Prof Salvatore De Vita
University of Udine
Clinic of Rheumatology
Piazzale Santa Maria della Misericordia 15
Anti-CD20 monoclonal antibody therapy for Type II Mixed Cryoglobulinemia Syndrome versus best available treatment: a phase III controlled study
Type II mixed cryoglobulinemia (MC) or MC syndrome is a systemic vasculitis prevalently mediated by immune-complexes, and associated with hepatitis C virus (HCV) infection and B-cell lymphoproliferation. Despite the bone marrow pathologic findings often suggesting an indolent B-cell malignancy, type II MC is definitely a non-neoplastic disorder, as finally demonstrated by molecular analyses of B-cell clonal expansion in extensively characterized patients with long-term follow-up.
B-cell expansion and lymphoproliferation occur in target organs of HCV infection. There is evidence of an antigen-driven proliferation of rheumatoid factor (RF) - positive clones, with a restricted immunoglobulin gene usage, leading to cryoglobulin production. Future studies should clarify the preferential and persistent expansion of such RF-positive clones in the course of HCV infection if compared to other chronic inflammatory/infectious conditions. Since only a fraction of patients with HCV infection have positive serum cryoglobulins or develop MC syndrome, additional mechanisms, virus-or host-related, are implicated. Recent studies were focused on insertions or deletions in HCV gene (HVR1-E2 region), HLA genetic predisposition, C4 deficiency, anti-endothelium and anti-alpha enolase antibodies, T-helper 2 profile and cytokines. Finally, serum cryoglobulins and RF usually persists even after the negativization of HCV RNA with the antiviral therapy. Since RF-positive B-cells may be stimulated by immune complexes containing quite different antigens, HCV infection might be crucial for the induction of MC, while not for the survival of RF-positive clones, which might prove pathogenetically relevant also in the lack of HCV persistence.
In the lack of such informations, the treatment of HCV-associated MC remains difficult, and strategies should be necessarilly focused both on the viral trigger (when present) and on downstream pathogenetic events.
There is general clinical evidence that effective antiviral treatment with interferon (old studies) or with interferon plus ribavirin (recent studies) is often accompanied by clinical efficacy, but results may differ in the different systemic features. Thus, even if antiviral therapy has a strong rationale and represents a cornerstone for the treatment of MC, additional pathobiologic events should be dissected and targeted for the different organ manifestations. Furthermore, antiviral therapy may be uneffective, counterindicated or not tolerated, and finally does not allow a rapid improvement in progressive or life threatening MC manifestations.
On the other hand, standard immunosuppressive approaches may lead to severe complications in HCV-positive MC patients, including major infections, cytopenias, enhancement of viral replication, and may have direct oncogenetic properties. Thus, less toxic approaches are needed.
University of Udine Ethics Committee, 13 October 2003 ref: 6/2003
Randomised controlled multicenter non blinded phase III study
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet
Mixed cryoglobulinemia HCV- related or unrelated
NON-Rituximab (RTX) GROUP (conventional treatment, i.e., as chosen by the expert clinician in that individual patient among the following):
1. Glucocorticoids (maximal initial dose of 1 mg/kg/day of prednisone equivalents) with or without preceding 6-methylprednisolone pulses (500 to 1000 mg/day for 3 consecutive days), with subsequent reduction of the glucocorticoid dosage in the following months.
2. Azathioprine or cyclophosphamide, orally at 1-2 mg/kg/day, with or without glucocorticoids (as in point 1); if response was observed, azathioprine or cyclophosphamide might be suspended after the end of month +6 after randomization, and then reintroduced if clinical relapse occurred (as it occurs in the current clinical practice).
3. Plasmapheresis, with or without glucocorticoids (as in point 1); if response was observed, plasmapheresis could be suspended after the end of month +6 after randomization, and then reintroduced if clinical relapse occurred (current clinical practice). At least two plasmapheretic procedures per week were required in the first month after randomization, with subsequent reductions according to the response observed and to local protocols.
Rituximab (RTX) GROUP:
RTX 1 g intravenously on days 0 and 14, with premedication with 100 mg of methylprednisolone intravenously, paracetamol 1000 mg orally, and clorpheniramine maleate 10 mg intravenously, before each infusion. Only glucocorticoids were allowed as concomitant treatment, at the same dose given before randomization if already administered, or lower; if introduced with RTX, only low doses (≤ 0.1 mg/kg/day of prednisone equivalents) were allowed. In case of clinical disease relapse in this Group, retreatment with RTX, at the same schedule, was permitted in case of previous response to RTX.
Patients failing treatment in non-RTX Group could be switched to RTX in an open-label extension manner (RTX-switch Group).
Patients were randomized to treatment stratified for the following three disease manifestations:
1. Skin ulcers
2. Active glomerulonephritis (assessed by renal biopsy)
3. Peripheral neuropathy (assessed by electromyography); sensory: evolving or with severe pain unresponsive or insufficiently managed with analgesics and gabapentin or pregabalin; motor: of any type and duration).
Patients with two or three of these clinical manifestations simultaneously present were randomized within the group where the accrual of patients was lower.
Primary outcome measures
The proportion of patients surviving on treatment at the end and 12 months after randomization, i.e., after a follow-up considered sufficient to assess both the efficacy and safety of treatment.
Efficacy and safety issues were in fact considered equally relevant in the long term, and a single end point integrating both of them was then chosen. Survival of treatment was statistically higher in RTX Group in comparison to non-RTX Group (conventional treatment).
Secondary outcome measures
1. The proportion of patients surviving on treatment at the end month +24, i.e., to evaluate the long term efficacy and safety of treatment.
2. The proportion of patients surviving on treatment at the end month +6, i.e., to evaluate the short term efficacy and safety of treatment.
3. The proportion of patients surviving on treatment at the end month +3, i.e., to evaluate the very early efficacy and safety of treatment.
4. Superiority of RTX to decrease the global disease activity, as defined by the Birmingham Vasculitis Activity Score (BVAS).
5. Superiority of RTX for response in the single CV manifestations considered in the randomization scheme.
6. Efficacy of RTX in patients where conventional treatment had failed.
7. Duration of response to RTX and efficacy of retreatment.
8. Assessment of the profile of side effects of RTX, both in the short and the long term.
Overall trial start date
Overall trial end date
Participant inclusion criteria
1. Patients with CV with type II cryoglobulins
2. HCVrelated or unrelated, classified according to published criteria
3. With positive serum cryoglobulins
4. Suffered from severe active CV manifestations, i.e., skin ulcers, active glomerulonephritis, or worsening or refractory peripheral neuropathy
5. In patients with HCV-related CV, study inclusion implied that antiviral therapy with interferon plus ribavirin had failed, had been poorly tolerated, or was considered contraindicated.
6. Patients aged 18-80 years
7. Negative for antibodies against the human immunodeficiency virus (HIV), hepatitis B virus core antigen, and for hepatitis B virus surface antigen.
Target number of participants
Participant exclusion criteria
1. Active CV manifestations with immediate risk for patient survival
2. Acute renal failure or rapidly progressive glomerulonephritis
3. Severe concomitant uncontrolled illness CV-unrelated
4. Active or recurrent infections
5. History of cancer (except for CV-related indolent B-cell lymphoproliferation in the bone marrow, not requiring treatment)
6. Alcohol or drug abuse
7. Serum creatinin > 4 mg/dl
8. AST or ALT > 3 times the upper limit of normal
9. Haemoglobin < 8 g/dl
10. Neutrophils < 1000/mmc or total leukocytes < 1500/mmc
11. Platelets < 40.000/mmc
12. History of severe allergic reactions to monoclonal antibodies
13. Pregnancy (if reproductive potential, an accepted birth control method was required)
14. Previous treatment with RTX
15. Previous failure of all the following:
15.1. High dose glucocorticoids
15.2. Plasma exchange
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
University of Udine
Funding Body Type
private sector organisation
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Results - basic reporting