Abstract 253P
Background
SOLAR-1 investigated use of ALP+FLV in patients (pts) with HR+/HER2-, PIK3CA-mutated ABC after progression on endocrine-based therapy. SOLAR-1 demonstrated a clinically significant increase in all-grade (G) and G3-4 HG compared to placebo+FLV. Current guidance recommends an insulin sensitizer (metformin, thiazolidinedione, DPP-4 inhibitor) at HG onset. Given high rates of HG, a preventative protocol and ID of associated RFs was implemented to minimize HG, dose reductions and discontinuation.
Methods
This single-center, retrospective study included pts receiving at least one 28-day cycle of ALP+FLV between June 2019 and April 2021. One week prior to ALP initiation, pts initiated an insulin-sensitizer. Pts had fasting plasma glucose (FPG) levels drawn on day 8, 15, 28, and monthly while on ALP. G2-4 HG was the primary outcome. Descriptive statistics summarized demographics, clinical characteristics, and outcomes. Number of RFs for HG (age ≥ 65 years, BMI ≥ 25 kg/m2, baseline FPG ≥ 100 mg/dL, and A1c ≥ 5.7%) were compared between pts with and without HG using Wilcoxon rank-sum test.
Results
16 women were included with a median age of 59 years. The cohort was 69% White and 25% Black, 75% overweight/obese, and 50% had a history of type 2 diabetes mellitus (T2DM), gestational diabetes, or pre-diabetes. 15 pts received a CDK4/6 inhibitor prior to starting ALP. By day 28, 9 pts (56%) had G2-4 HG, with only 3 (19%) having G3 HG and zero having grade 4. Pts with G2-4 HG had a median of 2 RFs compared to only 1 RF if no HG (p=0.03). 5 pts (31%) required a temporary hold of ALP and 3 pts (19%) required a dose reduction in ALP due to HG. 13 pts permanently discontinued ALP – 9 due to disease progression and 4 due to an adverse event with only 1 due to HG. Median duration of ALP was 86 days (range 24-442), with 3 pts continuing to receive ALP at time of analysis.
Conclusions
Implementation of a HG prevention protocol with ALP in the real-world setting demonstrated fewer G3-4 HG events compared to that seen in SOLAR-1 (19% vs 36.6%). An increase in HG-associated RFs correlated with a higher incidence of G2-4 HG.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
J. Force: Financial Interests, Personal, Other, Consultant: Genomic Health; Financial Interests, Personal, Other, Consultant: Nanostring; Financial Interests, Personal, Other, Consultant: Pfizer. K. Westbrook: Financial Interests, Personal, Other, Consultant: Astrazeneca/Daiichi Sankyo. H. Moore: Financial Interests, Personal, Other, Consultant: Novartis; Financial Interests, Personal, Other, Consultant: Seattle Genetics; Financial Interests, Personal, Other, Consultant: Astrazeneca/Daiichi Sankyo. All other authors have declared no conflicts of interest.