OTL-103 is in clinical development for the treatment of Wiskott-Aldrich syndrome (WAS). WAS is a rare disease with immunological deficiency and reduced ability to form blood clots. This syndrome is caused by an abnormality in the gene found on the X chromosome that codes for WAS protein (WASP). This WAS gene defect and the severity of the condition varies widely between individuals. Severe cases may be present soon after birth or develop in the first year of life. WAS affects the functions of white blood cells and platelets, making people affected susceptible to serious infections and bleeding events. WAS occur almost exclusively in males. It is life-threatening and long-term debilitating disease due to recurrent infections that can lead to sepsis, bleeding episodes and cancer. Stem cell transplantation is the only treatment currently available to stabilize WAS.
OTL-103 is administered intravenously. It is made up of immature bone marrow cells (called CD34+ cells) taken from the patient. It works by correcting cells using a modified virus that contains the correct gene for the WAS protein. When these corrected cells are transplanted back into the patient, they populate the bone marrow and produce healthy platelets and immune cells that produce the WAS protein, thereby relieving the symptoms of the disease. If licensed, OTL-103 will provide a treatment option for patients with WAS.
Imetelstat is in clinical development for the treatment of relapsed/refractory low or intermediate-1 risk myelodysplastic syndrome (MDS) in transfusion-dependent patients, following erythropoiesis-stimulating agent (ESA) treatment. MDS are a group of disorders in which red blood cells, white blood cells, and platelets produced by the bone marrow do not grow and mature normally. MDS are long-term debilitating and life-threatening diseases. MDS patients may require repeated blood transfusions and currently have few treatment options.