RecruitingPhase 1Phase 2NCT06993844

Phase 1/2 Study of ETX-636 in Participants With Advanced Solid Tumors

A Phase 1/2, Open-label, First-in-human Study of the Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of ETX-636, a Pan-mutant-selective PI3Kα Inhibitor, as Monotherapy and in Combination With Other Anticancer Therapies in Participants With Advanced Solid Tumors

Sponsor

Ensem Therapeutics

Enrollment

233 participants

Start Date

Jun 10, 2025

Study Type

INTERVENTIONAL

Conditions

Advanced Breast Cancer Advanced Solid Tumors

Summary

Phase 1/2, open-label study of ETX-636 in participants with advanced solid tumors

Eligibility

Min Age: 18 Years

Plain Language Summary

Simplified for easier understanding

This study is testing a new drug called ETX-636 in people with advanced solid tumors that have a specific mutation in a gene called PIK3CA, which drives uncontrolled cell growth. A focus of the study is on hormone receptor-positive, HER2-negative breast cancer. **You may be eligible if...** - You have an advanced or metastatic solid tumor that has not responded to available treatments - Your tumor has a PIK3CA gene mutation confirmed in tissue or blood - You have at least one measurable or evaluable tumor - You are in reasonably good health (ECOG 0–1) - For the breast cancer cohort: you have HR+/HER2- metastatic breast cancer and have already received a CDK4/6 inhibitor and anti-estrogen therapy **You may NOT be eligible if...** - You have had another distinct cancer diagnosis within the past 2 years - You have symptomatic brain or spinal metastases - You have type 1 diabetes or uncontrolled type 2 diabetes - You have received cancer therapy within the past 14 days - You have unresolved serious side effects from prior treatment Talk to your doctor to see if this trial is right for you.

This summary was AI-generated to explain the trial in plain language. It is not medical advice. Always discuss eligibility with your doctor before enrolling in a clinical trial.

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Interventions

DRUGETX-636 dose escalation

ETX-636 is a pan-mutant-selective PI3Kα Inhibitor and degrader in the form of an oral tablet that will be taken once per day in 28-day cycles, to evaluate escalating dose levels.

DRUGETX-636 dose escalation in combination with fulvestrant

ETX-636 is a pan-mutant-selective PI3Kα Inhibitor and degrader in the form of an oral tablet. ETX-636 will be taken in combination with fulvestrant in 28-day cycles, to evaluate escalating dose levels. EXT-636 is an oral tablet that will be taken once per day. Fulvestrant will be administered as an injection 2 weeks apart in the first 28 days, followed by monthly injections.

DRUGETX-636 dose expansion in combination with fulvestrant

ETX-636 is a pan-mutant-selective PI3Kα Inhibitor and degrader in the form of an oral tablet. ETX-636 will be taken in combination with fulvestrant in 28-day cycles, to expand selected dose levels. EXT-636 is an oral tablet that will be taken once per day. Fulvestrant will be administered as an injection 2 weeks apart in the first 28 days, followed by monthly injections.