Itovebi (inavolisib)-u200c What is inalisib?

Itovebi (inavolisib) is a phosphatidylinositol 3-kinase (PI3K) alpha inhibitor indicated for the treatment of endocrine resistance, PIK3CA mutations, and hormone receptor (HR) in combination with palbociclib and fulvestrant. Adult patients with locally advanced or metastatic breast cancer that is positive, human epidermal growth factor receptor 2 (HER2)-negative, U.S. Food and Drug Administration (FDA)-approved testing, and has relapsed on or after completion of adjuvant endocrine therapy.

Hormone receptor (HR)-positive breast cancer is the most common type of all breast cancers, accounting for approximately 70% of all cases. It is characterized by tumor cells having receptors attached to the hormones estrogen and/or progesterone, which may contribute to tumor growth. The PI3K signaling pathway is commonly dysregulated in HR-positive breast cancer, often due to activating PIK3CA mutations. Mutations in the PIK3CA gene may cause the PI3K enzyme to become overactive, causing cancer cells to grow. Itovebi works by inhibiting PIK3CA.

The FDA's approval of Itovebi is based on results from the Phase III INAVO120 study, which showed that in the first-line setting, the Itovebi combination reduced the risk of disease progression or death by 57% (15.0 months vs. 7.3 months) compared with palbociclib and fulvestrant alone, demonstrating a statistically significant and clinically meaningful benefit. Itovebi tablets are administered orally once daily with or without food.

Common adverse reactions of Itovebi include stomatitis, diarrhea, fatigue, nausea, rash, decreased appetite, COVID-19 infection and headache. Warnings and precautions related to Itovebi include hyperglycemia, severe stomatitis, diarrhea, and embryo-fetal toxicity. Common laboratory abnormalities include neutropenia, decreased hemoglobin, increased fasting blood glucose, decreased platelets, decreased lymphocytes, decreased calcium, decreased potassium, increased creatinine, increased ALT, decreased sodium, and decreased magnesium.