Status:
RECRUITING
Phase 3 Study of RLY-2608 + Fulvestrant vs Capivasertib + Fulvestrant as Treatment for Locally Advanced or Metastatic PIK3CA-mutant HR+/HER2- Breast Cancer
Lead Sponsor:
Relay Therapeutics, Inc.
Conditions:
PIK3CA Mutation
HER2- Negative Breast Cancer
Eligibility:
All Genders
18+ years
Phase:
PHASE3
Brief Summary
This is a global, multicenter, open-label, randomized Phase 3 study comparing the efficacy and safety of RLY-2608 + fulvestrant to capivasertib + fulvestrant for the treatment of patients with HR+/HER...
Eligibility Criteria
Inclusion
- Patient has ECOG performance status of 0-1
- One or more known primary oncogenic PIK3CA mutation(s)
- Adult females, pre- and/or post-menopausal, and adult males. Pre-menopausal (and peri-menopausal) women can be enrolled if amenable to treatment with a gonadotropin-releasing hormone (GnRH) agonist. Patients are to have commenced treatment with a GnRH agonist at least 4 weeks prior to randomization and must be willing to continue on it for the duration of the study.
- Histologically or cytologically confirmed diagnosis of HR+/HER2- locally advanced or metastatic breast cancer (ABC) with radiological or objective evidence of recurrence or progression; locally advanced disease must not be amenable to resection with curative intent
- Measurable disease per RECIST v1.1 or evaluable bone-only disease.
- Must have radiological evidence of progression on or after previous treatment for HR+/HER2- ABC with:
- At least 1 and no more than 2 lines of endocrine therapy (ET) in the (neo)adjuvant setting with recurrence on or within 12 months of completion or in the ABC setting
- 1 prior line of CDK4/6 inhibitor therapy in one of the following settings:
- CDK4/6 inhibitor + ET in the ABC setting
- CDK4/6 inhibitor therapy in the adjuvant setting if progression occurred during or within 12 months of completion of adjuvant CDK4/6 inhibitor with ET
- Patients who progressed during or within 12 months of completion of adjuvant CDK4/6 inhibitor and after receiving CDK4/6 inhibitor therapy in the advanced setting are considered to have had \>1 prior line of CDK4/6 inhibitor and are not eligible
Exclusion
- Prior treatment with any of the following:
- CDK2 or selective CDK4 inhibitors or any investigational therapies targeting cyclin dependent kinases
- PIK3, AKT, or mTOR inhibitors or any agent whose mechanism of action is the inhibit the PIK3/AKT/mTOR pathway
- Immunotherapy
- Antibody drug conjugates
- Type 1 diabetes, or Type 2 diabetes requiring antihyperglycemic medication, or fasting plasma glucose ≥ 140 mg/dL, or glycosylated hemoglobin (HbA1c) ≥7.0% (≥ 53 mmol/mol).
- Clinically significant, uncontrolled cardiovascular disease
- Any factors that increase the risk of QTc prolongation or risk of arrhythmic events
- Known active uncontrolled or symptomatic CNS metastases associated with progressive neurological symptoms or requiring ongoing corticosteroids or anticonvulsants for symptomatic control
- Past medical history of interstitial lung disease, drug-induced interstitial lung disease, radiation pneumonitis which required steroid treatment, or any evidence of clinically active interstitial lung disease
- History of hypersensitivity to fulvestrant or drugs in a similar class as fulvestrant, RLY-2608, or capivasertib, including their excipients
- Known activating AKT mutations, loss-of-function PTEN mutations, or loss of PTEN expression resulting in oncogenic pathway activation downstream of PI3K
Key Trial Info
Start Date :
August 26 2025
Trial Type :
INTERVENTIONAL
Allocation :
ESTIMATED
End Date :
December 31 2031
Estimated Enrollment :
540 Patients enrolled
Trial Details
Trial ID
NCT06982521
Start Date
August 26 2025
End Date
December 31 2031
Last Update
December 31 2025
Active Locations (41)
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1
Beverly Hills Cancer Center
Beverly Hills, California, United States, 90211
2
Cedars-Sinai Medical Center
Beverly Hills, California, United States, 90211
3
Stanford University School of Medicine
Palo Alto, California, United States, 94304
4
University of California San Francisco
San Francisco, California, United States, 94143