First-in-Human Study of Mutant-selective PI3Kα Inhibitor, RLY-2608, as a Single Agent in Patients With Advanced Solid Tumors and in Combination With Endocrine Therapy +/- a CDK4/6 or CDK4 Inhibitor in Patients With Advanced Solid Tumors or Advanced Breast Cancer

Summary

This is an open-label, FIH study designed to evaluate the maximum tolerated dose, recommended Phase 2 dose, safety, tolerability, PK, pharmacodynamics, and preliminary antineoplastic activity of RLY-2608, in advanced solid tumor patients with a Phosphatidylinositol-4,5-bisphosphate-3 kinase, catalytic subunit alpha (PIK3CA) mutation in blood and/or tumor per local assessment. The study will evaluate RLY-2608 as a single agent for patients with unresectable or metastatic solid tumors.

Shortened from the sponsor's brief summary. View official record on ClinicalTrials.gov

Conditions studied

• PIK3CA Mutation
• Solid Tumor, Adult
• HER2-negative Breast Cancer
• Breast Cancer
• Metastatic Breast Cancer
• Advanced Breast Cancer
• Unresectable Solid Tumor

Eligibility basics and study details

Study type

Interventional

Phase

Phase 1

Ages

18 years and older

Sex

All

Healthy volunteers

Not accepted

Sponsor

Relay Therapeutics, Inc.

Last updated on ClinicalTrials.gov

September 22, 2025

These are the basic criteria only. The full inclusion and exclusion criteria are on the official record, and the study team decides who can take part.

US recruiting sites