The board of directors of Simcere Pharmaceutical Group Limited announced that, on June 1, 2024, the latest data of the phase III clinical trial of ENZESHU (Suvemcitug for injection) combined with chemotherapy (the "Experimental Arm") versus placebo combined with chemotherapy (the "Control Arm") in patients with recurrent, platinum-resistant epithelial ovarian, fallopian tube or primary peritoneal cancer (the "SCORES Study") were presented through an oral report of the late-breaking abstract at the American Society of Clinical Oncology (ASCO) Annual Meeting. The study data demonstrated that: As assessed by the Blinded Independent Review Committee (the "BIRC"), among the full analysis population (that is intent-to-treat population, ITT), the progression-free survival (the "PFS") of the Experimental Arm was significantly extended compared to the Control Arm (the median PFS: 5.49 months versus. 2.73 months, hazard ratio [HR] 0.46, P<0.0001). Across all pre-defined subgroups (age, ECOG score, presence of ascites, sum of the diameters of baseline target lesions, number of prior lines of therapy, platinum-free interval, number of prior systemic therapies, presence of prior anti-angiogenic therapy, platinum refractory and combination chemotherapy regimen by investigator's choice), positive results and significant improvements in PFS were observed in efficacy analyses. Among the 421 subjects enrolled in the SCORES Study, 50.1% has been treated with VEGF pathway-targeted therapy previously and 48.9% has been treated with PARP inhibitors previously, which was in line with the characteristics of the distribution of frontline treatments in current clinical practices. The study results suggested that, among the population with prior use of VEGF and/or PARP inhibitors, suvemcitug in combination with chemotherapy can improve the PFS of patients significantly. As of the analysis date of primary endpoint, the data of overall survival (the "OS") as the key secondary endpoint were immature and the median follow-up duration of the two groups was 14.36 months and 14.26 months, respectively. The results suggested
that, the OS of the Experimental Arm has shown a trend of benefit compared to the Control Arm (the median OS: 16.07 months vs. 14.88 months, hazard ratio [HR] 0.79, P=0.1244). Among other secondary efficacy endpoints, the data of the Experimental Arm compared to the Control Arm demonstrated that: the median PFS assessed by investigators was 5.39 months vs. 2.46 months, the objective response rates (the "ORR") as assessed by the BIRC was 26.0% vs. 12.1%, the ORR as assessed by the investigators was 23.1% vs. 8.6%, and the DCR and DOR as assessed by the BIRC and investigators have also shown
consistent benefits. Suvemcitug in combination with chemotherapy has a good overall safety profile, and there is no new safety signals compared to the other drugs of the same class. The SCORES Study is a multi-center, randomized, double-blinded and
placebo-controlled phase III clinical trial in China to evaluate the efficacy and safety of ENZESHU (Suvemcitug for injection) in combination with investigator's choice of chemotherapy (paclitaxel, liposomal doxorubicin or topotecan) in the treatment of
platinum-resistant ovarian cancer (the "PROC") as compared with placebo in combination with chemotherapy. The SCORES Study is led by the Cancer Hospital Chinese Academy of Medical Sciences, and has enrolled 421 patients with recurrent epithelial ovarian cancer, fallopian tube cancer and primary peritoneal cancer who failed to be treated with platinum chemotherapy regimen at 55 study sites in China from June 2021 to June 2023. On January 3, 2024, the SCORES Study met its primary endpoint PFS. Suvemcitug is a new-generation recombinant humanized anti-VEGF rabbit monoclonal antibody developed by the Group and Apexigen Inc. Pre-clinical studies have shown that suvemcitug has higher affinity and anti-tumor efficacy than Bevacizumab at the same dose in multiple tumor models. The phase Ib clinical studies of suvemcitug conducted in China for the treatment of ovarian cancer preliminary demonstrated its favorable safety profile and efficacy signals. On March 15,
2024, the New Drug Application of suvemcitug for injection was accepted by the National Medical Products Administration of China (NMPA). The indication is suvemcitug combined with chemotherapy for the treatment of recurrent platinum-resistant ovarian, fallopian tube or primary peritoneal cancer. It is expected to provide a new treatment option for PROC, which
is a long-standing disease that seriously threatens women's lives and health.