Core Viewpoint - Pfizer's new drug Marstacimab injection has received acceptance for a new indication to treat bleeding tendencies in patients with congenital hemophilia who have inhibitors to coagulation factors VIII or IX, classified as a 2.2 category registration by the National Medical Products Administration (NMPA) [1][3]. Group 1: Drug Information - Marstacimab (PF-6741086) is a monoclonal antibody targeting the K2 domain of tissue factor pathway inhibitor (TFPI), which plays a role in hemostasis and thrombus prevention [2]. - The drug has been approved in the US, EU, Japan, and China for treating severe hemophilia A and B in patients aged 12 and older, weighing at least 35 kg, to reduce bleeding episodes [3]. - Marstacimab is the first subcutaneous injection for hemophilia B that requires administration only once a week and is the first fixed-dose regimen for both hemophilia A and B [3]. Group 2: Regulatory and Market Developments - Pfizer announced the formal approval of Marstacimab in China in November 2025, marking a significant milestone for the drug's market presence [2]. - The new indication for Marstacimab was officially accepted by the CDE, indicating progress in expanding its therapeutic applications [3].