Alternative to ADT for Prostate Cancer: Older Men May Benefit From Combination Therapy
Posted: Monday, December 7, 2020
Older men with hormone-naive prostate cancer are at high risk of adverse events from androgen-deprivation therapy (ADT), so a research team conducted a phase II trial to see whether they might benefit from combination therapy with enzalutamide plus dutasteride or finasteride. According to Deepak Kilari, MD, of the Medical College of Wisconsin, Milwaukee, and colleagues, the regimen demonstrated efficacy in lowering prostate-specific antigen (PSA) and maintaining durable responses with a reasonable toxicity profile. It appeared to have no significant impact on most geriatric assessment domains. The findings of this final study analysis were presented during the virtual edition of the European Society for Medical Oncology (ESMO) Virtual Congress 2020 (Abstract 677P).
The 43 study enrollees' median age was 77 years; 93% had an Eastern Cooperative Oncology Group performance status of 0 or 1, and all had a PSA doubling time of up to 9 months. Their initial median PSA and testosterone levels were 11.38 ng/mL and 342 ng/dL, respectively.
Daily, the participants received enzalutamide plus dutasteride or finasteride until disease progression. Geriatric assessment, performed at baseline and at week 61 and/or at the time of disease progression, included five validated tests: Instrumental Activities of Daily Living, fall history, Short Physical Performance Battery, Geriatric Depression Scale, and Montreal Cognitive Assessment. Ultimately, at a median follow-up of 133 weeks, “only the prevalence of Instrumental Activities of Daily Living impairment showed a statistically significant increase from 18.6% at baseline to 40.6% at week 61 of treatment (P = .036),” reported the researchers.
With a median time to 90% PSA decline of 7 weeks, the median PSA nadir was 0.01 ng/mL. “At the time of analysis, 28 patients (65%) remained on study treatment, with ongoing responses beyond 122 weeks,” noted Dr. Kilari and co-investigators.
Almost all patients (95.3%) experienced at least one adverse event. The most common adverse event of any grade was fatigue and of grade 3 was hypertension.
Disclosure: The study authors reported no conflicts of interest.