Common breast cancer drug Alpelisib may have an alarming side effect, finds study

A recent retrospective study conducted at the Memorial Sloan Kettering Cancer Center has uncovered concerning rates of hyperglycemia among metastatic breast cancer patients treated with alpelisib, a promising PI3K inhibitor. The study, spanning from 2013 to 2021, aimed to shed light on the incidence, risk factors, and treatment options for this condition.

Metastatic breast cancer remains a significant health concern, especially for those with hormone receptor-positive, PIK3CA-mutant breast cancer.The comprehensive study, including data from 247 patients, has yielded crucial insights:

Hyperglycemia Prevalence: A staggering 61.5% of patients developed hyperglycemia of any grade, with 29.2% experiencing severe grade 3–4 hyperglycemia.

Clinical Trial vs. Standard Care: Patients enrolled in clinical trials experienced significantly lower rates of hyperglycemia compared to those receiving alpelisib as standard care. Any-grade hyperglycemia affected 80.3% of standard care patients, while only 34.0% of clinical trial participants were affected. Similarly, severe grade 3–4 hyperglycemia was reported in 40.2% of standard care patients and in only 13.0% of those in clinical trials.

Baseline HbA1c: The study also highlights the importance of assessing baseline hemoglobin A1c (HbA1c) levels. Elevated baseline HbA1c was significantly associated with the development of hyperglycemia and the need for alpelisib dose reduction or discontinuation.

Hyperglycemia Management: Among patients who developed hyperglycemia, 40.9% received treatment, with metformin being the most commonly prescribed medication. Additionally, 19.8% of patients were referred to endocrinologists, and this was found to be associated with SGLT2 inhibitor prescriptions .

Reference: Incidence, risk factors, and management of alpelisib-associated hyperglycemia in metastatic breast cancer, Sherry Shen MD et al, First published: 25 September 2023, DOI: https://doi.org/10.1002/cncr.34928