OBJECTIVES: Patients with advanced prostate cancer (PC) may develop resistance to androgen deprivation therapy and progress to metastatic castration-resistant prostate cancer (mCRPC). Limited evidence exists characterizing real-world healthcare costs of patients with mCRPC. This study described healthcare costs of patients pre- and post-progression to mCRPC as well as after first-line (1L) mCRPC therapy initiation.

METHODS: Linked data from the Flatiron Metastatic PC Core Registry and Komodo Health solutions were evaluated. Patients who initiated 1L mCRPC therapy (index date) on or after mCRPC diagnosis were included. Patients were excluded if they initiated a clinical trial drug in 1L, had <12 months of insurance eligibility prior to index, or no claims in Komodo for the Flatiron-defined index therapy. PC-related total costs (medical and pharmacy) per-patient-per-month (PPPM) were described from a payer’s perspective in the 12-month period prior to 1L therapy initiation, which included the periods pre- and post-progression to mCRPC, as well as during 1L therapy. Flatiron Health, Inc. did not participate in data analyses.

RESULTS: A total of 459 patients with mCRPC were identified (mean age 70 years, 57% white, 45% commercially insured, and 43% Medicare insured). On average pre-index, PC-related total costs PPPM were $2,821 with $2,439 pre-mCRPC and $6,402 following progression to mCRPC. The average duration of 1L mCRPC therapy was 8.5 months, during which mean PC-related total costs were $11,591 PPPM. PC-related medical costs PPPM increased from $1,445 pre-index, to $5,368 following 1L mCRPC therapy initiation.

CONCLUSIONS: Prior to 1L mCRPC therapy initiation, PC-related total costs were more than 2 times higher post- relative to pre-progression to mCRPC. Relative to before 1L mCRPC therapy initiation, PC-related medical costs more than tripled, and PC-related total costs were more than 4 times higher during 1L mCRPC therapy. Clinical interventions aiming to delay costly progression in patients with advanced PC are warranted.