Arbutus Biopharma Corporation (NASDAQ:ABUS) has reported on-going positive data from its continuing Phase 1a/1b AB-729 clinical trial. AB-729 is the company’s novel GaINAc delivered RNAi compound.
AB-729 shows a reduction of HBsAg at week-12
New data from the study has shown that a single 90 mg subcutaneous injection of AB-729 resulted in a mean HBsAg reduction of 1.23 log10 IU/mL at 12 weeks. The company’s CEO and President William Collier said that the single dose of 90 mg at 12 weeks combined with the previously announced 60 mg single injection 12-week results indicate that the company now has two doses that have shown considerable HBsAg reductions with favorable tolerability and safety profile. Colliers said that currently, the company is dosing chronic HBV subjects in four multi-dose groups using the 90 mg and 60 mg doses for every 8- and 12-weeks and 4-8 weeks, respectively, to ascertain the correct dosing regimen. He added that they are optimistic that AB-729 will offer chronic HBV patients a potential low-dose treatment well tolerated with fewer injections.
The company is expecting to present preliminary results from the on-going Phase 1a/1b clinical study for the 90 mg single-dose cohorts and 60 mg multi-dose cohorts in positive HBV DNA subjects. They will also release data from the long-term follow-ups of the 90 mg and 60 mg single-dose cohorts at a scientific meeting expected later this year. Besides the current 60 mg multi-dose cohorts in which subjects are doses at 4 weeks and 8 weeks, Arbutus has also commenced 90 mg multi-dose cohorts with dosing of subjects at intervals of 8- and 12-weeks.
Results consistent with previous single-dose cohort results
According to Gaston Picchio, the company’s Chief Development Officer said that the mean HBsAg decline witnessed in the 90 mg single dose group was consistent with what was observed in previous single-dose cohorts. Most important, the data shows consistent efficacy and a favorable safety profile at the intermediate dose. Picchio said that the findings support the company’s on-going evaluation of the 90 mg dose in the multi-dose portion in the on-going clinical trial.