The U.S. Food & Drug Administration (FDA) has granted Orphan Drug Designation to PRGN-3006 for the treatment of patients with relapsed or refractory (RR) acute myeloid leukemia (AML).1,2 PRGN-3006 is an investigational therapy which uses a proprietary UltraCAR-T™ therapeutic platform to reduce the time to manufacture chimeric antigen receptor (CAR) T cells, enabling the administration of CAR T cells one day after non-viral gene transfer. PRGN-3006 UltraCAR-T is a multigenic CAR T-cell product, co-expressing a CD33 CAR and membrane-bound interleukin-15 (mbIL15), together with a ‘kill switch’. CD33 CAR precisely targets malignant cells expressing CD33, while expression of mbIL15 allows the elimination of ex vivo expansion of T cells prior to cell administration. The kill switch provides a mechanism for selective depletion of PRGN-3006 post-administration in order to improve therapeutic control. There is an ongoing trial of PRGN-3006 (NCT03927261), in patients with RR AML and high-risk myelodysplastic syndromes, which has completed enrolment of the first cohort and initial data is expected later this year. Preclinical data on PRGN-3006 were presented at the 61st American Society for Hematology Annual Meeting & Exposition, in Orlando, US.3
Orphan drug status is granted to medicines aimed at treating, detecting or preventing rare diseases or disorders affecting < 200,000 people in the US. This status grants certain incentives such as a seven-year exclusivity marketing period, applications for funding for phase I and II clinical trials, reduced market application filing fees and rapid regulatory processing later on.