Unveiling New Insights into Alarming Side Effects of Cancer Drug Alpelisib

Updated on September 21, 2023

In the ongoing quest to combat breast cancer, groundbreaking research has emerged, shedding light on a concerning side effect associated with the cancer drug alpelisib. This discovery has the potential to transform the way we approach the treatment of metastatic breast cancer, offering valuable insights into the incidence, risk factors, and management of high blood sugar linked to this oral medication.

The Alarming Side Effect

Published by Wiley online in the esteemed peer-reviewed journal CANCER, this new study has uncovered startling findings. Alpelisib, a drug designed to target the phosphoinositide 3-kinase (PI3K) protein responsible for cell growth, has shown a troubling propensity to induce hyperglycemia, or high blood sugar, in patients with breast cancer. High blood sugar can lead to severe complications, including dehydration, kidney damage, and hospitalization.

Background on Alpelisib

Alpelisib earned its place in the medical arsenal against cancer in 2019 when the US Food and Drug Administration granted its approval for use with fulvestrant, an estrogen receptor blocker. This approval was specifically for cases of metastatic breast cancer characterized by mutations in the gene coding for a PI3K subunit.

The Alarming Statistics

The study, spearheaded by Dr. Sherry Shen and her colleagues at the Memorial Sloan Kettering Cancer Center, delved into the incidence, risk factors, and treatment patterns of alpelisib-associated hyperglycemia. Their research included patients treated as part of clinical trials and those receiving standard care.

Among 147 patients who received alpelisib as part of standard care, a staggering 80.3% experienced hyperglycemia, with 40.2% facing serious cases of high blood sugar. In contrast, among 100 patients enrolled in clinical trials, the rates were notably lower, at 34.0% for any grade of hyperglycemia and 13.0% for serious hyperglycemia. The study found that the median time to onset of hyperglycemia after initiating alpelisib was 16 days.

Identifying Risk Factors

The research also pinpointed a significant risk factor for developing hyperglycemia among patients: an initially elevated hemoglobin A1c level. Hemoglobin A1c serves as an indicator of high blood sugar, akin to prediabetes or diabetes. This discovery underscores the importance of proactive monitoring and intervention in patients who may be at risk.

The Importance of Early Intervention

Dr. Shen emphasized the critical nature of early intervention, stating, “If a patient is identified to have a PI3KCA mutation and thus eligible for treatment with alpelisib, we should be checking hemoglobin A1c levels and partnering with the patient’s primary care physician and/or endocrinologist to optimize their blood sugar levels.” She emphasized that this intervention should take place months before initiating alpelisib since hyperglycemia typically manifests within the first two weeks of treatment. Such pre-emptive measures can reduce the risk of developing hyperglycemia and the potential need to discontinue a drug that could prove effective against cancer.

Optimizing Treatment Efficacy

Senior author Dr. Neil M. Iyengar noted that optimizing a patient’s blood sugar levels often involves lifestyle changes, including dietary adjustments and exercise regimens. Medications, such as metformin, are commonly employed to manage hyperglycemia. Dr. Iyengar also highlighted ongoing clinical trials investigating whether metabolic interventions, like the ketogenic diet, or newer diabetes medications, could enhance the effectiveness of cancer therapies targeting the PI3K pathway.


The revelation of alpelisib’s potential to induce high blood sugar levels in breast cancer patients is a significant breakthrough in the field of oncology. It highlights the need for careful monitoring and intervention and underscores the importance of a multidisciplinary approach to patient care. This discovery may pave the way for tailored treatments that combat cancer and mitigate the side effects, bringing hope and progress to those battling metastatic breast cancer.

The Editorial Team at Healthcare Business Today is made up of skilled healthcare writers and experts, led by our managing editor, Daniel Casciato, who has over 25 years of experience in healthcare writing. Since 1998, we have produced compelling and informative content for numerous publications, establishing ourselves as a trusted resource for health and wellness information. We offer readers access to fresh health, medicine, science, and technology developments and the latest in patient news, emphasizing how these developments affect our lives.