Palumbo Raffaella, Torrisi Rosalba, Sottotetti Federico, Presti Daniele, Rita Gambaro Anna, Collovà Elena, Ferzi Antonella, Agostinetto Elisa, Maria Teragni Cristina, Saltalamacchia Giuseppe, Tagliaferri Barbara, Balletti Emanuela, Bernardo Antonio, Quaquarini Erica
Medical Oncology, IRCCS ICS Maugeri, Pavia, Italy.
Department of Medical Oncology and Hematology Unit, Humanitas Clinical and Research Center, IRCCS, Rozzano, Milan, Italy.
Ther Adv Med Oncol. 2021 Mar 10;13:1758835920987651. doi: 10.1177/1758835920987651. eCollection 2021.
The CDK4/6 inhibitor palbociclib combined with endocrine therapy (ET) has proven to prolong progression-free survival (PFS) in women with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC). Few data are available regarding the efficacy of such a regimen outside the clinical trials.
This is a multicentre prospective real-world experience aimed at verifying the outcome of palbociclib plus ET in an unselected population of MBC patients. The primary aim was the clinical benefit rate (CBR); secondary aims were the median PFS, overall survival (OS) and safety. Patients received palbociclib plus letrozole 2.5 mg (cohort A) or fulvestrant 500 mg (cohort B).
In total, 191 patients (92 in cohort A, 99 in cohort B) were enrolled and treated, and 182 were evaluable for the analysis. Median age was 62 years (range 47-79); 54% had visceral involvement; 28% of patients had previously performed one treatment line (including chemotherapy and ET), 22.6% two lines and 15.9% three. An overall response rate of 34.6% was observed with 11 (6.0%) complete responses and 52 (28.6%) partial responses. Stable disease was achieved by 78 patients (42.9%) with an overall CBR of 59.8%. At a median follow-up of 24 months (range 6-32), median PFS was 13 months without significant differences between the cohorts. When analysed according to treatment line, PFS values were significantly prolonged when palbociclib-based therapy was administered as first-line treatment (14.0 months), to decrease progressively in second and subsequent lines (11.7 and 6.7 months, respectively). Median OS was 25 months, ranging from 28.0 months in 1st line to 18.0 and 13.0 months in 2nd and subsequent lines, respectively.
Our data indicate that palbociclib plus ET is active and safe in HR+/HER2- MBC, also suggesting a better performance of the combinations in earlier treatment lines.
CDK4/6抑制剂帕博西尼联合内分泌治疗（ET）已被证明可延长激素受体阳性（HR+）/人表皮生长因子受体2阴性（HER2-）转移性乳腺癌（MBC）女性患者的无进展生存期（PFS）。关于这种治疗方案在临床试验之外的疗效数据很少。
这是一项多中心前瞻性真实世界研究，旨在验证帕博西尼联合ET在未经选择的MBC患者群体中的疗效。主要目标是临床获益率（CBR）；次要目标是中位PFS、总生存期（OS）和安全性。患者接受帕博西尼联合2.5mg来曲唑（A组）或500mg氟维司群（B组）治疗。
总共纳入并治疗了191例患者（A组92例，B组99例），其中182例可进行分析。中位年龄为62岁（范围47 - 79岁）；54%有内脏受累；28%的患者此前接受过一线治疗（包括化疗和ET），22.6%接受过二线治疗，15.9%接受过三线治疗。观察到总体缓解率为34.6%，其中11例（6.0%）完全缓解，52例（28.6%）部分缓解。78例患者（42.9%）病情稳定，总体CBR为59.8%。中位随访24个月（范围6 - 32个月），中位PFS为13个月，两组之间无显著差异。按治疗线分析时，以帕博西尼为基础的治疗作为一线治疗时PFS值显著延长（14.0个月），在二线及后续治疗中逐渐降低（分别为11.7个月和6.7个月）。中位OS为25个月，一线治疗为28.0个月，二线及后续治疗分别为18.0个月和13.0个月。
我们的数据表明，帕博西尼联合ET在HR+/HER2- MBC中有效且安全，也提示该联合方案在早期治疗线中的表现更佳。
