Abstract CT211: Palbociclib (P) in patients (pts) with lung cancer (LC) with CCND1 amplification (amp): Results from the Targeted Agent and Profiling Utilization Registry (TAPUR) Study

Abstract Background: TAPUR is a phase II basket study evaluating antitumor activity of commercially available targeted agents in pts with advanced cancers with specific genomic alterations. Results in a cohort of pts with LC with CCND1 amp treated with P are reported. Methods: Eligible pts had non-small cell (NSCLC) or small cell (SCLC) LC, measurable disease, ECOG performance status (PS) 0-2, adequate organ function, and no remaining standard treatment (tx) options. Genomic testing was performed in CLIA-certified, CAP-accredited site selected labs. Amp cut-offs were defined per NGS providers. Tumors must not have had mutations (mut) in the RB gene. P dosing was one 125 mg capsule taken orally once daily for 21 days followed by 7 days off, until disease progression. Primary endpoint was disease control (DC) per investigator defined as objective response (OR) or stable disease (SD) of at least 16+ weeks (wks) duration (SD16+) per RECIST v1.1. Simon 2-stage design tested the null DC rate of 15% vs. 35% (power = 0.85; α = 0.10). Secondary endpoints were progression-free survival (PFS), overall survival (OS), OR, duration of SD, and safety. Results: 29 pts with NSCLC (n=28) or SCLC (n=1) with CCND1 amp (n=28) or CCND1 amp and mut (n=1) were enrolled. Co-alterations in KRAS and CDKN2A/B included: KRAS mut (n=2), amp (n=2), and mut and amp (n=1); CDKN2A mut (n=6), deletion (del; n=1), and mut and del (n=1). 1 pt with NSCLC was unevaluable for efficacy. Table shows demographics, outcomes, and toxicity. SD16+ was observed in 5 pts, all with NSCLC and CCND1 amp for a DC rate of 25% (1-sided 90% CI, 10 to 100) and an OR rate of 0% (95% CI, 0 to 12). The null DC rate was not rejected (p=0.28). 4 pts had ≥1 grade 3-4 tx-related adverse events (AE) or serious adverse events (SAE). Conclusions: P did not meet prespecified criteria to declare a signal of activity in pts with LC with CCND1 amp. Other tx should be considered for these pts, including tx offered in clinical trials. Citation Format: Evan Pisick, Michael Rothe, Elizabeth Garrett-Mayer, Christopher M. Reynolds, Bamidele Adesunloye, Ramya Thota, Kathryn F. Mileham, Kelly Lynch, Rachel E. Sanborn, Timothy L. Cannon, Justin T. Moyers, Janet Tu, Mehmet Akce, Abigail Gregory, Dominique C. Hinshaw, Gina N. Grantham, Susan Halabi, Richard L. Schilsky. Palbociclib (P) in patients (pts) with lung cancer (LC) with CCND1 amplification (amp): Results from the Targeted Agent and Profiling Utilization Registry (TAPUR) Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(8_Suppl):Abstract nr CT211.