Arrowhead Pharmaceuticals’ ARO-HSD had its Phase Transition Success Rate (PTSR) increase by five points to 27% in nonalcoholic steatohepatitis (NASH) on the back of positive interim Phase I/II results. The data was presented at the virtual European Association of the Study of the Liver meeting this weekend. PTSR is the probability, given as a percentage, of a drug progressing successfully from one development stage to the next.

ARO-HSD is an RNA interference (RNAi) therapeutic that aims to reduce the mRNA and protein levels of hepatic HSD17B13, which would in turn reduce alanine aminotransferase (ALT ). ALT is a liver enzyme elevated in liver diseases like NASH. In the Phase I/II trial (NCT04202354), in five patients with suspected NASH, their HSD17B13 mRNA was reduced by a mean of 84%, ranging from 62%–96%, as per a 23 June media release. HSD17B13 protein was reduced by at least 83% (abstract no LBP-2580).

The PTSR was updated on 25 June. ARO-HSD’s Likelihood of Approval (LoA) is static at 3%. LoA is identified via GlobalData’s analysis using a combination of machine learning and its proprietary algorithm. It is calculated by compounding the PTSR at each stage the drug is yet to progress through. Both LoA and PTSR can be calculated for a drug by considering characteristics like therapy area, indication and molecule type.

Arrowhead has a $8.97bn market cap.

Reynald Castaneda is an Associate Editor for Clinical Trials Arena parent company GlobalData’s investigative journalism team. A version of this article originally appeared on the Insights module of GlobalData’s Pharmaceutical Intelligence Center. To access more articles like this, visit GlobalData.