(UroToday.com) The 2022 GU ASCO Annual meeting included a prostate cancer session highlighting work from Dr. Elisabetta Malangone-Monaco and colleagues presenting results of their study assessing real-world treatment patterns among patients with metastatic castration resistant prostate cancer (mCRPC) in the United States. mCRPC is an incurable disease with a poor prognosis. Though multiple treatments such as novel hormonal therapies (NHT: abiraterone, enzalutamide, docetaxel, cabazitaxel, sipuleucel-T, etc.) are approved, real-world data regarding treatment sequencing are lacking. This study assesses the real-world treatment patterns within the context of FDA-approved life-prolonging treatments for mCRPC.
The IBM MarketScan database was used to identify newly diagnosed (incident) mCRPC patients from January 1, 2014, to May 31, 2020. Adult males were required to have a diagnosis of prostate cancer, and subsequently evidence of metastasis and castration (medical or surgical). Incident mCRPC status (index) was determined in 3 ways:
- Treatment with an NHT within 3 months after castration and an FDA-approved mCRPC treatment ≥3 months after NHT
- First FDA-approved treatment ≥6 months after castration
- First FDA-approved treatment 3-6 months after castration and a second FDA-approved treatment ≥3 months after treatment
As follows is the algorithm for identifying mCRPC patients in administrative claims data:
Lines of therapy were measured in the variable-length follow-up of ≥1 month and consisted of all drugs observed within 28 days of first observed treatment. Duration of therapy was measured as start of line to start of next line or end of enrollment.
A total of 2,912 mCRPC patients met all study criteria and received ≥1 line of therapy with a mean duration of follow-up of 15.9 months (SD 12.5 months). Among these patients, 47.8% had ≥2 lines of therapy, and 21.8% had ≥3 lines of therapy. Patients were an average age of 71 years at index and used leuprolide (87%), abiraterone (10%), docetaxel (9%), and enzalutamide (8%) prior to index. In mCRPC, the most commonly observed first line monotherapy regimens were abiraterone (35%), enzalutamide (34%), and docetaxel (14%). The most common observed second-line treatments were enzalutamide (36%), abiraterone (27%), and docetaxel (14%). As follows is a summary of mCRPC treatments stratified by treatment line:
Mean duration of first line was 292 days compared to 245 days in second line. Many unique treatment sequences were observed. The most common first to second line treatment sequences were NHT to NHT (17.1%) followed by NHT to taxane chemotherapy (6.5%). Rechallenge with an alternate NHT was the most frequently observed treatment sequence (abiraterone to enzalutamide 7.2%; enzalutamide to abiraterone 5.5%):
Opioids (62%) and denosumab (47%) use were common in mCRPC patients.
Dr. Malangone-Monaco concluded this presentation by assessing real-world treatment patterns among patients with mCRPC with the following summary statements:
- Among mCRPC patients, NHTs were the most common first and second lines of therapy, and alternate NHT after a first NHT was the most common sequence
- With rapidly evolving treatment options in metastatic prostate cancer, these data can help guide estimation of eligible patients for different clinical trials
- Further studies are needed to understand the high attrition from first line to subsequent lines of therapy, the reasons for treatment preference, and impact on clinical outcomes with different treatment sequencings
Presented by: Elisabetta Malangone-Monaco, IBM Watson Health, Cambridge, MA
Co-Authors: Weiyan Li, Virginia Noxon, Shan Jiang, Suvina Amin, Sameer Ghate, Umang Swami, Neeraj Agarwal
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, @zklaassen_md on Twitter during the 2022 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, Thursday Feb 17 – Saturday Feb 19, 2022