Incidence, risk factors, and management of alpelisib-associated hyperglycemia in metastatic breast cancer.

PURPOSE: The combination of fulvestrant with alpelisib, a PI3K inhibitor, improves progression-free survival in metastatic hormone receptor-positive, PIK3CA-mutant breast cancer. This study describes the incidence, risk factors, and treatment of alpelisib-associated hyperglycemia. METHODS: Patients with metastatic breast cancer who received alpelisib from 2013 to 2021 at Memorial Sloan Kettering Cancer Center were included in this retrospective study. Alpelisib prescription dates and patient/tumor characteristics were abstracted from medical records. Risk factors associated with hyperglycemia and alpelisib dose reduction/discontinuation were evaluated using Pearson's χ2 tests. RESULTS: Among 247 patients, baseline median body mass index was 25.4 kg/m2 and median hemoglobin A1c (HbA1c) was 5.5%. A total of 152 patients (61.5%) developed any-grade hyperglycemia and 72 patients (29.2%) developed grade 3-4 hyperglycemia; median time to onset was 16 days. A total of 100 patients (40.5%) received alpelisib on a clinical trial; rates of hyperglycemia were significantly higher in patients treated as standard care versus on a clinical trial (any-grade hyperglycemia 80.3% vs. 34.0%, grade 3-4 hyperglycemia 40.2% vs. 13.0%, p < .001). Baseline HbA1c was significantly associated with development of hyperglycemia (p < .001) and alpelisib dose reduction/discontinuation (p = .015). Among those who developed hyperglycemia, 101 (40.9%) received treatment, most commonly with metformin. A total of 49 patients (19.8%) were referred to an endocrinologist, which was associated with SGLT2 inhibitor prescription (p = .007). CONCLUSIONS: Rates of hyperglycemia among patients treated with alpelisib as standard care were significantly higher than patients treated on clinical trials. Elevated baseline HbA1c is associated with alpelisib-induced hyperglycemia and requiring dose modification. Optimization of glycemic status before alpelisib initiation should become routine practice.

Phase 2 Study of Dose-Dense Doxorubicin and Cyclophosphamide Followed by Eribulin Mesylate With or Without Prophylactic Growth Factor for Adjuvant Treatment of Early-Stage Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer.

BACKGROUND: Eribulin has significantly improved overall survival for patients with metastatic breast cancer who received ≥ 2 prior chemotherapy regimens for advanced disease. This trial assessed eribulin as adjuvant therapy for patients with early-stage breast cancer. PATIENTS AND METHODS: Patients with human epidermal growth factor receptor 2-negative, stage I to III breast cancer received doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2 provided intravenously on day 1 of each 14-day cycle for 4 cycles, with pegfilgrastim on day 2, followed by 4 cycles of eribulin mesylate 1.4 mg/m2 provided intravenously on days 1 and 8 every 21 days. There were 2 cohorts, as follows: cohort 1: no prophylactic growth factor with eribulin (allowed at physician's discretion only); cohort 2: prophylactic filgrastim with eribulin. The primary end point was feasibility, defined as the percentage of patients who completed the eribulin portion of the regimen without a dose omission, delay, or reduction due to an eribulin-related adverse event. Relative dose intensity of eribulin and toxicities are summarized by cohort. Exploratory end points included 3-year disease-free survival and overall survival. RESULTS: Eighty-one patients (cohort 1, n = 55; cohort 2, n = 26) entered the treatment phase; 88% completed treatment. Feasibility was 72.9 % (90% confidence interval, 60.4, 83.2) in cohort 1 and 60.0% (90% confidence interval, 41.7, 76.4) in cohort 2. The most frequent eribulin-related adverse events (all grades) were fatigue (75.9%), peripheral neuropathy (54.4%), nausea (39.2%), neutropenia (35.4% [31.5% of patients in cohort 1; 44.0% in cohort 2]), and arthralgia (26.6%). CONCLUSION: The primary end point of > 80% feasibility was not met. No unexpected adverse events were observed, and 62% of patients received full dosing with no dose delay or reduction. Further investigation of this regimen with alternative dosing schedules or use of growth factors could be considered.