A 26-week, phase II, multicenter, randomized, double-blind, placebo-controlled study to assess the response to treatment (ACR50) and to determine a biomarker profile in responders to ACZ885 (anti-interleukin-1beta monoclonal antibody) plus MTX as compared to MTX alone in early rheumatoid arthritis patients.

1. Male and female patients aged 18 to 75 years.
2. Recent definite diagnosis of RA (less than 3 years ago), classified by American Rheumatism Association 1987 revised criteria.
3. Candidate for methotrexate or biologic due to erosive arthritis, with no contraindications to such therapy, including:
o Negative tuberculin skin test reaction at the screening visit or within 2 months prior to the screening visit. Patients who have a positive PPD skin test, but were previously treated with anti-tuberculosis drugs, or are known to have a negative chest X-ray (within the last year) can be included.
o Normal chest X-ray (within the last year).
4. Functional status class I, II or III classified according to the American College of Rheumatology 1991 revised criteria.
5. Active disease at screening and baseline evaluation, defined as at least 6 swollen and 6 painful tender joints of 28 joint count, and at least one of the following: hsCRP > 1.0 mg/dL, and/or ESR > 28 mm/h.
6. At Screening, and Baseline, vital signs (after 3 minutes of resting) should be within the following ranges:
Young subjects:
Oral body temperature between 35.0-37.5 °C
systolic blood pressure, 90-140 mm Hg
diastolic blood pressure, 50-90 mm Hg
pulse rate, 40 - 90 bpm
Elderly subjects (60-75 years of age):
Oral body temperature between 35.0-37.5 °C
systolic blood pressure, 100-160 mm Hg
diastolic blood pressure, 50-100 mm Hg
pulse rate, 50 - 100 bpm;After 3 minutes standing there shall be no more than a 20 mm Hg drop in systolic or 10 mm Hg drop in diastolic blood pressure and increase in heart rate (>20 bpm) associated with clinical manifestation of postural hypotension.
7. Women of child bearing potential may participate if they have a negative pregnancy test at screening and prior to dosing and are willing to practice double-barrier contraception during the study and for at least 3 months following last study drug administration.
Postmenopausal women must have no regular menstrual bleeding for at least 1 year prior to inclusion (plasma FSH level of >40 IU/L).
Surgically sterilized women must have been sterilized at least 6 months prior to screening.
Male patients must be using a double-barrier local contraception for the entire duration of the study, and refrain from fathering a child in the 3 months following last study drug administration.
8. Weight at least 45 kg.
9. Body mass index (BMI) within the range of 18 to 34.
10. Able to communicate well with the investigator, to understand and comply with the requirements of the study. Understand and sign the written informed consent.
11. Oral corticosteroids are permitted as long as patients are on a stable dose (up to 10 mg) for at least 4 weeks prior to randomization.

1. Contraindication for MRI of wrist.
2. Patients with magnetizable metal parts/devices on and in the body that could interfere with the interpretation of the MRI
3. Patients with an unstable active medical condition likely to impair evaluation of safety and biomarker results.
4. Previous treatment with biological therapy or MTX.
5. Limited kidney function.
6. Previous treatment with other DMARDS within 4 weeks of screening.
7. Intra-articular corticosteroids within 4 weeks prior to screening.
8. Participation in any clinical investigation within 4 weeks prior to dosing.
9. Donation or loss of 400 mL or more of blood within 8 weeks prior to first dosing.
10. Significant illness within two weeks prior to dosing.
11. A past medical history of clinically significant ECG abnormalities or a family history of a prolonged QT-interval syndrome.
12. History of autonomic dysfunction.
13. History of clinically significant acute or chronic bronchospastic disease (including asthma and chronic obstructive pulmonary disease, treated or not treated).
14. History of clinically significant drug allergy or history of atopic allergy. A known hypersensitivity to the study drug or drugs similar to the study drug.
15. History of disease of the blood building system.
16. History of serious or active infections.
17. History of gastric ulcers.
18. Any surgical or medical condition which might significantly alter the absorption, distribution, metabolism or excretion of drugs or which may jeopardize the patient in case of participation in the study. The investigator should be guided by evidence of any of the following:
19. History of immunodeficiency diseases, including a positive HIV test result.
20. A positive Hepatitis B surface antigen (HBsAg) or Hepatitis C test result.
21. History of drug or alcohol abuse within the 12 months prior to dosing or evidence of such abuse as indicated by the laboratory assays conducted during the screening or baseline evaluations.