Real-World outcome of apalutamide therapy in mHSPC patients depending on age, dose reduction, and PSA decline: Data from the German AmPel trial.

Abstract

e17094 Background: Data from the Titan Trial (apalutamide + ADT) showed a benefit for mHSPC patients who achieved low ( < 0.2 ng/ml) and ultra-low (UL-1 0.02–0.2 ng/ml / UL-2 < 0.02 ng/ml) PSA levels under apalutamide (APA) therapy. The AmPel study (Use of Apalutamide in Prostate Cancer in Middle-Hesse) has been collecting data from mHSPC patients in urology practices since November 2021. Methods: In this multicenter investigator initiated trial (IIT), patient data (demographic and tumor-specific) as well as outcomes (PSA response/course including UL ( < 0.2 ng/ml), UL-1 (0.02-0.2 ng/ml), UL-2 ( < 0.02 ng/ml)), side effects, and dose modifications are recorded. A positive approval from the ethics committee is available. Results: 127 pat (73 y, range 43-87, ECOG 0/1/2/3: 33.1/50.4/9.4/4.7%) were documented from 9 specialized urology practices (med FU 14 months). Synchronous mHSPC was present in 67.7%, an initial Gleason score ≥ 8 was observed in 65.3%, high-volume mHSPC in 56.7%, and the median PSA before starting APA was 15.4 ng/ml. After 3 months PSA decreased by 98.5% and after 12 months by 99.5%. There was no PFS difference neither in older pat ( > 75 years, p = 0.46) nor in case of dose reduction (15%) of APA (p = 0.7). After 12 months, 32.6% of pat reached a UL-2 PSA and nearly the same number (31.6%) reached a UL-1 PSA. There was a significant PFS advantage for UL-1 PSA (HR 0.28) and UL-2 PSA (HR 0.06). In the overall cohort, PFS has not been reached yet. Currently, 77.2% are still receiving APA. In 22.8% treatment was discontinued after a median of 8 months: in 9.4% due to progression. Overall, 7 pat died – 2 (1.6%) due to PCA. Conclusions: Our Real World Data show that APA therapy is highly effective in mHSPC and achieving UL-PSA quickly and sustainably (64.2% after 12 months) as well as PSA decrease of > 95% (91.6% after 12 months) - associated with significantly improved PFS in an unselected patient population and good tolerability in daily practice.