4CPS-200 Triple therapy for metastatic hormone-sensitive prostate cancer patients based on a pharmacological treatment algorithm

Background and Importance Standard treatment for metastatic hormone-sensitive prostate cancer (mHSPC) supplements androgen deprivation therapy (ADT) with docetaxel, second-generation hormonal therapy, or radiotherapy. However, the PEACE-1 study demonstrates that adding abiraterone plus prednisone to ADT and docetaxel improves survival with a moderate increase in toxicity, currently off label. Aim and Objectives To evaluate eligibility for abiraterone plus ADT and docetaxel in de novo metastatic hormone-sensitive prostate cancer (mHSPC) based on a pharmacological treatment algorithm. Material and Methods Observational, prospective, multidisciplinary study including all mHSPC patients scheduled for first-line treatment (July 2022/December 2022). The choice of triplet therapy was based on compliance with a pharmacological treatment algorithm, including: age 14, no fragility impression by the oncologist, ECOG 0–1, absence of comorbidities such as liver disease, coagulation problems, and/or active heart disease in the last 6 months; High Risk (at least two of the following characteristics): Gleason 8–10, ≥ 3 bone metastases and/or ≥ 1 visceral metastasis; High Volume (CHAARTED trial); and Prognostic Grade Group (ISSUP 2014-OMS 2016) 4–5. Other variables: PSA, comorbidities, polypharmacy, treatment. Progression-free survival (PFS) and treatment duration. Adverse reactions (AR). Results Twenty-nine patients were included, 75.9% were de novo mHSPC, 44.8% had high volume, of which 69.2% met all algorithm criteria. Patients treated with the triplet had a median age of 65 years, 100% had G8>14, 66.6% had ECOG 1, 77.7% had multiple bone metastases, mean PSA at the start was 136.32ng/ml, 77.7% had Gleason 9, 88.8% had ISSUP 5, only one patient had >3 comorbidities, and three patients were on polypharmacy. The median treatment duration was 5.97 months, and PFS has not been reached yet, with only one patient progressing during docetaxel treatment, while the rest completed the proposed six cycles. 77.7% of patients experienced some AR, none of which were G3–4. The most common AR was skin-related (44.4%), followed by edema (33.3%), insomnia (22.2%), digestive toxicity (11.1%), neurotoxicity (11.1%), and elevated transaminases (11.1%). Conclusion and Relevance Choosing triplet therapy based on a studied algorithm helps identify patients who can benefit more from treatment, focusing on those at higher risk and with worse prognosis, leading to favourable outcomes in efficacy and safety. References and/or Acknowledgements Conflict of Interest No conflict of interest.