Study of RLY-2608 for Advanced Solid Tumors and Breast Cancer
This study is testing a new medication called RLY-2608, which is designed to target a specific genetic change (mutation) in cancer cells called PIK3CA. It's being studied in adults with advanced solid tumors, including those with HER2-negative breast cancer. Researchers want to find the safest and most effective dose of RLY-2608, both on its own and when combined with other approved cancer treatments like fulvestrant, palbociclib, or ribociclib. To join, you must have a PIK3CA mutation in your tumor or blood. The main goal is to determine the best dose and see how safe and effective RLY-2608 is.
- Study design
- This is an open-label study, meaning both you and your doctors will know which treatment you are receiving. It plans to enroll about 930 participants.
- What's involved
- Not specified in the trial record.
- Compensation
- Not stated in the trial record.
- Follow-up
- The study will measure outcomes at the end of every 4-week cycle until you stop treatment, for approximately 24 months.
AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.
NCT05216432
First-in-Human Study of Mutant-selective PI3Kα Inhibitor, RLY-2608, as a Single Agent in Patients With Advanced Solid Tumors and in Combination With Endocrine Therapy +/- a CDK4/6 or CDK4 Inhibitor in Patients With Advanced Solid Tumors or Advanced Breast Cancer
Recruiting
PHASE1Ages 18+InterventionalTreatmentRelay Therapeutics, Inc.
~930 participants
Updated 2025-09-22 on ClinicalTrials.gov
What's tested:RLY-2608FulvestrantPalbociclib 125mgRibociclib 400mgRibociclib 600mgPF-07220060 100mg
At a glance
Recruiting sites
36 of 37 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Determination of maximum tolerated dose (MTD) and/or recommended Phase 2 dose (RP2D) of RLY-2608 as a single agent
Measured over Cycle 1 (4-week cycle) of treatment for MTD and at the end of every cycle (4-week cycles) for RP2D until study discontinuation, approximately 24 months
+5 more outcomes measured
Conditions
Where it's being run
37 sites across 27 statesNew York3
Spain3
Florida2
Massachusetts2
Texas2
Virginia2
Victoria2
France2
Who to contact
Opens a ready-to-send draft in your own email app — review before sending.
Do you actually qualify for this trial?
Add a private profile and we'll compare every criterion below against your situation — and tell you which ones are met, uncertain, or excluding.
Eligibility criteria
Inclusion
\[For Part 1: Escalation\]: Evaluable disease per RECIST v1.1
\[For Part 2: Expansion\]: Measurable disease per RECIST v1.1
Disease that is refractory to standard therapy, intolerant to standard therapy, or has declined standard therapy.
Part 1- histologically or cytologically confirmed diagnosis of unresectable or metastatic solid tumor
Part 2 - Unresectable or metastatic solid tumor with PIK3CA mutation(s) and one of the following tumor types:
Doublet combination arms \[Part 1 and Part 2\]: Evaluable disease per RECIST v1.1
Triplet combination arms:
\[Part 1 and Part 2 Dose Expansion, Group 1\]: Evaluable disease per RECIST.
\[Part 2 Dose Expansion, Group 2\]: Measurable disease per RECIST. Bone-only lytic or lytic/blastic disease with at least 1 measurable soft-tissue component per RECIST may be eligible.
\[For Part 1 and Part 2\]: Male or female with histologically or cytologically confirmed diagnosis of HR+, HER2- unresectable or metastatic breast cancer that is not amenable to curative therapy. Females may be postmenopausal, premenopausal, or perimenopausal. Premenopausal or perimenopausal females must have a histologically or cytologically confirmed diagnosis of HR+ HER2- locally advanced or metastatic breast cancer that is not amenable to curative therapy and must have initiated treatment with a gonadotropin-releasing hormone (GnRH) agonist at least 4 weeks prior to start of study drug with continuation of GnRH agonist for the duration of study treatment (GnRH agonist recommended for males).
Had previous treatment for breast cancer with: \[Does not apply to triplet combination arms, Part 2 Dose Expansion, Group 2\]:
Exclusion
Mean resting corrected QT interval (QTc) \>460 msec
For triple combination arm with ribociclib: Mean QTcF ≥450 msec (this is what we confirmed is shown in the redacted version of the protocol.
What this trial measures
- Determination of maximum tolerated dose (MTD) and/or recommended Phase 2 dose (RP2D) of RLY-2608 as a single agentCycle 1 (4-week cycle) of treatment for MTD and at the end of every cycle (4-week cycles) for RP2D until study discontinuation, approximately 24 months
- Determination of maximum tolerated dose (MTD) and/or recommended Phase 2 dose (RP2D) of RLY-2608 in combination with fulvestrantCycle 1 (4-week cycle) of treatment for MTD and at the end of every cycle (4-week cycles) for RP2D until study discontinuation, approximately 24 months
- Determination of maximum tolerated dose (MTD) and/or recommended Phase 2 dose (RP2D) of RLY-2608 in combination with fulvestrant and a CDK 4/6 inhibitor (palbociclib, ribociclib), and in combination with CDK4 inhibitor (PF-07220060) and fulvestrantCycle 1 (4-week cycle) of treatment for MTD and at the end of every cycle (4-week cycles) for RP2D until study discontinuation, approximately 24 months
- Number of patients with adverse events and serious adverse events of RLY-2608 as a single agentEvery cycle (4-week cycles) until study discontinuation, approximately 24 months
- Number of patients with adverse events and serious adverse events of RLY-2608 in combination with fulvestrantEvery cycle (4-week cycles) until study discontinuation, approximately 24 months
- Number of patients with adverse events and serious adverse events of RLY-2608 in combination with fulvestrant and a CDK 4/6 inhibitor (palbociclib, ribociclib), and in combination with CDK4 inhibitor (PF-07220060) and fulvestrantEvery cycle (4-week cycles) until study discontinuation, approximately 24 months