5PSQ-071 Safety profile of apalutamide for the treatment of prostate cancer in clinical practice

<h3>Background and Importance</h3> Apalutamida is a second-generation androgen receptor inhibitor used for the treatment of prostate cancer (PC). Its safety was demonstrated in the phase 3 studies (ARN-509–003 and 56021927PCR3002). <h3>Aim and Objectives</h3> Study of safety of apalutamide in a third-level hospital <h3>Material and Methods</h3> Observational, retrospective, descriptive study in which all patients who started treatment with apalutamide were included (2022 and 2023). The data were obtained from the electronic medical record and the pharmacotherapeutic history elaborated in the oncohaematological pharmaceutical care consultation. The following variables were collected: age, sex, quality of life (ECOG, Eastern Cooperative Oncology Group scale), baseline PSA (prostate-specific antigen) values, type of metastasis and adverse effects (AEs), as well as duration, discontinuation or suspension of treatment and reasons for discontinuation. <h3>Results</h3> Thirty-four patients were included with a median age of 73 (IQR ‘Interquartile Range’, 69 – 82), 88% of them diagnosed with mHSPC (Metastatic Hormone-Sensitive PC, M1a 23%, M1b 47% and M1c 30%) and 12% nmCRPC (Nonmetastatic castration-resistant PC). The baseline ECOG was 0–1 in 97% (33/34), and ECOG 2 in 3% (1/34). The median PSA at baseline was 2.88 ng/mL (IQR 14.75–0.63). Regarding safety, 94.1% (32/34) of patients reported any AE. A total of 78 AEs were analysed, the most common being hot flushes (19%, 15/78), asthenia (19%, 15/78), and arthralgia (18%, 14/78), followed by skin rashes (15%, 12/78) and diarrhoea (6%, 5/78). Falls accounted for 4% (3/78), hypothyroidism 3% (2/78) and tachycardia 3% (2/78) of AEs. Less frequently detected AEs (&lt;2%) were hypertension, hypotension, hypercholesterolaemia, headache, lacrimation, salivation, taste alteration, irritability, somnolence, weight loss. During the study period, 29% (10/34) of patients discontinued treatment due to lack of efficacy (9%, 3/34) and 20% (7/34) for safety reasons (falls (60%, 4/7) and tachycardia (28%, 2/7). Median duration of treatment was 4.6 months (IQR 10.5–2). <h3>Conclusion and Relevance</h3> Results showed a safety profile of apalutamide in accordance with the data obtained in the literature. Most patients reported treatment-related AEs. A high percentage of patients discontinued treatment for safety reasons, mostly related to falls or tachycardia. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest