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Study identifier: NCT05768139 Synced from ClinicalTrials.gov · July 28, 2026
● Recruiting

First-in-Human Study of Tersolisib (STX-478) as Monotherapy and in Combination With Other Antineoplastic Agents in Participants With Advanced Solid Tumors

Condition: Breast Cancer · Solid Tumors, Adult  ·  Sponsor: Eli Lilly and Company

PhasePhase 1/Phase 2
Planned participants880
Who can joinAll sexes, 18 Years to no upper limit
Healthy volunteersNo

About this study

Study STX-478-101 (LY4064809) is a multipart, open-label, phase 1/2 study evaluating the safety, tolerability, pharmacokinetics (PK), and preliminary antitumor activity of STX-478 (LY4064809) in participants with advanced solid tumors with P13Ka mutations. Part 1 will evaluate STX-478 as monotherapy in participants with advanced solid tumors. Part 2 will evaluate STX-478 therapy as combination therapy with fulvestrant in participants with hormone receptor positive (HR+) breast cancer. Part 3 will evaluate STX-478 as combination therapy with endocrine therapy (aromatase inhibitors, fulvestrant, tamoxifen, or imlunestrant) and a CDK4/6 Inhibitor (either Ribociclib, Palbociclib or Abemaciclib) in participants with HR+ breast cancer. Each study part will include a 28-day screening period, followed by treatment with STX-478 monotherapy or combination therapy.

This description comes directly from the study's public registry record.

Talk to the study team

Trial questions or participation questions: 1-877-CTLILLY (1-877-285-4559) or  ·  1-317-615-4559  ·  LillyTrials@Lilly.com

Physicians interested in becoming principal investigators please contact  ·  clinical_inquiry_hub@lilly.com

Always discuss trial participation with your own doctor first.

Locations (65)

Ellison Clinic at Saint John'sLos Angeles, California, United StatesRecruiting
UCSF Medical Center at Mission BaySan Francisco, California, United StatesRecruiting
University of Colorado Cancer CenterAurora, Colorado, United StatesRecruiting
Yale-New Haven HospitalNew Haven, Connecticut, United StatesCompleted
Florida Cancer Specialists ORLANDO/DDULake Mary, Florida, United StatesCompleted
Moffitt Cancer CenterTampa, Florida, United StatesRecruiting
Winship Cancer Institute, Emory UniversityAtlanta, Georgia, United StatesRecruiting
University of IowaIowa City, Iowa, United StatesRecruiting
Louisiana State University Health Sciences CenterNew Orleans, Louisiana, United StatesRecruiting
Massachusetts General HospitalBoston, Massachusetts, United StatesRecruiting
Dana-Farber Cancer InstituteBoston, Massachusetts, United StatesRecruiting
Barbara Ann Karmanos Cancer InstituteDetroit, Michigan, United StatesTerminated

+ 53 more locations — full list on the registry record.

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Source record: clinicaltrials.gov/study/NCT05768139