Calcium Electroporation for Urinary Bladder Tumors: A First-in-Human Feasibility, Safety, and Early Response Trial (CALCIFER)

Calcium Electroporation for Urinary Bladder Tumors: A First-in-human Feasibility, Safety, and Early Response Trial - The CALCIFER Trial

This phase I study evaluates intravesical calcium electroporation (CaEP) with a new transurethral electrode. The study is primarily designed to assess the safety of CaEP and secondarily, to preliminary explore the efficacy in patients with limited alternative therapies. The anticipated benefits and structured safety precautions justify the ethical conduct of the investigation.

Study Overview

• Status: Not yet recruiting
• Conditions: Urothelial Carcinoma Bladder; Bladder Tumor; Bladder Tumors; Urothelial Carcinoma (UC)
• Intervention / Treatment: Procedure: Calcium electroporation; Drug: Intratumoral calcium injection; Device: Transurethral electroporation

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Juan Luis Vásquez; Phone Number: 0045 25603442; Email: julv@regsj.dk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥ 18 years and able to understand participant information and give informed consent
• Histologically verified urothelial bladder tumor
• Unfit for cystectomy and/or radiotherapy
• Patients with recurrence after radiotherapy unfit for salvage cystectomy
• Disease where other treatments are considered unsuitable or have been declined by the patient
• The patient may receive simultaneous systemic treatment
• Selected high-burden non-muscle-invasive bladder tumors after MDT assessment
• Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) ≤ 2
• Life expectancy of ≥ 3 months
• Patients must be deemed able to tolerate general anesthesia
• Sexually active participants in the reproductive age must use contraception. Accepted contraception includes the use of intrauterine device (IUD), oral contraceptives, male or female condom, vasectomy or female sterilization
• Patients must stop treatment with anticoagulants before surgery in accordance with national guidelines
• Plasma ionized Ca2+ must be within the normal upper limit. Correction is allowed

• Hematology

  • Thrombocytes ≥ 50 billion/L
  • International normalized ratio (INR) ≤ 1.5. Correction is allowed

Exclusion Criteria:

• Pregnancy (confirmed by a blood sample) or lactation
• Allergy to calcium gluconate or any of its excipients
• Any clinical condition or previous treatment, that in the investigators' opinion made the patient ineligible

• Contraindications to treatment with calcium gluconate as described:

  • Hypersensitivity to calcium gluconate or any of its excipients
  • Hypercalcemia (e.g. due to hyperparathyroidism, hypervitaminosis D, decalcifying malignancies, renal insufficiency, immobilization osteoporosis, sarcoidosis, milk-alkali syndrome)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Intervention arm with participants treated with calcium electroporation

Procedure: Calcium electroporation; Calcium electroporation involves injection of calcium gluconate into the urinary bladder tumor followed by short, electric pulses (electroporation) with the transurethral electrode; Drug: Intratumoral calcium injection; Intratumoral injection of calcium gluconate in the urinary bladder; Device: Transurethral electroporation; After injection of calcium into tumor, electroporation is applied using the transurethral electrode; Other Names: OpField electrode

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety within 3 months post-treatment assessed by adverse and serious adverse events.	Safety within 3 months post-treatment assessed by adverse and serious adverse events (CTCAE ver. 6.0).	From treatment to follow-up after 3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety within 12 months post-treatment assessed by adverse and serious adverse events.	Safety within 12 months post-treatment assessed by adverse and serious adverse events (CTCAE ver. 6.0).	From treatment to 12 months follow-up
Response rate of tumor	Response rate of tumor will be evaluated by visualization of the treated area with cystoscopy and biopsies of tumor or tumor site in case of remission. Using an adaptation of the revised RECIST ver. 1.1 criteria the response to treatment will be evaluated	From treatment to 12 months follow-up
Local control of tumor	Local control of tumor will be evaluated by visualization of the treated area with cystoscopy and biopsies of tumor or tumor site in case of remission. Using an adaptation of the revised RECIST ver. 1.1 criteria the response to treatment will be evaluated	From treatment to 12 months follow-up
Tumor response to CaEP	A biopsy at every follow-up will be histologically examined for presence of malignancy and immune cell infiltration (hematoxylin and eosin (H&E) stain)	From treatment to 12 months follow-up
Dissemination of tumor to other sites of the bladder	Dissemination of tumor to other sites of the bladder will be evaluated by visualization by cystoscopy and biopsy	From treatment to 12 months follow-up
Metastasis of tumor to other sites in the body will be evaluated by CT scan		From treatment to 12 months follow-up
Time to progression evaluated by the revised RECIST criteria on CT scan		From treatment to 12 months follow-up
Progression-free survival rate evaluated by cystoscopy, biopsy and CT scan		From treatment to 12 months follow-up
Evaluation of quality of life using EORTC-QLQ-C30 before treatment and at follow-up	Quality of life assessed by the European Organization for Research and Treatment of Cancer Quality of Life Core Questionnaire (EORTC-QLQ-C30). The questionnaire consists of three scales, and each scale is scored from 0 to 100. Higher scores indicate higher level of function on the the functional scale and higher quality of life on the global health scale, but higher level of symptomatology on the symptom scale.	From treatment to 12 months follow-up
Evaluation of urinary symptoms registered in the ICIQ-FLUTS/ICIQ-MLUTS	Urinary symptoms registered using the International Consultation on Incontinence Questionnaire Female/Male Lower Urinary Tract Symptoms Modules (ICIQ-FLUTS (0-48 points)/ICIQ-MLUTS (0-44 points). Higher level of points indicate higher level of symptoms.	From treatment to 12 months follow-up
Evaluation of sexual matters registered in the ICIQ-FLUTSsex/ICIQ-MLUTSsex	Evaluation of sexual matters using the International Consultation on Incontinence Questionnaire Female/Male Sexual Matters Associated with Lower Urinary Tract Symptoms Module (ICIQ-FLUTSsex (0-14 points)/ICIQ-MLUTSsex (0-12 points)). Greater values indicating increasing problems with sexual matters.	From treatment to 12 months follow-up
All-cause mortality and cancer related mortality within 12 months		From treatment to 12 months follow-up
Experiences and opinions of up to ten of the patients that participate in the qualitative interviews	A subset of up to 10 patients will participate in the qualitative interviews at 3 months.	From treatment to 3 months follow-up
Concentration of calcium in a blood sample before injection of calcium gluconate 30 minutes and 2 hours after injection		Before treatment (Baseline), 30 minutes after injection of calcium gluconate, and 2 hours after injection of calcium gluconate

Collaborators and Investigators

• Sponsor: Juan Luis Vásquez

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): April 1, 2030
• Study Completion (Estimated): April 1, 2030

Study Registration Dates

• First Submitted: April 14, 2026
• First Submitted That Met QC Criteria: April 21, 2026
• First Posted (Actual): April 29, 2026

Study Record Updates

• Last Update Posted (Actual): April 29, 2026
• Last Update Submitted That Met QC Criteria: April 21, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: bladder tumors; electroporation; calcium electroporation; transurethral electroporation; urothelial tumor
• Additional Relevant MeSH Terms: Urogenital Diseases; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Male Urogenital Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Neoplasms by Histologic Type; Neoplasms, Glandular and Epithelial; Urologic Neoplasms; Carcinoma; Urinary Bladder Diseases; Urinary Bladder Neoplasms; Carcinoma, Transitional Cell
• Other Study ID Numbers: 2026-526388-39-00 (Ctis)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All individual participant data will be available after deidentification. Furthermore, the study protocol with statistical analysis plan will also be available. The data will be available immediately following publication in supplementary material to anyone with access to the publication. Data can be used for any purposes. Data is available as long as the publication is available.
• IPD Sharing Time Frame: The data will be available immediately following publication in supplementary material to anyone with access to the publication. Data is available as long as the publication is available.
• IPD Sharing Access Criteria: The data will be available immediately following publication in supplementary material to anyone with access to the publication.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No