The board of directors of Simcere Pharmaceutical Group Limited announced that, on April 9, 2024, Beijing Time, SIM0500 for injection, a humanized GPRC5D-BCMA-CD3 trispecific antibody, which is a new investigational anti-tumor drug independently developed by the Group, has been granted a Fast Track Designation by the U.S. Food and Drug Administration ("FDA") for patients with multiple myeloma, who are refractory to, or intolerant of, established therapies known to provide clinical benefit and have received 3 prior lines of therapy including a proteasome inhibitor (PI), an immunomodulatory agent (IMiD) and an anti-CD38 monoclonal antibody. The FDA Fast Track Designation is an approach to expedite development and review of potential medicines. A drug which is granted Fast Track Designation is intended to treat a serious condition and address unmet medical need, and may be the first therapy for a specific condition, or offer clinically significant advantages over available therapies, or benefit patients who are unresponsive to or intolerant of available therapies.

SIM0500 is a humanized GPRC5D-BCMA-CD3 trispecific antibody, which is a potential best-in-class (BIC) drug for the treatment of multiple myeloma based on the preclinical data. Through the research and development platform of multispecific antibody drugs with the Group's own T-cell engagers, SIM0500 is a tumor-targeted T-cell activating drug, composed with the Group's self-developed CD3 antibody with the feature activated by low affinity and high target activation and the antibody with anti-tumor associated antigen. It has the advantages of excellent tumor-killing effect and good tolerance.

SIM0500 can potentially overcome the drug resistance caused by the existing treatments, and show excellent anti-tumor activity in various animal pharmacodynamic models with different expression levels of BCMA or GPRC5D and has multiple advantages, such as low effective dose and no recurrence of tumors after drug withdrawal. On March 9 and March 12, 2024, the Investigational New Drug (IND) application of SIM0500 has been approved by the FDA and the National Medical Products Administration of China (NMPA), respectively.