KEY TAKEAWAYS
- The Phase 3 study explored the efficacy of more than 6 cycles of D-ADT for certain mHSPC patients.
- The study suggested that exceeding 6 cycles of D-ADT in mHSPC is possible without added toxicity but doesn’t show better efficacy than the standard 6 cycles.
Several phase III clinical studies have evaluated the effectiveness and safety of administering 6 cycles of docetaxel in combination with androgen deprivation therapy (D-ADT) for treating metastatic hormone-sensitive prostate cancer (mHSPC). This regimen currently serves as the standard treatment for a specific patient subgroup. This study aimed to determine if extending the treatment beyond 6 cycles offers greater effectiveness than this standard protocol.
Researchers conducted a retrospective analysis of patient data from a large tertiary care facility. The patients (pts) had confirmed adenocarcinoma of the prostate and verified metastatic involvement through radiological testing. All mHSPC pts initially received D-ADT (75 mg/m2) via intravenous injection on day one of each 21-day cycle. A fraction of these pts received more than the typical 6 cycles.
Researchers analyzed clinical and pathological variables of treatment-associated toxicities and measured outcomes like progression-free survival on D-ADT (PFS1), progression-free survival on subsequent treatments (PFS2), and overall survival (OS) using the log-rank test.
From 2018 to 2022, 88 mHSPC pts were treated and monitored for an average duration of 11.9 months. The average age was 66.3 years, 78.4% had a Gleason score of 8 or higher, 69.3% met the CHAARTED high-volume criteria, and 73.9% met the LATITUDE high-risk criteria. A total of 56 pts received 6 or fewer cycles (average of 5.2 cycles), while 32 pts received more than 6 cycles (average of 9.2 cycles).
The incidence of toxicities was similar between the groups. No marked differences in median PFS1 (14.0 vs. 13.7 months) or PFS2 (5.5 vs. 8.9 months) were observed. The median OS for the standard group was 39.9 months, while the median OS for the extended treatment group is still pending.
Although administering more than 6 cycles of D-ADT in mHSPC is feasible without substantial added toxicity, it does not display improved efficacy over the 6-cycle standard. While overall survival data is still incomplete, the advantage of additional upfront chemotherapy is questionable. This prompts the need for additional research, especially considering the emergence of new triplet combinations that could make the current doublet D-ADT approach obsolete.
Source: https://www.auajournals.org/doi/10.1097/JU.0000000000003257.17
Clinical Trial: https://classic.clinicaltrials.gov/ct2/show/NCT00309985
Aydogdu, Can; Urban, Florian; Tamalunas, Alexander; Berg, Elena; Götz, Melanie; Rodler, Severin; Heinemann, Volker; Stief, Christian G.; Casuscelli, Jozefina MP29-17 EFFICACY AND FEASIBILITY OF ADDITIONAL CYCLES OF DOCETAXEL IN COMBINATION WITH ANDROGEN DEPRIVATION THERAPY IN METASTATIC HORMONE-SENSITIVE PROSTATE CANCER, Journal of Urology: April 2023 – Volume 209 – Issue Supplement 4 doi: 10.1097/JU.0000000000003257.17
