New uniQure findings likely to diffuse hemophilia B gene therapy scare

Shares of Netherlands-based gene therapy company uniQure (Nasdaq: QURE) were up more than 9% at $32.00 in pre-market US trading, as the company revealed new evidence regarding a safety scare related to its hemophilia B gene therapy.

uniQure today announced the results of a comprehensive investigation into the case of hepatocellular carcinoma (HCC) diagnosed in one patient in the HOPE-B pivotal trial of etranacogene dezaparvovec.

Multiple analyses conducted by an independent laboratory and reviewed by leading external experts in the field show that AAV vector integration in the patient’s tissue sample was extremely rare and accounted for 0.027% of the cells in the sample. The integration events were distributed randomly across the genome, and there was no evidence of clonal expansion or any dominant integration event. Additionally, whole genome sequencing of the tumor confirmed that the patient had several genetic mutations that are characteristic of HCC and are independent of vector integration. Finally, gene expression analysis of the tumor and adjacent tissue suggested a precancerous state in the liver consistent with several risk factors that predispose this patient to HCC.