A Phase 2a Study Evaluating the Safety and Efficacy of ABT-981 in Patients With Erosive Hand Osteoarthritis

Inclusion Criteria:

1. Male or female between the ages of 35 to 80.

2. Must fulfill 1990 American College of Rheumatology (ACR) hand osteoarthritis (OA)
criteria

3. Must have radiographic evidence of erosive hand OA

4. Have one or more clinical signs and symptoms of active inflammation in at least three
hand joints

5. Subject Assessment of Hand Pain Intensity in at least one hand is ≥ 6.

Exclusion Criteria:

1. Previous exposure to any anti-interleukin-1 treatment, to corticosteroids within 1
month prior to Screening, to intra-articular hyaluronic acid injection into hand
joint(s) within 6 months prior to Screening, to any immunosuppressive biologic
therapy within 1 month or 5 half-lives (whichever is longer) prior to the first dose
of study drug, OR current use of immunosuppressive oral medications within 3 months
or 5 half-lives (whichever is longer) prior to the first dose of study drug.

2. Absolute neutrophil count < 2,000 mm3

3. Diagnosis of one or more of the following:

- Fibromyalgia,

- Inflammatory arthritis such as rheumatoid arthritis, peripheral seronegative
spondyloarthropathy,

- Psoriatic arthritis, psoriasis,

- Microcrystalline (including gout and pseudo gout) arthritis affecting the hands,

- Any OA of the hands due to an infectious origin or acute traumatic episode,
secondary OA or OA linked to cartilage and bone dysplasia,

- Other chronic painful syndromes that could interfere with assessment of pain at
the hand(s).

4. Any uncontrolled medical illness or an unstable treatment or therapy.

5. Clinically significant cardiac disease.

6. Evidence of dysplasia or history of malignancy other than a successfully treated
non-metastatic cutaneous squamous cell or basal cell carcinoma or localized carcinoma
in situ of the cervix.

7. History of persistent chronic or active infection(s) requiring hospitalization or
treatment with antimicrobials/antibiotics.

8. Any reason that prohibits a subject to undergo an MRI.