Our Therapeutic Pipeline

Our therapeutic pipeline includes novel gene therapies for hemophilia A and B, neuroblastoma, hemophagocytic lymphohistiocytosis (HLH), T cell leukemia/lymphoma, and acute myeloid leukemia (AML).  

Gene therapy can be defined as the use of nucleic acids (DNA/RNA) as pharmaceutical agents to induce therapeutic gene/protein expression in a patient. Vectors are the vehicles used to transfer the genetic material to the patient. We work with recombinant Lentivirus (LV) and Adeno-associated Virus (AAV) derived vectors as our gene therapy vehicles.

Expression used in the context of gene therapy applies to the entire process of converting a nucleic acid (i.e. a transgene cassette) delivered to a target cell into a functional protein that confers therapeutic benefit to the patient. This process includes transcription of the transgene DNA into messenger RNA, translation of messenger RNA into protein and trafficking of the therapeutic protein to its site of function, which could be inside the cell, on the surface of the cell, or outside the cell (e.g. into the bloodstream). Expression Therapeutics utilizes an integrated expression-focused engineering platform that facilitates custom tailoring of each gene therapy for its specific therapeutic application.  

Hemophilia A and B are inherited bleeding disorders caused by the deficiency of blood clotting factor VIII (FVIII) or factor IX (FIX). Without treatment, severe hemophilia is crippling and fatal by late adolescence to early adulthood. Existing treatment consists of FVIII or FIX infusion products that are administered under intensive regimens involving intravenous infusion several times a week. Expression Therapeutics is developing gene therapies for both hemophilia A and B.

Our lead product for hemophilia A is an ex vivo hematopoietic stem cell (HSC) LV gene therapy that works with cells derived from the patient (“autologous” cells). For this therapy, white blood cells are harvested from the blood of a patient through a process called apheresis. Then, in the laboratory, hematopoietic (blood) stem and progenitor cells are enriched through a process termed CD34+ selection. Subsequently, the CD34+ cells are genetically-modified (transduced) using our proprietary LV-FVIII vector and then transplanted back into the patient via a simple peripheral vein infusion. The CD68-ET3-LV CD34+ cell product functions by engrafting back into the stem cell compartment within the bone marrow and resuming its normal function of blood cell production. Following the genetic modification procedure, these millions of daughter blood cells now provide a continuous supply of functional FVIII to the bloodstream. We are also pursuing an in vivo AAV-FVIII gene therapy in collaboration with another biotechnology firm and an in vivo AAV-FIX gene therapy in house at Expression Therapeutics.


Neuroblastoma is a type of childhood cancer that often originates from one of the adrenal glands and has usually already spread at the time of diagnosis. Neuroblastoma overwhelmingly occurs in children under 5 years of age. Long term survival rates for children who fall into a “high-risk” version of this disease are less than 40 percent, despite aggressive treatment with high-dose chemotherapy, surgery, radiation, or immunotherapy.  Expression Therapeutics is developing a gamma delta (γδ) T cell therapy that, when used in conjunction with existing protein immunotherapeutics, would effectively target neuroblastoma tumor cells.     

Hemophagocytic lymphohistiocytosis (HLH) is a devastating immune disorder in which the activated immune cells accumulate and attack other blood cells. There are two forms of the disorder: familial and acquired. Currently, treatment options are limited, and the long-term outlook remains poor. Expression Therapeutics is developing autologous gene therapy for HLH that incorporates LV gene transfer of expression optimized HLH transgenes. This mode of therapy has the potential to provide a lifelong cure to patients and families who otherwise have little hope.

Chimeric antigen receptor (CAR) T cell therapies are demonstrating success in the treatment of B cell cancers. However, the adaptation of this platform to other liquid and solid tumors has proven more challenging. Expression Therapeutics has developed novel gene therapy strategies to overcome these challenges utilizing AAV-based gene transfer, novel CAR-designs and γδ T cells. The initial indications include T-cell leukemia/lymphoma and acute myeloid leukemia (AML).

Organ System Indication Gene Therapy Platform Discovery IND-Enabling IND Approval Phase 1/2 Clinical
Blood Hemophilia A LV - HSC
Hemophilia A *AAV - Liver
Hemophilia B AAV - Liver
Nervous Neuroblastoma γδ-T cell
Immune Hermophagocytic Lymphohistiocytosis LV - HSC
Acute Myeloid Leukemia LV - T cell
T-Cell Leukemia/Lymphoma AAV - γδ-T cell