There is inadequate evidence to draw strong conclusions on the efficacy or safety of the drug interventions included in this review. There is some low quality evidence from a meta-analysis of two studies investigating urokinase (various strengths) and some very low evidence from two single studies investigating alteplase 2 mg/2 mL that suggest that these two drug interventions may be effective in treating withdrawal or total occlusion of CVC lumens caused by thrombosis. Further high quality, sufficiently powered research is still required to look at the efficacy and safety of urokinase, alteplase and other chemical, surgical and drug interventions for treating CVC lumen occlusion. Research studies which exclusively include child participants are especially warranted.
Phase II trial of alfimeprase, a novel-acting fibrin degradation agent, for occluded central venous access devices.
Alfimeprase is a recombinantly produced, genetically modified variant of the metalloproteinase, fibrolase. Alfimeprase proteolytically cleaves fibrin, independent of plasminogen activation to plasmin, and directly dissolves thrombi. Based on the direct fibrin degradation effect of alfimeprase, rapid activity in patients with occluded central venous access devices (CVADs) was hypothesized.
                We performed a phase II, randomized, double-blind, active-control, multicenter, dose-ranging study to compare the safety and efficacy of one or two instillations of three intraluminal doses of alfimeprase (0.3, 1.0, and 3.0 mg) and alteplase 2.0 mg in re-establishing patency to occluded CVADs in 55 adult patients.
                All three alfimeprase doses were more successful than alteplase during the first 15 and 30 minutes of treatment. The alfimeprase 3.0-mg dose resulted in 40%, 50%, and 60% patency restoration rates at 5, 15, and 30 minutes, respectively, compared with 0%, 0%, and 23% for alteplase. The difference at 15 minutes was highly significant (P = .0075). Alfimeprase 3.0 mg produced the highest patency rate at 120 minutes after the first (60%) and second (80%) doses. No major hemorrhagic or embolic events were reported.
                A single 1- or 3-mg dose of alfimeprase has the potential to restore function to occluded CVADs rapidly and safely, and to facilitate on-time infusion of vital therapies.