What Patients With Breast Cancer Need to Know About Itovebi and Blood Sugar

The Food and Drug Administration (FDA) approved treatment with Itovebi (inavolisib) with Ibrance (palbociclib) and Faslodex (fulvestrant) for certain patients with advanced or metastatic breast cancer in 2024 — and Dr. Yuan Yuan told CURE® that there are side effects associated with the treatment regimen that patients need to be mindful of.

The Itovebi regimen was approved by the FDA for the treatment of adults with endocrine-resistant, PIK3CA-mutated, hormone receptor (HR)-positive, HER2-negative, locally advanced or metastatic breast cancer.

The approval was based on the findings of the INAVO120 trial, and the most common side effects experienced by at least 20% of patients included decreased neutrophils (a type of white blood cell), decreased hemoglobin, increased fasting glucose, decreased platelets, decreased lymphocytes, stomatitis (inflammation of the mouth and lips), diarrhea, decreased calcium, fatigue, decreased potassium, increased creatinine, increased ALT (enzyme in the liver), nausea, decreased sodium, decreased magnesium, rash, decreased appetite, COVID-19 infection and headache.

Yuan, a professor of medicine, director of breast oncology and medical director of breast cancer research at Cedars-Sinai Medical Center in Los Angeles, as well as a health sciences clinical professor at UCLA, sat down for an interview with CURE® as part of the “Speaking Out” video series.

“There are important toxicity side effect profiles that our audience should be aware [of], especially when we hit the PIK3CA pathway, which is also instrumental for our normal physiological metabolism of glucose,” Yuan said.

For example, there are toxicities such as hyperglycemia, or high blood sugar.

“The patient may develop oral mucositis, mouth sores, the patient may have diarrhea,” Yuan said. “So, all of these toxicities need to be carefully managed and very carefully treated. And also, If you look at the baseline eligibility criteria for this trial, patients have a very strict hemoglobin A1C, which has to be less than 6.0. So in reality, we may have patients who have diabetes, [and it’s] not so controlled.

“So, I think we will need to work very cohesively with our endocrinologist and try to monitor the patient and [work with] … support from nursing, from pharmacy. I think it's all needed in order to have a successful program treating patients on Itovebi.”

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