背景:通过CEACAM5xCD3双特异性抗体(BsAbs)进行T细胞重新靶向以消除表达CEACAM5的癌细胞到目前为止显示出有限的临床活性,主要是由于T细胞活化不足,剂量限制毒性,和形成抗药物抗体(ADA)。
方法:我们在此介绍NILK-2301的产生和临床前发展,NILK-2301是一种由共同重链和两条不同轻链组成的BsAb,一个卡帕和一个λ,确定特异性(所谓的κλ体格式)。
结果:NILK-2301通过其λ轻链臂以≈100nM的亲和力与T细胞上的CD3炭黑结合,和CEACAM5A2结构域通过其κ轻链臂在肿瘤细胞上,亲和力约为5nM。FcγR结合被“LALAPA”突变废除(Leu234Ala,Leu235Ala,Pro329Ala)。NILK-2301诱导T细胞活化,扩散,细胞因子释放,CEACAM5阳性肿瘤细胞系的T细胞依赖性细胞毒性(5/5结直肠,2/2胃,2/2肺),例如,SK-CO-1(Emax=89%),MKN-45(Emax=84%),和H2122(Emax=97%),EC50为0.02至0.14nM。NILK-2301既不与CEACAM5阴性或原发性结肠上皮细胞结合,也不与其他CEACAM家族成员结合。NILK-2301单独或与检查点抑制组合在器官型肿瘤组织切片和结肠直肠癌类器官模型中显示活性。在体内,10mg/kg的NILK-2301在结肠和胰腺腺癌模型中显著延迟肿瘤进展。单剂量药代动力学(PK)和耐受性在食蟹猴在0.5或10mg/kg静脉内或20mg皮下显示与剂量成正比的PK,生物利用度≈100%,预计在人类中的半衰期为13.1天。NILK-2301耐受性良好。在人FcRnTG32小鼠中证实了数据。
结论:总之,NILK-2301结合了有希望的临床前活性和安全性,由于其格式与其他分子相比,ADA生成的可能性较低,并计划于2023年底进入临床试验。
T-cell retargeting to eliminate CEACAM5-expressing cancer cells via CEACAM5xCD3 bispecific antibodies (BsAbs) showed limited clinical activity so far, mostly due to insufficient T-cell activation, dose-limiting toxicities, and formation of anti-drug antibodies (ADA).
We present here the generation and preclinical development of NILK-2301, a BsAb composed of a common heavy chain and two different light chains, one kappa and one lambda, determining specificity (so-called κλ body format).
NILK-2301 binds CD3ɛ on T-cells with its lambda light chain arm with an affinity of ≈100 nM, and the CEACAM5 A2 domain on tumor cells by its kappa light chain arm with an affinity of ≈5 nM. FcγR-binding is abrogated by the \"LALAPA\" mutation (Leu234Ala, Leu235Ala, Pro329Ala). NILK-2301 induced T-cell activation, proliferation, cytokine release, and T-cell dependent cellular cytotoxicity of CEACAM5-positive tumor cell lines (5/5 colorectal, 2/2 gastric, 2/2 lung), e.g., SK-CO-1 (Emax = 89%), MKN-45 (Emax = 84%), and H2122 (Emax = 97%), with EC50 ranging from 0.02 to 0.14 nM. NILK-2301 binds neither to CEACAM5-negative or primary colon epithelial cells nor to other CEACAM family members. NILK-2301 alone or in combination with checkpoint inhibition showed activity in organotypic tumor tissue slices and colorectal cancer organoid models. In vivo, NILK-2301 at 10 mg/kg significantly delayed tumor progression in colon- and a pancreatic adenocarcinoma model. Single-dose pharmacokinetics (PK) and tolerability in cynomolgus monkeys at 0.5 or 10 mg/kg intravenously or 20 mg subcutaneously showed dose-proportional PK, bioavailability ≈100%, and a projected half-life in humans of 13.1 days. NILK-2301 was well-tolerated. Data were confirmed in human FcRn TG32 mice.
In summary, NILK-2301 combines promising preclinical activity and safety with lower probability of ADA-generation due to its format compared to other molecules and is scheduled to enter clinical testing at the end of 2023.