Celcuity Inc. announced that an abstract accepted for a Spotlight Poster presentation at the 2022 San Antonio Breast Cancer Symposium (SABCS) is now available on the SABCS website. The 2022 San Antonio Breast Cancer Symposium (SABCS) is being held virtually and in-person from December 6-10, 2022. The presentation will include updated efficacy and safety data and sub-group analysis by PIK3CA mutation status in the four expansion arms of a Phase 1b study of gedatolisib (a dual PI3K/mTOR inhibitor) plus palbociclib (a CDK4/6 inhibitor) and endocrine therapy in women with hormone receptor positive advanced breast cancer.

The primary endpoint was investigator assessed objective response rate (ORR). Secondary endpoints included safety, duration of response and progression free survival (PFS). Promising ORR and PFS were seen in all arms, regardless of PIK3CA mutation status.

Arm D, which treated patients whose disease progressed on a CDK4/6 inhibitor, reported ORR of 63% overall, 73% in PIK3CA-mutation patients, and 60% in PIK3CA-wild type patients; overall PFS was 12.9 months. Arm A, which evaluated patients who were treatment-naïve in the advanced disease setting, reported ORR of 85% overall, 81% in PIK3CA-wild type patients, and 100% in PIK3CA-mutations patients; median PFS was not reached after a median follow-up period of 33.1 months. These preliminary findings demonstrate promising activity for gedatolisib plus palbociclib and endocrine therapy in patients who were CDK4/6 inhibitor-naïve and in those whose disease progressed on or after treatment with a CDK4/6 inhibitor, regardless of PIK3CAmutation status.

Arm D results provide a strong rationale for Celcuity's Phase 3 clinical trial (VIKTORIA-1) in patients with advanced breast cancer whose disease progressed on or after CDK4/6 therapy. The encouraging results in treatment-naïve advanced breast cancer patients warrant further evaluation of gedatolisib in combination with a CDK4/6 inhibitor and endocrine therapy in early line settings, including front-line, neoadjuvant, or adjuvant indications.