Abstract 351P
Background
There are limited data on the association between nadir testosterone levels following ADT and outcomes in Chinese patients with mPC.
Methods
This single center, retrospective study collected data from the medical records of patients with mPC who received first-line continuous triptorelin pamoate 15 mg, as monotherapy, or in combination with non-steroidal anti-androgens or chemotherapy, for ≥1 year between 01 Jan 2010 and 31 Oct 2023. Non-responders to ADT were excluded. The primary endpoint was time to castration-resistant prostate cancer (CRPC; time from initiating ADT to CRPC, estimated using the Kaplan–Meier method), in patients with nadir testosterone <50 ng/dL within 1 year of ADT. Secondary endpoints included time to CRPC in patients with nadir testosterone <20 ng/dL, median testosterone levels, and safety. A Cox proportional hazards model was used to assess factors impacting time to CRPC.
Results
In total, 83 patients were included, with a mean (standard deviation [SD]) age and BMI of 75.8 (9.0) years and 23.8 (3.4) kg/m2, respectively. Most patients (90.4% [75/83]) received combined therapy. Within 1 year of ADT, 89.2% (74/83) of patients achieved nadir testosterone <20 ng/dL. The average (SD) median testosterone level among all patients over the 1 year following ADT was 14.4 (6.1) ng/dL and the median (range) time to nadir was 5.6 (0.5–12.7) months. By the cut-off date (31 Oct 2023), 43.4% (36/83) of patients with nadir testosterone <50 ng/dL had progressed to CRPC, with a median time to CRPC of 22.8 (95% CI 18.4–30.3) months. For patients with nadir testosterone <20 ng/dL, 45.9% (34/74) had progressed to CRPC, with a median time to CRPC of 22.3 (95% CI 18.4–30.3) months. Adverse events were reported in 10.8% of patients (9/83); all were grade 2 and not considered treatment related. No serious adverse events were reported.
Conclusions
In this real-world study, Chinese patients with mPC receiving triptorelin pamoate 15 mg, as a mono- or combined therapy, who achieved a nadir testosterone level of <50 ng/dL, reached a time to CRPC consistent with previous international studies.
Clinical trial identification
Editorial acknowledgement
The authors thank Jake Burrell PhD of Rude Health Consulting Limited, UK for providing medical writing support, which was sponsored by Ipsen Tianjin, China.
Legal entity responsible for the study
Ipsen Group – Ipsen (Tianjin) Pharmaceutical Trade Co., Ltd.
Funding
Ipsen.
Disclosure
S. Zhang, X. Qiu, J. Zhuang, Q. Zhang, L. Xu, V. Perrot, H. Guo: Financial Interests, Personal, Other, Received investigator fees for conduct of the study by corporate-sponsored research: Ipsen.