Study of CTX-471 in Patients With Neural Cell Adhesion Molecule (NCAM) Positive Neuroendocrine Neoplasms

NCT07684170 | Not Yet Recruiting Phase 2 FDA Drug

• 1 other identifier: CTX-471-002
• Study Type: interventional
• Target: 58
• Locations: 0 countries
• Sites: N/A

Brief Summary

This study will enroll patients with central lab confirmed NCAM (CD56 IHC) positive metastatic neuroendocrine neoplasms that have progressed after standard of care treatment. CTX-471 to be administered as an intravenous (IV) infusion at either 0.3 mg/kg or 0.6 mg/kg every 2 weeks until disease progression or unacceptable toxicity. The study will be conducted in two stages. In Stage 1, 18 patients will be accrued for each dose level. If there are less than 2 objective responses in these 18 patients at either dose level, the dose level will be stopped. Otherwise, an additional 22 patients will be accrued in Stage 2 with 11 patients for each dose level.

Conditions

Neuroendocrine Tumors; Neuroendocrine Neoplasm; Neuroendocrine Carcinomas

Outcome Measures

Primary Outcomes (3)

• Evaluate the clinical activity of CTX-471

  Objective Response Rate (ORR) (Percentage of Participants With Objective Response) as per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1

  Baseline until confirmed disease progression (up to 1 year)

• Evaluate the safety of CTX-471

  Incidence of treatment emergent adverse events (TEAEs), treatment-related AEs (TREAEs), and serious adverse events (SAEs)

  From first dose of CTX-471 (Cycle 1 Day 1, Cycle = 2 weeks) until 30 days after the last dose of CTX-471

• Determine the recommended phase 2 dose (RP2D) for CTX-471

  Efficacy, exposure, safety events, and markers of response will be aggregated to select a Phase 2 dose

  From first dose of CTX-471 (Cycle 1 Day 1, Cycle = 2 weeks) until 30 days after the last dose of CTX-471

Secondary Outcomes (13)

• Duration of Response (DOR) as per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1

  From the date of first confirmed PR or CR until date of progression or death, whichever occurs first (up to 1 year)

• Disease Control Rate (DCR) as per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1

  From first dose of CTX-471 (Cycle 1 Day 1,Cycle = 2 weeks) until until disease progression or death, whichever occurs first (up to 1 year)

• Progression-Free Survival (PFS) as per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1

  From first dose of CTX-471(Cycle 1 Day 1,Cycle = 2 weeks ) until disease progression or death, whichever occurs first (up to 1 year)

• Median Progression-Free Survival (PFS) as per Response Evaluation Criteria in Solid Tumors(RECIST) Version 1.1

  From first dose of CTX-471(Cycle 1 Day 1, Cycle = 2weeks ) until date of progression or death, whichever occurs first, for 50% of the study population, including time intervals of at 6 months and 12 months.

• Median Overall Survival (OS)

  From first dose of CTX-471 (Cycle 1 Day 1,Cycle = 2weeks) until death for 50% of the study population, including time intervals at 6 months and 12 months.

Study Arms (2)

Dose Level 0.3 mg/kg

EXPERIMENTAL

Drug: CTX-471

Dose Level 0.6 mg/kg

EXPERIMENTAL

Drug: CTX-471

Interventions

CTX-471 DRUG

Patients will receive CTX-471 as an intravenous (IV) infusion every 2 weeks until disease progression or unacceptable toxicity.

Dose Level 0.3 mg/kg; Dose Level 0.6 mg/kg

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 18 years or older.
• Positive immunohistochemical staining for NCAM (defined as ≥ 1% of malignant cells with membranous/cytoplasmic staining of any intensity) on an archived (≤ 3 months) or freshly taken biopsy specimen (centrally tested) with histologically confirmed diagnosis of metastatic tumors.
• Locally advanced unresectable or metastatic neuroendocrine neoplasm (NEN) defined by World Health Organization (WHO) (Rindi et al 2022) Grade 3 neuroendocrine tumor (NET) or neuroendocrine carcinoma (NEC) (Ki-67 \> 20% and/or \> 20 mitoses/10 hpf) and confirmed by histopathology or cytology (eg, gastroentero-pancreatic NECs (GEP-NEC) and lung NEC, other rare sites of origin such as genitourinary, gynecological, larynx, thyroid, or unknown origin).
• Patients must have received at least one prior line of chemotherapy and must have exhausted any other standard-of-care treatment option.
• a. Patients with histologically confirmed prostate NEC are not required to have received prior androgen deprivation therapy (ADT) or castrated levels of testosterone.
• A washout period of 4 weeks or at least 5-fold half-life of the last dose (whichever is shorter) of prior systemic therapy prior to receiving the first dose of CTX-471.
• The eligibility of patients who received unapproved drugs will be determined by discussion with the Sponsor Medical Monitor.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-1.
• At least one measurable lesion definable by MRI or CT scan per RECIST version 1.1 criteria.
• All toxicities related to previous anti-cancer therapies have resolved to (CTCAE) Grade 1 prior to trial treatment administration (except for alopecia, peripheral neuropathy, fatigue and endocrinopathies controlled by replacement therapy which must be CTCAE Grade 2 and amenorrhea/menstrual disorders which can be any grade).
• Adequate organ function and laboratory values:
• 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).
• Adequate hepatic function defined as serum total bilirubin ≤ 1.5 × ULN, AST/ALT ≤ 2.5 × ULN (or ≤ 5 × ULN in patients with liver metastases or ≤3 x ULN for patients with Gilbert's syndrome).
• Adequate renal function defined as creatinine clearance ≥ 30 mL/min by Cockcroft-Gault equation.
• Females of childbearing potential (FOCBP) should have a negative serum pregnancy within 72 hours prior to receiving the first dose of study medication.

You may not qualify if:

• Diagnosis of well differentiated G1/G2 neuroendocrine neoplasm.
• Prior history of interstitial lung disease.
• Prior treatment of CD137 targeted therapy (investigational and approved).
• 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 central nervous system (CNS) or brain lesions require imaging during screening to confirm stability.
• Prior solid organ transplantation and/ or an allogeneic tissue transplant.
• Active hepatitis B virus (HBV), hepatitis C virus (HCV) or human immunodeficiency virus (HIV) infection or a positive serological test at Screening within 35 days of dosing with CTX-471.
• Hepatitis B surface antigen (HBsAg) positive patients are eligible if they have received HBV antiviral therapy for at least 4 weeks and have undetectable HBV viral load prior to randomization.
• HBV+ patients should remain on anti-viral therapy throughout study intervention and follow local guidelines for HBV anti-viral therapy post completion of study intervention.
• History of HCV infection is eligible if HCV viral load is undetectable at screening.
• HCV+ patients must have completed curative anti-viral therapy at least 4 weeks prior to randomization.
• HIV-infected patients must be on anti-retroviral therapy (ART) and have a well-controlled HIV infection/disease defined as:
• Patients on ART must have a CD4+ T-cell count \< 350 cells/mm3 at time of screening.
• Patients on ART must have achieved and maintained virologic suppression defined as confirmed HIV RNA level below 50 copies/mL or the lower limit of qualification (below the limit of detection) using the locally available assay at the time of screening and for at least 12 weeks prior to screening.
• Patients on ART must have been on a stable regimen, without changes in drugs or dose modification, for at least 4 weeks prior to study entry (Day 1).
• Active autoimmune disease or medical conditions requiring chronic steroid (ie, \> 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.

Sponsors & Collaborators

• Compass Therapeutics: lead

MeSH Terms

Conditions

Neuroendocrine Tumors; Carcinoma, Neuroendocrine

Condition Hierarchy (Ancestors)

Neuroectodermal Tumors; Neoplasms, Germ Cell and Embryonal; Neoplasms by Histologic Type; Neoplasms; Neoplasms, Nerve Tissue; Adenocarcinoma; Carcinoma; Neoplasms, Glandular and Epithelial

Central Study Contacts

Compass Study Email

CONTACT

617-500-8099; CTX-471-002@compasstherapeutics.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 17, 2026
• First Posted: July 6, 2026
• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): September 1, 2028
• Study Completion (Estimated): September 1, 2029
• Last Updated: July 6, 2026

Record last verified: 2026-06