Abstract 677P
Background
Older men are at high risk for adverse events (AEs) from androgen deprivation therapy (ADT). In this phase II study, we evaluated Enz and Dut/Fin in lieu of ADT for at-risk older men with HNSPCa.
Methods
Eligible patients were >=65 years (y) and at high risk of AE from ADT per geriatric assessment (GA) or treating physicians; metastatic (M1) or non-metastatic (M0) HNSPCa with a PSA doubling time ≤9 months, and testosterone>50ng/dl. Enz 160mg daily and Dut 0.5mg daily or Fin 5mg daily was administered until disease progression. GA was performed at baseline and week (wk) 61 and/or at the time of progression. GA included validated tests: Instrumental Activities of Daily Living (IADLs), fall history, Short Physical Performance Battery (SPPB), Geriatric Depression Scale (GDS), and Montreal Cognitive Assessment (MOCA). The prevalence of impairment for each assessment was calculated; change in prevalence from baseline to wk. 61 was analyzed using paired sample t-test.
Results
43 men enrolled in the study. At study entry, median age was 77 y (range 66-91) and 93% were ECOG 0-1; 63% (n=27) had M1 HNSPCa, with the majority (67%) having Gleason 6 or 7 disease. Median PSA was 11.38 ng/ml (2-144). Median testosterone level was 342 ng/dl (56-639). 18.6% met the cutoff for impairment for IADLs, 53.7% for SPPB, 7.9% for GDS, 64.3% for MOCA, and 9.8% had a recent fall. Median follow-up was 133 wks (3-229). At the time of analysis, 28 patients (65%) remain on study treatment with ongoing responses beyond 122 weeks. The median time to 90% PSA decline was 7 wks (7-20). Median PSA nadir was 0.01 ng/ml. 95.3% (n=41) of patients experienced at least one AE; the most common any grade AE was fatigue (65%) and Grade 3 AEs were hypertension (27%). No patient had treatment-related Grade 4 or 5 AEs. Of the GA domains, only the prevalence of IADLs impairment showed a statistically significant increase from 18.6% at baseline to 40.6% at wk 61 of treatment (p = 0.036).
Conclusions
Enz with Dut/Fin demonstrated efficacy in lowering PSA and maintaining durable responses with a reasonable toxicity profile, and no significant impact on the majority of GA domains in older men with HNSPCa.
Clinical trial identification
NCT02213107.
Editorial acknowledgement
Legal entity responsible for the study
Chunkit Fung.
Funding
Astellas, Pfizer.
Disclosure
All authors have declared no conflicts of interest.