| E.1 Medical condition or disease under investigation | 
| E.1.1 | Medical condition(s) being investigated |  | 
| MedDRA Classification | 
| E.1.3 | Condition being studied is a rare disease | No | 
| E.2 Objective of the trial | 
| E.2.1 | Main objective of the trial | 
| Comparison of the efficacy of PD P 506 A photodynamic therapy (PD P 506 A-PDT) with placebo-PDT (PD P 506 P-PDT) for the treatment of mild to moderate actinic keratoses located on head and face 12 weeks after PDT on lesion basis. |  | 
| E.2.2 | Secondary objectives of the trial | 
| - Comparison of the efficacy of PD P 506 A-PDT with placebo-PDT on patient basis 12  weeks after PDT. - Comparison of the efficacy of PD P 506 A-PDT with placebo-PDT on lesion and patient basis 6, 9 and 12 months after PDT.
 - Comparison of safety and tolerability of (a) application of study medications and (b) PD P 506 A-PDT and placebo-PDT.
 - Cosmetic outcome 3, 6, 9 and 12 months after PDT in case of no recurrence of the lesion.
 
 |  | 
| E.2.3 | Trial contains a sub-study | Information not present in EudraCT | 
| E.3 | Principal inclusion criteria | 
| - Written informed consent has been signed prior to or at Screening Visit - Caucasian male and female patients
 - Age > 18 years
 - Diagnosis of actinic keratosis (AK) with at least three locally separated lesions located on the head (hairless areas)
 - Selected AK study lesions have clearly defined margins and are mild to moderate (grades I or II): Mild grade (I): Flat, pink maculae or patch on sun-damaged skin, background mottling, no roughness or hyper-keratosis. Moderate grade (II): Pink to red papule or plaque with rough, hyperkeratotic surface, variable induration.
 - The distance between the study lesion borders is > 1.0 cm
 - Maximum diameter of each study lesion is 1.8 cm
 - Skin sun sensitivity type I to IV according to Fitzpatrick
 
 |  | 
| E.4 | Principal exclusion criteria | 
| - PDT Non-responder - Pre-treatment of the AK lesions eligible for study procedures with pharmaceuticals approved for the treatment of AK during the 4 weeks preceding PDT (e.g. antineoplastic topical formulations as e.g. Metvix®, Solaraze®, Aldara®, 5-FU or vitamin A acid containing formulations)
 - Pre-treatment of the AK lesions eligible for study procedures during the 2 weeks preceding PDT with keratolytic agents e.g. TCA, urea or salicylic acid containing formulations
 - Pre-treatment with hypericin during the 2 weeks preceding PDT
 - Treatment with systemic retinoids during the 3 months preceding PDT
 - Treatment with cytostatics or radiation during the 3 months preceding PDT
 - Female patients of childbearing potential
 - Patients with clinically relevant suppression of the immune system
 - Diagnosis of Porphyria
 - Skin diseases that might interfere with response evaluation of study PDT
 - Skin sun sensitivity type V or VI according to Fitzpatrick
 - Known intolerance to one or more of the ingredients of the study medication
 - Dementia or psychic condition that might interfere with the ability to understand the study and thus give a written informed consent
 - Simultaneous participation in another clinical study or participation in another clinical study in the 30 days directly preceding inclusion
 - Suspected lack of compliance
 
 |  | 
| E.5 End points | 
| E.5.1 | Primary end point(s) | 
| Complete clinical clearance rate of treated actinic keratosis lesions 12 weeks after PDT |  | 
| E.6 and E.7 Scope of the trial | 
| E.6 | Scope of the trial | 
| E.6.1 | Diagnosis | No | 
| E.6.2 | Prophylaxis | No | 
| E.6.3 | Therapy | Yes | 
| E.6.4 | Safety | No | 
| E.6.5 | Efficacy | Yes | 
| E.6.6 | Pharmacokinetic | No | 
| E.6.7 | Pharmacodynamic | No | 
| E.6.8 | Bioequivalence | No | 
| E.6.9 | Dose response | No | 
| E.6.10 | Pharmacogenetic | Information not present in EudraCT | 
| E.6.11 | Pharmacogenomic | No | 
| E.6.12 | Pharmacoeconomic | No | 
| E.6.13 | Others | No | 
| E.7 | Trial type and phase | 
| E.7.1 | Human pharmacology (Phase I) | No | 
| E.7.1.1 | First administration to humans | No | 
| E.7.1.2 | Bioequivalence study | No | 
| E.7.1.3 | Other | No | 
| E.7.1.3.1 | Other trial type description |  | 
| E.7.2 | Therapeutic exploratory (Phase II) | No | 
| E.7.3 | Therapeutic confirmatory (Phase III) | Yes | 
| E.7.4 | Therapeutic use (Phase IV) | No | 
| E.8 Design of the trial | 
| E.8.1 | Controlled | Yes | 
| E.8.1.1 | Randomised | Yes | 
| E.8.1.2 | Open | No | 
| E.8.1.3 | Single blind | No | 
| E.8.1.4 | Double blind | Yes | 
| E.8.1.5 | Parallel group | Yes | 
| E.8.1.6 | Cross over | No | 
| E.8.1.7 | Other | Yes | 
| E.8.1.7.1 | Other trial design description |  | 
| E.8.2 | Comparator of controlled trial | 
| E.8.2.1 | Other medicinal product(s) | No | 
| E.8.2.2 | Placebo | Yes | 
| E.8.2.3 | Other | No | 
| E.8.3 | The trial involves single site in the Member State concerned | No | 
| E.8.4 | The trial involves multiple sites in the Member State concerned | Yes | 
| E.8.5 | The trial involves multiple Member States | No | 
| E.8.6 Trial involving sites outside the EEA | 
| E.8.6.1 | Trial being conducted both within and outside the EEA | No | 
| E.8.6.2 | Trial being conducted completely outside of the EEA | Information not present in EudraCT | 
| E.8.7 | Trial has a data monitoring committee | Information not present in EudraCT | 
| E.8.8 | Definition of the end of the trial and justification where it is not the last
                        visit of the last subject undergoing the trial |  | 
| E.8.9 Initial estimate of the duration of the trial | 
| E.8.9.1 | In the Member State concerned years | 1 | 
| E.8.9.1 | In the Member State concerned months | 4 | 
| E.8.9.1 | In the Member State concerned days |  | 
| E.8.9.2 | In all countries concerned by the trial years | 1 | 
| E.8.9.2 | In all countries concerned by the trial months | 4 |