Final analysis of SCORES, a phase III randomized, double-blinded, placebo-controlled study of suvemcitug combined with chemotherapy for platinum-resistant ovarian cancer.

5554 Background: At the SCORES interim analysis, suvemcitug (a recombinant humanized anti-VEGF rabbit monoclonal antibody) plus chemotherapy demonstrated a significant improvement of progression free survival (PFS) compared with single-agent chemotherapy (CT) in patients with platinum-resistant Ovarian Cancer (PROC). Here we present the preplanned final analysis of OS for the SCORES along with the updating analysis of safety, PFS, and other endpoints. Methods: This randomized, double-blind, placebo-controlled, phase 3 trial (SCORES) conducted at 55 centers in China enrolled women with histologically-confirmed epithelial ovarian, fallopian tube or primary peritoneal cancer. Patients were required to have platinum- resistant or refractory disease with at least one measurable lesion. Eligible patients were randomly assigned (2:1) to either Suvemcitug (1.5 mg/kg q2w) or placebo combined with investigators chose CT (weekly paclitaxel, topotecan or pegylated liposomal doxorubicin) until progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS) by blinded independent review committee (BIRC) according to the RECIST 1.1. And the key secondary endpoint is the overall survival (OS). Results: Between June 5, 2021 and October 11, 2024, 421 patients were enrolled. At the data cutoff for the final analysis (October 11, 2024), the median follow-up duration was 23.7 and 23.4 months for the suvemcitug arm and the placebo arm. A total of 279 OS events (66.3%) occurred, the median OS was 15.31 months versus 14.03 months (stratified hazard ratio, 0.768; 95% CI, 0.595-0.991; P = 0.0304). Suvemcitug plus chemotherapy led to a significant improvement of OS versus placebo plus chemotherapy, with a 23% reduction in the risk of death and a more than 10% improvement of the 24-month OS rate (33.0% vs 22.3%). The efficacy results are summarized below. The most common grade ≥ 3 TEAEs (treatment-emergent adverse events) in suvemcitug arm included neutrophil count decreased, white blood cell count decreased, and hypertension. No Suvemcitug-related grade 5 TEAE occurred. Conclusions: The addition of suvemcitug to chemotherapy significantly improved the outcomes of patients with PROC with manageable toxicities. To the best of our knowledge, this is the first phase III study demonstrated a significant OS benefit of anti-angiogenic agent in patients with PROC. Clinical trial information: NCT04908787 . Suvemcitug + CT(N = 281) Placebo+CT(N = 140) OS, month (95% CI) 15.31 (13.73,17.81) 14.03 (11.27,16.56) Hazard Ratio (95% CI) 0.768 (0.595,0.991) P value (rerandomization log-rank) 0.0304 24-month OS rate, % (95% CI) 33.0 (26.8-39.2) 22.3 (14.8-30.8) Median PFS by BIRC, month (95% CI) 5.49 (4.93,6.64) 2.73 (1.94,3.75) Median PFS by investigator, month (95% CI) 5.39 (4.80,5.59) 2.46 (1.94,3.65) ORR by BIRC, % 26.0 12.1 DCR by BIRC, % 76.5 49.3