A Study to Test a New Immunotherapy, ABX-001, Alone and in Combination With the Marketed Drug, Pembrolizumab, for the Treatment of Tumors Previously Treated With Other Therapies

NCT07231458 | Recruiting Phase 1 DMC

• 2 other identifiers: ABX-001-012024-512403-39-01
• Study Type: interventional
• Target: 27
• Locations: 2 countries
• Sites: 5

Brief Summary

This is a Phase I/Ib first-in-human, open-label, non-randomized, multicenter, multi-country study to evaluate the safety and tolerability and to establish a recommended Phase 2 dose (RP2D) as well as assess preliminary clinical activity of ABX-001 administered intravenously (IV) alone (Part A) or co-administered with pembrolizumab (Part B) in participants with refractory/relapsed advanced solid tumors.

Conditions

Advanced Solid Tumors

Keywords

Immunotherapy; Non-oncolytic virus; Arenavirus

Outcome Measures

Primary Outcomes (2)

• Number of participants with Dose Limiting Toxicities (DLTs) in the DLT evaluation period

  3 weeks from start of treatment

• Incidence and severity of Adverse Events (AEs) throughout the study

  Part A: Up to 12 weeks, Part B: Up to 2 years

Secondary Outcomes (2)

• Objective Responses (OR) based on Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria and immune RECIST

  From start of treatment until progression, death, or end of study, whichever occurs first (Part A: Up to 12 weeks, Part B: Up to 2 years)

• Best percentage change from baseline in size of target lesions

  From start of treatment until progression, death, or end of study, whichever occurs first (Part A: Up to 12 weeks, Part B: Up to 2 years)

Study Arms (2)

Part A

EXPERIMENTAL

ABX-001 is administered intravenously (IV) alone

Drug: ABX-001

Part B

EXPERIMENTAL

ABX-001 is co-administered intravenously (IV) with pembrolizumab

Drug: ABX-001; Drug: Pembrolizumab

Interventions

ABX-001 DRUG

ABX-001 administered intravenously (IV)

Part A; Part B

Pembrolizumab DRUG

Pembrolizumab administered intravenously (IV)

Part B

Eligibility Criteria

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

You may qualify if:

• Participants must satisfy all of the following criteria at the screening visit unless otherwise stated:
• Participant must be capable of giving consent and at least 18 years of age at the time of signing the informed consent.
• Participants with advanced/recurrent solid tumors.
• Part A: Participants who have progressed despite standard therapy OR are intolerant of standard therapy, OR for whom no standard therapy exists.
• Part B: Participant has histologically confirmed locally advanced or metastatic disease, who have progressed despite standard therapy OR are intolerant of standard therapy, OR for whom no standard therapy exists. Participant must have received pembrolizumab as approved standard of care and have primary refractory or acquired secondary resistance. Participants must have a tumor lesion amenable to biopsy and must have another lesion that can be followed for response.
• As defined by the Society for Immunotherapy of Cancer:
• Primary resistance/refractory to anti-programmed cell death ligand-1 \[anti-PD-(L)1\]: minimum drug exposure of 8 to 12 weeks or 2 doses of the immunotherapy with lack of benefit, defined as progressive disease (PD) at the time of the first planned assessment of stable disease (SD) lasting less than 6 months.
• Secondary resistance: participants who experience disease progression following complete response (CR)/partial response (PR) or SD ≥6 months or immunotherapy treatment exposure.
• Histological or cytological documentation of an advanced solid tumor.
• Participants are willing to undergo tumor biopsy procedures. For tumor biopsies at screening, it is acceptable if a participant has a biopsy within 3 months from screening and/or during or after the most recent line of therapy (with no intervening anticancer therapy), if there is enough material to fulfil the requirements.
• Measurable disease per RECIST version 1.1. Palpable lesions that are measurable by radiologic or photographic evaluations may be utilized as the only measurable lesion.
• Eastern Cooperative Oncology Group performance status 0-1.
• Life expectancy of at least 12 weeks.
• Adequate organ functions:
• absolute neutrophil count ≥1.5 × 10\^9/Liter,

You may not qualify if:

• Participants will be excluded from the study if they satisfy any of the following criteria at the screening visit unless otherwise stated:
• Malignancy other than disease under study with the exception of those from which the participant has been disease-free for more than 2 years and not expected to affect the safety of the participant or the endpoints of the study. Curatively treated non-melanoma skin cancer is permitted.
• Symptomatic central nervous system (CNS) metastases or asymptomatic CNS metastases that have required steroids within 2 weeks prior to first dose of study treatment.
• Participants with carcinomatous meningitis or leptomeningeal spread are excluded regardless of clinical stability. Note: Participants with controlled brain metastases will be allowed but must have completed radiotherapy or surgery for CNS metastases \>2 weeks prior to study entry. Participants must be neurologically stable, having no new neurologic deficits on clinical examination, and without evidence of progression for at least 4 weeks by repeat imaging (which should be performed during study screening).
• Active autoimmune disease that has required systemic disease modifying or immunosuppressive treatment within the last 2 years. Replacement therapy (eg, thyroxine or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is permitted.
• Concurrent medical condition requiring the use of systemic immunosuppressive treatment within 28 days before the first dose of study treatment. Physiologic doses of corticosteroids for treatment of endocrinopathies or steroids with minimal systemic absorption, including topical, inhaled, or intranasal corticosteroids may be continued if the participant is on a stable dose, such as:
• Intranasal, inhaled, topical steroids, or local steroid injection (eg, intra-articular injection)
• Systemic corticosteroids at physiologic doses ≤ 10 mg/day of prednisone or equivalent
• Steroids as premedication for hypersensitivity reactions (eg, CT scan premedication).
• Current unstable liver or biliary disease per investigator assessment defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminemia, esophageal or gastric varices, persistent jaundice, or cirrhosis. Stable chronic liver disease (including Gilbert's syndrome or asymptomatic gallstones) or hepatobiliary involvement of malignancy is acceptable if participant otherwise meets entry criteria.
• History of vasculitis at any time prior to study treatment.
• Evidence or history of significant active bleeding or severe coagulation dysfunction within the last 6 months prior to receiving the first dose of study treatment.
• Known human immunodeficiency virus infection, and active and chronic hepatitis B, or hepatitis C.
• Participants with any kind of active infection, regardless of ongoing systemic treatment.
• QT interval corrected for heart rate using Fridericia's method \>450 msec or QTcF \>480 msec for participants with bundle branch block. A QTcF is the QT interval corrected for heart rate according to Fridericia's formula, machine-read or manually over-read.

Sponsors & Collaborators

• Abalos Therapeutics GmbH: lead

Study Sites (5)

Charite-Universitaetsmedizin Berlin - Campus Benjamin Franklin (CBF)

Berlin, 12200, Germany

RECRUITING

Universitaetsklinikum Tuebingen

Tübingen, 72076, Germany

RECRUITING

Vall d'Hebron Institut d'Oncologia

Barcelona, 08035, Spain

RECRUITING

Hospital Universitario Fundacion Jimenez Diaz

Madrid, 28040, Spain

RECRUITING

The START Center for Cancer Care - CIOCC

Madrid, 28050, Spain

RECRUITING

MeSH Terms

Interventions

pembrolizumab

Central Study Contacts

Thomas Bogenrieder, Chief Medical Officer, MD, PhD

CONTACT

+49 173162 2682; bogenrieder@abalos-tx.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 14, 2025
• First Posted: November 17, 2025
• Study Start: October 14, 2025
• Primary Completion (Estimated): October 30, 2026
• Study Completion (Estimated): October 30, 2026
• Last Updated: January 16, 2026

Record last verified: 2026-01

Locations

DE (2); ES (3)