Cost-Effectiveness Analysis of PI3K Inhibitors for Relapsed or Refractory Follicular Lymphoma in China: A Comparison Between Linperlisib and Duvelisib.

[BACKGROUND] Linperlisib, a highly selective PI3K-δ inhibitor, was firstly approved in China in November 2022 for the treatment of patients with relapsed or refractory follicular lymphoma (r/r FL) who had received at least two prior lines of systemic therapy (3L+ FL), demonstrating compelling clinical efficacy.

[OBJECTIVE] This study aimed to evaluate the cost effectiveness of linperlisib compared to duvelisib for patients with 3L+ FL from the perspective of Chinese healthcare system.

[METHODS] A lifetime three-state partitioned survival model was developed to integrate comparative efficacy and direct costs. An unanchored matching-adjusted indirect comparison (MAIC) was conducted using individual data from NCT04370405 and published aggregate data from the DYNAMO trial, aiming to derive comparative efficacy data and calculate patients' life-years gained. Utility values were from GADOLIN study, as neither trial collected them. Quality-adjusted life-years (QALYs) were calculated by multiplying life-years by utility values. Direct costs included costs of drug acquisition, adverse events, subsequent salvage therapy, health-care resource use (HCRU), and end-of-life care. A 5% annual discount rate was applied to both future QALYs and costs. The primary outcome was the incremental cost-effectiveness ratio (ICER), calculated as discounted incremental costs divided by incremental QALYs. The willingness-to-pay (WTP) threshold was set at China's 2023 per capita GDP (CNY89,358/QALY), with an ICER below this threshold indicating linperlisib was more cost effective. Model robustness was verified via one-way deterministic and probabilistic sensitivity analyses (DSA and PSA).

[RESULTS] In the base-case analysis, linperlisib yielded an additional 1.58 QALYs (4.13 vs 2.55) at an incremental cost of CNY108,780 (CNY292,805 vs CNY184,025) compared with duvelisib. The resulting ICER was CNY68,996 per QALY, which was below the WTP. Although drug costs were the main cost driver, improved survival reduced end-of-life care costs by CNY1,507. Deterministic sensitivity analysis identified the price of linperlisib as the top influential parameter, yet all ICERs stayed below the WTP threshold. Probabilistic sensitivity analysis showed a 91.2% cost-effectiveness probability at the preset WTP, confirming robust findings.

[CONCLUSIONS] Linperlisib is cost effective compared to duvelisib for 3L+ FL patients in China, as verified in sensitivity analyses. Further study is warranted to confirm that it meets an unmet need in China.