What happened
Shares of Arbutus Biopharma (ABUS -0.26%) were trading down by 12.6% as of 11:04 a.m. ET Tuesday. The decline came after the company announced that the Food and Drug Administration (FDA) had placed a clinical hold on its Investigational New Drug (IND) application for AB-101, its experimental chronic hepatitis B virus therapy.
So what
It's unknown at this point exactly why the FDA placed the clinical hold on AB-101. The clinical-stage biopharmaceutical company said that the FDA indicated that it would send an official letter with more details within 30 days.
The company had hoped to advance the oral PD-L1 inhibitor into phase 1 clinical testing quickly enough to report initial data on it in the second half of 2023. Arbutus said it no longer expects to meet that timeline.
This FDA decision put a speed bump in Arbutus' path after what had up until that point been a great year. The biotech stock was up 24% year to date prior to Tuesday's announcement.
Arbutus presented positive preclinical data for experimental COVID-19 therapy AB-343 at the International Conference on Antiviral Research in March. It also dosed the first patient in a phase 1 study evaluating AB-161, an experimental oral therapy that holds the potential to provide a functional cure for patients infected by the hepatitis B virus.
Now what
There should be plenty of developments for investors to watch with Arbutus in the coming months. The company expects to report data from its phase 1 study of AB-161 in the second half of 2023. It also plans to announce preliminary results from a phase 2a study evaluating AB-729, a nucleoside/nucleotide analog therapy, and Vaccitech's VTP-300 in treating hepatitis B virus in the second half of the year as well.
