Chloroquine is useful in:

Hydroxychloroquine​ Hydroxychloroquine is used for early, mild RA, often combined with methotrexate. This agent is also used in the treatment of lupus and malaria. Its mechanism of action in auto-immune disorders is unknown, and onset of effects takes 6 weeks to  6  months. Monotherapy may be initiated with any of the DMARDs (methotrexate, leflunomide, hydroxychloroquine or sulfasalazine) for patients with low disease activity.​ ​DMARDs = Disease modifying Anti-Rheumatic Drugs. Reference: Lippincott Illustrated Reviews: Pharmacology Wolters Kluwer Sixth Edition page no 457,458​