Erectile DysfunctionPhase 2NCT07537855
Efficacy of Intracavernosal Xeomin With Tadalafil for Mild-Moderate Erectile Dysfunction
A Phase 2 study testing IncobotulinumtoxinA (100 Units) and Tadalafil 20 MG in people with Erectile Dysfunction, run by Northwestern University.
Trial summary
Erectile dysfunction (ED) affects approximately 30 million men in the United States and is associated with factors such as aging, smoking, diabetes, hypertension, obesity, and sedentary lifestyle. ED can also negatively impact the quality of life of patients and their partners. Read more about this study
- Who is it for?
- Ages 18 to 80 years, men only
- Conditions the study is for
- Erectile Dysfunction
- What is being tested?
- IncobotulinumtoxinA (100 Units) and Tadalafil 20 MG
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 30 participants
- Where
- No sites listed yet
- Study dates
- Sep 2026to Sep 2028
- Phase
- Phase 2
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Written informed consent obtained from the subject
- History of ED for at least 6 months prior to screening, defined as "the inability to achieve and maintain an erection of the penis sufficient to complete satisfactory sexual intercourse" (NIH), the diagnosis of ED has to be confirmed by a physician
- Understanding of study procedures and willingness to abide by all procedures during the course of the study
- Male subject aged ≥18 to ≤ 80 years at visit 1
- Have a monogamous relationship with a female sexual partner (vaginal penetration required for several of the primary efficacy variables) for at least 6 months prior to screening
- Highly motivated to obtain treatment for ED
- History of previous use of at least 1 marketed PDE5 inhibitor and insufficient therapeutic efficacy despite use of the highest approved dose
Who cannot join
- Hypersensitivity to the active substance (Clostridium Botulinum neurotoxin type A) or to any of the excipients (Human albumin, sucrose)
- BW <50 kg
- Diagnosis of spinal cord injury
- ED caused by other primary sexual disorders including premature ejaculation or ED caused by untreated endocrine disease (e.g., hypopituitarism, hypothyroidism, or hypogonadism)
- History of penile implant.
- The presence of clinically significant penile deformity in the opinion of the investigator.
Show all 31Show fewer
- Concomitant diagnosis of Peyronie's disease
- Patients with chronic stable angina treated with long-acting nitrates, or patients with chronic stable angina who have required short-acting nitrates in the last 90 days, or angina occurring during sexual intercourse in the last 6 months.
- Patients having met the criteria for unstable angina within 6 months prior to Visit 1, history of myocardial infarction or coronary artery bypass graft surgery within 90 days prior to Visit 1, or percutaneous coronary intervention (e.g., angioplasty or stent placement) within 90 days prior to Visit 1.
- Any supraventricular arrhythmia with an uncontrolled ventricular response (mean heart rate >100 bpm) at rest despite medical or device therapy, or any history of spontaneous or induced sustained ventricular tachycardia (heart rate >100 bpm for 30 sec) despite medical or device therapy, or the presence of an automatic internal cardioverter-defibrillator.
- A history of sudden cardiac death (arrest) despite medical or device therapy.
- Any evidence of congestive heart failure within 6 months prior to Visit 1.
- A significant conduction defect within 90 days prior to Visit 1.
- Systolic blood pressure >170 or <90 mm Hg or diastolic blood pressure >100 or <50 mm Hg at screening (if stress is suspected, retest under basal conditions), or patients with malignant hypertension.
- <12 weeks since most recent injection of BTX-A/B into any body region for any indication
- Neurological disorder associated with neuro muscular dysfunction of any kind in medical history.
- Planned concomitant treatment with BTX -A/B of any body region during the study.
- Known hypersensitivity to human serum albumin, sucrose, or the active substance BTX-A.
- Generalized disorders of muscles activity (e.g. myasthenia gravis, Lambert-Eaton-Syndrome, amyotrophic lateral sclerosis) or any other significant peripheral neuromuscular dysfunction which might interfere with the study.
- Any condition that would interfere with the patient's ability to provide informed consent or comply with study instructions, would place patient at increased risk, or might confound the interpretation of the study results.
- Current treatment with nitrates (as outlined in previous Exclusion Criterion, cancer chemotherapy, or anti-androgens.
- History of drug, alcohol, or substance abuse within the past 6 months.
- Investigators, site personnel directly affiliated with this study, and their immediate families. Immediate family is defined as a spouse, parent, child or sibling, whether biological or legally adopted.
- Treatment within the last 30 days with a drug or device that has not received regulatory approval at the time of study entry.
- Ongoing severe or uncontrolled systemic disease, current malignancy, hemophilia, or HIV infection in medical history.
- Severe or uncontrolled respiratory disease in medical history.
- Evidence or suspicion that the subject is not willing or unable (e.g. Due to severe cognitive communication impairment) to understand the information that is given to him as part of the informed consent, in particular regarding the risks and discomfort which he would agree to be exposed to.
- Any reason which in the investigator's opinion is likely to compromise the subject's ability to participate in the study.
- Subject who is imprisoned or is lawfully kept in an institution
- Participation in a clinical study within 12 weeks prior to screening or planned participation during this study.
- Previous participation in this clinical study.
About this study
Official title: Clinical Efficacy of Intracavernosal Xeomin as an Adjunctive Therapy to on Demand Tadalafil 20 mg for the Treatment of Mild to Moderate Erectile Dysfunction: A Randomized Crossover Pilot Study
Erectile dysfunction (ED) affects approximately 30 million men in the United States and is associated with factors such as aging, smoking, diabetes, hypertension, obesity, and sedentary lifestyle. ED can also negatively impact the quality of life of patients and their partners. Treatment decisions are typically made jointly between patients and their urologists, often starting with less invasive options. Oral phosphodiesterase-5 inhibitors (PDE5 inhibitors), including sildenafil, tadalafil, and vardenafil, are commonly used as first-line therapy. While these medications improve erectile function in many patients, approximately 30-40% do not respond adequately to PDE5 inhibitor therapy alone. Patients who do not achieve sufficient benefit may require additional or more invasive treatment options.
- Conditions
- Erectile Dysfunction
- Being tested
- IncobotulinumtoxinA (100 Units), Placebo, Tadalafil 20 MG
- Keywords
- xeomin, Incobotulinumtoxin A
- Medical subject headings
- Erectile Dysfunction
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
IncobotulinumtoxinA (100 Units)Drug
Intracavernosal Xeomin
PlaceboOther
Placebo
Tadalafil 20 MGDrug
PDE5 Inhibitor Medication
| Study group | Role | What they receive |
|---|---|---|
| Xeomin + PDE5i | Experimental | Subjects in this portion of the trial will be administered 20 mg of Tadalafil in conjunction with 100 units of Xeomin Receives: Drug: IncobotulinumtoxinA (100 Units); Drug: Tadalafil 20 MG |
| Placebo + PDE5i | Placebo comparator | Subjects in this portion of the trial will be administered 20 mg of Tadalafil in conjunction with a placebo Receives: Other: Placebo; Drug: Tadalafil 20 MG |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in erectile function
Change in erectile function as measured by the validated IIEF-EF domain (3-6 months) following Xeomin portion of the crossover study. This domain provides a score on a scale of 6-30, where scores can be interpreted as follows:
- 26-30: No Erectile Dysfunction
- 22-25: Mild Erectile Dysfunction
- 17-21: Mild to Moderate Erectile Dysfunction
- 11-16: Moderate Erectile Dysfunction
- 6-10: Severe Erectile Dysfunction
Measured: 3-6 months
Change in erectile hardness
Change in erectile hardness as measured by the validated erectile hardness scale (EHS) (3-6 months) following Xeomin portion of the crossover study. The scale ranges from Grade 0 - Grade 4. It measures the firmness of an erection using the following grade interpretation:
- Grade 0: Penis does not enlarge.
- Grade 1: Penis is larger, but not hard.
- Grade 2: Penis is hard, but not hard enough for penetration.
- Grade 3: Penis is hard enough for penetration, but not completely hard.
- Grade 4: Penis is completely hard and fully rigid
Measured: 3-6 months
Secondary outcomes (2)
Persistence of efficacy in erectile function
Persistence of efficacy in erectile function as measured by the validated IIEF-EF domain (3-6 months in placebo portion of crossover study). This domain provides a score on a scale of 6-30 over a period of time, where scores can be interpreted as follows:
- 26-30: No Erectile Dysfunction
- 22-25: Mild Erectile Dysfunction
- 17-21: Mild to Moderate Erectile Dysfunction
- 11-16: Moderate Erectile Dysfunction
- 6-10: Severe Erectile Dysfunction
Measured: 3-6 months
Persistence of efficacy in erectile hardness
Persistence of efficacy in erectile hardness as measured by the validated erectile hardness scale (EHS) (3-6 months in placebo portion of crossover study). The scale ranges from Grade 0 - Grade 4. It measures the firmness of an erection over a period of time using the following grade interpretation:
- Grade 0: Penis does not enlarge.
- Grade 1: Penis is larger, but not hard.
- Grade 2: Penis is hard, but not hard enough for penetration.
- Grade 3: Penis is hard enough for penetration, but not completely hard.
- Grade 4: Penis is completely hard and fully rigid
Measured: 3-6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Apr 2026
- Study startSep 2026 (estimated)
- Primary completionSep 2028 (estimated)
- Study completionSep 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (8)Papers the sponsor has linked to this study.
- Other trials for Erectile DysfunctionStudies of the same condition, open and under way.
- More trials run by Northwestern UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Northwestern University
- Sponsor type
- University, hospital or other
- Collaborators
- Merz North America, Inc.
- Responsible party
- Principal investigator, Nelson Bennett, Northwestern University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07537855
- Sponsor's protocol ID
- IIT12255
- Status last verified
- Aug 2026
- First submitted
- 12 Apr 2026
- Last updated
- 14 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Abou Zahr R, Bou Kheir G, Mjaess G, Jabbour T, Chalhoub K, Diamand R, Roumeguere T. Intra-Cavernosal Injection of Botulinum Toxin in the Treatment of Erectile Dysfunction: a Systematic Review and Meta-Analysis. Urology. 2022 Dec;170:5-13. doi: 10.1016/j.urology.2022.08.039. Epub 2022 Sep 15.
PubMed 36115427Giuliano F, Joussain C, Denys P, Laurin M, Behr-Roussel D, Assaly R. Intracavernosal OnabotulinumtoxinA Exerts a Synergistic Pro-Erectile Effect When Combined With Sildenafil in Spontaneously Hypertensive Rats. J Sex Med. 2022 Jun;19(6):899-906. doi: 10.1016/j.jsxm.2022.03.213. Epub 2022 Mar 29.
PubMed 35365400Giuliano F, Joussain C, Denys P. Safety and Efficacy of Intracavernosal Injections of AbobotulinumtoxinA (Dysport(R)) as Add on Therapy to Phosphosdiesterase Type 5 Inhibitors or Prostaglandin E1 for Erectile Dysfunction-Case Studies. Toxins (Basel). 2019 May 21;11(5):283. doi: 10.3390/toxins11050283.
PubMed 31117236Giuliano F, Joussain C, Denys P. Long Term Effectiveness and Safety of Intracavernosal Botulinum Toxin A as an Add-on Therapy to Phosphosdiesterase Type 5 Inhibitors or Prostaglandin E1 Injections for Erectile Dysfunction. J Sex Med. 2022 Jan;19(1):83-89. doi: 10.1016/j.jsxm.2021.10.011. Epub 2021 Dec 20.
PubMed 34937674Giuliano F, Denys P, Joussain C. Effectiveness and Safety of Intracavernosal IncobotulinumtoxinA (Xeomin(R)) 100 U as an Add-on Therapy to Standard Pharmacological Treatment for Difficult-to-Treat Erectile Dysfunction: A Case Series. Toxins (Basel). 2022 Apr 16;14(4):286. doi: 10.3390/toxins14040286.
PubMed 35448895Giuliano F, Denys P, Joussain C. Safety and Effectiveness of Repeated Botulinum Toxin A Intracavernosal Injections in Men with Erectile Dysfunction Unresponsive to Approved Pharmacological Treatments: Real-World Observational Data. Toxins (Basel). 2023 Jun 5;15(6):382. doi: 10.3390/toxins15060382.
PubMed 37368683Lowe G, Bahnson R. Non-invasive management of primary phosphodiesterase type 5 inhibitor failure in patients with erectile dysfunction. Ther Adv Urol. 2009 Dec;1(5):235-42. doi: 10.1177/1756287210362069.
PubMed 21789070Burnett AL, Nehra A, Breau RH, Culkin DJ, Faraday MM, Hakim LS, Heidelbaugh J, Khera M, McVary KT, Miner MM, Nelson CJ, Sadeghi-Nejad H, Seftel AD, Shindel AW. Erectile Dysfunction: AUA Guideline. J Urol. 2018 Sep;200(3):633-641. doi: 10.1016/j.juro.2018.05.004. Epub 2018 May 7.
PubMed 29746858