Inavolisib (Itovebi) in combination with palbociclib and fulvestrant for endocrine-resistant, PIK3CA-mutated, hormone receptor–positive (HR+), human epidermal growth factor receptor 2–negative (HER2−), locally advanced or metastatic breast cancer following recurrence on or after adjuvant endocrine therapy.
A highly potent and selective inhibitor of the alpha isoform of the p110 catalytic sub unit of the PI 3K complex.
The FDA FoundationOne Liquid CDx assay can identify patients who qualify for the newly approved treatment.
A first-line option for people living with HR+ breast cancer with a PIK3CA mutation.
The oncogenic PIK3CA mutation is found in approximately 40% HR+ metastatic breast cancers.
Novartis’ alpelisib (Piqray) also targets the mutation and carries a similar breast cancer indication for combination with fulvestrant.
Approval of inavolisib was based on the INAVO120 trial, which randomized 325 qualifying patients equally to receive either inavolisib 9 mg or placebo orally once daily on a background of palbociclib and fulvestrant in 28-day treatment cycles.
In the INAVO120 study, patients taking inavolisib had a median progression-free survival of 15 months, compared to 7.3 months for those taking a placebo.
The overall response rate was also higher for patients taking inavolisib.
Common side effects include decreased neutrophils, increased fasting glucose, and fatigue.
In patients with PIK3CA mutated hormone receptor positive, HER2 negative locally advanced or metastatic breast cancer inavolisib plus palbociclib-fulvestrant led to longer progression free survival than placebo plus palbociclib-fulvestrant with a greater incidence of toxic effects.