Chesapeake Urology, Towson, MD.
Analysis Group, Inc., Montréal, QC, Canada.
Urol Oncol. 2023 May;41(5):252.e19-252.e27. doi: 10.1016/j.urolonc.2023.03.013. Epub 2023 Apr 19.
Deep prostate-specific antigen (PSA) response (≥90% reduction in PSA [PSA90]) is an important early response indicator of radiographic progression-free survival and overall survival in patients with metastatic castration-sensitive prostate cancer (mCSPC). This study compared PSA90 responses by 6 months between patients with mCSPC at first use of apalutamide or abiraterone acetate, both androgen receptor signaling inhibitors.
Clinical data from 77 community urology practices in the United States were analyzed. Patients with mCSPC were classified into treatment cohorts based on their first filled prescription (index date) for apalutamide or abiraterone acetate on or after September 17, 2019 (approval date of apalutamide for mCSPC). Patients were followed from the index date until the earliest of index treatment discontinuation, treatment switch, end of clinical activity, or end of data availability (September 17, 2021). Inverse probability of treatment weighting (IPTW) was used to ensure similarity in distribution of baseline characteristics between cohorts. PSA90 was defined as the earliest attainment of ≥90% reduction in PSA relative to baseline (most recent value within 13 weeks pre-index). Time to PSA90 between cohorts was compared by weighted Kaplan-Meier analysis and with Cox proportional hazards models.
A total of 364 patients treated with apalutamide and 147 treated with abiraterone acetate met the study criteria. Patient characteristics were well balanced after IPTW. By 6 months post-index, patients initiated on apalutamide were 53% more likely to achieve PSA90 than those initiated on abiraterone acetate (P = 0.016). Similar results were observed by 9 and 12 months post-index (both P ≤ 0.019). The median time to PSA90 was 3.5 months for the apalutamide cohort and not reached for the abiraterone acetate cohort.
In real-world patients with mCSPC, significantly more patients achieved PSA90 with apalutamide than with abiraterone acetate, and this response was achieved earlier with apalutamide.
深度前列腺特异性抗原（PSA）应答（PSA 降低≥90%[PSA90]）是转移性去势敏感前列腺癌（mCSPC）患者放射学无进展生存和总生存的重要早期应答指标。本研究比较了首次使用阿帕鲁胺或醋酸阿比特龙的 mCSPC 患者在 6 个月时的 PSA90 应答情况，两者均为雄激素受体信号抑制剂。
分析了美国 77 家社区泌尿科实践的数据。根据首次开具阿帕鲁胺或醋酸阿比特龙处方的日期（索引日期），将 mCSPC 患者分为治疗队列，日期为 2019 年 9 月 17 日（阿帕鲁胺用于 mCSPC 的批准日期）或之后。患者从索引日期开始随访，直至最早发生索引治疗停药、治疗转换、临床活动结束或数据可用结束（2021 年 9 月 17 日）。采用逆概率治疗加权（IPTW）确保队列间基线特征分布相似。PSA90 定义为与基线相比 PSA 最早达到≥90%的降低（索引前 13 周内最近一次值）。通过加权 Kaplan-Meier 分析和 Cox 比例风险模型比较队列间 PSA90 的时间。
共有 364 例患者接受阿帕鲁胺治疗，147 例患者接受醋酸阿比特龙治疗，符合研究标准。经 IPTW 后患者特征均衡。索引后 6 个月，阿帕鲁胺组患者 PSA90 应答的可能性比醋酸阿比特龙组高 53%（P=0.016）。索引后 9 个月和 12 个月也观察到类似结果（均 P≤0.019）。阿帕鲁胺组 PSA90 的中位时间为 3.5 个月，而醋酸阿比特龙组未达到。
在真实世界的 mCSPC 患者中，阿帕鲁胺组达到 PSA90 的患者比例明显高于醋酸阿比特龙组，且阿帕鲁胺组更早达到 PSA90。
