Preclinical Profiles of SKB264, a Novel Anti-TROP2 Antibody Conjugated to Topoisomerase Inhibitor, Demonstrated Promising Antitumor Efficacy Compared to IMMU-132
Overview
Authors
Affiliations
Purpose: The aim of this study was to improve the intratumoral accumulation of an antibody-drug conjugate (ADC) and minimize its off-target toxicity, SKB264, a novel anti-trophoblast antigen 2 (TROP2) ADC that was developed using 2-methylsulfonyl pyrimidine as the linker to conjugate its payload (KL610023), a belotecan-derivative topoisomerase I inhibitor. The preclinical pharmacologic profiles of SKB264 were assessed in this study.
Methods: The and pharmacologic profiles of SKB264, including efficacy, pharmacokinetics-pharmacodynamics (PK-PD), safety, and tissue distribution, were investigated using TROP2-positive cell lines, cell-derived xenograft (CDX), patient-derived xenograft (PDX) models, and cynomolgus monkeys. Moreover, some profiles were compared with IMMU-132.
Results: , SKB264 and SKB264 monoclonal antibody (mAb) had similar internalization abilities and binding affinities to TROP2. After cellular internalization, KL610023 was released and inhibited tumor cell survival. , SKB264 significantly inhibited tumor growth in a dose-dependent manner in both CDX and PDX models. After SKB264 administration, the serum or plasma concentration/exposure of SKB264 (conjugated ADC, number of payload units ≥1), total antibody (Tab, unconjugated and conjugated mAb regardless of the number of the payload units), and KL610023 in cynomolgus monkeys increased proportionally with increasing dosage from 1 to 10 mg/kg. The linker stability of SKB264 was significantly enhanced as shown by prolonged payload half-life (SKB264 . IMMU-132, 56.3 h . 15.5 h). At the same dose, SKB264's exposure in tumor tissue was 4.6-fold higher than that of IMMU-132.
Conclusions: Compared with IMMU-132, the longer half-life of SKB264 had a stronger targeting effect and better antitumor activity, suggesting the better therapeutic potential of SKB264 for treating TROP2-positive tumors.
Development of Antibody-Drug Conjugates for Malignancies of the Uterine Corpus: A Review.
Yamanaka T, Nishikawa T, Yoshida H Cells. 2025; 14(5).
PMID: 40072062 PMC: 11898814. DOI: 10.3390/cells14050333.
Jiang K, Wang S Transl Breast Cancer Res. 2025; 6:9.
PMID: 39980806 PMC: 11836745. DOI: 10.21037/tbcr-24-38.
A novel shark VNAR antibody-based immunotoxin targeting TROP-2 for cancer therapy.
Xi X, Wang Y, An G, Feng S, Zhu Q, Wu Z Acta Pharm Sin B. 2024; 14(11):4806-4818.
PMID: 39664437 PMC: 11628804. DOI: 10.1016/j.apsb.2024.08.023.
Xu J, Liu J, Mei S, Zhou Q Zhongguo Fei Ai Za Zhi. 2024; 27(10):763-776.
PMID: 39631833 PMC: 11629093. DOI: 10.3779/j.issn.1009-3419.2024.101.25.
Antibody-Drug Conjugates: A Start of a New Era in Gynecological Cancers.
Fasih S, Welch S, Lohmann A Curr Oncol. 2024; 31(11):7088-7106.
PMID: 39590153 PMC: 11593302. DOI: 10.3390/curroncol31110522.