The US Food and Drug Administration (FDA) has granted orphan drug designation to ATA230 for the treatment of cytomegalovirus (CMV) viremia and disease in immunocompromised patients.
ATA230 is an allogeneic, cytotoxic T-lymphocyte (CTL) product targeting antigens expressed by CMV.
The product is under investigation in phase 2 trials of patients with CMV viremia and disease who are refractory or resistant to antiviral treatment.
Atara Biotherapeutics, Inc., the company developing ATA230, said it will evaluate development plans for this therapy with the FDA and other global health authorities after beginning phase 3 studies of another product, ATA129.
The company said it decided to prioritize ATA129, which is being developed to treat patients with Epstein-Barr-virus-associated post-transplant lymphoproliferative disorder.
Phase 2 trial of ATA230
Researchers reported phase 2 results with ATA230 at the 2016 ASH Annual Meeting.
The data encompassed 15 patients with documented CMV mutations conferring resistance to antiviral therapies. The patients had received a median of 3 prior therapies.
Eleven of the 15 patients (73.3%) responded to ATA230, 6 with complete responses and 5 with partial responses.
At 6 months, the overall survival was 72.7% in responders and 25% in non-responders.
Within the 6 months of follow-up, 1 of the 11 responders died of CMV, and 3 of the 4 non-responders died of CMV.
Adverse events occurred in 6 patients. One grade 3 event and 1 grade 4 event were considered possibly related to ATA230.
About orphan designation
The FDA grants orphan designation to products intended to treat, diagnose, or prevent diseases/disorders that affect fewer than 200,000 people in the US.
The designation provides incentives for sponsors to develop products for rare diseases. This may include tax credits toward the cost of clinical trials, prescription drug user fee waivers, and 7 years of market exclusivity if the product is approved.