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

Source: https://onco.cc/trials/pik3ca-2/  
OnCo record `pik3ca-2` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A phase 3 trial testing Tersolisib in HR-positive / HER2-negative breast cancer, now recruiting.

## Summary

A Study of Tersolisib (LY4064809/STX-478) With Other Anti-Cancer Treatments in Participants With Advanced Breast Cancer With a Genetic Change (PIK3CA) is a phase 3 interventional study registered as NCT07174336, led by Eli Lilly and with Pfizer, and recruiting on the registry. Official title: A Phase 2, Randomised, Open-Label Dose Optimization and Phase 3, Randomised, 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). Planned enrolment is 800 participants (estimated). The study started in 2025-12-22 and primary completion is expected in 2029-05. No results have been posted on ClinicalTrials.gov.

## Fields

- Kind: Trial
- Status: recruiting
- Last checked: 2026-09-11
- Also known as: PIKALO-2
- Tags: ctgov-ingest
- Registry id: NCT07174336
- Phase: 3
- Setting: A Phase 2, Randomized, Open-Label Dose Optimization and 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)
- Sponsor: Eli Lilly and
- Enrolled: 800

## Sources

- ClinicalTrials.gov NCT07174336: https://clinicaltrials.gov/study/NCT07174336

## Connected records

- cancers: [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [HR-positive metastatic breast cancer after CDK4/6 inhibitors](https://onco.cc/cancers/hr-positive-metastatic-post-cdk46/)
- drugs: [Tersolisib](https://onco.cc/drugs/tersolisib/)
- companies: [Eli Lilly (incl. Loxo)](https://onco.cc/companies/eli-lilly/)

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JSON: https://onco.cc/api/v1/entities/pik3ca-2.json