A Trial to Investigate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of NNC0215-0384 Administered to Subjects With Moderate to Severe Rheumatoid Arthritis

Inclusion Criteria: * Male or female, age between 18 and 75 years (both years inclusive), for Russia only: Age between 18-65 years (both years inclusive) * Moderate to severe RA, confirmed by a Disease Activity Score based on 28 joints and C-reactive protein (DAS28 (CRP)) equal to or above 4.5 and a minimum of five tender and five swollen joints based on a 28 joint count (a joint can score as both tender and swollen) * MTX (10-25 mg/week both inclusive) for at least 16 weeks, with an unchanged dose for at least 6 weeks prior to screening and until randomisation * Females who are not of child-bearing potential must have been post-menopausal for at least 1 year confirmed by follicle-stimulating hormone (FSH) equal to or above 26.7 U/L or be surgically sterile Exclusion Criteria: * Past or current inflammatory joint disease other than RA (e.g. gout \[crystal proven\], psoriatic arthritis, juvenile idiopathic arthritis, reactive arthritis or Lyme disease * Any active or ongoing chronic infectious disease (e.g. chronic osteomyelitis, chronic pyelonephritis) within 4 weeks prior to randomisation * Clinically significant cardiac or cardiovascular disease * Past or current malignancy * Evaluation of tuberculosis screening indicative of latent or active tuberculosis (TB)