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.
Indications and Usage
The FDA approved this indication in October 2024, as stated in 1. The typical dosing is not explicitly mentioned in the most recent study, but based on previous studies such as 2 and 3, the dosing 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 mentioned 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, as described in 4. By blocking this pathway, inavolisib helps overcome resistance to endocrine therapy.
Common Side Effects
Common side effects include hyperglycemia, diarrhea, rash, and stomatitis, as reported in 2 and 3, so regular monitoring of blood glucose levels is recommended, especially in patients with diabetes.
Key Considerations
When prescribing inavolisib, it is essential to consider the potential for adverse events and monitor patients closely, as well as to select patients who are most likely to benefit from this treatment based on the presence of a PIK3CA mutation.
- The most recent and highest quality study, 1, provides the strongest evidence for the current indications and usage of inavolisib.
- Previous studies, such as 2 and 3, provide additional information on the dosing, patient selection, and common side effects of inavolisib.
- The mechanism of action of inavolisib, as described in 4, highlights its potential to overcome resistance to endocrine therapy in breast cancers with PIK3CA mutations.