Efficacy and Safety of Namilumab (MT203) for Plaque Psoriasis

Inclusion Criteria

• Is male or female aged 18 to 70 years, inclusive.
• Is suffering from active but clinically stable plaque psoriasis (for at least 6 months) involving >=10% of their body surface area and Psoriasis Area and Severity Index (PASI) score >=12.
• Must have been a candidate for, or have received, >= phototherapy or systemic psoriasis therapy.
• A male participant who is non-sterilized and sexually active with a female partner of childbearing potential agrees to use adequate contraception from signing of the informed consent throughout the duration of the study (including the treatment period and 18 weeks after last dose of study medication).
• A female participant of childbearing potential who is sexually active with a non-sterilized male partner agrees to routinely use adequate contraception from signing of the informed consent throughout the duration of the study (including the treatment period and 18 weeks after last dose of study medication).
• In the opinion of the investigator, is capable of understanding and complying with protocol requirements.
• The participant or, when applicable, the participant's legally acceptable representative signs and dates a written informed consent form and any required privacy authorization prior to the initiation of any study procedures.

Exclusion Criteria

• Has received any investigational agent during an interval equivalent to 5 half- lives for that agent agent - or an interval of 30 days if longer - prior to the study Baseline clinic visit, or is participating / plans to participate in any other clinical trial during this study.
• Has received namilumab, any other Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) / GM-CSF receptor or granulocyte stimulating factor (G-GSF) signaling inhibitor either in a previous clinical study or as a therapeutic agent.
• Is required to take excluded medications.
• Has a history of hypersensitivity or allergies to namilumab or any of the contents of the formulation.
• Has other forms of psoriasis (eg drug-induced psoriasis, pustular, erythrodermic, exfoliative, inverse and/or guttate psoriasis).
• Evidence of skin conditions other than psoriasis (eg, eczema) at the time of the Screening clinic visit, or between the Screening visit and study drug initiation, that would interfere with evaluations of the effect of investigational product on psoriasis.
• Has a history or evidence of a clinically significant disorder (including but not limited to cardiopulmonary, oncologic, renal, metabolic, hematologic or psychiatric), condition or disease that, in the opinion of the investigator and Takeda physician would pose a risk to participant safety or interfere with the study evaluation, procedures or completion.
• Evidence of clinically uncontrolled respiratory disease (including sarcoidosis) on the basis of data from the subjects' respiratory assessments - including chest X-ray, lung function tests (forced expiratory volume in one second [FEV1], forced vital capacity [FVC], peak expiratory flow rate [PEFR]) and pulse oximetry performed at Screening. The subjects must have saturation of peripheral oxygen (SpO2) ≥ 94%, FEV1 and/or FVC ≥ 60 % of predicted values at Screening and Baseline and no uncontrolled lung disease. Subject treatment initiated or modified to control lung disease within 24 weeks prior to Screening must be considered exclusionary.
• History of clinically significant interstitial lung disease - e.g. chronic or recurrent pulmonary infection where macrophages are important for the clearance of the infection (such as Pneumocystis (carinii) jiroveci pneumonia, allergic bronchopulmonary aspergillosis, Nocardia infections, Actinomyces infection).
• Presence or history of active tuberculosis (TB) or latent TB infection, where no anti-TB treatment has been given or where successful completion of an appropriate course of anti-TB therapy cannot be documented.
• A positive QuantiFERON-TB Gold test and / or evide