Department of Discovery Biotherapeutics, Bristol Myers Squibb, San Diego, CA, USA.
Oncogenesis Thematic Research Center, Bristol Myers Squibb, San Diego, CA, USA.
MAbs. 2024 Jan-Dec;16(1):2310248. doi: 10.1080/19420862.2024.2310248. Epub 2024 Feb 13.
Cluster of differentiation 47 (CD47) is a transmembrane protein highly expressed in tumor cells that interacts with signal regulatory protein alpha (SIRPα) and triggers a "don't eat me" signal to the macrophage, inhibiting phagocytosis and enabling tumor escape from immunosurveillance. The CD47-SIRPα axis has become an important target for cancer immunotherapy. To date, the advancement of CD47-targeted modalities is hindered by the ubiquitous expression of the target, often leading to rapid drug elimination and hematologic toxicity including anemia. To overcome those challenges a bispecific approach was taken. CC-96673, a humanized IgG1 bispecific antibody co-targeting CD47 and CD20, is designed to bind CD20 with high affinity and CD47 with optimally lowered affinity. As a result of the detuned CD47 affinity, CC-96673 selectively binds to CD20-expressing cells, blocking the interaction of CD47 with SIRPα. This increased selectivity of CC-96673 over monospecific anti-CD47 approaches allows for the use of wild-type IgG1 Fc, which engages activating crystallizable fragment gamma receptors (FcγRs) to fully potentiate macrophages to engulf and destroy CD20 cells, while sparing CD47CD20 normal cells. The combined targeting of anti-CD20 and anti-CD47 results in enhanced anti- tumor activity compared to anti-CD20 targeting antibodies alone. Furthermore, preclinical studies have demonstrated that CC-96673 exhibits acceptable pharmacokinetic properties with a favorable toxicity profile in non-human primates. Collectively, these findings define CC-96673 as a promising CD47 × CD20 bispecific antibody that selectively destroys CD20 cancer cells via enhanced phagocytosis and other effector functions.
CD47(分化群 47)是一种在肿瘤细胞中高度表达的跨膜蛋白,它与信号调节蛋白α(SIRPα)相互作用,向巨噬细胞发出“不要吃我”的信号,抑制吞噬作用,使肿瘤逃避免疫监视。CD47-SIRPα 轴已成为癌症免疫治疗的一个重要靶点。迄今为止,CD47 靶向治疗方法的进展受到靶标的广泛表达的阻碍,通常导致药物快速清除和血液学毒性,包括贫血。为了克服这些挑战,采用了双特异性方法。CC-96673 是一种靶向 CD47 和 CD20 的人源化 IgG1 双特异性抗体,设计为高亲和力结合 CD20 和最佳降低亲和力结合 CD47。由于 CD47 亲和力失调,CC-96673 选择性结合表达 CD20 的细胞,阻断 CD47 与 SIRPα 的相互作用。CC-96673 对单特异性抗 CD47 方法的这种更高选择性允许使用野生型 IgG1 Fc,它与激活的可结晶片段 γ 受体(FcγRs)结合,以充分增强巨噬细胞吞噬和破坏 CD20 细胞的能力,同时保留 CD47CD20 正常细胞。与仅靶向 CD20 的抗体相比,抗 CD20 和抗 CD47 的联合靶向可导致增强的抗肿瘤活性。此外,临床前研究表明,CC-96673 在非人类灵长类动物中具有可接受的药代动力学特性和有利的毒性特征。总之,这些发现定义了 CC-96673 是一种有前途的 CD47×CD20 双特异性抗体,它通过增强吞噬作用和其他效应功能选择性地破坏 CD20 癌细胞。