PEP005 Gel - Biological Effects in Actinic Keratosis Assessed by Reflectance Confocal Microscopy

• Leucocyte infiltration [ Time Frame: From baseline till day 57 ] [ Designated as safety issue: No ]
• Degree of necrosis [ Time Frame: From baseline till day 57 ] [ Designated as safety issue: No ]
• Changes in pigmentation, solar elastosis and fibrosis [ Time Frame: From baseline till day 57 ] [ Designated as safety issue: No ]
• Confirmation of subclinical AK [ Time Frame: From baseline till day 57 ] [ Designated as safety issue: No ]
• AK clearance [ Time Frame: From baseline till day 57 ] [ Designated as safety issue: No ]

This trial will be conducted to explore the biological effects in the skin following treatment with PEP005 Gel, 0.05% administered for two consecutive days, assessed by reflectance confocal microscopy.

• Drug: Ingenol mebutate
  0.05% Ingenol mebutate Gel once daily for 2 consecutive days
  Other Name: PEP005
• Drug: Placebo Gel
  Gel vehicle of PEP005

• Active Comparator: PEP005 Gel 0.05%
  active ingredient of PEP005: Ingenol mebutate
  Intervention: Drug: Ingenol mebutate
• Placebo Comparator: Placebo Gel
  Vehicle of PEP005 Gel
  Intervention: Drug: Placebo Gel

Inclusion Criteria:

1. Male or female subjects at least 18 years of age
2. Subjects with AK lesions and subclinical AK lesions within a contiguous 25 cm2 area on the upper extremity
3. Subjects must have a 25 cm2 area of normal skin on the inner upper arm
4. Female subjects must be of either:• Non-childbearing potential, post-menopausal, or have a confirmed clinical history of sterility or • Childbearing potential, with a confirmed negative urine pregnancy test prior to exposure.
5. Female subjects of childbearing potential must be willing to consent to using high effective methods of contraception
6. Ability to follow trial instructions and likely to complete all trial requirements
7. Obtained written informed consent prior to any trial-related procedures

Exclusion Criteria:

1. Location of the selected treatment areas:• Within 5 cm of an incompletely healed wound or infected area of the skin • Within 10 cm of a suspected basal cell carcinoma (BCC) or squamous cell carcinoma(SCC)
2. History or evidence of skin conditions other than the trial indication that would interfere with evaluation of the investigational product
3. Clinical diagnosis/history or evidence of any medical condition that would expose a subject to an undue risk of a significant AE or interfere with assessments of safety during the course of the trial, as determined by Investigator clinical judgment
4. Anticipated need for in-patient hospitalisation or in-patient surgery during the trial period.
5. Current participation in any other interventional clinical trial
6. Subjects who have received treatment with any non-marketed drug product within the last two months
7. Previous enrolment in this clinical trial
8. Prohibited Therapies and/or Medications 2 weeks prior to the Screening visit within 2 cm of selected treatment area:•Cosmetic or therapeutic procedures •Use of acid-containing therapeutic products • Use of topical salves or topical steroids
9. Prohibited Therapies and/or Medications: within 4 weeks prior to the Screening visit: • Treatment with immunomodulators, cytotoxic drugs or interferon/interferon inducers,systemic medications that suppress the immune system, or with UVB
10. Prohibited Therapies and/or Medications: within 8 weeks prior to the Screening visit: • Treatment with 5-FU, imiquimod, diclofenac, or photodynamic therapy: within 2 cm of the selected treatment areas.
11. Use of systemic retinoids