Findings from randomized clinical trials may have limited generalizability to patients treated in routine clinical practice. This study examined the effectiveness of first-line palbociclib plus letrozole versus letrozole alone on survival outcomes in patients with hormone receptor–positive (HR+)/human epidermal growth factor receptor–negative (HER2−) metastatic breast cancer (MBC) treated in routine clinical practice in the USA. This was a retrospective observational analysis of electronic health records within the Flatiron Health Analytic Database. A total of 1430 patients with ≥ 3 months of follow-up received palbociclib plus letrozole or letrozole alone in the first-line setting between February 3, 2015, and February 28, 2019. Stabilized inverse probability treatment weighting (sIPTW) was used to balance baseline demographic and clinical characteristics. Real-world progression-free survival (rwPFS) and overall survival (OS) were analyzed. After sIPTW adjustment, median follow-up was 24.2 months (interquartile range [IQR], 14.2–34.9) in the palbociclib group and 23.3 months (IQR, 12.7–34.3) in those taking letrozole alone. Palbociclib combination treatment was associated with significantly longer median rwPFS compared to letrozole alone (20.0 vs 11.9 months; hazard ratio [HR], 0.58; 95% CI, 0.49–0.69; P < 0.0001). Median OS was not reached in the palbociclib group and was 43.1 months with letrozole alone (HR, 0.66; 95% CI, 0.53–0.82; P = 0.0002). The 2-year OS rate was 78.3% in the palbociclib group and 68.0% with letrozole alone. A propensity score matching analysis showed similar results. In this “real-world” population of patients with HR+/HER2− MBC, palbociclib in combination with endocrine therapy was associated with improved survival outcomes compared with patients treated with letrozole alone in the first-line setting. Clinicaltrials.gov; NCT04176354

中文翻译：

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在美国真实临床实践中，一线哌柏西利联合来曲唑与单独使用来曲唑治疗 HR+/HER2− 转移性乳腺癌的疗效比较


随机临床试验的结果对于常规临床实践中治疗的患者的普遍性可能有限。本研究检验了一线哌柏西利联合来曲唑与单用来曲唑对常规临床治疗的激素受体阳性 (HR+)/人表皮生长因子受体阴性 (HER2−) 转移性乳腺癌 (MBC) 患者生存结果的有效性在美国练习。这是对 Flatiron 健康分析数据库中电子健康记录的回顾性观察分析。 2015年2月3日至2019年2月28日期间，共有1430名随访≥3个月的患者在一线接受哌柏西利加来曲唑或单用来曲唑治疗。使用稳定逆概率治疗权重（sIPTW）来平衡基线人口统计和临床特征。分析了现实世界的无进展生存期 (rwPFS) 和总生存期 (OS)。 sIPTW 调整后，哌柏西利组的中位随访时间为 24.2 个月（四分位距 [IQR]，14.2-34.9），而单独服用来曲唑组的中位随访时间为 23.3 个月（IQR，12.7-34.3）。与单用来曲唑相比，Palbociclib 联合治疗的中位 rwPFS 显着延长（20.0 个月与 11.9 个月；风险比 [HR]，0.58；95% CI，0.49–0.69；P < 0.0001）。哌柏西利组未达到中位 OS，单用来曲唑组为 43.1 个月（HR，0.66；95% CI，0.53–0.82；P = 0.0002）。哌柏西利组的 2 年 OS 率为 78.3%，而单独使用来曲唑组的 2 年 OS 率为 68.0%。倾向得分匹配分析显示了类似的结果。 在这个“现实世界”的 HR+/HER2− MBC 患者群体中，与一线治疗中单独使用来曲唑治疗的患者相比，哌柏西利联合内分泌治疗可改善生存结果。临床试验。政府； NCT04176354