272,244) per quality-adjusted life-year (QALY) gained. One-way sensitivity analyses showed that the ICER was sensitive to utilities in the progression-free state, price of pertuzumab and time horizon. When the price for trastuzumab reference biologic (branded) was applied, the ICER was even higher (SGD426,996 [USD317,045]/QALY). CONCLUSION: Although trastuzumab biosimilar reduced the cost of the pertuzumab combination regimen, the ICER remained high and was not cost effective in Singapore's context. As pertuzumab contributed 80% of the overall combination treatment cost, price reductions for pertuzumab will be required to improve the cost-effectiveness of combination treatment to an acceptable level.

Cost-effectiveness of ribociclib as initial treatment for premenopausal women with advanced breast cancer in Singapore.

BACKGROUND: CDK4/6 inhibitors have shown promising results for treating advanced breast cancer (ABC) and are routinely used in Singapore. In view of their high costs, it is important to assess their relative value compared to existing standards of care in the local setting. AIMS: This study evaluates the cost-effectiveness of adding ribociclib to goserelin and a nonsteroidal aromatase inhibitor or tamoxifen as initial therapy for premenopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) ABC in Singapore. METHODS: A partitioned survival model with four health states (progression-free on first-line treatment, progression-free on second-line treatment, progressed disease, and death) was developed from a healthcare system perspective over a 10-year time horizon. Key clinical inputs were derived from the MONALEESA-7 trial, and survival curves were extrapolated beyond the trial period. Health state utilities were derived from the literature and direct medical costs were obtained from local public healthcare institutions. A discount rate of 3% was applied to both costs and outcomes. One-way deterministic and probabilistic sensitivity analyses were conducted to explore uncertainties. RESULTS: The base-case analysis resulted in an incremental cost-effectiveness ratio (ICER) of SGD197, 667 per quality-adjusted life-year. Sensitivity analyses showed that the ICER was sensitive to the survival parametric distribution, ribociclib price, time horizon, and utility weights used. Even when these were varied, ICERs remained high and not cost-effective in the local context. CONCLUSION: At its current price, adding ribociclib to endocrine therapy is unlikely to be cost-effective in Singapore for HR+, HER2- ABC. Results from this study are useful to inform future funding decisions for CDK4/6 inhibitors alongside other factors including clinical effectiveness, safety, and budget impact considerations.

Cost-effectiveness analysis of pembrolizumab monotherapy versus chemotherapy for previously untreated advanced non-small cell lung cancer.

Objective: To assess the cost-effectiveness of pembrolizumab monotherapy compared with standard chemotherapy for the treatment of advanced non-small cell lung cancer (NSCLC) in previously untreated adults who have a high programmed death ligand 1 (PD-L1) tumor proportion score of 50% or greater in Singapore.Materials and methods: A partitioned-survival analysis model was developed from a healthcare system's perspective that extrapolated clinical and economic outcomes of first-line pembrolizumab (maximum treatment duration of 2 years) versus platinum doublet chemotherapy over a 10-year time horizon for patients with advanced NSCLC. The model consisted of three health states: alive with no progression, alive with progression, and dead. Key clinical inputs were based on Kaplan-Meier survival curves from the interim (median follow-up = 11.2 months) and updated analysis (median follow-up = 25.2 months) of the KEYNOTE-024 randomized controlled trial. Local cost data were applied. Utilities were derived from published international estimates. Both one-way and multivariate probabilistic sensitivity analyses (PSA) were conducted to identify key drivers of the results.Results: Using the results from the updated analysis of KEYNOTE-024, patients treated with pembrolizumab experienced more quality adjusted life-years (QALYs), but incurred higher costs compared to chemotherapy over a 10-year time horizon (pembrolizumab: 1.9983 QALYs, SGD215,761; chemotherapy: 1.1317 QALYs, SGD70,444). The base-case incremental cost-effectiveness ratio (ICER) was SGD167,692 per QALY gained. One-way sensitivity analysis showed the ICER was most sensitive to the cost of pembrolizumab, followed by the time horizon. Multivariate PSA indicated that pembrolizumab had 0% probability of being cost-effective at a hypothetical willingness-to-pay threshold of SGD100,000 per QALY gained.Conclusion: While pembrolizumab is superior to standard chemotherapy in improving overall survival and progression-free survival, results suggest that it is unlikely to be cost-effective at its current price in Singapore. Factors including clinical effectiveness, safety, and budget impact should also be considered when making national funding decisions.