Presentation (CTI)

OBJECTIVES: In India, cost-effectiveness (CE) analysis typically uses 1x GDP-per-capita as the willingness-to-pay (WTP) threshold. Recently, the first WTP/QALY estimates for decisions in India were published (Chugh et al. 2026). Previously, Gupta et al. (2020) found that one-year trastuzumab is not cost-effective in India, but a 35% price reduction would make adjuvant trastuzumab cost-effective. This study examines whether the decision to recommend 1-year of adjuvant trastuzumab for BC would be impacted by using different CE thresholds.
METHODS: We adapted the Markov model structure published in Gupta et al. (2020): five health states; 1-year cycle; lifetime horizon; and 3% discounting. Costs were updated to 2025-26 prices in Indian rupees (INR), using Pradhan Mantri Jan Aushadhi rates for biosimilar trastuzumab and CGHS tariffs for management costs. Disease-free survival was modelled with either year-varying (primary) or constant (sensitivity) hazard ratios. Probabilistic sensitivity analysis was performed. The probability of cost-effectiveness was evaluated using thresholds from two sources: (1) Chugh WTP/QALY estimate (INR 170,414-258,985), and (2) 1× GDP/capita (INR 251,393).
RESULTS: In the primary analysis, trastuzumab was associated with 1.42 incremental QALYs and INR 267,759 incremental costs (ICER, INR 188,268/QALY). The probabilistic cost-effectiveness ranged from 38.6% at the lowest published estimate, 62.5% at the weighted mean (INR 212,307/QALY), and 76.6% at 1× GDP/capita. Interpretation shifted from not cost-effective to cost-effective as the threshold increased across the WTP/QALY range. In the sensitivity analysis, the ICER was INR 142,241/QALY (1.91 incremental QALYs, INR 272,216 incremental costs). The probabilistic cost-effectiveness ranged from 68.3% to 90.2%, with interpretation remaining cost-effective across all thresholds tested.
CONCLUSIONS: Whether trastuzumab is judged cost-effective in India depends as much on the chosen threshold as on the clinical data used. Published WTP/QALY estimates such as those from Chugh et al. (2026) could inform a future threshold for India, offering a study-derived alternative to the current GDP-per-capita benchmark.