First-in-Human Study of STX-478, a Mutant-Selective PI3Kα Inhibitor as Monotherapy and in Combination With Other Antineoplastic Agents in Participants With Advanced Solid Tumors

Summary

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.

Eligibility

Age range

18+ years

Sex

All

Healthy volunteers

No

Interventions

• Drug
  STX-478

  STX-478 is a mutant-selective PI3Kα inhibitor

• Drug
  Fulvestrant

  Fulvestrant

• Drug
  Ribociclib

  Ribociclib

• Drug
  Palbociclib

  Palbociclib

• Drug
  Letrozole

  Letrozole

• Drug
  Anastrozole

  Anastrozole

• Drug
  Exemestane

  Exemestane

• Drug

Locations (66)