The US Food and Drug Administration (FDA) has granted orphan drug designation to AMV564, a CD33/CD3 bispecific antibody, for the treatment of acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS).
AMV564 is a T-cell engager, derived from human protein sequences, that binds both CD33 and CD3 to mediate T-cell directed lysis of CD33-positive cancer cells.
Amphivena Therapeutics Inc., is currently conducting a phase 1 trial of AMV564 in relapsed or refractory AML. The company plans to launch a phase 1 trial in patients with MDS in early 2018.
According to Amphivena, AMV564 has demonstrated “potent activity” in AML patient samples, and that activity was independent of CD33 expression level, disease stage, and cytogenetic risk.
AMV564 also eliminated nearly all blasts from the bone marrow and spleen in a stringent AML patient-derived xenograft murine model.
In addition, Amphivena established a therapeutic window for AMV564 in cynomolgus monkeys, with rapid and sustained elimination of CD33-expressing cells during AMV564 dosing and rapid hematopoietic recovery following dosing.
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.