The results of a Phase III clinical trial indicate that emicizumab prophylaxis significantly reduces the rate of bleeding events in individuals with hemophilia A. Activated factor VIII is deficient in this population, but emicizumab restores it by bridging activated factor IX and factor X. In the multi-site study, researchers recruited 109 males aged 12 years or older who had a hemophilia A diagnosis with factor VIII inhibitors. Any participant who had previously undergone prophylactic treatment with bypassing agents was automatically assigned to emicizumab prophylaxis and classified as group C. The remaining patients, who had previously received episodic treatment with bypassing agents, were randomized to either group A—which received emicizumab prophylaxis—or group B, which did not. The annualized bleeding rate was markedly lower in group A compared with group B at 2.9 events vs. 23.3 events, respectively. Moreover, 63% of patients randomized to prophylaxis did not suffer any bleeding events at all, while the same was true for only 6% of patients who did not undergo prophylaxis. In a subset of group C patients who participated in a noninterventional study, meanwhile, the bleeding rate was reduced nearly by 80% with emicizumab prophylaxis compared with earlier prophylaxis using another agent.