Efficacy and Safety Study of HRO350 in Patients with Mild-to-moderate Psoriasis (the 'HeROPA' Study).

Inclusion Criteria:

1. Signed and dated informed consent.

2. Males or females ≥18 years of age.

3. Diagnosis of chronic, active plaque psoriasis of mild to moderate severity since atleast 6 months prior to screening.

4. Psoriasis Area and Severity Index (PASI) score ≥ 3 and ≤ 10 at screening andbaseline

5. Body Surface Area (BSA) ≥ 3 at screening and baseline

6. Static Physician's Global Assessment (sPGA) ≥ 2 and ≤ 4 at screening and baseline.

7. Males, and females of child-bearing potential1, must be willing to use highlyeffective methods of birth control during the study period and until 30 days afterend of treatment. Highly effective methods of birth control are defined as thosewhich result in a low failure rate (i.e. less than 1% per year) when usedconsistently and correctly. Such methods include:

• Combined (oestrogen and progestogen containing hormonal contraceptionassociated with inhibition of ovulation -oral -intravaginal

• transdermal

• progestogen-only hormonal contraception associated with inhibition of ovulation -oral

• injectable

• implantable

• intrauterine device

• intrauterine hormone-releasing system

• bilateral tubal occlusion

• vasectomized partner

• sexual abstinence (if this is the preferred and usual lifestyle of the patient)

1. Female patients will be considered to be of childbearing potential as perthe Clinical Trial Facilitation Group (CTFG) definition of woman ofchildbearing potential: Fertile, following menarche and until becomingpost-menopausal unless permanently sterile. Permanent sterilisationmethods include hysterectomy, bilateral salpingectomy and bilateraloophorectomy. A postmenopausal state is defined as no menses for 12 monthswithout an alternative medical cause. A high follicle stimulating hormone (FSH) level in the postmenopausal range may be used to confirm apostmenopausal state in women not using hormonal contraception or hormonalreplacement therapy (HRT). However, in the absence of 12 months ofamenorrhea, confirmation with more than one FSH measurement is required.

Exclusion Criteria:

1. Diagnosis of other psoriasis clinical subtypes such as guttate, erythrodermic orpustular psoriasis.

2. Phototherapy [(i.e., ultraviolet radiation (UVB), psoralens and long-waveultraviolet radiation (PUVA)] within 8 weeks of randomisation and during the trial.

3. Any investigational drug administered within 4 weeks of randomisation or <5 timeshalf-lives, whichever is the longer, and during the trial.

4. Systemic anti-psoriatic treatment last 3 months (for biologics last 6 months) beforerandomisation or during the trial.

5. Topical anti-psoriatic treatment last 2 weeks before randomisation.

6. Any change in anti-inflammatory medication (for other chronic diseases thanpsoriasis) last 4 weeks before randomisation and during the trial.

7. Any intake of omega-3 fatty acid supplements or medicines last 2 weeks beforerandomisation and during the trial.

8. Known fish or vegetable oil (including soy) allergy, or allergy to other ingredientsin the study medication, placebo or rescue medication.

9. Baseline white blood cell count <3.0x109/L or lymphocyte count <1.0x109/L, or otherpathological results identified during a complete blood count, which in the opinionof the investigator may preclude the patient being enrolled.

10. Previous malignancies (except for non-melanoma skin cancer).

11. Symptomatic coronary or cerebral vascular disease.

12. Known congestive heart failure Grade IV by the New York Heart Association

13. Myocardial infarction within 6 months prior to signing the ICF

14. Onset of unstable angina within 6 months prior to signing the ICF

15. Chronic kidney disease as evidenced by a calculated glomerular filtration rate (GFR) < 60ml/min/1.73m2 at screening.

16. Abnormal liver function tests defined by:

a. AST (SGOT), ALT (SGPT) or alkaline phosphatase (ALP) >3x the upper limit of the normal range (ULN). Elevated gamma-GT (GGT) values exceeding >3x ULN are allowed but these GGT cases will be carefully assessed alongside other clinical and laboratory data by the investigator. q. History of severe gastrointestinal problems. r. Ongoing, active infectious disease. s. Known human immunodeficiency virus (HIV)-positive status or suffering from any other immunosuppressive disease. t. History of major psychiatric illness that could interfere with the conduct of the study.

u. Patients with documented or suspected, clinically significant, alcohol (i.e., > 12g/d for women and 24 g/d for men) or drug abuse within the past 12 months.

v. Any other significant, unstable medical condition that would interfere with the completion of the study or interpretation of results.

w. Women of child-bearing potential* must have a negative serum pregnancy test at Visit 1 (Screening) and a negative urine pregnancy test at Visit 2 (Baseline). x. Females who are pregnant, breast feeding, refuse to use birth control methods or who wish to become pregnant during the study period.

y. Unable to comply with the requirements of the study or who in the opinion of the investigator is unable to comply with the requirements of the study.