A Randomized Double-Blind Clinical Study of Intracavernosal OnabotulinumtoxinA Injection in Patients With Erectile Dysfunction Refractory to Phosphodiesterase-5 Inhibitors (BTXDE)

September 15, 2026 updated by: Clinica Universidad de Navarra, Universidad de Navarra

This study aims to evaluate the clinical efficacy of intracavernosal treatment with onabotulinumtoxinA (Botox) in 114 men aged 30 years or older with erectile dysfunction who have not responded to first-line oral pharmacological treatment.

For this purpose, the effects of onabotulinumtoxinA are compared with those of a placebo consisting of an intracavernosal injection of physiological saline. The study is patient-blinded.

Participants in the experimental group receive 100 U of onabotulinumtoxinA diluted in 1 mL of physiological saline, while participants in the control group receive 1 mL of physiological saline.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

114

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 Locations

  • Spain
    • Navarre
      • Pamplona, Navarre, Spain, 31008
        • Clinica Universidad de Navarra

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

30 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • Patients diagnosed with erectile dysfunction (ED) with an inadequate response to phosphodiesterase type 5 inhibitors (PDE5 inhibitors) or to intracavernosal injections with Caverject or Bimix/Trimix (IIEF-15 questionnaire score ≤12).
  • Patients aged 30 years or older.
  • Patients who have provided informed consent to participate in the study.
  • Patients who, in the investigator's opinion, are able to comply with all clinical trial requirements.
  • Patients who agree to attend follow-up visits and undergo the required assessments.

Exclusion Criteria:

  • Severe infections or diseases, or hepatic, renal, or bone marrow insufficiency, that, in the investigator's opinion, contraindicate participation in the study.
  • Known hypersensitivity to onabotulinumtoxinA (BoNT-A).
  • Patients who do not consent to participate in the study.
  • Patients younger than 30 years.
  • Patients who underwent robotic radical prostatectomy less than 6 months prior to study enrollment.
  • Patients with a known history of neurogenic injury.
  • Patients with a history of radiation therapy.
  • Patients with a known psychiatric disorder.
  • Patients with anatomical abnormalities of the penis.
  • Patients who do not agree to, or are unable to commit to, attending the scheduled follow-up visits.

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: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: OnabotulinumtoxinA (Botox) 100 U

Participants receive an intracavernosal injection of 100 U of onabotulinumtoxinA (Botox) diluted in 1 mL of physiological saline.
Drug: OnabotulinumtoxinA (Botox ®) Injections

OnabotulinumtoxinA 100 U diluted in 1 mL of physiological saline, administered by intracavernosal injection
Placebo Comparator: Placebo (Normal Saline)

Participants receive an intracavernosal injection of 1 mL of physiological saline as placebo.
Drug: Saline (0.9% NaCl)

1 mL of physiological saline, administered by intracavernosal injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
BOTOX efficacy
Time Frame: 6 months

Check if intracavernosal injections of onabotulinum toxin A improve erectile dysfunction in refractory patients to oral medication using questionnaires.
6 months

Collaborators and Investigators

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

Sponsor

Clinica Universidad de Navarra, Universidad de Navarra

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)

November 25, 2024

Primary Completion (Actual)

June 12, 2026

Study Completion (Actual)

July 2, 2026

Study Registration Dates

First Submitted

September 8, 2026

First Submitted That Met QC Criteria

September 15, 2026

First Posted (Actual)

September 22, 2026

Study Record Updates

Last Update Posted (Actual)

September 22, 2026

Last Update Submitted That Met QC Criteria

September 15, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • BTXDE

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

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

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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