Siler H. Panowski

Fig. S2. DLL3 CAR T cells demonstrate specific cytotoxicity against DLL3-positive but not DLL3-negative targets.

Fig. S7. DLL3 CAR T cells demonstrate activity in intracranial tumor model without causing toxicity.

Fig. S4. In vivo activity of DLL3 CAR T cells.

Fig. S6. Infusion of DLL3 CAR T cells did not induce toxicity in non-tumor-bearing model or subcutaneous tumor model.

Fig. S3. DLL3 CAR T cells with rituximab off-switch can be detected by rituximab and eliminated by ADCC.

Fig. S1 DLL3 is expressed in small cell lung tumors, PDX models and cell lines, with limited expression in normal tissue.

Fig. S5. Clone 4 showed pancreatic membrane staining in one of three TCR studies but other derisking studies suggest the staining may be artifactual.

Purpose:Small cell lung cancer (SCLC) is an aggressive disease with limited treatment options. Delta-like ligand 3 (DLL3) is highly expressed on SCLC and several other types of neuroendocrine cancers, with limited normal tissue RNA expression in brain, pituitary, and testis, making it a promising CAR T-cell target for SCLC and other solid tumor indications.Experimental Design:A large panel of anti-DLL3 scFv-based CARs were characterized for both in vitro and in vivo activity. To understand the potential for pituitary and brain toxicity, subcutaneous or intracranial tumors expressing DLL3 were implanted in mice and treated with mouse cross-reactive DLL3 CAR T cells.Results:A subset of CARs demonstrated high sensitivity for targets with low DLL3 density and long-term killing potential in vitro. Infusion of DLL3 CAR T cells led to robust antitumor efficacy, including complete responses, in subcutaneous and systemic SCLC in vivo models. CAR T-cell infiltration into intermediate and posterior pituitary was detected, but no tissue damage in brain or pituitary was observed, and the hormone-secretion function of the pituitary was not ablated.Conclusions:In summary, the preclinical efficacy and safety data presented here support further evaluation of DLL3 CAR T cells as potential clinical candidates for the treatment of SCLC.

Supplementary Figure from Preclinical Development and Evaluation of Allogeneic CAR T Cells Targeting CD70 for the Treatment of Renal Cell Carcinoma