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PIK3CA MutationPhase 1NCT05759949

First-in-Human Study of RLY-5836 in Advanced Breast Cancer and Other Solid Tumors

A Phase 1 study testing RLY-5836, Fulvestrant and Palbociclib in people with PIK3CA Mutation and Solid Tumor, Adult, run by Relay Therapeutics, Inc. at 7 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This is a Phase 1, first-in-human, open-label study designed to evaluate the maximum tolerated dose (MTD), recommended phase 2 dose (RP2D), safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary anti-tumor activity of RLY-5836 in advanced solid tumors in participants harboring a PIK3CA mutation in… Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
RLY-5836, Fulvestrant and Palbociclib
Could I receive a placebo?
No, everyone receives an active treatment
How many people
41 participants
Where
7 sitesUnited States
Study dates
29 Mar 2023to 11 Apr 2025
Phase
Phase 1
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Patient has ECOG performance status of 0-1
  • One or more documented primary oncogenic PIK3CA mutation(s) in blood and/or tumor per local assessment
  • RLY-5836 single agent arm key inclusion criteria
  • Disease that is refractory to standard therapy, intolerant to standard therapy, or participant has declined standard therapy.
  • A histologically or cytologically confirmed diagnosis of unresectable or metastatic solid tumor
  • Combination arms key inclusion criteria
Show all 9Show fewer
  • Males, postmenopausal females, or pre-/perimenopausal females previously treated with gonadotropin-releasing GnRH agonist at least 4 weeks prior to start of study drug with histologically or cytologically confirmed diagnosis of HR+, HER2- unresectable or metastatic breast cancer that is not amenable to curative therapy.
  • Had previous treatment for advanced or metastatic breast cancer with antiestrogen therapy including, but not limited to, selective estrogen receptor degraders (e.g., fulvestrant), selective estrogen receptor modulators (e.g., tamoxifen), and aromatase inhibitors (AI) (letrozole, anastrozole, exemestane)
  • Part 1: Prior PI3Kα inhibitor treatment is allowed if taken for < 14 days and not discontinued due to disease progression, hypersensitivity, or ≥ Grade 3 TEAEs.

Who cannot join

  • Part 2: Prior treatment with PI3Kα inhibitors.
  • Type 1 or Type 2 diabetes requiring antihyperglycemic medication, or fasting plasma glucose ≥140 mg/dL and glycosylated hemoglobin (HbA1c) ≥7.0%.

Trial locations and contacts

7 sites in 1 country.

7 sites in 1 country

United States7 sites
  • Massachusetts General Hospital

    Boston, Massachusetts, 02114

  • Community Cancer Center North

    Indianapolis, Indiana, 46250

  • Tennessee Oncology, PLLC

    Nashville, Tennessee, 37203

  • Rutgers Cancer Institute of New Jersey

    New Brunswick, New Jersey, 08903

  • Memorial Sloan Kettering Cancer Center-Main Campus

    New York, New York, 10065

  • Sarah Cannon Research Institute at Florida Cancer Specialists

    Orlando, Florida, 32827

  • Huntsman Cancer Institute, University of Utah

    Salt Lake City, Utah, 84112

Other trials in United States

About this study

Official title: A First-in-Human Study of PI3Kα Inhibitor, RLY-5836, in Combination With Targeted and Endocrine Therapies in Participants With Advanced Breast Cancer and as a Single Agent in Advanced Solid Tumors

This is a Phase 1, first-in-human, open-label study designed to evaluate the maximum tolerated dose (MTD), recommended phase 2 dose (RP2D), safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary anti-tumor activity of RLY-5836 in advanced solid tumors in participants harboring a PIK3CA mutation in blood and/or tumor per local assessment. The study consists of 2 parts, a dose escalation (Part 1) and a dose expansion (Part 2).

Being tested
RLY-5836, Fulvestrant, Palbociclib, Ribociclib, Abemaciclib
Medical subject headings
Breast Neoplasms

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • RLY-5836Drug

    RLY-5836 is a mutant-selective, oral PI3Kα inhibitor.

  • FulvestrantDrug

    Also called Faslodex

    Fulvestrant (500 mg) is administered IM into the buttocks (gluteal area) slowly (1 to 2 minutes per injection) as 2×5 mL injections, 1 in each buttock, on Cycle 1 Day 1, Cycle 1 Day 15, and Day 1 of each subsequent cycle.

  • PalbociclibDrug

    Also called Ibrance

    Palbociclib 125 mg once daily is taken orally in combination with RLY-5836 and fulvestrant for 28-day cycles that include 21 days of treatment followed by 7 days off treatment.

  • RibociclibDrug

    Also called Kisqali

    Ribociclib 600 mg once daily is taken orally in combination with RLY-5836 and fulvestrant for 28-day cycles that include 21 days of treatment followed by 7 days off treatment.

  • AbemaciclibDrug

    Also called Verzenio

    Abemaciclib 150 mg BID will be taken orally in combination with RLY-5836 and fulvestrant for 28-day cycles.

Study groups in NCT05759949
Study groupRoleWhat they receive
RLY-5836 Single Agent ArmExperimentalRLY-5836 single agent arm for participants with unresectable or metastatic solid tumors
Receives: Drug: RLY-5836
RLY-5836 + Fulvestrant ArmExperimentalRLY-5836 + fulvestrant combination arm for participants with HR+, HER2- locally advanced or metastatic breast cancer
Receives: Drug: RLY-5836; Drug: Fulvestrant
RLY-5836 + Palbociclib + Fulvestrant ArmExperimentalRLY-5836 + palbociclib + fulvestrant triple combination arm for participants with HR+, HER2- locally advanced or metastatic breast cancer
Receives: Drug: RLY-5836; Drug: Fulvestrant; Drug: Palbociclib
RLY-5836 + Ribociclib + Fulvestrant ArmExperimentalRLY-5836 + ribociclib + fulvestrant triple combination arm for participants with HR+, HER2- locally advanced or metastatic breast cancer
Receives: Drug: RLY-5836; Drug: Fulvestrant; Drug: Ribociclib
RLY-5836 + Abemaciclib + Fulvestrant ArmExperimentalRLY-5836 + abemaciclib + fulvestrant triple combination arm for participants with HR+, HER2- locally advanced or metastatic breast cancer
Receives: Drug: RLY-5836; Drug: Fulvestrant; Drug: Abemaciclib

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Maximum Tolerated Dose (MTD) and Recommended Phase 2 Dose (RP2D) of RLY-5836

    Measured: 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

  2. Number of participants with any dose-limiting toxicity (DLT)

    Measured: Cycle 1, up to 28 days.

  3. Number of participants with adverse events (AEs)

    Measured: Every cycle (4-week cycles) until study discontinuation, approximately 24 months

  4. Number of participants with serious adverse events (SAEs)

    Measured: Every cycle (4-week cycles) until study discontinuation, approximately 24 months

Secondary outcomes (13)
  1. PIK3CA genotype in blood and tumor tissue by next generation nucleic acid sequencing

    Measured: Every cycle (4-week cycles) through Cycle 3 and every other cycle thereafter until study discontinuation, approximately 24 months

  2. PK of RLY-5836: area under the concentration-time curve (AUC)

    Measured: Approximately every 2 weeks in Cycle 1 (4-week cycle) and every cycle through end of treatment (4-week cycles), approximately 24 months

  3. PK of RLY-5836: maximum plasma concentration (Cmax)

    Measured: Approximately every 2 weeks in Cycle 1 (4-week cycle) and every cycle through end of treatment (4-week cycles), approximately 24 months

  4. PK of RLY-5836: time to maximum concentration (tmax)

    Measured: Approximately every 2 weeks in Cycle 1 (4-week cycle) and every cycle through end of treatment (4-week cycles), approximately 24 months

  5. PK of RLY-5836: half-life (t½)

    Measured: Approximately every 2 weeks in Cycle 1 (4-week cycle) and every cycle through end of treatment (4-week cycles), approximately 24 months

  6. PK of RLY-5836: clearance following oral dose (CL/F)

    Measured: Approximately every 2 weeks in Cycle 1 (4-week cycle) and every cycle through end of treatment (4-week cycles), approximately 24 months

  7. Changes in circulating markers of glucose metabolism: changes in circulating glucose

    Measured: Approximately every week in Cycle 1 (4-week cycle), every 2 weeks in Cycle 2 (4-week cycle), and every cycle through end of treatment (4-week cycles), approximately 24 months

  8. Changes in circulating markers of glucose metabolism: changes in circulating insulin

    Measured: Approximately every week in Cycle 1 (4-week cycle), every 2 weeks in Cycle 2 (4-week cycle), and every cycle through end of treatment (4-week cycles), approximately 24 months

  9. Changes in circulating markers of glucose metabolism: changes in circulating C-peptide

    Measured: Approximately every week in Cycle 1 (4-week cycle), every 2 weeks in Cycle 2 (4-week cycle), and every cycle through end of treatment (4-week cycles), approximately 24 months

  10. Changes in circulating markers of glucose metabolism: changes in circulating glycosylated hemoglobin [HbA1c]

    Measured: Approximately every week in Cycle 1 (4-week cycle), every 2 weeks in Cycle 2 (4-week cycle), and every cycle through end of treatment (4-week cycles), approximately 24 months

  11. Preliminary antitumor activity of RLY-5836: duration of response (DOR) per Response Evaluation Criteria in Solid Tumors (RECIST Version 1.1)

    Measured: Approximately every 8 weeks until progressive disease, approximately 36 months

  12. Preliminary antitumor activity of RLY-5836: disease control rate (DCR) per Response Evaluation Criteria in Solid Tumors (RECIST Version 1.1)

    Measured: Approximately every 8 weeks until progressive disease, approximately 36 months

  13. Preliminary antitumor activity of RLY-5836: objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors (RECIST Version 1.1)

    Measured: Approximately every 8 weeks until progressive disease, approximately 36 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted8 Mar 2023
  2. Study start29 Mar 2023
  3. Primary completion18 Mar 2025
  4. Study completion11 Apr 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1
Primary purpose
Treatment
Allocation
Non-randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
41 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05759949
Sponsor's protocol ID
RLY-5836-101
Status last verified
May 2025
First submitted
23 Jan 2023
Last updated
16 May 2025
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing RLY-5836, Fulvestrant and Palbociclib in people with PIK3CA Mutation and Solid Tumor, Adult, run by Relay Therapeutics, Inc. at 7 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 9 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 16 May 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 7 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Maximum Tolerated Dose (MTD) and Recommended Phase 2 Dose (RP2D) of RLY-5836 (time frame: 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). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 May 2025.

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