NeoPalAna: Neoadjuvant palbociclib, a cyclin-dependent kinase 4/6 inhibitor, and anastrozole for clinical stage 2 or 3 estrogen receptor–positive breast cancer

Cynthia X. Ma, Feng Gao, Jingqin Luo, Donald W. Northfelt, Matthew Goetz, Andres Forero, Jeremy Hoog, Michael Naughton, Foluso Ademuyiwa, Rama Suresh, Karen S. Anderson, Julie Margenthaler, Rebecca Aft, Timothy Hobday, Timothy Moynihan, William Gillanders, Amy Cyr, Timothy J. Eberlein, Tina Hieken, Helen KrontirasZhanfang Guo, Michelle V. Lee, Nicholas C. Spies, Zachary L. Skidmore, Obi L. Griffith, Malachi Griffith, Shana Thomas, Caroline Bumb, Kiran Vij, Cynthia Huang Bartlett, Maria Koehler, Hussam Al-Kateb, Souzan Sanati, Matthew J. Ellis

Research output: Contribution to journalArticlepeer-review

230 Scopus citations


Purpose: Cyclin-dependent kinase (CDK) 4/6 drives cell proliferation in estrogen receptor–positive (ER+) breast cancer. This single-arm phase II neoadjuvant trial (NeoPalAna) assessed the antiproliferative activity of the CDK4/6 inhibitor palbociclib in primary breast cancer as a prelude to adjuvant studies. Experimental Design: Eligible patients with clinical stage II/III ER+/HER2 breast cancer received anastrozole 1 mg daily for 4 weeks (cycle 0; with goserelin if premenopausal), followed by adding palbociclib (125 mg daily on days 1–21) on cycle 1 day 1 (C1D1) for four 28-day cycles unless C1D15 Ki67 > 10%, in which case patients went off study due to inadequate response. Anastrozole was continued until surgery, which occurred 3 to 5 weeks after palbociclib exposure. Later patients received additional 10 to 12 days of palbociclib (Cycle 5) immediately before surgery. Serial biopsies at baseline, C1D1, C1D15, and surgery were analyzed for Ki67, gene expression, and mutation profiles. The primary endpoint was complete cell cycle arrest (CCCA: central Ki67 ≤ 2.7%). Results: Fifty patients enrolled. The CCCA rate was significantly higher after adding palbociclib to anastrozole (C1D15 87% vs. C1D1 26%, P < 0.001). Palbociclib enhanced cell-cycle control over anastrozole monotherapy regardless of luminal subtype (A vs. B) and PIK3CA status with activity observed across a broad range of clinicopathologic and mutation profiles. Ki67 recovery at surgery following palbociclib washout was suppressed by cycle 5 palbociclib. Resistance was associated with nonluminal subtypes and persistent E2F-target gene expression. Conclusions: Palbociclib is an active antiproliferative agent for early-stage breast cancer resistant to anastrozole; however, prolonged administration may be necessary to maintain its effect.

Original languageEnglish (US)
Pages (from-to)4055-4065
Number of pages11
JournalClinical Cancer Research
Issue number15
StatePublished - Aug 1 2017
Externally publishedYes

ASJC Scopus subject areas

  • General Medicine


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