Kiadis Pharma N.V., a clinical stage biopharmaceutical company developing innovative T-cell immunotherapy treatments for blood cancers and inherited blood disorders, announced that its lead product, ATIR101, has been granted an expansion to its existing Orphan Drug designation (ODD) by the European Medicines Agency (EMA) to include treatment in a hematopoietic stem cell transplantation (HSCT).

Kiadis Pharma was previously granted an ODD for ATIR101 by both EMA and the United States Food and Drug Administration (FDA) for the prevention of Graft-versus-Host-Disease (GVHD) following an allogeneic HSCT. A further ODD was granted by the FDA for the prevention of Transplant Related Mortality following an allogeneic HSCT and a fourth ODD was granted by EMA for the treatment of acute myeloid leukemia (AML) following an allogeneic HSCT. This latter ODD has now been expanded by EMA to cover all uses of ATIR101 as treatment in HSCT, regardless of the underlying disease.

Manfred Rüdiger, PhD, chief executive officer of Kiadis Pharma, commented, “This expanded Orphan Drug designation in the European Union for our lead product ATIR101 attests to the understanding and belief that ATIR101 could be used in the context of a hematopoietic stem cell transplantation independent of the underlying disease. Therefore its use in, for example, chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML), amongst many other diseases, is now also covered by this newly issued ODD. We believe this extension to the ODD significantly strengthens our value proposition for ATIR101 and will also make this potentially lifesaving therapy available to even more people in desperate need of a transplant.”

The EMA’s ODD is reserved for new therapies being developed to treat life-threatening or chronically debilitating diseases or conditions that are relatively rare in the European Union and for which no satisfactory therapy is available. The ODD designation provides incentives to support development, including fee reductions and a ten-year period of market exclusivity in the European Union after product approval.

For patients suffering from blood cancers, an allogeneic hematopoietic stem cell transplantation (HSCT) is generally regarded as the most effective curative approach. During an HSCT treatment, the bone marrow, harboring the diseased cancer cells, is completely destroyed and subsequently replaced by stem cells in the graft from a healthy donor. After an HSCT treatment it usually takes the patient at least six to twelve months to recover to near-normal blood cell levels and immune cell functions. During this period, the patient is highly vulnerable to infections caused by bacteria, viruses and fungi but also to disease relapse.

ATIR101 (Allodepleted T-cell ImmunotheRapeutics) provides for a safe donor lymphocyte infusion (DLI) from a partially matched (haploidentical) family member without the risk of causing severe Graft-versus-Host-Disease (GVHD). The T-cells in ATIR101 will help fight infections and remaining tumor cells and thereby bridge the time until the immune system has fully re-grown from stem cells in the transplanted graft.

In ATIR101, T-cells that would cause GVHD are eliminated from the donor lymphocytes using Kiadis Pharma’s photodepletion technology, minimizing the risk of GVHD and eliminating the need for prophylactic immune-suppression. At the same time, ATIR101 contains potential cancer killing T-cells from the donor that could eliminate residual cancer cells and help prevent relapse of the disease, known as the Graft-versus-Leukemia (GVL) effect.

Therefore, ATIR101, administered as an adjunctive immuno-therapeutic on top of HSCT, provides the patient with functional, mature immune cells from a partially matched family donor that can fight infections and tumor cells but that do not cause GVHD. ATIR101 thus has the potential to make curative HSCT a viable option to many more patients.

The company estimates that approximately 35% of patients who are eligible and in urgent need of HSCT will not find a matching donor in time. A partially matched (haploidentical) family donor, however, will be available to over 95% of patients.

ATIR101, consisting of donor T-cells that fight infections and residual tumor cells while not eliciting severe GVHD, is designed to result in low relapse rates and low rates of death due to infections, in the absence of severe acute GVHD.