Prospective Outcomes Study: Vectra® DA Guided Care Compared to Usual Care

To determine whether a strategy of Vectra DA guided care (Arm A), compared with usual care
(Arm B), achieves non-inferior clinical outcomes while reducing the cost of treatment in
patients with active RA and an inadequate response to MTX monotherapy.

Inclusion Criteria:

Subjects will be eligible to participate in the study if they meet all the following
criteria:

1. Willing and able to sign an ICF

2. Age 18 to 80 years at enrollment

3. Meets the 2010 ACR/EULAR criteria and/or 1987 criteria for RA, as determined by a
board-certified rheumatologist ≥3 months prior to enrollment

4. Received uninterrupted treatment with weekly MTX begun ≥3 months prior to enrollment,
at a stable dose of ≥15 mg per week for at least 4 weeks prior to enrollment. A
history of therapy with split dose oral MTX or parenteral MTX is acceptable only if
the weekly MTX dose was always ≤20 mg/week during the 3 months prior to enrollment.

5. CDAI >10 as assessed by the Investigator at screening

6. At least 3 swollen joints (SJC ≥3) and 3 tender joints (TJC ≥3) out of 28 joints as
assessed by the Investigator at screening

7. Must be eligible for treatment intensification with non-biologic and biologic DMARDs

8. Documented evidence of seropositivity (RF and/or anti-CCP antibodies). Seronegative
subjects are allowed if erosive disease attributable to RA is documented on X-rays.

Exclusion Criteria:

Subjects will be ineligible to participate in the study if they meet any of the following
criteria:

1. Use of a non-biologic DMARD other than MTX within 3 months prior to enrollment

2. MTX administered SQ or as an oral split dose at >20 mg/week any time during the 3
months prior to enrollment

3. Two or more DMARDs used in combination (i.e., concomitantly), including but not
limited to: MTX, HCQ, SSZ, LEF, cyclosporine, azathioprine, gold or penicillamine any
time prior to enrollment

4. Biologic DMARD or JAKi use any time prior to enrollment

5. Any contraindication to use of MTX, HCQ, LEF or biologic DMARDs

6. Opiate use during the 2 weeks prior to enrollment

7. Oral corticosteroids during the month prior to enrollment at a dosage >10 mg/day
prednisone (or equivalent) or at a non-stable dose ≤10 mg/day prednisone (or
equivalent)

8. MTX intolerance prior to enrollment that limits its use

9. Inflammatory joint disease (other than RA) or any other systemic autoimmune disorder.
(Osteoarthritis is not a basis for exclusion.)

10. Primary or secondary immunodeficiency

11. Active infection (excluding fungal infection of nail beds); or acute or chronic
infection requiring hospitalization or treatment with parenteral systemic antibiotics
within one month of enrollment or treatment with oral antibiotics within 2 weeks of
enrollment

12. IA, intravenous or IM corticosteroids during the month prior to enrollment

13. Initiation or non-stable dosing of NSAIDs within 2 weeks prior to enrollment

14. Vectra DA testing within 3 months prior to enrollment

15. Live vaccine within 90 days of enrollment

16. Active substance abuse or psychiatric illness likely to interfere with protocol
conduct

17. History of severe allergic or anaphylactic reaction to any monoclonal antibody therapy

18. Known infection with HIV (HIV testing will not be a requirement for trial entry); a
past or current history of hepatitis B virus or hepatitis C virus infection

19. History of malignancy within the past five years or any evidence of persistent
malignancy, except fully excised basal cell or squamous cell carcinomas of the skin,
or cervical carcinoma in situ that has been treated or excised in a curative procedure

20. Pregnancy or inadequate contraception in women of childbearing potential

21. Breast feeding or lactating

22. Medical, psychiatric, cognitive or other conditions that, in the opinion of the
Investigator, may compromise the ability of the subject to understand the study
information, to give informed consent, to comply with the trial protocol, or to
complete the study

23. Presently enrolled in another clinical trial

24. Vectra DA score at screening that is outside the applicable range as required for
subject enrollment

Note: Screening for TB is not required for subjects participating in the study. If an
Investigator is considering a subject for treatment with a biologic DMARD in the study,
guidelines for TB screening need to be followed.