Cost-effectiveness analysis of eight treatments for metastatic hormone-sensitive prostate cancer (mHSPC) stratified by homologous recombination repair (HRR) status.

e17060 Background: After approval of androgen deprivation therapy (ADT) with niraparib and abiraterone/prednisone (NAAP) for homologous recombination repair (HRR) -deficient mHSPC, we conducted a U. S. public-payer cost-effectiveness analysis (CEA) comparing NAAP with abiraterone/prednisone (AAP). We also assessed CEA for seven established first-line mHSPC options regardless of HRR status: ADT mono, and ADT combined with docetaxel (DA), abiraterone (AAP), apalutamide (AAT), enzalutamide (ET), darolutamide plus docetaxel (DAD), and enzalutamide plus docetaxel (EAD). Methods: A partitioned-survival model with monthly cycles over a lifetime horizon (progression-free, post-progression, death) incorporated overall survival (OS) and radiographic progression free (rPFS) data derived from survival curves. Drug acquisition costs were from 2025 Federal Supply Schedule. Administration, subsequent-therapy, and adverse event costs and utilities were obtained from literature. Incremental cost-effectiveness ratio (ICER) was estimated at a willingness-to-pay (WTP) threshold of 150, 000-200, 000/Quality of life Years (QALY). Deterministic and probabilistic sensitivity analyses assessed parameter uncertainty. Results: A CEA model for NAAP Vs. AAP showed that mean lifetime costs were 62, 180 for AAP and 768, 069 for NAAP. Mean QALYs were higher for NAAP than AAP (3. 31vs 3. 01). ICER for NAAP was 2. 35M/QALY, far exceeding WTP. Across seven treatment strategies (N = 8, 333 pts) lifetime costs ranged from 43K (ADT) to 728K (DAD) and Quality of Life Years (QALYs) from 3. 38 to 4. 42. ET, EAD, and AAT regimens were more costly and less effective than alternatives. Among non-dominated options, DA had an ICER of 30, 823/QALY vs ADT, and AAP yielded 314, 796/QALY. Although DAD achieved the highest lifetime QALYs (4. 42), its incremental cost was large (ICER 1. 41M/QALY). Conclusions: From a U. S. public-payer perspective, the addition of NAAP offered incremental benefit for pts with HRR-positive mHSPC; however, the ICER for NAAP was 2. 35M/QALY. In mHSPC pts without considering HRR status, DA is consistently cost-effective, and AAP may be considered cost-effective at higher WTP thresholds. Cost-effectiveness results. HRR-deficient mHSPC Cost (2025-USD) Effectiveness (QALY) ICER AAP +ADT 62, 180 3. 01 NAAP +ADT 768, 069 3. 31 2, 352, 600 non-HRR deficient status ADT mono 43, 120 3. 38 DA 59, 656 3. 92 30, 823 AAP +ADT 71, 878 3. 95 314, 796 ET 359, 095 2. 57 Dominated a EAD 493, 402 4. 12 Dominated b AAT 558, 518 4. 27 Dominated b Darolutamide + ADT + Docetaxel (DAD) - results in text. a This treatment strategy is more costly and less effective than another treatment strategy (ie, absolute dominance). b This treatment strategy is more costly and less effective than a linear combination of other treatment strategies (ie, extended dominance).