Animal model or human cells: efficacy evidence for approved bispecifics

“In vivo, zenocutuzumab showed antitumor activity in a HER2-positive breast cancer cell line xenograft model, which was associated with inhibition of HER2:HER3 dimerization and PI3K/Akt signaling.”

“Table 1. Summary of in vivo studies in NOD/SCID mice xenograft models”

“Blinatumomab bound to B and T lymphocytes from human and chimpanzee peripheral blood mononuclear cells (PBMC) but it did not bind to PBMC from the mouse, rat, beagle dog, squirrel monkey, African Green monkey, cynomolgus monkey, rhesus monkey, and baboon.”

“In vivo activity was investigated in both non-tumor bearing HSC-NOG mice and in tumor-bearing HSG-NOG and HSG-NSG mice.”

“The choice of the cynomolgus monkey as the pharmacological and toxicological species is considered justified as comparable cross-reactivity is observed between human and monkey B cells while no cross-reactivity is observed for rodent, dog or minipig CD20 or CD3ε.”

“The anti-tumor activity of elranatamab was evaluated in MM xenograft models (with MM.1S, OPM2, and MOLP8 cell lines) that had varying levels of BCMA expression.”

“The in vivo antitumor activity of epcoritamab was evaluated in various human lymphoma cell line-derived xenograft (CDX) mouse models and in one patient-derived xenograft (PDX) mouse model.”

“Epcoritamab bound a cell line transfected with rabbit CD20 (KD=6.93 nM), but did not bind cells expressing dog, pig, rat, or mouse CD20 under the conditions tested.”

“The in vivo pharmacological effects of emicizumab were assessed in cynomolgus monkey models of acute and chronic hemophilia A as described below.”

“In an enzyme assay using purified Cynomolgus monkey, rat and mouse FIXa and FX, emicizumab was found to cross-react only with the corresponding clotting factors of Cynomolgus monkeys.”

“As tarlatamab does not cross-react to mouse CD3, the xenograft models used in the nonclinical pharmacology studies were conducted in immunocompromised mice (non-obese diabetic/severe combined immunodeficiency, interleukin 2 receptor gamma [NSG]) that were injected with activated, expanded human T cells before treatment with tarlatamab.”

“Because tarlatamab does not bind mouse CD3, the in vivo anti-tumor activity of tarlatamab was evaluated using immunodeficient mice administered human PBMCs or T cells by IV infusion prior to treatment with tarlatamab.”

“In vivo, the anti‐tumor activity of tebentafusp was evaluated in mice engrafted with HLA‐A*02:01/gp100‐positive Mel526 human melanoma cancer cells mixed with PBMCs isolated from human whole blood. In this study, administration of 5 doses of tebentafusp resulted in tumor growth inhibition compared to controls.”

“Since, tebentafusp is specific for human gp100 and CD3 with no affinity to e.g. monkey, rat or mice, secondary and safety pharmacology was evaluated using in vitro methods on human tissues and cells..”

“In vivo pharmacology of catumaxomab was investigated in a xenograft model of malignant ascites in immuno-deficient SCID mice. Mice received a human ovarian carcinoma xenograft i.p. and were treated one day later with human PBMCs (i.p.) together with a single i.p. injection of catumaxomab.”

“Due to the lack of catumaxomab reactivity with murine CD3, the variant antibody BiLu (anti-human EpCAM & anti-mouse CD3) was used to demonstrate proof of concept in syngeneic mouse tumour models expressing human EpCAM.”

“In vivo studies were performed to evaluate the anti-tumor efficacy and minimum effective dose of linvoseltamab in immunodeficient NSG mice SC co-implanted with human PBMC and either NCI-H929 (BCMA-high) or MOLP-8 (BCMA-low) MM cells.”

“Overall, data indicate that linvoseltamab bound human and Cynomolgus monkey BCMA, but not rat or mouse BCMA.”

“The applicant has submitted 3 in vivo studies utilising two in vivo mouse models, consisting of humanized (BRG) mice and immunodeficient NSG mice, to evaluate antitumour activities of odronextamab in a repeat-dose setting.”

“Odronextamab was not able to bind to rat or mouse CD3 or CD20.”

“The variant antibody BiLu (anti-human EpCAM & anti-mouse CD3) was used to demonstrate proof of concept in a syngeneic mouse tumour model expressing human EpCAM. Anti-tumour activity of catumaxomab was observed in a human ovarian carcinoma xenograft study.”

“The non-clinical programme was adapted to the fact that catumaxomab is a protein, and its binding properties are essentially specific for humans.”

“In mice bearing patient derived tumors with exon 20 insertion mutations, administration of intraperitoneal (i.p.) amivantamab twice weekly resulted in significant tumor growth inhibition and complete responses in several animals, as did cetuximab and osimertinib.”

“For the pharmacology efficacy studies, mouse models with human cell xenografts were used, and Amivantamab did not exhibit any interaction with murine c-Met or EGFR in cross-reactivity studies while beneficial properties against human c-Met or EGFR have been shown, which is satisfactory.”

“The in vivo antitumor activity of talquetamab was evaluated in cell line-derived xenograft (CDX) mouse models. These studies evaluated the prevention of tumorigenesis in a prophylactic model (H929 cell line) and tumor growth inhibition (TGI) in established tumor models (MM.1S and RPMI 8226 cell lines).”

“Talquetamab does not bind murine CD3; therefore, the CDX studies were conducted in immunodeficient mice that were humanized by intravenous (IV) implantation of human peripheral blood mononuclear cells (PBMCs) or human T-cells.”

“Teclistamab conferred dose-dependent antitumor activity in both xenograft mouse models of MM.”

“Teclistamab binds only weakly to rodent BCMA and does not cross-react with rodent or rabbit CD3.”

“In a laser-induced model of choroidal neovascularization (CNV) in cynomolgus monkeys, faricimab reduced the formation of CNV and subsequent injury to the retina due to lesion formation to a significantly greater degree compared to anti-VEGF-A monoclonal antibody (mAb) alone.”

“An alternative rodent model for DME was not tested because the antibody in question reacts with human VEGF-A antigen and not with rodent, so classical animal models of diabetes could not work according to the applicant.”

“In a third assay, the antitumour activity of a single high dose level of zanidatamab was evaluated in GXA 3054, a patient-derived HER2 3+ gastric cancer xenograft model in nude mice (ZW25-29).”

“In the double-transgenic mouse model, it was also shown that 2H7v16/40G5c and mosunetuzumab have comparable profiles in potently depleting peripheral and tissue B cells as well as activation of T cells.”

“2H7v16/40G5c displays the same properties as mosunetuzumab, as it cross-reacts with CD20 and CD3 in both humans and cynomolgus monkeys, but not in rodents.”