Background
In the PEACE-1 trial (Fizazi, ESMO 2021), in pts with dn-hv-mCSPC, the addition of abiraterone to ADT + docetaxel (triplet therapy arm) resulted in a median OS of 61 months (OS on ADT + docetaxel arm was 42 months). However, independent contribution of docetaxel to efficacy of ADT + abiraterone in the triplet therapy arm of PEACE-1 trial is not clear. Furthermore, the efficacy of an novel hormonal therapy (NHT) specifically in dn-hv-mCSPC population has not been reported (LATITUDE trial’s eligibility did not include volume status). Herein, our objective was to assess PFS and OS in a cohort of dn-hv-mCSPC pts undergoing intensified ADT with either NHT (i.e. novel androgen receptor or androgen synthesis inhibitors) or docetaxel.
Methods
In this IRB-approved study, patient-level data were collected retrospectively. Eligibility: presence of dn-hv-mCSPC (hv per CHAARTED criteria) undergoing intensified ADT with either NHT or docetaxel started within 3 months of diagnosis. Study endpoints: PFS was calculated per PCWG-2 - defined PSA progression or radiographic progression or clinical progression whichever occurred first; OS was defined as start of therapy to date of death or censored at last follow-up. A multivariate analysis using the Cox proportional hazards (Cox-ph) model was used; the relationship between treatment intensification with both PFS and OS was assessed and adjusted for age at diagnosis, Gleason score, presence of visceral metastases, and PSA at baseline.
Results
85 pts with dn-hv-mCSPC were included: 45 received ADT + NHT; 40 received ADT + docetaxel. In the NHT vs docetaxel arms: median PFS were 23 vs 14 months; and median OS were 63 vs 36 months respectively. See the table for Cox-ph and adjusted co-variate results.
Conclusions
We for the first-time report the real-world survival outcomes with ADT + NHT specifically in pts with dn-hv-mCSPC. In addition, in these hypothesis-generating data, the OS of pts with dn-hv-mCSPC undergoing ADT + NHT or ADT + docetaxel were similar to those in the triplet therapy arm or ADT + docetaxel arm of PEACE-1 trial respectively. A randomized trial in pts with dn-hv-mCSPC comparing ADT + NHT vs triplet therapy may better characterize the benefit of the docetaxel component in the triplet therapy.