Real-world baseline characteristics and first-line (1L) treatment (Tx) in patients (pts) with de novo metastatic castration-sensitive prostate cancer (mCSPC) by disease volume.

Abstract

e17081 Background: Intensification of androgen deprivation therapy (ADT) using novel hormonal therapies (NHT) has been established as a new standard of care for pts with mCSPC. Tx intensification still remains suboptimal, and data in de novo mCSPC pts is limited. Moreover, prior studies utilized claims data and so could not assess the impact of disease burden on Tx intensification. This study assessed baseline characteristics and 1L Tx patterns in pts with high-volume (HV) vs low-volume (LV) de novo mCSPC. Methods: This retrospective study used the Veterans Affairs Informatics and Computing Infrastructure to identify adult men who had ≥1 ICD code for prostate cancer and de novo mCSPC diagnosed between February 2018 and June 2020 confirmed by clinical chart review and initiated either ADT alone, ADT + first-generation non-steroidal anti-androgens [NSAA], or ADT+NHT. Index date was defined as ADT initiation date. The volume of disease was defined as HV or LV per the CHAARTED trial criteria (presence of visceral metastasis and/or ≥4 bone metastases, with ≥1 metastasis beyond the pelvis and vertebral column). Clinical data was hand abstracted from the medical record. Baseline characteristics and 1L Tx were analyzed descriptively. Results: Of the 380 de novo mCSPC pts reviewed, 57% had HV and 43% had LV disease. Mean age of pts was similar between HV and LV cohorts, 74.5 vs 75.2 years, respectively. In addition, the proportion of Black vs White pts in the HV and LV cohorts was similar, 34% and 35% were Black, and 66% and 65% were White, respectively. At index date, HV pts had higher median prostate-specific antigen (153.1 ng/mL vs 73.8 ng/mL) and alkaline phosphatase (192.0 IU/L vs 106.0 IU/L) vs LV pts. HV pts were less likely to have diabetes and cardiovascular comorbidities than LV pts (Table); however, the distribution of Charlson Comorbidity Index score was similar between cohorts (mean [SD]: 4.4 [3.1] vs 4.2 [3.1]). Among the pts with bone metastases only, HV pts had higher proportion (65%) of “too numerous to count” bone metastases vs LV pts (9%). While ADT+NHT use was slightly more common among HV pts (35%) vs LV pts (27%), in both HV and LV cohorts, ADT±NSAA was the most common 1L Tx (Table). The median 1L Tx duration was shorter in the HV pts compared with the LV pts (286 vs 358 days). Conclusions: The results showed that Tx intensification was underutilized in de novo mCSPC pts, even among those with HV, pointing toward an unmet need among pts with de novo mCSPC regardless of disease burden. [Table: see text]