The Priority Review is based on the positive Phase III INAVO120 results, which showed the inavolisib-based regimen more than doubled progression-free survival, reducing the risk of disease worsening or death by 57% compared to palbociclib and fulvestrant alone (15.0 months vs. 7.3 months; hazard ratio [HR]=0.43, 95% CI: 0.32-0.59, p<0.0001) in the first-line setting. Overall survival (OS) data were immature at the time of primary analysis, but a clear positive trend was observed (stratified HR=0.64, 95% CI: 0.43-0.97, p=0.0338 [boundary of 0.0098]). Follow-up for OS is continuing to the next analysis.

“The addition of inavolisib to standard of care treatment significantly delayed disease progression in the first-line setting and has the potential to extend survival for people with metastatic breast cancers that harbor PIK3CA mutations,” said Levi Garraway, M.D., Ph.D., Genentech’s chief medical officer and head of Global Product Development. “We welcome the FDA’s Priority Review designation for inavolisib, which underscores the urgency to bring this potential best-in-class treatment option to patients as quickly as possible.”

The PIK3CA mutation is found in approximately 40% of HR-positive metastatic breast cancers. Early testing for mutations like PIK3CA prior to initiating first-line treatment can help identify people who may benefit from targeted therapy.

Based on the Priority Review designation, the FDA has set a Prescription Drug User Fee Act date of November 27, 2024. Data from INAVO120 are also being used for filing submissions to other global health authorities, including the European Medicines Agency. Priority Review designation is granted to medicines that the FDA has determined to have the potential to provide significant improvements in the treatment, prevention or diagnosis of a disease.

Genentech recently announced the inavolisib-based regimen has been granted FDA Breakthrough Therapy Designation based on INAVO120, the 29th for Genentech’s oncology portfolio. Additional analyses of INAVO120 will be presented in an oral abstract session at the 2024 American Society of Clinical Oncology Annual Meeting, taking place May 31 - June 4.

Inavolisib is currently being investigated in three company-sponsored Phase III clinical studies (INAVO120, INAVO121, INAVO122) in PIK3CA-mutated locally advanced or metastatic breast cancer in various combinations. We continue to evaluate potential clinical development program expansion opportunities to address patient unmet needs in various tumor types across oncology.