• Number of patients in remission at 6 months from study entry. [ Time Frame: 6 Months ] [ Designated as safety issue: No ]
  

• Safety [ Time Frame: 1 Year ] [ Designated as safety issue: Yes ]
  

The purpose of this study is to assess the safety and efficacy of Rituximab (anti-CD20) in the treatment of patients with hepatitis C associated cryoglobulinemic vasculitis (HCV-CV) who have failed or are intolerant to interferon-alpha/ribavirin therapy. Up to 50 patients may be screened to enroll 34 adult patients with active HCV-CV in this randomized, non-blinded phase I/II trial. Patients will be randomized to receive either Rituximab 375 mg/M(2) on days 1, 8, 15 and 22 beginning at the time of enrollment or 6 months following enrollment. Patients in both groups will be maintained on stable doses of any immunosuppressive therapies that they were receiving at the time of enrollment. Response to Rituximab will be assessed by clinical and laboratory parameters.

• INCLUSION CRITERIA

Diagnosis of HCV-CV: must have all of the following

HCV infection documented by serology and/or plasma HCV RNA.

One or more organ system with objective evidence of active vasculitis such as:

Palpable purpura;

Glomerulonephritis (defined by the presence of glomerular hematuria and/or new or worsening proteinuria);

Acute peripheral neuropathy.

Detectable cryoglobulins and/or RF.

Failure of treatment with IFN-alpha and ribavirin to control manifestations of HCV-CV OR intolerance to IFN-alpha/ribavirin regimen.

Patients must have a personal physician responsible for the care of their HCV.

Ages of 18 and 75 years

Willingness to use effective contraception during and for 12 months following Rituximab treatment. Effective contraception methods include abstinence, surgical sterilization of either partner, barrier methods such as diaphragm, condom, cap or sponge, or hormonal contraception.

EXCLUSION CRITERIA

Recent (within 4 weeks) initiation of or increase in immunosuppressive therapy.

Active systemic infection (other than hepatitis C).

Pregnancy or breast feeding.

Prior treatment with Rituximab.

Known allergy to murine proteins.

Significant renal insufficiency (creatinine clearance less than 30 ml/min).

Presence of life-threatening HCV-CV; defined as rapidly progressive glomerulonephritis (defined as a doubling of the serum creatinine over a 3 month period), CNS vasculitis, cardiac disease due to active vasculitis, or GI vasculitis (defined by ischemic bowel, perforation, or infarction).

Significant hepatic insufficiency as manifested by Child-Pugh classification of B or C.

History of variceal bleeding, encephalopathy.

History of liver transplantation.

Co-infection with either HBV or HIV.

Any underlying medical condition that in the judgment of the investigator would put the patient at increased risk for serious infusion-related adverse events.