DISEASE CHARACTERISTICS:

• Histologically confirmed* newly diagnosed extensive chronic graft-versus-host disease (GVHD) of ≥ 1 organ system (e.g., lip, skin, or liver) documented by all of the following:

  • Clinicopathologic features of GVHD, including involvement of any of the following organ systems:

    • Skin changes
    • Oral changes
    • Hepatic involvement
    • Gastrointestinal involvement
    • Sicca syndrome
    • Pulmonary involvement
    • Myofascial
    • Skeletal
    • Other inflammatory conditions (e.g., myositis, arthritis, polyserositis, or unexplained pericardial, pleural, or peritoneal effusions)
    • Autoantibodies

  • Extent of disease, defined according to the following classification:

    • Limited chronic GVHD, defined by 1 of the following:

      • Localized skin involvement and/or liver dysfunction
      • Involvement of only 1 target organ

    • Extensive chronic GVHD, defined by 1 of the following:

      • Generalized skin involvement of ≥ 50% of body surface area

      • Localized skin involvement and/or liver dysfunction AND ≥ 1 of the following:

        • Liver histology showing chronic aggressive hepatitis, bridging necrosis, or cirrhosis
        • Eye involvement (Schirmer's test with < 5 mm wetting)
        • Involvement of minor salivary glands or oral mucosa on lip biopsy
        • Involvement of any other target organs
      • Involvement of ≥ 2 target organs

  • Timing of onset, including onset of any of the following types:

    • Progressive onset defined as, evolving directly from acute GVHD, commonly with the development of typical manifestations such as oral or skin lichenoid changes or sclerodermatous skin changes
    • Quiescent onset, defined as developing after the resolution of acute GVHD
    • De novo onset, defined as developing with no prior history of acute GVHD

• Must have ≥ 1 typical clinical manifestation of chronic GVHD that differs from that of acute GVHD (e.g., rash, anorexia, nausea, emesis, diarrhea, abdominal pain, or cholestasis)

  • Symptoms of acute GVHD allowed at the time of diagnosis of chronic GVHD
• Prior allogeneic bone marrow, peripheral blood stem cell, or cord blood transplantation from a family member or unrelated donor for malignancy required NOTE: *Histologic confirmation may be "consistent with GVHD"

PATIENT CHARACTERISTICS:

Age:

• 1 to 29

Performance status:

• Lansky 50-100% OR
• Karnofsky 50-100%

Life expectancy:

• At least 2 months

Hematopoietic:

• Absolute neutrophil count ≥ 1,000/mm^3, unless due to chronic GVHD (i.e., autoimmune neutropenia or bone marrow suppression)

Hepatic:

• See Disease Characteristics

Renal:

• Creatinine < 1.5 times upper limit of normal OR
• Creatinine clearance ≥ 60 mL/min

Other:

• Not pregnant
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 3 months after study participation
• No lysosomal storage disorder
• No uncontrolled infection (e.g., persistent bacterial, fungal, or viral infection despite appropriate antimicrobial therapy)
• No G6PD deficiency
• No history of psoriasis or porphyria
• No hypersensitivity to 4-aminoquinolines
• No prior retinal or visual field changes due to 4-aminoquinolines

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• See Disease Characteristics
• No concurrent dacluzimab or infliximab
• No concurrent thalidomide

Chemotherapy:

• Not specified

Endocrine therapy:

• Prior topical steroids for treatment of extensive chronic GVHD allowed
• Prior adjustment to prednisone dose allowed if done as a reversal of a taper
• Prior steroids (prednisone ≤ 1 mg/kg/day (or equivalent) for symptom management for up to 1 week before study entry allowed
• Concurrent steroids for treatment and/or prophylaxis of acute GVHD allowed if prednisone dose is ≤ 2 mg/kg/day (or equivalent)
• Concurrent topical steroids allowed

Radiotherapy:

• Not specified

Surgery:

• Not specified

Other:

• No prior treatment for extensive chronic GVHD except the following:

  • Topical treatment (e.g., tacrolimus ointment or pimecrolimus cream)
  • Adjustments of cyclosporine or tacrolimus doses for GVHD prophylaxis or treatment of acute GVHD

• Concurrent cyclosporine or tacrolimus allowed

  • Cyclosporine must have been started before study entry

• No other concurrent systemic or topical immunosuppressants, including any of the following:

  • Azathioprine
  • Mycophenolate mofetil
  • Psoralen-ultraviolet light therapy
  • Photopheresis

• No administration of any of the following for 1 hour before until 2 hours after study drug administration:

  • Antacids
  • Sucralfate
  • Cholestyramine
  • Bicarbonate