Recruiting
Phase 1/2 Study of ETX-636 in Participants With Advanced Solid Tumors
Phase 1/2, open-label study of ETX-636 in participants with advanced solid tumors
ClinicalTrials.gov IDNCT06993844
PhasePHASE1, PHASE2
Enrollment233
SponsorEnsem Therapeutics
Age18 Years
SexALL
Conditions studied
Advanced Solid Tumors, Advanced Breast Cancer
About this study
Phase 1/2, open-label study of ETX-636 in participants with advanced solid tumors
Interventions
- Drug: ETX-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.
- Drug: ETX-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.
- Drug: ETX-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.
Primary outcomes
- Evaluate Safety and Tolerability of ETX-636 monotherapy in Part A and ETX-636 plus fulvestrant combination therapy in Part B (First 28 days of treatment)
- Evaluate Safety and Tolerability of ETX-636 monotherapy in Part A and ETX-636 plus fulvestrant combination therapy in Part B (Average of 6 months)
- Select the Recommended Phase 2 Dose(s) (RP2D) in Part B to be further explored in Part C (combination therapy expansion) (Average of 6 months)
- Evaluate efficacy of ETX-636 plus fulvestrant combination therapy at the RP2D(s) in Part C (Average of 6 months)
Eligibility information
Key Inclusion Criteria:
* Metastatic or locally advanced and unresectable solid tumor that has progressed on or after at least one available therapy.
* Tumor harboring an activating PIK3CA mutation detected in either tumor tissue or ctDNA.
* At least 1 measurable lesion or evaluable disease per RECIST v1.1.
* An ECOG performance status score of 0 or 1.
* Adequate organ function.
Additional key inclusion criterion for Parts B and C:
\- Confirmed metastatic or locally advanced HR+/HER2- breast cancer not amenable to surgical resection with curative intent and must have received at least 1 prior CDK4/6 inhibitor and at least 1 prior anti-estrogen therapy.
Key Exclusion Criteria:
* Has history (within ≤2 years before screening) of a solid tumor or hematological malignancy that is histologically distinct from the cancers being studied.
* Has symptomatic brain or spinal metastases or a known or suspected history of untreated or uncontrolled central nervous system (CNS) involvement.
* Has an established diagnosis of diabetes mellitus type 1 or has uncontrolled diabetes mellitus type 2.
* Has received treatment with any local or systemic anticancer therapy or investigational anticancer agent within 14 days prior to start of treatment.
* Has toxicities from previous anticancer therapies that have not resolved to baseline levels with the exception of alopecia and peripheral neuropathy.
* Has had radiotherapy outside the target tumor lesions within 14 days prior to start of treatment.
Study locations
- Hoag Memorial Hospital Presbyterian, Newport Beach, California 92663 United States
- UCSF Helen Diller Family Comprehensive Cancer Center, San Francisco, California 94158 United States
- Yale University, Yale Cancer Center, New Haven, Connecticut 06520 United States
- Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215 United States
- Dana-Farber Cancer Institute, Boston, Massachusetts 02215 United States
- Carolina BioOncology Institute, Huntersville, North Carolina 28078 United States
- The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 United States
- START, San Antonio, Texas 78229 United States
- NEXT, Fairfax, Virginia 22031 United States
- Fred Hutchinson Cancer Center, Seattle, Washington 98109 United States
Showing 10 of 15 reported sites. See the official listing for all locations.
Before you participate: Varda Clinical is an independent discovery tool, not the study sponsor or a medical provider. Eligibility can only be determined by the official study team. Discuss potential risks and benefits with a qualified healthcare professional.
Source: ClinicalTrials.gov. Record last refreshed by Varda Clinical: 2026-09-27.