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First-in-Human Study of STX-478 as Monotherapy and in Combination With Other Antineoplastic Agents in Participants With Advanced Solid Tumors

Registration Number
NCT05768139
Lead Sponsor
Scorpion Therapeutics, Inc.
Brief Summary

Study STX-478-101 is a multipart, open-label, phase 1/2 study evaluating the safety, tolerability, pharmacokinetics (PK), and preliminary antitumor activity of STX-478 (LY4064809) in participants with advanced solid tumors with P13Ka mutations.

Part 1 will evaluate STX-478 as monotherapy in participants with advanced solid tumors. Part 2 will evaluate STX-478 therapy as combination therapy with fulvestrant in participants with hormone receptor positive (HR+) breast cancer. Part 3 will evaluate STX-478 as combination therapy with endocrine therapy (aromatase inhibitors, fulvestrant or imlunestrant) and a CDK4/6 Inhibitor (either Ribociclib, Palbociclib or Abemaciclib) in participants with HR+ breast cancer.

Each study part will include a 28-day screening period, followed by treatment with STX-478 monotherapy or combination therapy.

Detailed Description

Not available

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
720
Inclusion Criteria
  1. Has an advanced or refractory solid tumor malignancy that is metastatic or locally advanced and unresectable (as specified by Cohort)
  2. Has a new or recent tumor biopsy (collected at screening, if feasible) or will provide an adequate tissue sample prior to screening
  3. Has a tumor that harbors a documented PI3Kα mutation (cohort specific criterion for cohort-specific mutation types)
  4. Is ≥18 years of age at the time of signing the ICF
  5. Has an ECOG performance status score of 0 or 1 at screening
  6. Has adequate organ function as defined per protocol

Key

Exclusion Criteria
  1. Has history (within ≤2 years before screening) of a solid tumor or hematological malignancy that is histologically distinct from the cancers being studied
  2. Has symptomatic brain or spinal metastases
  3. Has an established diagnosis of uncontrolled diabetes mellitus (defined as HbA1c ≥8% and/or FBG ≥140 mg/dL [7.7 mmol/L] and/or requiring or required insulin).
  4. Has had prior treatment with PI3K/AKT/mTOR inhibitor(s), except in certain circumstances
  5. Has had treatment with any local or systemic antineoplastic therapy or investigational anticancer agent within 14 days or 4 half-lives, whichever is longer, prior to the initiation of study treatment up to a maximum washout period of 28 days. Endocrine therapy does not require a washout period if the patient is enrolling in a cohort with the same combination endocrine therapy.
  6. Has toxicities from previous anticancer therapies that have not resolved to baseline levels or CTCAE grade ≤1, with the exception of alopecia and peripheral neuropathy.
  7. Has had radiotherapy within 14 days before the initiation of study treatment

Study & Design

Study Type
INTERVENTIONAL
Study Design
SEQUENTIAL
Arm && Interventions
GroupInterventionDescription
Dose Escalation (Advanced Solid Tumors)STX-478* Cohort A0: Advanced Solid tumors expressing PI3Kα mutations * Cohort A1: HR+ breast cancer expressing PI3Kα mutations
Dose ExpansionSTX-478* Cohort A1: HR+/HER2- breast cancer expressing PI3Ka mutations * Cohort A2: Gynecologic cancers * Cohort A3: Head and Neck Squamous Cell Carcinoma * Cohorts A4/A5: Other solid tumors not included in Cohorts A1, A2, or A3 expressing PI3Kα mutations * Cohort A6: Endometrial cancer
Dose Selection/Expansion: Combination STX-478 + fulvestrantSTX-478Cohort B: HR+/HER2- or HR+/HER2low breast cancer expressing PI3Kα mutations
Dose Selection/Expansion: Combination STX-478 + fulvestrantFulvestrantCohort B: HR+/HER2- or HR+/HER2low breast cancer expressing PI3Kα mutations
Dose Selection/Expansion CombinationSTX-478STX-478 + Endocrine therapy + CDK4/6 inhibitor Cohort C/D/E: HR+/HER2- or HR+/HER2low breast cancer expressing PI3Ka mutations
Dose Selection/Expansion CombinationFulvestrantSTX-478 + Endocrine therapy + CDK4/6 inhibitor Cohort C/D/E: HR+/HER2- or HR+/HER2low breast cancer expressing PI3Ka mutations
Dose Selection/Expansion CombinationRibociclibSTX-478 + Endocrine therapy + CDK4/6 inhibitor Cohort C/D/E: HR+/HER2- or HR+/HER2low breast cancer expressing PI3Ka mutations
Dose Selection/Expansion CombinationPalbociclibSTX-478 + Endocrine therapy + CDK4/6 inhibitor Cohort C/D/E: HR+/HER2- or HR+/HER2low breast cancer expressing PI3Ka mutations
Dose Selection/Expansion CombinationLetrozoleSTX-478 + Endocrine therapy + CDK4/6 inhibitor Cohort C/D/E: HR+/HER2- or HR+/HER2low breast cancer expressing PI3Ka mutations
Dose Selection/Expansion CombinationAnastrozoleSTX-478 + Endocrine therapy + CDK4/6 inhibitor Cohort C/D/E: HR+/HER2- or HR+/HER2low breast cancer expressing PI3Ka mutations
Dose Selection/Expansion CombinationExemestaneSTX-478 + Endocrine therapy + CDK4/6 inhibitor Cohort C/D/E: HR+/HER2- or HR+/HER2low breast cancer expressing PI3Ka mutations
Primary Outcome Measures
NameTimeMethod
Number of participants who experience at least 1 Dose Limiting Toxicity (DLT)First 28 days of treatment
Proportion of participants who experience at least 1 DLT during the first 28 days of treatmentFirst 28 days of treatment
Cmax of STX-47812 months
AUC(0-inf) of STX-47812 months
AUC(0-t) of STX-47812 months
AUC(0-τ) of STX-47812 months
Change from baseline in ctDNA levels12 months
Changes in circulating markers of glucose metabolism as assessed by changes in circulating glycosylated hemoglobin (HbA1c)12 months
Changes in circulating markers of glucose metabolism as assessed by circulating fasting plasma glucose12 months
Changes in circulating markers of glucose metabolism as assessed by circulating C-peptide12 months
Objective response rate (ORR) defined as the percentage of participants with partial response or complete response based on RECIST 1.112 months
Incidence of TEAEs/SAEs ≥ grade 212 months
Frequency of TEAEs according to CTCAE v5.0 criteria12 months
Change in ECOG performance status12 months
Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (33)

Providence Cancer Institute

🇺🇸

Portland, Oregon, United States

Angeles Clinic and Research Institute

🇺🇸

Los Angeles, California, United States

University of California, San Francisco

🇺🇸

San Francisco, California, United States

University of Colorado Anschutz Medical Center

🇺🇸

Aurora, Colorado, United States

Yale University

🇺🇸

New Haven, Connecticut, United States

Florida Cancer Specialists & Research Institute

🇺🇸

Lake Mary, Florida, United States

Moffitt Cancer Center

🇺🇸

Tampa, Florida, United States

Massachusetts General Hospital

🇺🇸

Boston, Massachusetts, United States

Dana Farber Cancer Center

🇺🇸

Boston, Massachusetts, United States

Karmanos Cancer Institute

🇺🇸

Detroit, Michigan, United States

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Providence Cancer Institute
🇺🇸Portland, Oregon, United States

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