To Evaluate The Safety of SAR153191 (REGN88) and Tocilizumab Added to Other RA Drugs in Patients With RA Who Are Not Responding to or Intolerant of Anti-TNF Therapy (SARIL-RA-ASCERTAIN)

Total study duration is up to 34 weeks: Screening up to 28 days, treatment phase of 24
weeks, and post-treatment follow-up of 6 weeks.

After completion of the treatment phase of this study, patients are eligible to enter a long
term safety study (LTS11210) for active treatment with SAR153191 (REGN88).

Inclusion criteria:

Diagnosis of RA, according to the American College of Rheumatology (ACR)/European League
against Rheumatism (EULAR) 2010 Rheumatoid Arthritis Classification Criteria with ≥ 3
months disease duration.

ACR Class I-III functional status, based on the 1991 revised criteria.
Moderate-to-severely active RA. Anti-TNF therapy failures, defined as patients with an
inadequate clinical response defined by the investigator, after being treated for at least
3 consecutive months, and/or intolerance to at least 1 TNF-antagonist, resulting in or
requiring their discontinuation. TNF-antagonists may include, but are not limited to,
etanercept, infliximab, adalimumab, golimumab and/or certolizumab pegol.

Continuous treatment with one or a combination of non-biologic disease modifying
antirheumatic drugs (DMARDs) for at least 12 consecutive weeks prior to screening and on a
stable dose(s) for at least 6 consecutive weeks prior to screening:

- Methotrexate - 10 to 25 mg/wk orally or parenteral (or per local labeling
requirements if the dose range differs)

- Leflunomide - 10 to 20 mg orally daily

- Sulfasalazine (SSZ) - 1000 to 3000 mg orally daily

- Hydroxychloroquine (HCQ) - 200 to 400 mg orally daily

Exclusion criteria:

Patients <18 years of age. Use of parenteral corticosteroids or intra-articular
corticosteroids within 4 weeks prior to screening.

Use of oral corticosteroids in a dose higher than prednisone 10 mg or equivalent per day,
or a change in dosage within 4 weeks prior to screening.

Past history of, or current, autoimmune or inflammatory systemic or localized joint
disease(s) other than RA.

History of juvenile idiopathic arthritis or arthritis onset prior to age 16. Severe
systemic RA, including but not limited to vasculitis, pulmonary fibrosis, and/or Felty's
syndrome.

Participation in any clinical research study that evaluated an investigational drug or
therapy within 5 half-lives or 60 days of the Screening Visit, whichever is longer.

Patients with active tuberculosis or latent tuberculosis infection. Prior or current
history of interstitial lung disease. Prior treatment with anti-IL-6 or anti-IL-6R
therapies, including but not limited to tocilizumab or sarilumab.

Treatment with anti-TNF agents, as follows:

- Etanercept: within 28 days prior to randomization

- Infliximab, adalimumab, golimumab, certolizumab pegol: within 42 days prior to
randomization.

Treatment with RA-directed biologic agents with non- TNF-α antagonist mechanisms without
adequate washout as follows:

- Anakinra: within 28 days prior to randomization

- Abatacept: within 42 days prior to randomization

- Rituximab or other cell depleting agent: Within 6 months prior to randomization or
until total lymphocyte count and CD 19+ lymphocyte count are normalized, or whichever
is longer.

Prior treatment with a janus kinase (JAK) inhibitor (eg, tofacitinib). Patients with a
history of invasive opportunistic infection. Prior or current history of malignancy,
including lymphoproliferative diseases, other than adequately-treated carcinoma in-situ of
the cervix, nonmetastatic squamous cell or basal cell carcinoma of the skin, within 5
years prior to the randomization (baseline) visit.

Prior or current history of other significant concomitant illness(es) that, according to
Investigator's judgment, would adversely affect the patient's participation in the study.

The above information is not intended to contain all considerations relevant to a
patient's potential participation in a clinical trial.