NCT07174336

A Study of Tersolisib (LY4064809/STX-478) With Other Anti-Cancer Treatments in Participants With Advanced Breast Cancer With a Genetic Change (PIK3CA)

A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study of LY4064809 Combined With a CDK4/6 Inhibitor and Endocrine Therapy in Adults With HR+, HER2-Advanced Breast Cancer With a PIK3CA Mutation Who Received No Prior Treatment for Advanced Breast Cancer (PIKALO-2)

• Status: Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 920 (estimated)
• Sponsor: Eli Lilly and Company · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The purpose of the study is to assess the efficacy and safety of the addition of Tersolisib (LY4064809/STX-478) to other anti-cancer drugs as first treatment for advanced hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer. Participants can remain in the study as long as the drug is helping the cancer without unbearable side effects.

Conditions

• Breast Neoplasms
• Neoplasm Metastasis

Interventions

Type	Name	Description
DRUG	LY4064809	Administered orally
DRUG	Placebo	Administered orally
DRUG	Ribociclib	Administered orally
DRUG	Palbociclib	Administered orally
DRUG	Abemaciclib	Administered orally
DRUG	Anastrozole	Administered orally
DRUG	Letrozole	Administered orally
DRUG	Exemestane	Administered orally
DRUG	Fulvestrant	Administered intramuscular

Timeline

• Start date: 2025-12-22
• Primary completion: 2029-05-01
• Completion: 2033-05-01
• First posted: 2025-09-15
• Last updated: 2026-04-17

Locations

317 sites across 18 countries: United States, Argentina, Australia, Belgium, Brazil, Canada, China, France, Germany, Greece, Ireland, Italy, Japan, South Korea, Spain, Taiwan, Turkey (Türkiye), United Kingdom

Regulatory

• FDA-regulated drug study