Incidence of Tendon Rupture After Collagenase Clostridium Histolyticum Injection for Treatment of Dupuytren Contracture in Adults: A Postmarketing Safety Analysis

PURPOSE: Based, in part, on the clinical study reports of tendon rupture events after collagenase clostridium histolyticum (CCH) (Xiaflex, Endo Pharmaceuticals Inc) treatment for Dupuytren contracture (DC), a Risk Evaluation and Mitigation Strategy program was instituted in 2010 by Auxilium Pharmaceuticals (now Endo Pharmaceuticals Inc) to ensure that the benefits of CCH injection outweighed the risks when treating DC. Using the postmarketing surveillance data collected in this program, a retrospective analysis was conducted to evaluate the incidence of flexor tendon rupture after CCH treatment for DC in the clinical practice setting. METHODS: The Endo Pharmaceuticals Inc safety database was searched for cases of tendon rupture reported between February 2, 2010, and October 8, 2015. Total number of CCH treatments for DC and incidence of tendon rupture were estimated using CCH dosing derived from clinical trial experience (1.7 CCH vials/treatment) or clinical practice evidence (1.08 CCH vials/treatment). RESULTS: Over the 5.8-year surveillance period, 97,609 vials of CCH were distributed for the treatment of DC, equivalent to an estimated total of 57,416 treatments (at 1.7 CCH vials/treatment) or 90,378 treatments (at 1.08 CCH vials/treatment). Although CCH distribution increased during the surveillance period, reports of tendon rupture were infrequent (approximately 13 cases/y; total cases: flexor tendon, n = 57; ligament/pulley, n = 2), corresponding to a 0.10% (1.7 CCH vials/treatment) or 0.06% (1.08 CCH vials/treatment) mean estimated incidence of tendon rupture in patients with DC after CCH treatment. CONCLUSIONS: This retrospective analysis showed that flexor tendon rupture occurred infrequently in patients with DC who were treated with CCH in real-world practice settings between 2010 and 2015. On the basis of these findings and other favorable safety evidence, the Risk Evaluation and Mitigation Strategy program requirement for CCH for the treatment of DC was ended by the US Food and Drug Administration in November 2016. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.