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 .