A Phase IIb Study for ALX-0061 Monotherapy in Subjects With Rheumatoid Arthritis

Inclusion Criteria:

- Diagnosis of RA (according to the 2010 EULAR/Americal College of Rheumatology (ACR)
classification criteria) for at least 6 months prior to screening, and ACR functional
class I-III.

- Received previous or current treatment with methotrexate (MTX), and is considered
intolerant to MTX, or for whom continued treatment with MTX is inappropriate or has
contraindications for MTX use.

- Subjects must not have received MTX for at least 4 weeks before first administration
of the study drug.

- Have active RA with at least 6 swollen and 6 tender joints(66/68 joint count) at the
time of screening and baseline

- Others as defined in the protocol

Exclusion Criteria:

- Have been treated with DMARDs(Disease Modifying Antirheumatic Drugs)/systemic
immunosuppressives during the 4 weeks, or 12 weeks for hydroxychloroquine,
chloroquine, or leflunomide (except when an adequate wash-out procedure for
leflunomide was completed), prior to first administration of study drug.

- Have received approved or investigational biological or targeted synthetic DMARD
therapies for RA (including tumor necrosis factor alpha-inhibitors, abatacept,
rituximab, or Janus kinase [JAK]-inhibitors) less than 6 months prior to screening.

- Have a history of toxicity, non-tolerance, primary non-response or inadequate response
to a biological therapy, or targeted synthetic DMARDs (including JAK inhibitors), for
RA.

- Have received prior therapy blocking the interleukin-6 (IL-6) pathway, at any time.

- Others as defined in the protocol.