Phase 1/2 Clinical Trial of CP-506 (HAP) in Monotherapy or With Carboplatin or ICI

October 2, 2025 updated by: Maastricht University Medical Center

Phase 1/2 Modular Dose Escalation With Cohort Expansion of CP-506 (HAP) in Patients With Solid Tumor Types With High Incidence of HRD/FAD in Monotherapy or With Carboplatin or Patients With Solid Tumour and OPD Receiving ICI

A modular, first time in human, open label, multiple dose, accelerated escalation with cohort expansion study of the safety and pharmacokinetics of intravenous infusion of CP-506, a tumor agnostic Hypoxia Activated Prodrug in patients with HRD/FAD solid tumours or tumor types with high incidence of HRD/FAD in monotherapy or in combination with carboplatin or patients with solid tumour and oligoprogressive disease receiving immune checkpoint inhibitors (ICI): a phase I-IIa clinical trial

Study Overview

Detailed Description

This study is a First in Human, early phase (I/IIa), 3 modules, 2 parts (A- dose escalation and B- cohort expansion), open-label, uncontrolled, multi-center, multiple dose, accelerated 3+3 dose escalation study. The study consist of 3 study modules. Module 1 is monotherapy with accelerated dose escalation. Modules 2 and 3 are also accelerated dose escalation modules, but with a combination of CP-506 with either Carboplatin or ICI. Initiation of modules 2 and 3 are dependent on the decision by the Independent Data Monitoring Committee (IDMC) based on the safety, tolerability and feasibility information from the study as a whole.

Each study modules will consist of a Part A (dose finding) and an optional Part B (cohort expansion). The option to start Part B will be decided by the IDMC based on safety, tolerability and feasibility information from the study as a whole. The expansion cohorts will explore preliminary efficacy.

Modules 2 and 3 will start after completion of module 1 and definition of the "minimal biological effective dose" (MBED) as the dose that results in 1) a decrease of 20% of hypoxia radiomics score on sequential CT of at least one lesion OR 2) a decrease of 20% of the initial tumour volume of at least one lesion.

MBED is assessed by CT scan at visit 7, 12 and 13. After observation of an MBED in three patients, the data supporting the MBED assessment will be reviewed by the IDMC for confirmation.

A maximum of 126 patients with advanced or metastatic cancer will be recruited in this study.

  • Module 1 - Monotherapy: up to 24 patients for Part A and 10 patients for Part B for whom no standard of care or known effective treatment options are available and with cancers that show a considerable incidence of Homologous Recombination or Fanconi Anaemia DNA repair defects (HRD/FAD)
  • Module 2 - Combination with Carboplatin: up to 24 patients for Part A and 22 patients for Part B for patients that receive carboplatin as standard of care: triple negative breast cancer and ovarian cancer.
  • Module 3 - Combination with ICI: up to 24 patients for Part A and 22 patients for Part B with advanced or metastatic cancer for whom standard of care immune checkpoint inhibitor (ICI) are currently administered for at least 6 months, would still be administered according to the treating clinician, outside any clinical trial but resulted in oligoprogression.

The complete CP-506 therapy consists of three cycles of CP-506 treatment. Each treatment cycle consists of three consecutive days of IV infusion for two hours and one day for observation and blood sampling, and a recovery time of 3 weeks. Patients are expected to come to the hospital for 18 visits. They consist of 1 screening visit, 3 cycles of CP-506 treatment. Each cycle will be followed by a post cycle visit after 14 and 21 days. The follow up visit will take place at day 105.

Study Type

Interventional

Enrollment (Estimated)

126

Phase

  • Phase 2
  • 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

      • Brussels, Belgium
        • Not yet recruiting
        • Institut Jules Bordet
        • Contact:
          • Nuria Kotecki, MD
      • Ghent, Belgium, 9000
        • Not yet recruiting
        • UZ Gent
        • Contact:
          • Sylvie Rottey, MD, PhD
          • Phone Number: +32 9 332 28 11
      • Rotterdam, Netherlands
        • Recruiting
        • Erasmus MC
        • Contact:
          • Henk Verheul, MD, PhD
    • Limburg
      • Maastricht, Limburg, Netherlands, 6229HX
        • Recruiting
        • Academisch Ziekenhuis Maastricht (Leading Centre)
        • Contact:
          • Loes Latten-Jansen, MD, PhD
      • Barcelona, Spain, 08035
        • Not yet recruiting
        • Institut Vall d'Hebron
        • Contact:
          • Irene Brana, MD, PhD
          • Phone Number: 0034 93 274 60 85

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Male or female, aged 18 years or more at the time of signing the informed consent
  2. Be willing and able to provide written informed consent for the trial
  3. Life expectancy of at least 3 months
  4. Be willing to have a biopsy collection procedure
  5. ECOG Performance status <= 2
  6. Must have adequate organ and bone marrow function, defined as the following:

    6.1. ANC ≥ 1500 µL 6.2. Hemoglobin ≥ 9.0 g/dL 6.3. Platelets ≥ 100 000 µL 6.4. Total bilirubin ≤ 1.5 × ULN OR direct bilirubin ≤ ULN for participants with total bilirubin levels >1.5 × ULN 6.5. AST (SGOT) and ALT (SGPT) ≤ 2.5 × ULN (≤ 5 × ULN for participants with liver metastases) 6.6. Creatinine ≤ 1.5 × ULN 6.7. Coagulation: INR ≤ 1.5 × ULN (or within therapeutic ranges for participants on anticoagulant treatment)

  7. Measurable disease on CT scan (RECIST 1.1)
  8. If female, not pregnant, not breastfeeding, and at least one of the following conditions applies:

    8.1. Not a woman of childbearing potential (WOCBP) 8.2. A WOCBP who agrees to follow contraceptive guidance during the treatment period and for at least 4 weeks after the last dose of study treatment and shows a negative pregnancy test before the start of the treatment

  9. If male, must agree to use contraception during the treatment period and for at least 4 weeks after the last dose of study treatment
  10. Able and willing to comply with the protocol Module 1 - monotherapy
  11. Have histologically or cytologically-confirmed advanced or metastatic solid tumour for whom no standard of care or known effective treatment options are available
  12. Have indications of Homologous Recombination (HR) or Fanconi Anaemia (FA) DNA damage repair defects, based on hereditary cancer diagnostics (e.g. BRCA1/2 carriers), dedicated HRD genomic assays (including exome-sequencing) from liquid or tissue biopsies. Presence of such a defect must have been established via a tissue based next generation sequencing test, performed --in a CAP/CLIAcertified (or comparable local or regional certification) laboratory, or via a germline test from one of the following approved providers: Myriad Genetics; Invitae; Ambry; Quest; Color Genomics; MSKCC-IMPACT; GeneDx; Foundation Medicine OR Have cancers with an increased incidence of HRD/FAD: ovarian (41%), breast (18%), pancreas (10%), prostate (9%), and head and neck (5%) OR Patients who were previously responsive to alkylating agent (Partial Response/Complete Response according to RECIST criteria).

    Module 2 - Carboplatin combination

  13. Patient must be eligible to carboplatin treatment.
  14. Have histologically or cytologically-confirmed advanced or metastatic solid tumour for whom no standard of care or known effective treatment options are available.
  15. Receive carboplatin as standard of care: triple negative breast cancer or ovarian cancer.

    Module 3 - ICI combination

  16. Have histologically or cytologically-confirmed advanced or metastatic solid tumour
  17. Receiving immune checkpoint inhibitor (ICI) monotherapy as standard of care for at least 6 months prior to the beginning of the study and who are oligoprogressive. Oligoprogression disease is defined as localized treatment failure at one or two anatomic sites, with one to five progressive and measurable (according to RECIST 1.1) lesions, either new or with ≥ 20% growth of their longest diameter (short-axis in lymph nodes), while other tumor manifestations could shrink or grow less than 20% in diameter

Exclusion Criteria:

Core:

  1. Prior radiotherapy to more than 25% of bone marrow
  2. Not recovered from all acute toxic effects of prior anticancer therapy (excluding CTCAE Grade 1 alopecia or peripheral neuropathy)
  3. Patients with significant cardiac co-morbidity, such as NYHA Class III or IV CHF, unstable angina, MI within the previous 6 months, or ventricular arrhythmias requiring drug therapy, pacemaker or implanted defibrillator. Serious, uncontrolled cardiac arrhythmia or clinically significant electrocardiogram abnormalities including second degree (Type II) or third-degree atrioventricular block. This does not apply to patient with a pace maker. Cardiomyopathy, myocardial infarction, acute coronary syndromes (including unstable angina pectoris), coronary angioplasty, stenting or bypass grafting. Congestive heart failure (Class II, III, or IV) as defined by the New York Heart Association functional classification system. Symptomatic pericarditis
  4. A marked baseline prolongation of QT/QTc interval (> 450 ms)
  5. History of risk factors for Torsade de Pointe (e.g. heart failure, hypokalemia, family history of Long QT syndrome)
  6. Use of concomitant medication prolonging the QT/QTc interval
  7. Evidence of uncontrolled infection or infection requiring a concomitant parenteral antibiotic
  8. Evidence of any other significant clinical disorder or laboratory finding that in the opinion of the Investigator may compromise patient safety during study participation.
  9. Patients with a diagnosis (or strong suspicion) of a rare genetic disorder related to germline biallelic HR/FA and DNA repair gene mutations, such as Fanconi anemia patients of any subtype, Ataxia telangiectasia, Xeroderma pigmentosum, Cockayne, Nijmegen breakage, Werner and Bloom syndrome patients
  10. Patient or physician plans concomitant chemotherapy, radiation therapy, hormonal and/or biological treatment for cancer including immunotherapy while on study
  11. Patient has been treated with any investigational drug or investigational therapeutic device within 30 days (60 days in case of biological compound) of initiating study treatment
  12. Less than 4 weeks since prior major surgery
  13. Known positive for HIV, Hepatitis B surface antigen positive or Hepatitis C positive with abnormal liver function tests
  14. Known allergy to alkylating agents
  15. Central nervous system (CNS) metastases, with the following exception:
  16. Participants with asymptomatic CNS metastases who are clinically stable and have no requirement for steroids for at least 14 days prior to randomization. Note: Participants with carcinomatous meningitis or leptomeningeal spread are excluded regardless of clinical stability
  17. Invasive malignancy or history of invasive malignancy other than disease under study within the last 3 years, except as noted below:

    17.1. Any other invasive malignancy for which the participant was definitively treated, has been disease-free for ≤ 3 years and in the opinion of the principal investigator will not affect the evaluation of the effects of the study treatment on the currently targeted malignancy, may be included in this clinical study 17.2. Curatively treated non-melanoma skin cancer or successfully treated in situ carcinoma 17.3. Low-risk early-stage prostate cancer defined as follows: Stage T1c or T2a with a Gleason score ≤ 6 and prostatic-specific antigen <10 ng/mL either treated with definitive intent or untreated in active surveillance that has been stable for the past year prior to randomization

  18. Autoimmune disease (current or history; refer to Table 19) or syndrome that required systemic treatment within the past 2 years Note: Replacement therapies which include physiological doses of corticosteroids for treatment of endocrinopathies (for example, adrenal insufficiency) are not considered systemic treatments
  19. Has a diagnosis of immunodeficiency or is receiving systemic steroids (>10 mg oral prednisone per day or equivalent) or other immunosuppressive agents within 7 days prior to randomization Note:

    19.1. 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, up to a maximum of 10 mg prednisone per day or equivalent 19.2. Steroids as premedication for hypersensitivity reactions (e.g., computed tomography [CT] scan premedication) are permitted.

  20. Receipt of any live vaccine within 30 days prior randomization
  21. Prior allogeneic/autologous bone marrow or solid organ transplantation
  22. Has current pneumonitis or history of non-infectious pneumonitis that required steroids or other immunosuppressive agents Note: post-radiation changes in the lung related to prior radiotherapy and/or asymptomatic radiation-induced pneumonitis not requiring treatment (Grade 1) may be permitted if agreed upon by the investigator and Medical Monitor.
  23. Recent history (within the past 6 months) of uncontrolled symptomatic ascites, pleural or pericardial effusions
  24. Recent history (within the past 6 months) of gastrointestinal obstruction that required surgery, acute diverticulitis, inflammatory bowel disease, or intraabdominal abscess
  25. Recent history of allergen desensitization therapy within 4 weeks of randomization
  26. Cirrhosis or current unstable liver or biliary disease per investigator assessment defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminemia, esophageal or gastric varices, or persistent jaundice. Note: Stable non-cirrhotic, chronic liver disease (including Gilbert's syndrome or asymptomatic gallstones) or hepatobiliary involvement of malignancy is acceptable if participant otherwise meets entry criteria
  27. Known history of active tuberculosis
  28. Any psychiatric disorder, or other condition that could interfere with participant's safety, obtaining informed consent, or compliance to the study procedures in the opinion of the investigator Module 1 - monotherapy
  29. Patients who have received anticancer therapy (including radiotherapy) within 4 weeks of inclusion Module 2 - Carboplatin combination
  30. Patients who have received anticancer therapy (including radiotherapy) within 4 weeks of inclusion with exclusion of carboplatin.

    Module 3 - ICI combination

  31. Patients who have received anticancer therapy (including radiotherapy) within 4 weeks of inclusion with exception of ICI
  32. Patients progressive under ICI justifying the immediate discontinuation of ICI
  33. Patients who would not receive further treatment with ICI as standard of care
  34. Patients with Complete Response under ICI

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: Module 1A Monotherapy Multiple Ascending Dose
Multiple ascending dose cohorts dosing CP-506 monotherapy in all patients up to a maximally tolerated or maximally feasible dose Intervention: Drug: CP-506
CP-506 is a hypoxia-activated DNA alkylating agent specifically designed to have a bystander effect, aqueous solubility, oral bioavailability, and no off-mechanism activation by the human aerobic reductase AKR1C3
Other Names:
  • HAP CP-506
Experimental: Module 1B Monotherapy Dose Expansion Cohort
Expansion cohort dosing CP-506 monotherapy in patients at recommended phase 2 dose (RP2D) Intervention: Drug: CP-506
CP-506 is a hypoxia-activated DNA alkylating agent specifically designed to have a bystander effect, aqueous solubility, oral bioavailability, and no off-mechanism activation by the human aerobic reductase AKR1C3
Other Names:
  • HAP CP-506
Experimental: Module 2A Combination with carboplatin Multiple Ascending Dose
Multiple ascending dose cohorts dosing CP-506 in combination with carboplatin in all patients up to a maximally tolerated or maximally feasible dose Intervention: Drug: CP-506
CP-506 is a hypoxia-activated DNA alkylating agent specifically designed to have a bystander effect, aqueous solubility, oral bioavailability, and no off-mechanism activation by the human aerobic reductase AKR1C3
Other Names:
  • HAP CP-506
Antineoplastic agent, ATC Code: LO1X A02
Other Names:
  • Paraplatin
Experimental: Module 2B Combination with carboplatin Dose Expansion Cohort
Expansion cohort dosing CP-506 in combination with carboplatin in patients at recommended phase 2 dose (RP2D) Intervention: Drug: CP-506
CP-506 is a hypoxia-activated DNA alkylating agent specifically designed to have a bystander effect, aqueous solubility, oral bioavailability, and no off-mechanism activation by the human aerobic reductase AKR1C3
Other Names:
  • HAP CP-506
Antineoplastic agent, ATC Code: LO1X A02
Other Names:
  • Paraplatin
Experimental: Module 3A Combination with Immune Checkpoint Inhibitor Multiple Ascending Dose
Multiple ascending dose cohorts dosing CP-506 in combination with Immune Checkpoint Inhibitor in all patients up to a maximally tolerated or maximally feasible dose Intervention: Drug: CP-506
CP-506 is a hypoxia-activated DNA alkylating agent specifically designed to have a bystander effect, aqueous solubility, oral bioavailability, and no off-mechanism activation by the human aerobic reductase AKR1C3
Other Names:
  • HAP CP-506
Drug that blocks immune checkpoint proteins: PD-1, PD-L1, CTLA-4
Other Names:
  • Pembrolizumab
  • Durvalumab
  • Atezolizumab
  • Nivolumab
  • Ipilimumab
  • Cemiplimab
  • Avelumab
Experimental: Module 3B Combination with carboplatin Dose Expansion Cohort
Expansion cohort dosing CP-506 in combination with Immune Checkpoint Inhibitor in patients at recommended phase 2 dose (RP2D) Intervention: Drug: CP-506
CP-506 is a hypoxia-activated DNA alkylating agent specifically designed to have a bystander effect, aqueous solubility, oral bioavailability, and no off-mechanism activation by the human aerobic reductase AKR1C3
Other Names:
  • HAP CP-506
Drug that blocks immune checkpoint proteins: PD-1, PD-L1, CTLA-4
Other Names:
  • Pembrolizumab
  • Durvalumab
  • Atezolizumab
  • Nivolumab
  • Ipilimumab
  • Cemiplimab
  • Avelumab

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of treatment-emergent adverse events including dose-limiting toxicities
Time Frame: Baseline until 60 days after last administration of CP-506
The proportion of patients with treatment-emergent (serious) adverse events including dose-limiting toxicity (DLT)
Baseline until 60 days after last administration of CP-506
Incidence of clinically significant abnormal measurements in physical examination, vital signs, electrocardiogram (ECG), lab tests and ECOG performance status
Time Frame: Baseline until 60 days after last administration of CP-506
Physical examination; vital signs; electrocardiogram (ECG); haematology; clinical chemistry; urinalysis; plasma/renal makers; tumour markers; ECOG performance status
Baseline until 60 days after last administration of CP-506

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Area under curve of CP-506 plasma concentration
Time Frame: At the end of cycle 1 day 4
Measurement of CP-506 levels in plasma over time to calculate AUC Area under the curve (AUC) of CP-506 plasma concentration
At the end of cycle 1 day 4
Determine the minimal biological effective dose
Time Frame: Baseline until 60 days after last administration of CP-506
Number of patients that show 1) a decrease of 20% of hypoxia radiomics score on sequential CT of at least one lesion OR 2) a decrease of 20% of the initial tumour volume of at least one lesion
Baseline until 60 days after last administration of CP-506
Objective Response Rate
Time Frame: Baseline until 60 days after last administration of CP-506
Objective response rate (ORR) by RECIST 1.1 - the proportion of patients with a confirmed reduction in tumour burden of a predefined amount (this will include short lived responses).
Baseline until 60 days after last administration of CP-506
Percentage change in tumour size
Time Frame: Baseline until 60 days after last administration of CP-506
Percentage change in tumour size will be determined for patients with measurable disease at baseline and is derived at each visit by the percentage change from baseline in the sum of the diameters of target lesions. The best percentage change in tumour size will be the patient's value representing the largest decrease (or smallest increase) from baseline in tumour size
Baseline until 60 days after last administration of CP-506

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Henk Verheul, MD, PhD, Erasmus Medical Center
  • Principal Investigator: Nuria Kotecki, MD, PhD, Jules Bordet Institute
  • Principal Investigator: Loes Jansen, MD, Maastricht University Medical Center
  • Principal Investigator: Sylvie Rottey, MD, PhD, UZ Gent
  • Principal Investigator: Irene Brana, MD, PhD, Institut Vall d'Hebron

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

May 30, 2023

Primary Completion (Estimated)

February 1, 2027

Study Completion (Estimated)

May 1, 2027

Study Registration Dates

First Submitted

June 16, 2021

First Submitted That Met QC Criteria

June 29, 2021

First Posted (Actual)

July 8, 2021

Study Record Updates

Last Update Posted (Estimated)

October 7, 2025

Last Update Submitted That Met QC Criteria

October 2, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

  • TUMAGNOSTIC(CP506-001)
  • 2021-000423-12 (EudraCT Number)
  • 694812 (Other Grant/Funding Number: Horizon 2020 Framework Programme)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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.

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