From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Inavolisib is currently indicated for the treatment of hormone receptor-positive (HR+), HER2-negative, PIK3CA-mutated advanced or metastatic breast cancer in adult patients, in combination with palbociclib and fulvestrant, after disease progression following at least one line of endocrine therapy, as supported by the most recent evidence from 1.
Indication and Usage
The FDA approved this indication in October 2024, and the typical dosing is not explicitly stated in the most recent study, but based on previous studies, it is likely to be around 7-9 mg once daily, taken orally with food, in combination with palbociclib and fulvestrant.
Patient Selection
Patients should be selected for treatment based on the presence of a PIK3CA mutation in tumor tissue or plasma specimens using an FDA-approved test, as stated in 1.
Mechanism of Action
Inavolisib works by selectively inhibiting the PI3Kα enzyme, which is often hyperactivated in breast cancers with PIK3CA mutations, leading to uncontrolled cell growth and proliferation. By targeting this specific pathway, inavolisib helps overcome resistance to endocrine therapy, as described in 2.
Common Side Effects
Common side effects include hyperglycemia, diarrhea, rash, and stomatitis, so regular monitoring of blood glucose levels is recommended, especially in patients with diabetes, as reported in 3 and 4.
Key Considerations
When prescribing inavolisib, it is essential to consider the potential for adverse events, such as grade 3 or 4 neutropenia, hyperglycemia, stomatitis, and diarrhea, and to monitor patients closely for these effects, as noted in 3.
- The most recent study 1 provides the strongest evidence for the current indications of inavolisib.
- Previous studies, such as 3 and 4, provide additional information on the safety and efficacy of inavolisib in combination with palbociclib and fulvestrant.
- The mechanism of action of inavolisib, as described in 2, highlights its potential to overcome resistance to endocrine therapy in patients with PIK3CA-mutated breast cancer.