Phase 2a Topical Sildenafil Proof-of-Concept Study in Men With Mild to Moderate ED
Condition: Erectile Dysfunction
MeSH terms: Erectile Dysfunction
Study type: Interventional
Phase: Phase 2

Summary: 
      This is a Phase 2a, single-dose, double-blind, placebo-controlled, 2-way crossover study in
      men with ED. A single 2 gram dose of SST-6006 topical cream 5% w/w (formulated to deliver 100
      mg of sildenafil) or a topical placebo cream will be applied to the penile shaft and glans.
      There are 4 study phases: the Initial Patient Screening Phase (Visit 1, an Off Site 4-Week
      Run-in Period and Visit 2), the Final Patient Screening Phase (Visit 3), the SST-6006/Placebo
      Double-Blind Dosing Phase (Visits 4-5), and the Follow-up Phase. Primary outcomes will be be
      evaluated at Weeks 7 and 8 of the study
    

Detailed description: 
      Initial Patient Eligibility: Visit 1 (Day 1) After the patient provides written informed
      consent, the initial screening procedures will be performed. Patients who meet all
      eligibility criteria will be instructed on completion of the SEP Diary, the need for a one
      week washout of any ED medications before starting the Off-Site 4-Week Run-In Period and that
      the use of any ED medications will be prohibited throughout the entire 4-week duration and up
      until the completion of Visit 5. Site staff will contact patients by phone between 4 and 7
      days following Visit 1 (on Days 4- 7) to communicate eligibility (met laboratory parameters
      and the one week washout) to participate in the Off-Site 4-Week Run-In Period. Site staff
      will also schedule the Topical Placebo RigiScan Qualification Visit (Visit 2) to be within
      two days of completion of the 4-Week Run-In Period for eligible patients. Ineligible patients
      will be instructed to discard their SEP Diary and will be discontinued from further study
      participation Off-Site 4-Week Run-In Period (Day 8-35) Eligible patients will participate in
      an Off-Site 4-Week Run-In Period during which time they will attempt intercourse a minimum of
      4 times. Use of any ED medications will be prohibited throughout the entire 4-week duration
      and up until the completion of Visit 5. Patients will be asked to maintain a Sexual Encounter
      Profile (SEP) diary during the 4-Week Run-In Period to be completed after each intercourse
      attempt.

      Topical Placebo RigiScan Qualification: Visit 2 (Day 36 [+ 2 days]) Patients who successfully
      complete the 4-Week Run-In will be instructed to complete the IIEF questionnaire at the
      beginning of Visit 2. Eligible patients must have documented mild-moderate ED as demonstrated
      by a score of 11-21 in the International Index of Erectile Function (IIEF) Erectile Function
      domain of the IIEF questionnaire.

      Eligible patients will then complete a single-blind (patient) 60 minute plethysmography
      procedure using placebo cream to familiarize patients with the plethysmography device (i.e.
      RigiScan) and evaluate the placebo response with Visual Sexual Stimulation (VSS).

      Patients who demonstrate a topical placebo response (i.e. achieve an erection of ≥ 60%
      rigidity at the base of the penis for a cumulative duration of > 4 minutes) will be
      ineligible for further study participation. Any patients with an adverse dermatologic
      reaction to the placebo cream will be excluded from further participation in the study but
      will be followed until normalization of symptoms.

      Safety data for all patients, regardless of continued eligibility, will be included in the
      database as patients will have been exposed to IP (placebo cream only) during this visit.
      There will be a 7 (± 1) day washout period between Visits 2 and 3.

      Oral Sildenafil RigiScan Qualification: Visit 3 (Day 43 [± 2 days]) Patients who meet the
      eligibility criteria will then complete the Oral Sildenafil RigiScan Qualification visit,
      consisting of a single-blind (patient) plethysmography procedure with 60 minutes of VSS to
      evaluate the patient's response to oral sildenafil.

      Patients who do not respond to oral sildenafil (i.e., do not achieve ≥ 60% rigidity at the
      base of the penis for a cumulative duration of >15 minutes and an EHS Score of 3 or 4) will
      be excluded from further study participation.

      There will be a 7 (± 1) day washout period between Visit 3 and Visit 4 (i.e., the first visit
      in the SST-6006/Placebo Double-Blind Dosing Phase).

      SST-6006/Placebo Double-Blind Dosing Phase: Visits 4 & 5 (Days 50 and 57 [± 2 days]) Eligible
      patients will be randomized to a sequence of dosing (i.e., placebo cream then SST-6006 or
      SST-6006 then placebo cream). The SST-6006/Placebo Double-Blind Dosing Phase will consist of
      two plethysmography procedures with 60 minutes of VSS. One will evaluate the patient's
      response to SST-6006 and the other will evaluate the patient's response to placebo cream.
      Patients will be instructed to complete a 4-Point Erection Hardness Scale (EHS) immediately
      following completion of the plethysmography procedure at each visit. There will be a 7 (± 1)
      day wash-out between Visit 4 and Visit 5.
    

Intervention name(s): Sildenafil Cream; Placebo Cream; Penile Plethysmography (RigiScan)
Intervention type(s): Drug; Drug; Device
Intervention description(s): Patients will be instructed to apply pre-weighed SST-6006 to the non-erect penile skin area at the time of dosing. Patients will then massage the cream into the penile shaft and glans for a maximum of 3 minutes.; Patients will be instructed to apply the pre-weighed placebo cream to the non-erect penile skin area at the time of dosing. Patients will then massage the cream into the penile shaft and glans for a maximum of 3 minutes.; During each dosing period, penile plethysmography will be utilized to evaluate efficacy of SST-6006 verses placebo cream. Each plethysmography session will be approximately 75 minutes.This includes a 15 minute 'baseline' period where patients are told to remain in the flaccid state and 60 minutes during which time patients will watch a series of erotic videos.
Other intervention name(s): SST-6006
Intervention MeSH terms: Sildenafil Citrate
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Treatment