FDA Approves Inavolisib Combo in PIK3CA+ Advanced Breast Cancer

Data from the INAVO120 trial support the approval of the inavolisib combination for those with PIK3CA-mutant breast cancer.

The FDA has approved inavolisib (Itovebi) in combination with palbociclib (Ibrance) and fulvestrant (Faslodex) for those with endocrine-resistant, hormone receptor–positive, HER2-negative, locally advanced or metastatic breast cancer harboring PIK3CA mutations, according to a news release from the agency.¹

The FoundationOne Liquid CDx assay also received approval as a companion diagnostic for use in identifying those who may be eligible to receive treatment with this regimen.

Supporting data for the approval came from the phase 3 INAVO120 trial (NCT04191499), in which investigators assessed treatment among 325 patients with disease progression on prior adjuvant endocrine therapy.

Data showed a median progression-free survival of 15.0 months (95% CI, 11.3-20.5) with the inavolisib-based combination vs 7.3 months (95% CI, 5.6-9.3) with placebo in combination with palbociclib and fulvestrant (HR, 0.43; 95% CI, 0.32-0.59; P <.0001). Additionally, the objective response rate was 58% (95% CI, 50%-66%) vs 25% (95% CI, 19%-32%) in each respective arm, and the median duration of response was 18.4 months (95% CI, 10.4-22.2) vs 9.6 months (95% CI, 7.4-16.6), respectively. Although overall survival data did not reach statistical significance, investigators noted that these findings supported the overall risk/benefit profile of the inavolisib combination (HR, 0.64; 95% CI, 0.43-0.97).

Common toxicities in this trial included decreased neutrophil counts, decreased platelets, stomatitis, diarrhea, fatigue, and decreased potassium.

References

FDA approves inavolisib with palbociclib and fulvestrant for endocrine-resistant, PIK3CA-mutated, HR-positive, HER2-negative, advanced breast cancer. News release. FDA. October 10, 2024. Accessed October 10, 2024. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-inavolisib-palbociclib-and-fulvestrant-endocrine-resistant-pik3ca-mutated-hr-positive