Collagenase Clostridium histolyticum. Short-term benefit in Dupuytren's contracture, unknown long-term risks

Dupuytren's contracture is due to fibroblast overgrowth in the aponeuroses of the hand and fingers, leading to excessive collagen production. This can cause functional impairment due to retraction of one or several fingers.The standard treatment is surgery, but relapses are frequent. A product containing collagenolytic bacterial enzymes (collagenases) is now marketed for local treatment of these retractions. Two double-blind placebo-controlled trials in 308 and 66 patients show that 1 to 3 local injections at one-month intervals lead to near-total reduction in finger retraction in about 50% of cases, versus about 5% of cases after placebo injections. A non-comparative follow-up of 830 successfully treated patients, lasting an average of 7.4 months, showed a relapse rate of 4%. The Most patients experience local reactions such as swelling, bruising, bleeding and pain. These reactions were rarely severe in clinical trials (1% of patients), but cases of tendon rupture have been described. Nearly all treated patients develop anticollagenase antibodies. The only known consequence of this immune reaction is pruritus, reported by about 11% of patients participating in clinical trials. The possible impact of these antibodies on the efficacy of subsequent injections is not known. A certain antigenic kinship between the bacterial collagenases and certain human enzymes raises the possibility of long-term autoimmune reactions. In practice, the limitations of surgical management and the simplicity of local collagenase injections make it a valid option for the treatment of Dupuytren's contracture. Uncertainties concerning the long-term harm-benefit balance mean that this treatment should only be considered when surgery is not an option.