Acute Myeloid Leukemia Drug Granted Second Orphan Drug Status

T-cell immunotherapy enables stem cell transplants using partially mismatched family members as donors.

Acute myeloid leukemia patients unable to find a matched donor for a life-saving stem cell transplant may soon have expanded options for a mismatched donor.

The European Medicines Agency on Thursday granted a second Orphan Drug Designation to Kiadis Pharma’s lead product ATIR. The product is a T-cell immunotherapy that enables stem cell transplants from partially mismatched family members as donors for blood cancer patients who lack a matching stem cell donor.

ATIR was previously granted orphan drug status by the FDA.

"This second Orphan Drug Designation for our lead product ATIR in the European Union represents another very important milestone in the development of our product,” Manfred Ruediger, PhD, chief executive officer of Kiadis Pharma said in a press release. “This, coupled with the previously granted ODDS for ATIR by the FDA and EMA, further highlights our product's importance as a novel approach which may help provide a potentially life-saving transplant from a family member to those patients who otherwise do not find a matched donor in time. In many cases, this will be the only remaining option for these patients."

The T-cells in a mismatched donor graft cause graft-versus-host-disease. ATIR facilitates early immune reconstitution without causing the life-threatening complications.

In earlier studies in which high-risk leukemia patients with poor prognosis received escalating doses of ATIR after a haploidentical stem cell transplant, the drug exhibited long-term safety, efficacy, and proof of concept in terms of the absence of life-threatening acute graft-versus-host-disease.

ATIR also reduced rates of infection, reduced transplant related mortality, and had a high overall survival rate. In 9 patients who received a higher dose of ATIR, follow-up results from the trial showed 78% survival after a year, 67% survival after 5 years, and no transplant related mortality.

An ongoing international multi-center Phase II study is set to include patients with acute myeloid leukemia, acute lymphoblastic leukemia, and myelodysplastic syndrome to corroborate and extend the safety and efficacy results from the earlier studies.

The initial results are expected in the second half of 2014.