Conditioning Agent (JSP191) For Stem Cell Transplants Shows Promise in Patients With Fanconi Anemia
Ronald Martell, President, and CEO of Jasper Therapeutics, discusses the positive data from the ongoing phase 1/2 study testing JSP191 as a conditioning agent in the treatment of Fanconi anemia. These data were presented at the annual conference of the Inborn Errors Working Party (IEWP) Annual Conference 2022.
Fanconi anemia is a rare blood disorder often associated with a progressive deficiency of all bone marrow production of blood cells, red blood cells, white blood cells, and platelets. The disorder can also cause the bone marrow to make abnormal blood cells. It is usually inherited as an autosomal recessive genetic disorder, but X-linked inheritance is also possible. Birth defects, such as small size, abnormal thumbs and/or radial bones, skin pigmentation, small heads, small eyes, abnormal kidney structures, and cardiac and skeletal anomalies, can aid early diagnoses. Individuals with Fanconi anemia have an increased risk of developing acute myeloid leukemia (AML), or tumors of the head, neck, skin, gastrointestinal system, or genital tract. Treatment of Fanconi anemia may include blood transfusions or medication to create more red blood cells, but a hematopoietic stem cell transplant (HSCT) is the only curative option. However, HSCT usually requires the patient to undergo chemotherapy to eliminate their own stem cells before receiving the foreign, healthy stem cells. In addition, graft-versus-host disease is a concern with HSCT.
As Mr. Martell explains, data from the company’s study testing JSP191 as a conditioning agent prior to transplant in patients with Fanconi anemia were presented at IEWP 2022. JSP191 is a conditioning agent designed to block stem cell factor receptor signaling to create an environment for transplanted stem cells to engraft.
The study is a phase 1/2 clinical trial using JSP191 to treat Fanconi anemia patients who are in bone marrow failure and require allogeneic transplant from non-sibling donors. The objective of the study is to develop cell therapy for Fanconi anemia which enables enhanced donor hematopoietic and immune reconstitution with decreased toxicity by transplanting TCR ab+ T-cell/CD19+ B-cell depleted stem cells from a donor, after using JSP191 as a part of conditioning. One of the primary outcome measures is the number of patients without treatment-emergent adverse events following the administration of JSP191.
As Mr. Martell states, the data presented was from the first two patients with Fanconi anemia who received JSP191. The data demonstrated that 100% complete donor chimerism was achieved through six months for the first patient and at one month for the second patient. Neutrophil engraftment was reached on day 11 for both patients and platelet engraftment was achieved on days 9 and 14. JSP191 was cleared by day 9 after dosing and no treatment-related adverse events or toxicities were observed.
Overall, these data suggest that a conditioning regimen that includes JSP191 has the potential to achieve successful donor transplant with minimal JSP191-related adverse events.
To learn more about Fanconi anemia and other rare blood disorders, visit checkrare.com/diseases/blood-diseases/
