Multi-peptide Vaccination and Bispecific PSMAxCD3 Antibody Treatment in Patients With Prostate Cancer (ImmProCure)

October 1, 2026 updated by: University Hospital Tuebingen

Randomized Phase II Study of Multi-peptide Vaccination and Bispecific PSMAxCD3 Antibody Treatment in Patients With Biochemical Relapse of Prostate Cancer

This trial is a phase II, randomized, open label study designed to evaluate safety, tolerability and efficacy of CC-1, a bispecific antibody (bsAb) with PSMAxCD3 specificity, and of VACXS15-PC01, a prostate cancer (PC)-specific multi-peptide vaccine, both administered as single agent or in combination to patients affected with biochemical recurrence (BCR) of PC after local therapy with curative intent. Patients will not receive other treatments during trial participation.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

CC-1 contains a PSMA binder with particular reactivity in PC and also binds to tumor vessels, thereby allowing for a dual mode of anti-cancer action. CC-1 was developed in a novel format which not only prolongs serum half-life, but most importantly reduces off-target T cell activation with expected fewer side effects. The multi-peptide vaccine VAC-XS15-PC01 is composed of 10 HLA-restricted antigens, comprising immunopeptidome-defined PC-associated epitopes, adjuvanted with the TLR1/2 ligand XS15 emulsified in Montanide ISA 51 VG.

The study entails three-arms: (1) the multi-peptide vaccine VAC-XS15-PC01 alone, (2) PSMAxCD3 bispecific antibody CC-1 alone and (3) combinatorial treatment of CC-1 and VAC-XS15-PC01. Up to 84 patients are recruited (n = up to 28 per arm) and patients are randomly assigned 1:1:1 (drop-out rate of 15% anticipated). A translational research program comprising, among others, a strict evaluation of prostate specific antigen (PSA) course integrated with analysis of CC-1 induced immune response and immunogenicity of VAC-XS15-PC01 serves to detect early signs of efficacy. Furthermore, safety of the investigational medical products is evaluated, and tolerability of their combination are assessed.

Study Type

Interventional

Enrollment (Estimated)

84

Phase

  • Phase 2

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

  • Germany
    • Baden-Wurttemberg
      • Heidelberg, Baden-Wurttemberg, Germany, 69120
        • Not yet recruiting
        • NCT Studienzentrale; Nationales Centrum für Tumorerkrankungen (NCT) Heidelberg
        • Contact:
      • Tübingen, Baden-Wurttemberg, Germany, 72076
        • Recruiting
        • CCU Transltional Immunolgy, University Hospital Tübingen
        • Contact:
    • Beriln
      • Berlin, Beriln, Germany, 12203
        • Not yet recruiting
        • Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin - Studienzentrale Onkologie
        • Contact:
    • North Rhine-Westphalia
      • Essen, North Rhine-Westphalia, Germany, 45147
        • Not yet recruiting
        • Universitätsklinikum Essen, Abteilung Urologie
        • 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

18 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • Understand and voluntarily sign an IC document prior to any study related assessments/procedures

    • Understand and voluntarily sign an IC document prior to any study related assessments/procedures

    • Patient is able to understand and comply with the protocol for the duration of the study including treatment and scheduled visits and examinations

    • Men aged ≥ 18 and ≤80 years

    • Histologic diagnosis of prostatic adenocarcinoma

    • Biochemical recurrence (BCR): PSA recurrence after treatment with curative intent; PSA ≥0.2 ng/mL or PSA > nadir + 2 ng/mL (after definitive RT), with two increasing PSA values prior to study treatment; AND no distant metastasis upon PSMA-PET imaging

    • Patients are ineligible to receive available treatment alternatives

    • Low risk of rapid disease progression, defined as:

      o PSA-DT > 1 year AND pathological ISUP grade < 4 for men with prior RP OR Interval to BCR > 18 months AND biopsy ISUP grade < 4 for men with prior radiation therapy

    • In case of second relapse PSA-DT > 9 months

    • Eastern Cooperative Oncology Group (ECOG) performance status ≤1

Exclusion Criteria:

  • • PSA >5 ng/mL (at screening)

    • Patients who are receiving or have previously received androgen deprivation treatment.

Except testosterone has recovered to normal levels: patients who have previously received anti-hormonal treatment testosterone must be >12 nmol/l.

  • Patients who are planned to or are undergoing salvage therapy (e.g. radiation)
  • Clinically significant xerostomia (dry mouth >1grade according to CTCAE v6.0)
  • Untreated current or prior distant metastasis of PC
  • Other malignancy within the last 2 years except: adequately treated non-melanoma skin cancer and non-muscle invasive bladder cancer.
  • Concurrent or previous treatment within 30 days in another interventional clinical trial with an investigational anti-cancer therapy
  • Clinical signs of active infection (> grade 2 according to CTCAE v6.0)
  • History of HIV infection
  • Viral active or chronic hepatitis (HBV or HCV)
  • Autoimmune disease that requires or has required treatment with systemic immunosuppressive treatments, except low dose corticosteroids (< 10 mg/ day), in the past 1 year
  • Ongoing relevant CNS pathology (e.g. seizure, paresis, aphasia, cerebrovascular ischemia, severe brain injuries, dementia, Parkinson's disease, cerebellar disease, organic brain syndrome, psychosis, coordination or movement disorder)
  • Epilepsy requiring pharmacologic treatment
  • Major surgery within 4 weeks of starting study treatment. Patients must have recovered from any effects of major surgery.
  • Heart failure NYHA III/IV
  • Severe obstructive or restrictive ventilation disorder
  • Known intolerance to CC-1, or other immunoglobulin drug products as well as hypersensitivity to any of the excipients present in the respective drug products (CC-1, VAC-XS15-PC01)
  • Refrain from blood donation during the course of the study
  • Male patients have to refrain from sperm donations for 6 months after last IMP

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: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Multi-peptide vaccine VAC-XS15-PC01

The vaccine VAC-XS15-PC01 consists of 300 µg of each of 10 PC-associated peptides. The vaccine cocktail (final volume 500 µL) will be administered subcutaneously (SC), adjuvanted with the TLR1/2 ligand XS15 (50 µg) and emulsified in Montanide ISA 51 VG at a 1:1 ratio. A total of three vaccinations are planned in Arm 1, administered 4 weeks apart from each other.
Drug: Multipeptide Vaccine VAC-XS15-PC01

The vaccine VAC-XS15-PC01 consists of 300 µg of each of 10 PC-associated peptides. The vaccine cocktail (final volume 500 µL) will be administered subcutaneously (SC), adjuvanted with the TLR1/2 ligand XS15 (50 µg) and emulsified in Montanide ISA 51 VG at a 1:1 ratio. A total of three vaccinations are planned in Arm 1, administered 4 weeks apart from each other.
Active Comparator: PSMAxCD3 bispecific antibody CC-1

CC-1 is applied subcutaneously once per week for 12 weeks in Arm 2. Due to priming doses up to 14 applications are planned.
Drug: PSMAxCD3, bispecific antibody CC-1

CC-1 is applied subcutaneously once per week for 12 weeks in Arm 2. Due to priming doses up to 14 applications are planned.
Experimental: PSMAxCD3 bispecific antibody CC-1 + Multi-peptide vaccine VAC-XS15-PC01

The vaccine VAC-XS15-PC01 consists of 300 µg of each of 10 PC-associated peptides. The vaccine cocktail (final volume 500 µL) will be administered subcutaneously (SC), adjuvanted with the TLR1/2 ligand XS15 (50 µg) and emulsified in Montanide ISA 51 VG at a 1:1 ratio. A total of three vaccinations are planned in Arm 3, administered 4 weeks apart from each other.

CC-1 is applied subcutaneously once per week for 12 weeks in Arm 3. Due to priming doses up to 14 applications are planned.
Drug: Multipeptide Vaccine VAC-XS15-PC01

The vaccine VAC-XS15-PC01 consists of 300 µg of each of 10 PC-associated peptides. The vaccine cocktail (final volume 500 µL) will be administered subcutaneously (SC), adjuvanted with the TLR1/2 ligand XS15 (50 µg) and emulsified in Montanide ISA 51 VG at a 1:1 ratio. A total of three vaccinations are planned in Arm 1, administered 4 weeks apart from each other.

Drug: PSMAxCD3, bispecific antibody CC-1

CC-1 is applied subcutaneously once per week for 12 weeks in Arm 2. Due to priming doses up to 14 applications are planned.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
PSA response defined as ≥50% reduction in PSA at FU1 compared to baseline.
Time Frame: Screening: 21 days before Cycle (C1);C1: Day (D) -1, D0 to D3, D8, D15, and D22; C2-3: D1, D8, D15, and D22 (each cycle is 22 days); End of Treatment (EOT): D29 of C3; Follow-Up 1-5: every 30 days after the EOT; End of study (EOS): 12 months after EOT

PSA serum levels [ng/ml] are determined during screening, before every treatment, and then every 30 days until end of follow up. PSA serum levels for one study patient should be locally assessed in the same lab during the whole study treatment. Furthermore, 5ml serum are taken and should be processed locally and stored at -80 °C at the study site. Tübingen for central assessment of PSA.
Screening: 21 days before Cycle (C1);C1: Day (D) -1, D0 to D3, D8, D15, and D22; C2-3: D1, D8, D15, and D22 (each cycle is 22 days); End of Treatment (EOT): D29 of C3; Follow-Up 1-5: every 30 days after the EOT; End of study (EOS): 12 months after EOT

Collaborators and Investigators

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

Sponsor

University Hospital Tuebingen

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 (Estimated)

September 24, 2026

Primary Completion (Estimated)

March 31, 2029

Study Completion (Estimated)

March 31, 2030

Study Registration Dates

First Submitted

September 24, 2026

First Submitted That Met QC Criteria

October 1, 2026

First Posted (Actual)

October 6, 2026

Study Record Updates

Last Update Posted (Actual)

October 6, 2026

Last Update Submitted That Met QC Criteria

October 1, 2026

Last Verified

October 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ImmProCure
  • 2025 (U.S. NIH Grant/Contract)
  • 2025-522144-41-00 (Ctis)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

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.

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