ProNAi Therapeutics, Inc., a clinical-stage oncology company advancing novel therapeutics for patients with cancer and hematological diseases, announced that its oncology drug candidate PNT2258 has been granted Orphan Drug Designation by the US Food and Drug Administration (FDA) for the treatment of diffuse large B-cell lymphoma (DLBCL). This is the second orphan drug designation obtained by ProNAi for PNT2258 for the treatment of DLBCL, following a similar grant by the European Commission in August 2015.

"Achieving this regulatory milestone for PNT2258 is an important advancement in our registration-oriented development plan for this cancer drug in DLBCL, a disease for which there are limited treatment options, particularly in patients who relapse or do not respond to front-line therapies." said Dr. Nick Glover, president and CEO of ProNAi.

Orphan drug designation is typically granted for novel drugs or biologics that are intended to treat rare medical diseases or conditions that affect less than 200,000 people in the United States. The designation qualifies the sponsor for certain incentives including seven years of market exclusivity after a drug's approval, tax credits for clinical research costs, and certain application fee waivers.

ProNAi has also previously received European Commission Orphan Drug Designation for PNT2258 for the treatment of patients with DLBCL. In addition to a 10-year period of market exclusivity in the EU following marketing authorization, receiving orphan drug designation provides other incentives for companies, including scientific advice and protocol assistance during the product's development phase.

ProNAi is actively enrolling patients in "Wolverine", a phase 2 trial evaluating PNT2258 for the treatment of relapsed or refractory DLBCL and in "Brighton", a Phase 2 trial evaluating PNT2258 for the treatment of Richter's transformation.

PNT2258 is designed to target cancers that overexpress BCL2, an important and validated oncogene known to be dysregulated in many types of cancer. BCL2 overexpression is thought to be a key driver of DLBCL, an aggressive form of cancer that is the most prevalent form of Non-Hodgkin lymphoma (NHL), comprising approximately 30% of the annual NHL diagnoses in the United States according to the Leukemia & Lymphoma Society (2013).

DLBCL affects mostly middle aged and older adults and is aggressive but potentially curable. First-line treatment of intensive combination chemotherapy involving rituximab may cure approximately 67% of patients. If this fails, second-line treatment is typically platinum-based chemotherapy along with continued rituximab. In the event that a response is achieved with second-line treatment, patients may be given a hematopoietic stem cell transplant. If second-line treatment or the transplant fails, patients are left with few options and little hope of a curative therapy. The median survival for third-line DLBCL patients is less than a year.