Efficacy and safety of recombinant human bone morphogenetic protein-2/calcium phosphate matrix for closed tibial diaphyseal fracture: a double-blind, randomized, controlled phase-II/III trial.

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) applied on an absorbable collagen sponge improves open tibial fracture-healing as an adjunct to unreamed intramedullary nail fixation. We evaluated rhBMP-2 and a new, injectable calcium phosphate matrix (CPM) formulation in acute closed tibial diaphyseal fractures treated with reamed intramedullary nail fixation. METHODS: Patients were randomized (1:2:2:1) to receive standard of care, which consisted of definitive fracture fixation within seventy-two hours of injury with a locked intramedullary nail after reaming; standard of care and injection with 1.0 mg/mL of rhBMP-2/CPM; standard of care and injection with 2.0 mg/mL of rhBMP-2/CPM; or standard of care and injection with buffer/CPM, to evaluate the activity of the CPM delivery matrix and provide for sponsor and investigator blinding. The co-primary end points of the study were the effects of rhBMP-2/CPM on the time to fracture union (based on blinded assessment of radiographs) and the time to return to normal function (based on blinded assessment of the time to full weight-bearing without pain at the fracture site) compared with standard of care alone. RESULTS: Three hundred and sixty-nine patients were randomized and included in the intent-to-treat population. This study was terminated after an interim analysis (180 patients with six months of follow-up) revealed no shortening in the time to fracture union in the active treatment arms compared with the standard of care control (the SOC group). In the final primary analysis, the median time to radiographic fracture union was not significantly different for the SOC (13.1 weeks), 1.0-mg/mL rhBMP-2/CPM (13.0 weeks), 2.0-mg/mL rhBMP-2/CPM (15.9 weeks), or buffer/CPM (15.4 weeks) treatment groups. The median time to pain-free full weight-bearing was also not significantly different among the SOC (13.4 weeks), 1.0-mg/mL rhBMP-2/CPM (13.4 weeks), 2.0-mg/mL rhBMP-2/CPM (14.3 weeks), and buffer/CPM (16.4 weeks) treatment groups. CONCLUSIONS: In patients with closed tibial fractures treated with reamed intramedullary nailing, the time to fracture union and pain-free full weight-bearing were not significantly reduced by rhBMP-2/CPM compared with standard of care alone. 24306696

Recombinant human bone morphogenetic protein-2: a randomized trial in open tibial fractures treated with reamed nail fixation.

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) improves healing of open tibial fractures treated with unreamed intramedullary nail fixation. We evaluated the use of rhBMP-2 in the treatment of acute open tibial fractures treated with reamed intramedullary nail fixation. METHODS: Patients were randomly assigned (1:1) to receive the standard of care consisting of intramedullary nail fixation and routine soft-tissue management (the SOC group) or the standard of care plus an absorbable collagen sponge implant containing 1.5 mg/mL of rhBMP-2 (total, 12.0 mg) (the rhBMP-2/ACS group). Randomization was stratified by fracture severity. The absorbable collagen sponge was placed over the fracture at wound closure. The primary efficacy end point was the proportion of subjects with a healed fracture as demonstrated by radiographic and clinical assessment thirteen and twenty weeks after definitive wound closure. RESULTS: Two hundred and seventy-seven patients were randomized and were the subjects of the intent-to-treat analysis. Thirteen percent of the fractures were Gustilo-Anderson Type IIIB. The proportions of patients with fracture-healing were 60% and 48% at week 13 (p = 0.0541) and 68% and 67% at week 20 in the rhBMP-2/ACS and SOC groups, respectively. Twelve percent of the subjects underwent secondary procedures in each group; more invasive procedures (e.g., exchange nailing) accounted for 30% of the procedures in the rhBMP-2/ACS group and 57% in the SOC group (p = 0.1271). Infection was seen in twenty-seven (19%) of the patients in the rhBMP-2/ACS group and fifteen (11%) in the SOC group (p = 0.0645; difference in infection risk = 0.09 [95% confidence interval, 0.0 to 0.17]). The adverse event incidence was otherwise similar between the treatment groups. CONCLUSIONS: The healing of open tibial fractures treated with reamed intramedullary nail fixation was not significantly accelerated by the addition of an absorbable collagen sponge containing rhBMP-2.