Development and characterization of NILK-2301, a novel CEACAM5xCD3 κλ bispecific antibody for immunotherapy of CEACAM5-expressing cancers
Anja Seckinger, Sara Majocchi, Valéry Moine, Lise Nouveau, Hoang Ngoc, Bruno Daubeuf, Ulla Ravn, Nicolas Plèche, Sébastien Calloud, Lucile Broyer, Laura Cons, Adeline Lesnier, Laurence Chatel, Anne Papaioannou, Susana Salgado-Pires, Sebastian Krämer, Ines Gockel, Florian Lordick, Krzysztof Masternak, Yves Poitevin, Giovanni Magistrelli, Pauline Malinge, Limin Shang, Sonja Kallendrusch, K. Strein, Dirk Hose
Abstract
Abstract Background 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). Methods 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). Results 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 ( E max = 89%), MKN-45 ( E max = 84%), and H2122 ( E max = 97%), with EC 50 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. Conclusions 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.