A Phase 1 of CTX-8371 in Patients With Advanced Malignancies

April 15, 2026 updated by: Compass Therapeutics

A Phase 1, Open-Label, Multiple-Ascending Dose Study of the Safety and Tolerability of CTX-8371 in Patients With Advanced Malignancies

This is a Phase 1, open-label, first-in-human study of CTX-8371 administered as a monotherapy in patients with metastatic or locally advanced malignancies. The study will be conducted in 2 cohorts: Dose Escalation and Dose Expansion.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This Phase 1, open-label, first-in-human study will evaluate the safety, tolerability, immunogenicity, and pharmacokinetic profile of CTX-8371 monotherapy. Preliminary anti-tumor activity of CTX-8371 will also be assessed. The study will be conducted in 2 cohorts: Dose escalation and Dose expansion. The Dose Escalation Cohort will utilize a 3+3 design to evaluate five dose levels (0.1-10.0 mg/kg) of CTX-8371 given as an IV infusion once every 2 weeks. Patients in the Dose Expansion Cohort will receive CTX-8371 as an IV infusion at 3.0 mg/kg or 10.0 mg/kg at a 1:1 allocation.

Study Type

Interventional

Enrollment (Estimated)

85

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • Florida
      • Margate, Florida, United States, 33063
        • Withdrawn
        • D&H Cancer Research Center
      • Orlando, Florida, United States, 32827
        • Recruiting
        • Florida Cancer Specialists - Lake Nona
        • Principal Investigator:
          • Cesar Perez Batista, MD
        • Contact:
      • Sarasota, Florida, United States, 34236
        • Recruiting
        • Florida Cancer Specialists - Sarasota
        • Principal Investigator:
          • Judy Wang, MD
    • Georgia
      • Athens, Georgia, United States, 30607
        • Recruiting
        • University Cancer & Blood Center
        • Contact:
        • Principal Investigator:
          • Frederick Flynt, MD, FACP
    • Massachusetts
      • Boston, Massachusetts, United States, 02215
        • Recruiting
        • Dana-Farber Cancer Institute
        • Contact:
        • Principal Investigator:
          • Patrick Ott, MD, PhD
      • Boston, Massachusetts, United States, 02215
        • Recruiting
        • Beth Israel Deaconess Medical Center
        • Contact:
        • Principal Investigator:
          • Hollis Viray, MD
    • New York
      • Buffalo, New York, United States, 14263
        • Recruiting
        • Roswell Park Cancer Institute
        • Contact:
        • Principal Investigator:
          • Benjamin Switzer, DO
    • Tennessee
      • Nashville, Tennessee, United States, 37203
        • Recruiting
        • Tennessee Oncology
        • Contact:
        • Principal Investigator:
          • Jeff Russell, MD
    • Washington
      • Spokane, Washington, United States, 99208
        • Recruiting
        • Summit Cancer Center
        • Principal Investigator:
          • Arvind Chaudhry, MD
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Age 18 years or older

  2. Patients must have a histologically or cytologically confirmed diagnosis of locally advanced unresectable or metastatic disease that is relapsed/refractory to standard therapy or for which no effective standard therapy is available, including

    1. Malignant Melanoma (MM)

      • Patients who have progressed after a minimum of 2 doses of a PD-1/PD-L1 treatment. Study enrollment (C1D1) must be within 12 weeks of the last dose of the anti-PD-1/PD-L1 blocking antibody
      • Patients must have had prior testing for BRAF V600 mutations. Patients with BRAF V600 activating mutation must have received prior therapy with a BRAF/MEK inhibitor
      • Uveal and mucosal melanoma are excluded

    2. Head and Neck squamous cell carcinoma (HNSCC)

      • HNSCC of oral cavity, oropharynx, hypopharynx, or larynx
      • Patients who have progressed after a minimum of 2 doses of a PD-1/PD-L1 treatment. Study enrollment (C1D1) must be within 12 weeks of the last dose of the anti-PD-1/PD-L1 blocking antibody
      • Patients must have received prior treatment with platinum-based chemotherapy

    3. Non-Small Cell Lung Cancer (NSCLC)

      • Patients who have progressed after a minimum of 2 doses of a PD-1/PD-L1 treatment. Study enrollment (C1D1) must be within 12 weeks of the last dose of the anti-PD-1/PD-L1 blocking antibody
      • Patients must have received prior treatment with platinum-based chemotherapy

    4. Triple Negative Breast Cancer (TNBC)

      • ER/PR and HER2 status should be defined by ASCO/CAP guidelines (JCO Allison et al 2020)
      • Patients with HER2-low cancers (HER2 IHC 1+ or 2+/ISH negative) are excluded
      • Patients must have received prior sacituzumab govitecan and if PD-L1 ≥10% by CPS pembrolizumab with chemotherapy

    5. Classical Hodgkin Lymphoma (HL)

      • Patients must have received at least two prior systemic therapies including brentuximab vedotin (if eligible) and a prior PD-1 inhibitor
      • Patients must have experienced less than a CR (according to Lugano criteria) to anti- PD-1 treatment

    6. (Cohort 2 Dose Expansion): Non-Small Cell Lung Cancer (NSCLC)

      • Patients who have progressed after a minimum of 2 doses of a PD-1/PD-L1 treatment
      • Patients must have received prior treatment with platinum-based chemotherapy

    7. (Cohort 2 Dose Expansion) Triple Negative Breast Cancer (TNBC)

      • ER/PR and HER2 status should be defined by ASCO/CAP guidelines (JCO Allison et al 2020)
      • Patients must have received prior sacituzumab govitecan and if PD-L1 ≥10% by CPS pembrolizumab with chemotherapy
      • Patients with HER2-low tumors (HER2 IHC 1+ or 2+/ISH negative) need to have received fam-trastuzumab deruxtecan (Enhertu)

    8. (Cohort 2 Dose Expansion) Classical Hodgkin's Lymphoma (HL)

      • Patients must have received at least two prior systemic therapies including brentuximab vedotin (if eligible) and a prior PD-1 inhibitor.
      • Patients must have received at least 12 weeks of treatment with a PD-1/PD-L1 inhibitor as a monotherapy or in combination and had at least stable disease or progressive disease (PD) with overall clinical benefit.
  3. Patients with NSCLC, MM, TNBC, and HNSCC must have measurable disease per RECIST 1.1. Patients with HL must have at least one measurable lesion > 1.5 cm for nodal, > 1.0 cm for extranodal FDG-avid disease by the Lugano (2014) response criteria. Tumor sites that are considered measurable must not have received prior radiation
  4. Eastern Cooperative Oncology Group (ECOG) performance status 0-1

  5. Adequate bone marrow function defined by absolute neutrophil (ANC) of ≥ 1.5×109/L, platelet count of ≥ 100.0×109/L, and hemoglobin of ≥ 9.0 g/dL (with or without transfusion)

    a. (Cohort 2 Dose Expansion) Adequate bone marrow function defined by absolute neutrophil (ANC) of ≥ 1.5×109/L, platelet count of ≥ 100.0×109/L, and hemoglobin of ≥ 9.0 g/dL (with or without transfusion) within 2 weeks from the first dose of CTX-8371.

    - Blood transfusion is not allowed within 2 weeks from the first dose of CTX-8371

  6. Adequate hepatic function defined as serum total bilirubin ≤ 1.5 × ULN, AST/ALT ≤ 2.5 × ULN (or ≤ 5 × ULN in patients with liver metastases)
  7. Adequate renal function defined as creatinine clearance ≥ 30mL/min by Cockcroft-Gault equation
  8. Female patients must be surgically sterile (or have a monogamous partner who is surgically sterile) or be at least 2 years postmenopausal or commits to use 2 acceptable forms of birth control (defined as the use of an intrauterine device (IUD), a barrier method with spermicide, condoms, any form of hormonal contraceptives) or abstinence for the duration of the study and for 4 months following the last dose of study treatment. Male patients must be sterile (biologically or surgically) or commit to the use of a reliable method of birth control (condoms with spermicide) for the duration of the study and for 4 months following the last dose of study treatment
  9. Female patients who are women of childbearing potential (WOCBP) must have a negative serum pregnancy test at Screening within 7 days of dosing with CTX-8371
  10. Last dose of previous PD-1 or PD-L1 therapy ≥ 28 days, other anticancer therapy > 21 days (or 2 half-lives for proteins, whichever is longer), radiotherapy >21 days (concurrent localized palliative radiotherapy is allowed during CTX-8371 treatment), or surgical intervention >21 days prior to the first dose of CTX-8371
  11. Resolution of all prior anti-cancer therapy toxicities ≤ Grade 2
  12. Life expectancy ≥ 12 weeks
  13. Capable of understanding and complying with protocol requirements
  14. Signed and dated institutional review board (IRB)/independent ethics committee (IEC)-approved informed consent form (ICF) before any protocol-directed screening procedures are performed

Exclusion Criteria:

  1. Developed clinically significant adverse reaction to PD-1 or PD-L1 therapy, including immune related adverse reactions, which led to discontinuation of treatment
  2. Systemic therapy with immunosuppressive agents within 7 days before the start of CTX-8371 treatment. Topical, intranasal, intraocular, or inhaled corticosteroids and physiologic replacement for patients with adrenal insufficiency are allowed
  3. Patient is a pregnant or lactating WOCBP
  4. Prior organ transplantation
  5. Patients with evidence of active hepatitis B virus (HBV), hepatitis C virus (HCV) or human immunodeficiency virus (HIV) infection. Patients with positive HBsAg and/or detectable HBV DNA are eligible only if adequately controlled on antiviral therapy according to institutional standards and liver function eligibility criteria are also met. HCV patients showing sustained viral response or patients with immunity to HBV infection may enroll.
  6. Active autoimmune disease or medical conditions requiring chronic steroid (i.e., > 10 mg/day prednisone or equivalent) or immunosuppressive therapy. Patients with a prior history of autoimmune disease may be eligible following discussion with the Medical Monitor
  7. History of primary malignancy other than the malignancy under study will be excluded, except for malignancies with a negligible risk of metastasis or death (e.g., 5-year OS rate >90%). Prior malignancy history will be evaluated on a case-by-case basis by the Sponsor Medical Monitor.
  8. Symptomatic or uncontrolled central nervous system and brain metastasis or active leptomeningeal disease. Patients with equivocal findings or with confirmed brain metastases are eligible for the study provided that they are asymptomatic and radiologically and neurologically stable without the need for corticosteroid treatment or seizure prophylaxis for ≥4 weeks before the first dose of study drug. Prior treatment with either surgery or radiation is permitted and all patients with a history of CNS or brain lesions require imaging during screening to confirm stability.

  9. Other medical condition that in the opinion of the Investigator and/or Sponsor Medical Monitor may interfere with the conduct and/or interpretation of the current study, including:

    • Congestive heart failure (> New York Heart Association Class II), active coronary artery disease, unevaluated new onset angina within 3 months or unstable angina (angina symptoms at rest) or clinically significant cardiac arrhythmias
    • QTc interval (using Fridericia correction calculation) > 480 msec

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Dose Escalation Cohort 1
Escalating doses of CTX-8371
Drug: CTX-8371
Intravenous (IV) infusion every two weeks.
Experimental: Dose Expansion Cohort 2
Two CTX-8371 dose groups (3.0 mg/kg and 10.0 mg/kg) in three tumor type subgroups (NSCLC, TNBC, and HL)
Drug: CTX-8371
Intravenous (IV) infusion every two weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cohort 1: Evaluate the safety and tolerability of escalating doses of CTX-8371
Time Frame: From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until 30 days after the last dose of CTX-8371, average of 6 months
Number of participants with dose limiting toxicities (DLTs), treatment-emergent adverse events (TEAEs), and/or changes in clinical laboratory abnormalities
From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until 30 days after the last dose of CTX-8371, average of 6 months
Cohort 1: Determine the dose(s) of CTX-8371 to be further examined in Cohort 2 and Phase 2 studies
Time Frame: From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks ) until 30 days after the last dose of CTX-8371 (average of 6 months )
From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks ) until 30 days after the last dose of CTX-8371 (average of 6 months )
Cohort 2: Evaluate the safety and tolerability of CTX-8371 at 3.0 mg/kg and 10.0 mg/kg
Time Frame: From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until 30 days after the last dose of CTX-8371 (up to 2 years)
Incidence of treatment-emergent adverse events (TEAEs)
From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until 30 days after the last dose of CTX-8371 (up to 2 years)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cohort 1 and 2: Objective Response Rate (ORR) (Percentage of Participants With Objective Response) as per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1
Time Frame: Baseline until confirmed disease progression (up to 2 years)
Baseline until confirmed disease progression (up to 2 years)
Cohort 1 and 2: Duration of Response (DOR) as per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1
Time Frame: From the date of first confirmed CR or PR until the first date of recurrent or progressive disease (up to 2 years)
From the date of first confirmed CR or PR until the first date of recurrent or progressive disease (up to 2 years)
Cohort 1 and 2: Progression-Free Survival (PFS) as per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1
Time Frame: From first dose of CTX-8371(Cycle 1 Day 1,Cycle = 2 weeks ) until disease progression or death, whichever occur first (up to 2 years)
From first dose of CTX-8371(Cycle 1 Day 1,Cycle = 2 weeks ) until disease progression or death, whichever occur first (up to 2 years)
Cohort 1 and 2: Overall Survival (OS) of CTX-8371
Time Frame: From first dose of CTX-8371 (Cycle 1 Day 1,Cycle = 2 weeks) until death (up to 2 years)
From first dose of CTX-8371 (Cycle 1 Day 1,Cycle = 2 weeks) until death (up to 2 years)
Cohort 1 and 2: Maximum serum concentration (Cmax) of CTX-8371
Time Frame: From first dose of CTX-8371 (Cycle 1 Day 1,Cycle = 2 weeks) until treatment discontinuation
From first dose of CTX-8371 (Cycle 1 Day 1,Cycle = 2 weeks) until treatment discontinuation
Cohort 1 and 2: Time of maximum observed serum concentration (Tmax) of CTX-8371
Time Frame: From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until treatment discontinuation
From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until treatment discontinuation
Cohort 1 and 2: Trough serum concentration (Ctrough) of CTX-8371
Time Frame: From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until treatment discontinuation
From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until treatment discontinuation
Cohort 1 and 2: Area under the serum concentrations of CTX-8371 versus time curve (AUC) for CTX-8371
Time Frame: From first dose of CTX-8371 (Cycle 1 Day 1,Cycle = 2 weeks) until treatment discontinuation
From first dose of CTX-8371 (Cycle 1 Day 1,Cycle = 2 weeks) until treatment discontinuation
Cohort 1 and 2: Clearance (CL) of serum concentrations of CTX-8371
Time Frame: From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until treatment discontinuation
From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until treatment discontinuation
Cohort 1 and 2: Volume of distribution (Vd) of serum concentrations of CTX-8371
Time Frame: From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until treatment discontinuation
From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until treatment discontinuation
Cohort 1 and 2: Half-life (t1/2) of serum concentrations of CTX-8371
Time Frame: From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until treatment discontinuation
From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until treatment discontinuation
Cohort 1 and 2: Dose Response for CTX-8371
Time Frame: From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until treatment discontinuation
From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until treatment discontinuation
Cohort 1 and 2: Assess the immunogenicity of CTX-8371
Time Frame: From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until end of treatment visit
Screen for the presence and development of antibodies against CTX-8371
From first dose of CTX-8371 (Cycle 1 Day 1, Cycle = 2 weeks) until end of treatment visit
Cohort 1 and 2: Objective Response Rate (ORR) (Percentage of Participants With Objective Response) as per Lugano (2014)
Time Frame: Baseline until confirmed disease progression (up to 2 years)
Baseline until confirmed disease progression (up to 2 years)
Cohort 1 and 2: Duration of Response (DOR) as per Lugano (2014)
Time Frame: From the date of first confirmed CR or PR until the first date of recurrent or progressive disease (up to 2 years)
From the date of first confirmed CR or PR until the first date of recurrent or progressive disease (up to 2 years)
Cohort 1 and 2: Progression-Free Survival (PFS) as per Lugano (2014)
Time Frame: From first dose of CTX-8371(Cycle 1 Day 1,Cycle = 2 weeks ) until disease progression or death, whichever occurs first
From first dose of CTX-8371(Cycle 1 Day 1,Cycle = 2 weeks ) until disease progression or death, whichever occurs first

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Compass Therapeutics

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 19, 2024

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

May 1, 2027

Study Registration Dates

First Submitted

November 17, 2023

First Submitted That Met QC Criteria

November 27, 2023

First Posted (Actual)

November 29, 2023

Study Record Updates

Last Update Posted (Actual)

April 20, 2026

Last Update Submitted That Met QC Criteria

April 15, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CTX-8371-001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Hodgkin Lymphoma

Clinical Trials on CTX-8371

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Austria

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe