The US Food and Drug Administration (FDA) has granted a priority review for Roche’s inavolisib as a combination therapy with fulvestrant and Pfizer’s Ibrance (palbociclib) as a treatment for breast cancer.

The US agency has set a target action date of 27 November for evaluating the combination therapy as a treatment for adult patients with PIK3CA-mutated, hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced or metastatic breast cancer, following recurrence on or within 12 months of completing adjuvant endocrine treatment.

Inavolisib is an oral PI3 kinase (PI3K) inhibitor that dysregulates PI3K signalling in the PI3K/Akt/mTOR pathway, which regulates cell growth and survival. Last week, it received a breakthrough therapy designation by the US FDA. Roche also plans to file for regulatory approval for inavolisib with other global health authorities, including the European Medicines Agency.

The priority review status was awarded based on the positive results from the Phase III INAVO120 trial (NCT04191499). The triple combination therapy demonstrated a progression-free survival (PFS) of 15 months, compared to a PFS of 7.3 months with the fulvestrant and Ibrance combination. The overall survival was not reached. Roche plans to present the data at the upcoming American Society of Clinical Oncology (ASCO) Annual Meeting being held in Chicago from 31 May to 4 June.

Roche is also investigating inavolisib as part of different combination treatments for PIK3CA-mutated advanced or metastatic breast cancer. A Phase III INAVO122 trial (NCT05894239) is investigating inavolisib in combination with the company’s breast cancer combination therapy Phesgo (pertuzumab/trastuzumab/hyaluronidase-zzfx).

The company is also evaluating the therapy in combination with fulvestrant, in comparison with a combination of fulvestrant and Novartis’ PI3K inhibitor Piqray (alpelisib) in the Phase III INAVO121 trial (NCT05646862). Oncology is one of the priority areas for Roche, with the company signing multiple collaboration agreements in recent times to expand its cancer drug pipeline. In January, the company signed a strategic partnership and licencing agreement with MOMA Therapeutics. The deal is expected to be worth $2bn in milestone-based payments. Roche also signed a partnership and licence deal with MediLink Therapeutics for the latter’s antibody drug conjugate, YL211, for solid tumours.