Pluristem Therapeutics Inc., a leading developer of placenta-based cell therapy products, announced that the US Food and Drug Administration (FDA) cleared the company’s Investigational New Drug (IND) application to begin its phase I trial of PLX-R18 cells to treat incomplete hematopoietic recovery following hematopoietic cell transplantation (HCT). The clinical trial is expected to begin in the first half of 2016.
PLX-R18 is Pluristem’s second cell therapy product cleared for clinical studies by the US FDA. It has already been studied in preclinical models of acute radiation syndrome, support of hematopoietic cell transplants, and side effects of radiotherapy and chemotherapies used to treat cancers. Preclinical data from trials conducted by the US National Institutes of Health, Hadassah Medical Center, and other prominent research institutions have shown that PLX-R18 cells secrete a range of specific proteins that trigger the resurgence of progenitor cells, supporting the recovery of blood cell counts. By this mechanism of action, PLX-R18 could potentially treat a broad range of hematologic indications.
“The PLX-R18 product is designed to be an entirely new and innovative treatment approach for a wide variety of hematopoietic disorders, and might save the lives of severely ill patients with no alternative treatment options. We are encouraged by the strong pre-clinical data, and intend to pursue early market access in the US for this important clinical indication,” stated Pluristem chairman and CEO, Zami Aberman.
The planned study is a phase 1, multi-center, open-label, dose-escalating study to evaluate the safety of intramuscular injections of PLX-R18 cells in subjects with incomplete hematopoietic recovery following HCT. This study will be conducted in 30 subjects with incomplete hematopoietic recovery persistent for 6 months or more after HCT. There will be three cohorts: 1) 3 subjects receiving two administrations of 1 million PLX-R18 cells/kg each, separated by a 1-week interval; 2) 12 subjects receiving two administrations of 2 million cells/kg each, separated by a 1-week interval; and 3) 15 subjects receiving two administrations of 4 million cells/kg each, separated by a 1-week interval. The follow up period will be 12 months. The primary endpoints will be safety endpoints and will include adverse events, laboratory values and vital signs. Exploratory endpoints will include changes in platelet and hemoglobin levels, changes in transfusion frequency, a shift from transfusion dependence to transfusion independence, quality of life and changes in the serum immunological parameters.
Bone marrow failure is the inability of bone marrow to produce sufficient numbers of platelets, white or red blood cells. This inability may result in serious illness or death, because these cells are necessary to prevent hemorrhage, infection or severe anemia. Bone marrow failure can be caused either by medical conditions such as aplastic anemia, myelodysplastic syndrome, hematologic malignancies, or as a side effect of radiation or chemotherapy cancer treatment. The incidence of bone marrow failure resulting from these conditions varies widely, but is increasing.
The only cure for bone marrow failure is HCT, although supportive therapies and treatments can reduce symptoms and prolong life for some patients. The hematopoietic cells for HCT can come from a donor or from the patient, and can be harvested from peripheral blood, bone marrow or umbilical cord blood. Transplant patients require extensive care and monitoring, and sometimes need intensive treatment for complications. In cases of incomplete engraftment, blood cell counts are insufficient causing the patient to be at high risk of severe or lethal complications. In severe cases the patient may need to undergo the arduous and dangerous process of a second transplant.