Chlorambucil for patients with primary biliary cirrhosis

Primary biliary cirrhosis is an autoimmune disease of the liver. Chlorambucil has been used for patients with primary biliary cirrhosis as it possesses immunosuppressive properties. This review aimed to assess the beneficial or harmful effects of chlorambucil for primary biliary cirrhosis. The authors identified only one randomised trial, with 24 participants included. This trial compared chlorambucil with no intervention. The trial is small and at a high risk of bias, which suggests that the results may not be reliable. Meta-analyses were not possible because of the inclusion of one trial only. Fisher's exact test and t-test were used instead. Chlorambucil was not associated with significantly lower mortality when compared with no intervention. All patients on chlorambucil experienced adverse events, especially bone marrow suppression. Chlorambucil led to a significant improvement in mean serum levels of bilirubin, albumin, immunoglobulin M, serum aspartate aminotransferase activity, and hepatic inflammatory infiltrates. However, these outcomes are unvalidated surrogate outcomes for patient-relevant outcomes. This means that improvement of these biochemistry measures cannot be taken as proof of improvement of patient-relevant outcomes. It remains unclear whether chlorambucil can be supported or rejected for use in patients with primary biliary cirrhosis.

Authors' conclusions: 

There is not sufficient evidence to support or reject the use of chlorambucil for patients with primary biliary cirrhosis. Chlorambucil may show benefit in some unvalidated surrogate outcome measures (for example, serum bilirubin and immunoglobulin M levels). Chlorambucil is, however, connected with a number of adverse events. Bone marrow suppression should be noted in particular. Further randomised clinical trials are necessary to assess the benefits and harms of chlorambucil in this indication.

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Background: 

Chlorambucil has been used for patients with primary biliary cirrhosis as it possesses immunosuppressive properties. But it is unknown whether it benefits or harms these patients.

Objectives: 

To evaluate the beneficial and any harmful effects of chlorambucil for primary biliary cirrhosis patients.

Search strategy: 

Eligible trials were identified by searching the Cochrane Hepato-Biliary Group Controlled Trials Register (March 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2012, Issue 2), MEDLINE (1946 to March 2012), EMBASE (1974 to March 2012), Science Citation Index EXPANDED (1900 to March 2012), The Chinese Biomedical Database (1976 to March 2012), The Chinese Medical Current Contents (1994 to March 2012), The China Hospital Knowledge Database (1994 to March 2012), and a database of ongoing trials (http://www.controlled-trials.com/mrct/) (accessed 6 March 2012). The reference lists of the retrieved publications and review articles were also read through, and pharmaceutical companies known to produce chlorambucil were contacted.

Selection criteria: 

Randomised clinical trials, irrespective of language, year of publication, and publication status, comparing chlorambucil at any dose versus placebo, no intervention, another active drug, or one dose of chlorambucil with another dose.

Data collection and analysis: 

We planned to assess continuous data with mean differences (MD), and dichotomous outcomes with relative risk (RR), both with 95% confidence intervals (CI). As we only identified one trial, Fisher's exact tests were employed.

Main results: 

Only one randomised trial was identified and included in the review. The bias risk in the trial was high. The trial compared chlorambucil versus no intervention in 24 patients with primary biliary cirrhosis. Fisher's exact test did not show a significant reduction of mortality when comparing chlorambucil with no treatment (0/13 (0%) versus (2/11 (18.2%); P = 0.20). There was no significant difference regarding adverse events for chlorambucil compared with no treatment, but all patients receiving chlorambucil experienced adverse events (13/13 (100%) versus (3/11 (27%); P = 0.1). According to the authors of the trial, chlorambucil led to a significant improvement in mean serum levels of bilirubin (P < 0.05), albumin (P < 0.05), immunoglobulin M (P < 0.01), serum aspartate aminotransferase activity (P < 0.01), and hepatic inflammatory infiltrates (P < 0.01).