Treatment utilization in metastatic renal cell carcinoma (mRCC) following implementation of a national cancer drug list (CDL) drug reimbursement program in Singapore: A real-world single-centre study.

Abstract

482 Background: Immune checkpoint inhibitor (ICI) based combination therapy and Cabozantinib have shown overall survival benefits, for first-line (1L) and post-treatment settings respectively, in Phase 3 trials for metastatic renal cell carcinoma (mRCC). However, high drug costs pose barriers to therapeutic utilization. In addition, treatment with Cabozantinib often necessitates dose reductions for control of toxicities which may significantly impact quality of life. Singapore’s national Cancer Drug List (CDL), implemented on 1 st September 2022, is intended to improve drug access through indication-based state-funded reimbursement of treatment. We describe treatment utilization and outcomes in a real-world cohort of mRCC in National Cancer Centre Singapore (NCCS). Methods: In this real world study, patients treated at NCCS for mRCC were consented for inclusion into the genitourinary cancer registry. Data on demographics, disease characteristics, treatment and toxicities were extracted from electronic medical records, with data cutoff at 30th June 2025, and treatment utilization compared pre- and post-CDL implementation. Results: Of 244 consented patients, 217 received palliative systemic therapy. 152 were male, ethnicity distribution was 170/26/11/10 for Chinese/Malay/ Indian/Others respectively. Median age at treatment initiation was 64.4 (range 25.0-92.2). Subtypes include 164 clear-cell, 14 papillary, 3 chromophobe and 36 with histology not otherwise specified (NOS). 205 had 1L treatment initiated from 2018 following approval of immunotherapy-based combinations in 1L. Of 132 initiated 1L treatments pre-CDL, 79 (54.5%) incorporated ICI-based combinations, compared to 52 (71.2%) out of 73 post-CDL. Of 193 who did not receive Cabozantinib in 1L, 58 received Cabozantinib monotherapy subsequently (37/16/5 in 2 nd /3 rd /4 th lines respectively), with 25 initiated pre-CDL, and 33 post-CDL. Only 17 (29.3%) were initiated at the full dose of 60mg daily, while 41 (70.7%) were initiated at a dose reduction (37 at 40mg daily, 4 at 20mg daily). Further dose reductions were required in 22 due to significant treatment-related toxicities. Progression-free survival (PFS) for Cabozantinib monotherapy in this cohort was 6.8 months (95% CI 3.8-9.8). Conclusions: The implementation of CDL in Singapore has increased utilization of ICI-based combination therapy in 1L (71.2% vs 54.5%) in our institution. Widespread employment of Cabozantinib dose reductions to manage toxicities, both at initiation and during treatment, did not significantly impact efficacy in this real-world Asian cohort, with median PFS comparable to historical cohorts.