5PSQ-081 Docetaxel, abiraterone and androgen deprivation therapy: efficacy and safety analysis

<h3>Background and Importance</h3> There are various strategies for treating high-volume hormone-sensitive metastatic prostate cancer (HSmPC). One such strategy is the combination of abiraterone, docetaxel and androgen deprivation therapy (Abi+Doc+ADT) based on the results of the PEACE-1 study. Treatment selection should consider patient characteristics, safety profiles, drug interactions and efficiency criteria. <h3>Aim and Objectives</h3> To analyse the safety and efficacy profile of the triple therapy: Abi+Doc+ADT in patients with high-volume-HSmPC. <h3>Material and Methods</h3> Retrospective, observational, multicentre study between November 2021to September 2024 in patients with high-volume-HSmPC who received Abi+Doc+ADT after off-label approval. Evaluated efficacy variables included: number of cycles, progression-free survival (PFS), percentage of response by PSA (Prostate-Specific Antigen) considering progression as three consecutive increases (PEACE-1 criteria) and type of radiological response according to RECIST v1.1 criteria. For safety: previous and subsequent comorbidities, addition of medications during treatment, interactions between home and oncology medications and the development of adverse reactions (ARs) were recorded according to CTCAE v5.0 criteria. Statistical analysis was performed using Jamovi software. <h3>Results</h3> Thirty patients were included, median age 63 (54–85) and ECOG score of 0–1. 83.3% patients received 6 cycles of docetaxel and treatment was discontinued in five (two due to progression, two due to docetaxel intolerance and one due to pneumonia). Based on PSA values, 22 (73.3%) responded. One-year PFS was 88% (76%-100%, 95% CI) and the median PFS was not reached. Radiological response rate was 60%, with six complete responses (20%), eight partial response (26.7%), four stable disease (13.3%) and four with progression. 70% had pre-existing comorbidities, the most common: hypertension (33.3%), dyslipidaemia (33.3%) and type-2-diabetes mellitus (16.7%). Six patients (20%) developed lipid profile alterations, but no treatment modifications were necessary. Pharmacological interactions with abiraterone were observed in 40%, mainly an increased risk of statin-induced myotoxicity (type C), but no cases were reported. ARs occurred in 21 patients(70%):7 cases of asthenia and 5 gastrointestinal. Of these, 14 (46.7%) were grade 1–2. Seven patients (23.3%) had ARs related to abiraterone and treatment was discontinued in one case due to atrial fibrillation. No further clinical actions were required in the remaining cases. <h3>Conclusion and Relevance</h3> Our experience suggests that Abi+Doc+ADT is an effective therapy with promising results. Our study (2.8 years of follow-up) needs to evaluate whether the median PFS resembles that of the trial (4.46 years). It is a safe treatment, as most ARs were low-grade, manageable and the interactions were not clinically significant. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest