Fig 1: Cytokine release by multiple BsAbs plus T cells and multi-EATs. (A) TH1 cell cytokines (IL-2, IL-6, IL-10, IFN-γ, and TNF-α) were measured in the supernatants after 4 hours of incubation of 5 BsAbs plus T cells or 5 BsAb armed T cells (5BsAbs-EATs) with target cells at increasing doses of each BsAb (0.0003 µg/1×106 cells to 25 µg/1×106 cells). Mixture of multiple cancer cell lines consisting GD2(+) M14Luc, HER2(+) HCC1954, CD33(+) HL60, PSMA(+) LNCaP-AR, and STEAP1(+) TC32 were used as target cells. ET ratio (effector to target cell ratio) was 20:1. (B) In vitro cytokine release of multi-EATs was compared following an increase in the number of BsAb. ET ratio was 20:1, and mixture of multiple cancer cell lines consisting GD2(+) M14Luc, HER2(+) HCC1954, CD33(+) HL60, PSMA(+) LNCaP-AR, and STEAP1(+) TC32 were used as target cells. (C) In vivo TH1 cytokine levels were analyzed 4 hours after second dose of EAT in GD2loHER2lo 143BLuc osteosarcoma cell line xenograft (CDX) mouse model. G1, GD2-BsAb and unarmed T cells; G2, multi-EATs (GD2/HER2/CD33/PSMA/STEAP1-EATs); G3, GD2-EATs; G4, HER2-EATs; G5, unarmed T cells. BsAb dose and T cell number were fixed at 10 µg for each BsAb and 2×107 for T cell per injection. *P<0.05; **P<0.01; ***P<0.001; ****P<0.0001. BsAbs, bispecific antibodies; EATs, ex vivo armed T cells; ET, effector to target; NS, not significant.
Fig 2: In vivo antitumor effect of BC261 against a panel of STEAP1(+) EFT cell line xenografts (CDXs). (A) Ten micrograms of BC261 was administered with 2×107 of T cells twice per week for 2–3 weeks to treat EFT cell line xenografts. Subcutaneous IL-2 (1000 IU) was supplemented with each T cell injection. (B) In vivo antitumor effect of BC261 against EFT TC-71 cell line xenografts. Tumor growth and relative body weight of mice were monitored, and overall survivals were plotted. (C) In vivo antitumor effect of BC261 against EFT SK-ES-1 cell line xenografts. Tumor growth and relative body weight of mice were monitored, and overall survivals were plotted. EFT, Ewing sarcoma family of tumors; STEAP, six-transmembrane epithelial antigen of prostate.
Fig 3: In vivo antitumor effect of STEAP1 bispecific armed T cells. (A) T cells armed with six different formats of STEAP1 BsAb (10 µg of STEAP1 BsAb/2×107 of T cell) were administered to EFT PDX (ES15a) bearing mice. BsAb armed T cells or unarmed T cells were administered on day 0 and day 14, and subcutaneous (sc) IL-2 (1000 IU) was supplemented twice per week. (B) In vivo antitumor effect of six different formats of STEAP1 BsAb armed T cells against EFT PDXs (ES15a) and relative body weight of mice after treatment. (C) T cells were armed with six different formats of STEAP1 BsAb (10 µg of STEAP1 BsAb/2×107 of T cell) and tested for in vivo efficacy against different EFT PDXs (ES3a). BsAb armed T cells or unarmed T cells were administered on day 0 and day 4, and SC IL-2 was supplemented twice per week. (D) In vivo antitumor effect of six different formats of STEAP1 BsAb armed T cells against EFT PDX (ES3a) and relative body weight of mice after treatment. EFT, Ewing sarcoma family of tumors; PDXs, patient-derived tumor xenografts; STEAP, six-transmembrane epithelial antigen of prostate.
Fig 4: Antitumor activities of anti-STEAP1 T cell-engaging bispecific antibody. (A) Schematic representation of the six structural formats of STEAP1 BsAb.35 (B) Antibody-dependent T cell-mediated cytotoxicity (ADTC) assay against EFT cell lines (Tc32 ad TC71) using different formats of STEAP1 BsAb. Effector to target cell ratio (ET ratio) was 10:1. (C) Bioluminescence imaging (BLI) of Luc(+) T cells armed with six different formats of STEAP1 BsAb on (a) day 6 and (b) day 18 post treatment and quantitation of bioluminescence intensity in the lesions of tumor. Luciferase transduced T cells (Luc(+) T cells) were armed with various formats of STEAP1 BsAb (10 µg of STEAP1 BsAb/2×107 of T cells) and administered with supplementary IL-2 (1000) IU/dose) to the mice bearing EFT PDXs (ES15a), and the BLIs were followed. (D) TC32 EFT cell line xenografts were harvested on day 7 after two doses of STEAP1 BsAb armed T cell treatment (10 µg of BsAb/2×107 T cells/dose). Paraffin-embedded tumor sections were stained with CD3 (x10): a, no treatment; b, control BsAb; c, BC328; d, BC329; e, BC330; f, BC261; g, BC365; h, HD148. EFT, Ewing sarcoma family of tumors; PDXs, patient-derived tumor xenografts; STEAP, six-transmembrane epithelial antigen of prostate.
Fig 5: In vivo antitumor effect of BC261 against STEAP1(+) prostate cancers. (A) Ten micrograms of BC261 was administered with 2×107 of T cells twice per week for 2–3 weeks to treat prostate cancer PDXs. Subcutaneous IL-2 (1000 IU) was supplemented with each T cell injection. (B) In vivo antitumor effect of BC261 against prostate cancer PDX TM00298. (C) In vivo antitumor effect of BC261 against prostate cancer PDX J000077451. Tumor growth, relative body weight, and overall survival after treatment were plotted and compared. PDXs, patient-derived tumor xenografts; STEAP, six-transmembrane epithelial antigen of prostate.
Supplier Page from BioLegend for LEGENDplex™ HU Th1 Panel (5-plex) w/ FP V02