Nader El-Sayes, PhD

Recruited to the company with a charter to execute all of Clade’s in vivo studies to characterize the efficacy, biodistribution, and pharmacokinetic properties of Clade’s iPSC-derived CAR-T cells in models of multiple myeloma and acute myeloid leukemia. Responsibilities included assay development for analysis of ex vivo samples, execution of in vivo studies and model development, CRO management and tech transfer, processing and analysis of ex vivo samples, in vitro characterization of CAR-T efficacy and phenotype, coordination with other groups including Differentiation, T cell biology, Analytical Development, and Process Development. Key Accomplishments: ▪ Developed and utilized in vitro and ex vivo assays such as ddPCR, multi-color flow cytometry (20+ colors), ELISA, and cell-based assays to support mechanism of action and biomarker studies. ▪ Conceived, designed, and supported the execution of CDX in vivo efficacy studies and CDX in vivo model development studies. ▪ Independently served as point of contact to multiple CROs for preparation of SOWs, experimental design, coordination of sample delivery/processing, and analysis of data. ▪ Support in vitro characterization of CAR-T cells by executing cell-based cytotoxicity, activation, and proliferation assays. ▪ Experienced in purification, activation, and expansion of human T cells and supported the production of CAR-T cells. ▪ Effectively liaised with other teams to coordinate studies and align on research priorities/study designs. ▪ Independently generated and analyzed key decisional data that heavily influenced research priorities and go/no-go decisions.

Recruited to the company with a charter to contribute to lead selection for advancing SQZ biotech’s Tumor Infiltrating Lymphocyte (TIL) program for use in solid tumor indications by designing, planning, and executing in vitro and in vivo studies. Responsibilities included designing siRNA and mRNA constructs for use as T cell enhancements, utilization of molecular biology assays to validate enhancements, developing assays and models for in vitro and in vivo characterization of TIL efficacy. Key Accomplishments: ▪ Developed in vivo PDX tumor models of melanoma, lung cancer, and gastrointestinal cancers from patient tumor samples. ▪ Executed in vivo studies in PDX tumor models for characterization of TIL efficacy, pharmacokinetics . ▪ Isolated primary tumor cells from patient tumor samples for use in cell-based coculture assays with autologous T cells. ▪ Designed siRNA and mRNA constructs to be used as T cell enhancements (knockdown of inhibitory T cells pathways with siRNA and expression of membrane-bound cytokines for T cell enhancement). ▪ Developed molecular assays including western blots, qRT-PCR, and flow cytometry to validate mRNA expression or siRNA knockdown of molecular targets in T cells. ▪ Established cell-based assays, ELISA, and multi-color flow cytometry to functionally characterize molecular enhancements in T cells. ▪ Processed animal tissue for subsequent analysis of samples by multi-color flow cytometry. ▪ Contributed data and supported filing of patent application. ▪ Independently generated and analyzed key decisional data that heavily influenced research priorities and go/no-go decisions.

Research focus on sensitizing resistant tumors to therapy by utilizing a combination of chemotherapy and oncolytic virus therapy, with a focus on understanding mechanism of action and characterizing immune cell interactions in the tumor microenvironment. Key Accomplishments: ▪ Characterized the mechanism of action of the combination therapy and identified relevant dendritic cell populations that drive therapeutic outcomes. ▪ Characterized phenotype, antigen specificity, and activity of T cells in the tumor microenvironment. ▪ Identified tumor mechanisms of resistance to T-cells through IFN-α mediated immunosuppression. ▪ Utilized in vivo syngeneic murine tumor models to study mechanisms of resistance to immunotherapy. ▪ Experienced with several in vivo dosing routes, in-life and terminal blood collection, necropsy, and tissue processing. ▪ Utilized a variety of assays and techniques, including western blots, multi-color flow cytometry, qRT-PCR, ELISA, CRISPR/Cas9, and cell-based assays. ▪ Experienced with virus production, isolation, and quantification. ▪ Published findings in relevant scientific journals as first author on two research articles. ▪ Contributed data to 17 other research articles published in scientific journals, and 1 patent application.

Laboratory of Dr. Jean-Simon Diallo Characterization of small molecule enhancers of oncolytic virus (OV) therapy, termed Viral Sensitizers. Identification of the mechanism of action of viral sensitizers for the development of improved enhancers of OV therapy.