(UroToday.com) The 2023 ESMO annual meeting included a session on prostate cancer, featuring a presentation by Dr. Vivek Narayan discussing treatment patterns among novel hormonal therapy-experienced patients with metastatic castration-resistant prostate cancer (mCRPC). mCRPC represents the most aggressive form of prostate cancer and is associated with poor prognosis with an overall survival of less than two years. Patients with advanced prostate cancer are commonly treated with novel hormonal therapy, including enzalutamide, abiraterone, apalutamide, and darolutamide. However, treatment patterns following novel hormonal therapy remain unclear. The objective of this study was to evaluate treatment patterns among mCRPC patients with prior novel hormonal therapy.
This study used the Flatiron Health electronic health records data between January 1, 2013 to July 31, 2022. Novel hormonal therapy-experienced mCRPC patients with ≥ 1 line of therapy in the mCRPC setting and without chemotherapy in the last 365 days were included. The first line of therapy in the post-novel hormonal therapy mCRPC setting was defined as index line:
Treatment patterns in the post-novel hormonal therapy mCRPC setting were summarized.
A total of 804 patients were included and followed over a median 10.6 months (IQR 6.3 to 20.2). The study population was an average age of 72.8 years and consisted of 64.1% white and 10.2% black patients:
Among these patients, 239 (29.7%) patients used enzalutamide as index line of therapy, 191 (23.8%) patients used abiraterone, 171 (21.3%) used docetaxel, and 203 (25%) used other treatment:
Patients receiving prior novel hormonal therapy in the non-metastatic castration-resistant or metastatic castration-sensitive settings were more likely to cycle to novel hormonal therapies than those receiving prior novel hormonal therapy in the mCRPC setting. A total of 126 (16%) patients died within 90 days after index line of therapy while 494 (61%) patients received a second post-novel hormonal therapy line of therapy. Subsequently, 104 (13%) patients died within 90 days after the second post-novel hormonal therapy line of therapy while 265 (33%) patients received a third post-novel hormonal therapy line of therapy. Most patients received chemotherapy while fewer patients received novel hormonal therapies in the second and third post-novel hormonal therapy lines of therapy. Commonly observed treatment sequences included index enzalutamide followed by docetaxel (n = 62, 8%), index docetaxel followed by other chemotherapy (n = 54, 7%), and index abiraterone followed by docetaxel (n = 48, 6%). The median time on treatment for index line of therapy was 4.1 months, with 4.3 months for index enzalutamide, 4.0 months for index abiraterone, and 3.5 months for index docetaxel:
The median time to next therapy for index therapy was 6.2 months, with 7.2 months for index enzalutamide, 5.8 months for index abiraterone, and 5.8 months for index docetaxel:
There were several limitations associated with this study:
- The Flatiron Health network did not include urology practices where some patients may have received treatment for mCRPC. These patients may not have been captured in the database
- The Flatiron Health data were mostly collected from community-based oncology practices, thus results from the present study may not be representative of academic research centers
- Reasons for treatment discontinuation were not collected, which limits the ability to draw interference from the time on therapy and time to next therapy results, thus potential switch to practices not included in the data may also lead to mis-estimation
Dr. Narayan concluded his presentation by discussing treatment patterns among novel hormonal therapy-experienced patients with mCRPC with the following concluding statements:
- The real-world treatment patterns in the post-novel hormonal therapy mCRPC setting are heterogeneous
- Over 50% of patients attempted an additional novel hormonal therapy as the first treatment option during the post-novel hormonal therapy mCRPC period. In addition, approximately 40% of patients did not receive further treatment or died after the index therapy
- Following the failure of one additional line of novel hormonal therapy, a greater number of patients opted for chemotherapies rather than continuing with novel hormonal therapies
- The duration of therapies received in the post-novel hormonal therapy mCRPC was generally short
Presented by: Vivek K. Narayan, MD, MS, Assistant Professor of Medicine (Hematology-Oncology) at the Hospital of the University of Pennsylvania, Philadelphia, PA
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Associate Professor of Urology, Georgia Cancer Center, Wellstar MCG Health, @zklaassen_md on Twitter during the 2023 European Society of Medical Oncology (ESMO) Annual Meeting, Madrid, Spain, Fri, Oct 20 – Tues, Oct 24, 2023.