FDA Approves Gedatolisib in Breast Cancer

In VIKTORIA-1, gedatolisib-containing regimens resulted in longer median progression-free survival than fulvestrant alone.

By
Kathryn Wighton
July 14, 2026
2 min

MDSpire News

Objective:

To evaluate the efficacy of gedatolisib in combination with fulvestrant, with or without palbociclib, in patients with hormone receptor-positive, HER2-negative breast cancer.

Approach:

Study Design: An open-label, randomized, multicenter study (VIKTORIA-1 trial) enrolled 392 patients with locally advanced or metastatic hormone receptor-positive, HER2-negative breast cancer.
Treatment Groups: Patients were assigned to receive gedatolisib with fulvestrant and palbociclib, gedatolisib with fulvestrant, or fulvestrant alone.
Efficacy Measurement: Progression-free survival was assessed by blinded independent central review according to RECIST version 1.1.

Key Findings:

Median progression-free survival was 9.3 months for gedatolisib, fulvestrant, and palbociclib versus 2.0 months for fulvestrant alone.
Median progression-free survival was 7.4 months for gedatolisib and fulvestrant versus 2.0 months for fulvestrant alone.
Objective response rates were 32% with the three-drug regimen, 28% with gedatolisib and fulvestrant, and 1% with fulvestrant alone.
Median duration of response was 17.5 months with the three-drug regimen and 12.0 months with gedatolisib and fulvestrant.

Interpretation:

Overall survival data were not mature at the time of the progression-free survival analysis.

Limitations:

The study did not provide mature overall survival data.
Potential adverse reactions include stomatitis, dermatologic issues, hyperglycemia, and embryo-fetal toxicity.