Deep and rapid prostate-specific antigen (PSA) response is an important indicator to consider in treatment decision-making given its predictive value for long-term clinical outcomes in metastatic castration-sensitive prostate cancer (mCSPC).
This study compared early PSA90 response (⩾90% reduction in PSA levels) in a large and recent cohort of patients with mCSPC initiating apalutamide or enzalutamide in the United States.
A retrospective longitudinal analysis was conducted.
Patients with mCSPC were identified from linked claims and electronic medical record data from the United States and categorized into the apalutamide or enzalutamide cohorts based on the first claim/dispensation on or after December 16th, 2019. To adjust for differences observed in patient characteristics between the two cohorts, inverse probability of treatment weighting was used. Weighted Cox proportional hazards models were used to compare PSA90 response (PSA measurement ⩾90% lower than the most recent pretreatment PSA value) by 6 months post treatment initiation between the apalutamide and enzalutamide cohorts.
Among 1296 patients with mCSPC treated with apalutamide and 1111 treated with enzalutamide, pretreatment characteristics were balanced after weighting. PSA90 response by 6 months was achieved by 61.7% of patients in the apalutamide cohort and 55.2% of patients in the enzalutamide cohort (weighted hazard ratio: 1.20 [95% confidence interval: 1.07, 1.36]; p = 0.003). Patients in the apalutamide cohort achieved a PSA90 response earlier than those in the enzalutamide cohort (median time to PSA90 response: 3.7 vs 4.9 months, respectively).
In a large, real-world, retrospective analysis, patients with mCSPC treated with apalutamide were associated with a significantly higher rate of early PSA90 response compared to enzalutamide.
Comparing two treatment options for metastatic castration-sensitive prostate cancer: apalutamide versus enzalutamide This real-world study compared two medications used to treat men with advanced prostate cancer that has spread but still responds to hormone treatment. These oral medicines, apalutamide and enzalutamide, are taken with hormone therapy to help slow or stop cancer growth. Physicians often use a blood test called prostate‑specific antigen (PSA) to see how well the treatment is working. A large drop in PSA, by 90% or more, is called a PSA90 response and achieving this quicker can be a sign that treatment is working well and may help patients live longer. We reviewed insurance and medical records from more than 2,400 men with metastatic castration-sensitive prostate cancer in the United States who started either apalutamide or enzalutamide between 2019 and 2023 and compared how many patients reached a PSA90 response within six months of starting treatment. A larger percentage of patients treated with apalutamide (62%) achieved a PSA90 response by six months post-treatment than patients treated with enzalutamide (55%). Patients treated with apalutamide reached PSA90, on average, one month faster than those patients treated with enzalutamide. The findings from this study suggest an important clinical benefit of treatment with apalutamide in terms of producing a rapid and deep PSA response among patients with metastatic castration-sensitive prostate cancer.
Therapeutic advances in medical oncology. 2026 May 21*** epublish ***
Mehmet A Bilen, Benjamin H Lowentritt, Sabree Burbage, Charmi Patel, Carmine Rossi, Frederic Kinkead, Gordon Wong, Dominic Pilon, Neal D Shore
Winship Cancer Institute of Emory University, Atlanta, GA, USA., Chesapeake Urology, Towson, MD, USA., Johnson & Johnson, Horsham, PA, USA., Analysis Group, Inc., Montréal, QC, Canada., START Carolinas/Carolina Urologic Research Center, 823 82nd Parkway, Myrtle Beach, SC 29572, USA.