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

Phase 1RecruitingNCT05216432

Relay Therapeutics, Inc.930 enrolled

Overview

This is an open-label, FIH study designed to evaluate the maximum tolerated dose, recommended Phase 2 dose, safety, tolerability, PK, pharmacodynamics, and preliminary antineoplastic activity of RLY-2608, in advanced solid tumor patients with a Phosphatidylinositol-4,5-bisphosphate-3 kinase, catalytic subunit alpha (PIK3CA) mutation in blood and/or tumor per local assessment. The study will evaluate RLY-2608 as a single agent for patients with unresectable or metastatic solid tumors. It will also evaluate RLY-2608 in combination RLY-2608 + fulvestrant and in triple combination RLY-2608 + fulvestrant + CDK4/6 inhibitor (palbociclib or ribociclib) or CDK4 inhibitor (PF-07220060) for patients with HR+ HER2- locally advanced or metastatic breast cancer. The RLY-2608 single agent arm, RLY-2608 + fulvestrant combination arm, and triple combination arms will have 2 parts: a dose escalation (Part 1) and a dose expansion (Part 2).

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

930

Conditions

PIK3CA Mutation Solid Tumor, Adult HER2-negative Breast Cancer

Interventions

RLY-2608DRUG

RLY-2608 is a mutant-selective, oral PI3Kα inhibitor.

FulvestrantDRUG

500 mg fulvestrant is administered intramuscularly on Cycle 1 Day 1, Day 15, and Day 1 of each subsequent cycle (where a cycle is 28 days).

Palbociclib 125mgDRUG

125mg palbociclib is taken orally once daily for 28-day cycles that include 21 days of treatment followed by 7 days off treatment.

Ribociclib 400mgDRUG

400mg ribociclib is taken orally once daily for 28-day cycles that include 21 days of treatment followed by 7 days off treatment.

Ribociclib 600mgDRUG

600mg ribociclib is taken orally once daily for 28-day cycles that include 21 days of treatment followed by 7 days off treatment.

PF-07220060 100mgDRUG

PF-07220060 100 mg is taken orally twice daily at the same time with RLY-2608 during each 28-day cycle.

PF-07220060 300 mgDRUG

PF-07220060 300 mg is taken orally twice daily at the same time with RLY-2608 during each 28-day cycle.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Key Inclusion Criteria 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 Other potentially oncogenic PIK3CA mutations may be considered but must be approved by the Sponsor prior to enrollment. Part 1 \[Escalation\] - Ability to provide archived tumor tissue or be willing to undergo pretreatment tumor biopsy to assess PIK3CA status retrospectively Part 2 \[Expansion\] - Submit tumor tissue prior to study drug initiation for determination of PIK3CA mutation retrospectively. Key Inclusion for RLY-2608 Single Agent Arm * \[For Part 1: Escalation\]: 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: Group 1: clear cell ovarian cancer Group 2: head and neck squamous cell carcinoma Group 3: cervical cancer Group 4: other solid tumors, excluding colorectal, clear cell ovarian, head and neck squamous cell, and cervical cancers Group 5: unresectable or metastatic solid tumors with PIK3CA double mutations In addition, the SRC (with Sponsor approval) may choose to open additional group(s) of 20 participants to study the clinical activity, safety, and PK/PD with other specified solid tumor types. Key Inclusion for Combination Arms: * 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: \[Does not apply to triplet combination arms, Part 2 Dose Expansion, Group 2\]: 1. ≤1 line of chemotherapy in the metastatic setting 2. ≥1 CDK4/6 inhibitor in either the adjuvant and/or metastatic setting 3. ≥1 antiestrogen therapy in either adjuvant and/or metastatic setting, including, but not limited to, selective estrogen-receptor degraders (eg, fulvestrant), selective estrogen receptor modulators (eg, tamoxifen), and aromatase inhibitors (AI) (letrozole, anastrozole, exemestane), and 4. ≥1 PARP inhibitor, if appropriate, if documented germline BRCA1/2 mutation Note: Systemic local, loco-regional, or adjuvant treatment with chemotherapy and PARP inhibitors is not to be included in enumeration or previous treatment \[For double combination arm; Part 2 Dose Expansion, Group 2\]: Received prior treatment with a PI3Kα, AKT, or mTOR inhibitor and discontinued the inhibitor due to intolerance and not disease progression, where intolerance is defined as treatment discontinuation due to treatment related AE (eg. hyperglycemia, rash, diarrhea, stomatitis) other than severe hypersensitivity reaction and/or life-threatening reactions, such as anaphylaxis and Stevens-Johnson syndrome. \[For triple combination arms; Part 1 dose escalation\]: Participants who had previous treatment for breast cancer with PI3Kα, AKT, mTOR inhibitors and discontiuned due to participant/physician decision, intolerance, or disease progression will be considered. \[For triple combination arms, Part 2 Dose Expansion, Group 2\]: Participants must be intolerant to or have declined standard therapy for locally advanced or metastatic HR+/HER2- PIK3CA-mutated breast cancer. Prior endocrine therapy and CDK4/6inhibitors are allowed as follows: 1. Participants must have progressed during (neo)adjuvant endocrine therapy or within12 months of completing (neo)adjuvant endocrine therapy with an AI or tamoxifen. 2. If a CDK4/6 inhibitor was included as part of (neo)adjuvant therapy, disease must have recurred/progressed \>12 months after completion of the CDK4/6 inhibitor portion of (neo)adjuvant therapy Key Exclusion Criteria Prior treatment with: 1. PI3Kα, AKT, or mTOR inhibitors (all arms except for doublet RLY-2608 + fulvestrant arm, Part 2, Group 2; and triplet combinations, Part 1 dose escalation). 2. Immune checkpoint inhibitors. 3. Triplet combinations RLY-2608 + CDK4 or CDK4/6 inhibitor + fulvestrant, Part 2 expansion, Group 2 only: i. Prior systemic chemotherapy or antibody drug conjugate for locally advanced or metastatic disease. ii. Prior CDK2, CDK4, or CDK4/6 inhibitor as treatment for locally advanced or metastatic disease. iii. Prior treatment with fulvestrant or any selective ER degrader, with the exception of patients who have received fulvestrant or any selective ER degrader as part of neoadjuvant therapy only and with treatment duration ≤6 months. Type 1 or Type 2 diabetes requiring antihyperglycemic medication, or fasting plasma glucose ≥140 mg/dL and glycosylated hemoglobin (HbA1c) ≥7.0%. History of allergy or hypersensitivity to any components or excipients of PI3K inhibitors. For combination arms only: allergy or hypersensitivity to any components or excipients of fulvestrant, palbociclib, ribociclib, and/or PF-07220060 as appropriate for the combination. Past medical history of or ongoing ILD, or pneumonitis requiring intervention. Participants with past history of resolved Grade 1 pneumonitis may be considered, except in triple combination arms. The following cardiac criteria: * 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. CNS metastases or primary CNS tumor that is associated with progressive neurologic symptoms

Locations (37)

The University of Arizona Cancer Center

Tucson, Arizona, United States

RECRUITING

University of California-San Diego

San Diego, California, United States

RECRUITING

HealthONE

Denver, Colorado, United States

RECRUITING

Yale University

New Haven, Connecticut, United States

Outcomes

Primary Outcomes

Determination of maximum tolerated dose (MTD) and/or recommended Phase 2 dose (RP2D) of RLY-2608 as a single agent

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

Determination of maximum tolerated dose (MTD) and/or recommended Phase 2 dose (RP2D) of RLY-2608 in combination with fulvestrant

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

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 fulvestrant

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

Number of patients with adverse events and serious adverse events of RLY-2608 as a single agent

Time frame: Every 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

Time frame: Every 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 fulvestrant

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

Secondary Outcomes

PIK3CA gene status in plasma circulating tumor deoxyribonucleic acid (ctDNA) and tumor tissue

Time frame: Day 1 of Cycle 1 (each cycle is 28 days)

Pharmacokinetic parameters including maximum plasma drug concentration (Cmax) of RLY-2608 (and its metabolites, as appropriate) as single agent

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

Pharmacokinetic parameters including area under the plasma concentration versus time curve during a dose interval (AUC0-tau) of RLY-2608 (and its metabolites, as appropriate) as single agent

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

Pharmacokinetic parameters including half-life (t1/2) of RLY-2608 (and its metabolites, as appropriate) as single agent

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

Pharmacokinetic parameters including maximum plasma drug concentration (Cmax) of RLY-2608 (and its metabolites, as appropriate) when RLY-2608 is administered in combination with fulvestrant

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

Pharmacokinetic parameters including area under the plasma concentration versus time curve during a dose interval (AUC0-tau) of RLY-2608 (and its metabolites, as appropriate) when RLY-2608 is administered in combination with fulvestrant

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

Pharmacokinetic parameters including half-life (t1/2) of RLY-2608 (and its metabolites, as appropriate) when RLY-2608 is administered in combination with fulvestrant

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

PK parameters including maximum plasma drug concentration (Cmax) of RLY-2608 (and its metabolites, as appropriate) when RLY-2608 is administered in combination with fulvestrant + palbociclib or ribociclib, and in combination (PF-07220060) +fulvestrant

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

PK parameters including area under the plasma concentration vs time curve during a dose interval (AUC0-tau) of RLY-2608 (and its metabolites, as appropriate) administered with fulvestrant + palbociclib, or ribociclib, or PF-07220060

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

Pharmacokinetic parameters including half-life (t1/2) of RLY-2608 (and its metabolites, as appropriate) when RLY-2608 is administered in combination with fulvestrant + palbociclib or ribociclib, and in combination with PF-07220060 +fulvestrant

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

Changes in circulating blood of fasting glucose in RLY-2608 as a single agent