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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

Phase 1
Recruiting
Conditions
Breast Cancer
Gynecologic Cancer
HNSCC
Solid Tumors, Adult
Interventions
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 in participants with advanced solid tumors with certain mutations.

Part 1 will evaluate STX-478 as monotherapy in participants with advanced solid tumors and breast cancer; Part 2 will evaluate STX-478 therapy as combination therapy with fulvestrant in participants with 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
400
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 archival tumor specimen within 10 years prior to screening
  3. Has a tumor that harbors a documented PI3Kα mutation (cohort specific criterion for cohort-specific mutation types) obtained either from tumor or plasma samples, determined by PCR or NGS-based assay as an FDA-approved test in US, CE marked in EU, or obtained as part of normal clinical care in a CLIA certified or similarly certified laboratory.
  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

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 a tumor with known mutations/deletions in PTEN and activating mutations in AKT (E17K) confirmed by a CLIA-certified or similarly certified laboratory
  4. Has an established diagnosis of diabetes mellitus type 1 or has uncontrolled diabetes mellitus type 2 (based on FPG and HbA1c thresholds defined in the inclusion criteria) requiring antihyperglycemic medication
  5. Cohorts A0, A1, A2, A3, A4, A5 and B: Has had prior treatment with PI3K/AKT/mTOR inhibitor(s), except in certain circumstances
  6. 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
  7. 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
  8. 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
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 Combination STX-478 + fulvestrant + CDK4/6 inhibitorSTX-478Cohort C/D: HR+/HER2- or HR+/HER2low breast cancer expressing PI3Ka mutations
Dose Selection/Expansion Combination STX-478 + fulvestrant + CDK4/6 inhibitorFulvestrantCohort C/D: HR+/HER2- or HR+/HER2low breast cancer expressing PI3Ka mutations
Dose Selection/Expansion Combination STX-478 + fulvestrant + CDK4/6 inhibitorRibociclibCohort C/D: HR+/HER2- or HR+/HER2low breast cancer expressing PI3Ka mutations
Dose Selection/Expansion Combination STX-478 + fulvestrant + CDK4/6 inhibitorPalbociclibCohort C/D: 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)

START Barcelona_HM Nou Delfos

🇪🇸

Barcelona, Spain

Instituto de Investigacion Oncologica Vall d'Hebron

🇪🇸

Barcelona, Spain

Hospital Clínico San Carlos

🇪🇸

Madrid, Spain

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

START - Midwest

🇺🇸

Grand Rapids, Michigan, United States

Saint Luke's Cancer Institute

🇺🇸

Kansas City, Missouri, United States

Memorial Sloan Kettering Cancer Center

🇺🇸

New York, New York, United States

University Hospitals Cleveland Medical Center

🇺🇸

Cleveland, Ohio, United States

Stefanie Spielman Comprehensive Breast Cancer

🇺🇸

Columbus, Ohio, United States

University of Oklahoma

🇺🇸

Oklahoma City, Oklahoma, United States

Mary Crowley Cancer Research

🇺🇸

Dallas, Texas, United States

Texas Oncology - Baylor Charles A. Sammons Cancer Center

🇺🇸

Dallas, Texas, United States

The University of Texas MD Anderson Cancer Center

🇺🇸

Houston, Texas, United States

START - San Antonio

🇺🇸

San Antonio, Texas, United States

START Mountain Region

🇺🇸

West Valley City, Utah, United States

NEXT Virginia

🇺🇸

Fairfax, Virginia, United States

Institut Bergonie City: Bordeaux

🇫🇷

Bordeaux, France

Institut Claudius Regaud

🇫🇷

Toulouse, France

Institut Gustave Roussy

🇫🇷

Villejuif, France

NEXT Oncology - Hospital Quironsalud Madrid

🇪🇸

Pozuelo De Alarcón, Madrid, Spain

Fondazione Policlinico Universitario A Gemelli-Rome

🇮🇹

Roma, Lazio, Italy

Istituto Europeo di Oncologia

🇮🇹

Milano, Lombardia, Italy

START Madrid_Hospital Universitario Fundacion Jimenez Diaz

🇪🇸

Madrid, Spain

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

START Madrid_Hospital Universitario HM Sanchinarro

🇪🇸

Madrid, Spain

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