Cost-effectiveness of capivasertib plus abiraterone for PTEN-deficient metastatic hormone-sensitive prostate cancer in the United States

Background: On June 12, 2026, the US Food and Drug Administration (FDA) approved capivasertib (Truqap; AstraZeneca) in combination with abiraterone and prednisone for adult patients with metastatic androgen pathway modulation-naive or -sensitive (mAPMN/S) prostate cancer, corresponding clinically to metastatic hormone-sensitive prostate cancer (mHSPC), that is PTEN-deficient as detected by an FDA-authorized test. The pivotal CAPItello-281 trial demonstrated a statistically significant radiographic progression-free survival (rPFS) benefit (hazard ratio [HR] 0.81; p = 0.034) but a nonsignificant and immature overall survival (OS) benefit (HR 0.90; p = 0.401). Capivasertib carries a publicly available list price of approximately $23,762 per 28-day cycle. Objective: To estimate the incremental cost-effectiveness of capivasertib plus abiraterone and prednisone versus abiraterone and prednisone alone, both with androgen deprivation therapy (ADT), from the perspective of a US third-party payer. Methods: A three-state partitioned survival model (PSM) was developed with a lifetime horizon (40 years), 4-week cycle length, and 3% annual discount rate. Individual patient-level survival data were reconstructed from published Kaplan-Meier curves via the Guyot algorithm. Given OS immaturity and AIC differences of less than 1 point across six parametric families, a preregistered proportional hazards (PH) base case was applied: the trial OS HR of 0.90 was applied to the placebo parametric fit. Generic abiraterone, ADT, companion diagnostic, and monitoring costs used National Average Drug Acquisition Cost (NADAC) or Medicare reimbursement schedules; capivasertib used a publicly available list-price proxy, and the OS hazard ratio was sampled lognormally in PSA. Uncertainty was characterized via one-way sensitivity analysis, eight pre-specified OS extrapolation scenarios, four scenario analyses, and probabilistic sensitivity analysis (PSA; n = 10,000). Reporting followed CHEERS 2022 standards. Results: Capivasertib accrued 4.103 discounted QALYs at a total discounted cost of $1,455,507, versus 3.703 QALYs at $207,230 for abiraterone alone. Incremental cost was $1,248,277 and incremental QALYs 0.400, yielding an ICER of $3,120,720 per QALY. The probability of cost-effectiveness was 0% at willingness-to-pay thresholds of $100,000, $150,000, $200,000, and $500,000 per QALY. The most favorable OS extrapolation scenario (log-normal) yielded an ICER of $1,359,445 per QALY. The ratio of mean incremental cost to mean incremental QALY across PSA iterations was $3,148,744 per QALY; because a minority of iterations (13.54%) yielded a negative incremental QALY, the distribution of individual iteration ICERs is uninformative, and uncertainty was characterized using the cost-effectiveness acceptability curve and plane. Conclusions: At current list pricing, capivasertib plus abiraterone is not cost-effective for PTEN-deficient mHSPC from a US payer perspective. The result is structurally driven by high incremental drug acquisition cost and small incremental QALY gain under immature and nonsignificant OS data. Mature OS data and a major net-price reduction would likely be required for cost-effectiveness.