William Collier
Analyst · Chardan. Your line is now open
Thank you very much, Pam, and thank you, everyone, for joining us today. As I stated on our AB-506 call just a few weeks ago, as the new President and CEO of Arbutus, I really look forward to working with all of you.Now we appreciate that this is a very busy time for many of you, and so we're going to try and keep this call succinct as our objective remains unchanged, and that is to improve upon the existing standard of care in hepatitis B by developing a curative combination regimen that includes several different mechanisms of action.Currently, we're intensively focused on advancing our 2 lead compounds, AB-506 and AB-729, through Phase Ia/Ib trial and then moving into a combination proof-of-concept trial in subject with chronic hepatitis B in the second half of 2020.First, let me comment regarding AB-729. We've now initiated dosing in the healthy subject portion of the Phase Ia/Ib clinical trial. This will be followed by several single-dose cohort in chronic hepatitis B subject, and we intend to report preliminary safety and efficacy results from this portion of the Phase Ia/Ib clinical trial in the first quarter of 2020.Secondly, regarding the preliminary Phase Ia/Ib clinical trial results that we described in a press release and conference call on July 15 for AB-506, we believe these results demonstrate that this compound is a potent captive inhibitor, and we invite you to visit the company's website at www.arbutusbio.com to view the full press release and the recording of the conference call.But just to recap, mean HBV DNA and HBV RNA decreased at the end of treatment on day 28, range from minus 2 logs of 160-milligram dose to minus 2.8 logs for the 400-milligram dose and minus 2.4 logs for both doses effectively, which is comparable with other capsid inhibitors currently in development.Also, on July 15, we provided a very thorough description of these preliminary results and stated our belief that at least 1 of the 4 Grade 4 ALT players that we saw in the AB-506-treated patients was immune-mediated and beneficial. This subject had notable declines in S-antigen and E-antigen of minus 1.4 logs and minus 2 logs, respectively, by day 100 following discontinuation of the drug. It's also worth noting that serum-based cytokine analysis of this subject showed an abrupt increase in IFN-gamma at the time of the flare suggesting a beneficial immune-mediated response. And we continue to investigate the nature of the other 3 Grade 4 players. Importantly, none of the Grade 4 players in this trial met drug-induced liver injury criteria.Now as stated in the press release and during the conference call, no serious adverse events or clinically-significant safety findings were observed in the healthy subjects. And notably, ALT levels and other liver function tests remain normal throughout the 10 days of dosing in healthy subjects.Also, no serious adverse events were observed in the chronic hepatitis B subject. And based on these preliminary results, we continue to believe that 506 is a potent oral capsid inhibitor but warrants further development. These results - preliminary results also support our confidence in its potential to contribute to the inhibition of HBV replication as part of the combination regimen.Our next steps for AB-506 include a 28-day clinical trial in healthy subjects, and an absence of players in this trial, if observed, could help us understand flares that we've seen in some HBV subjects between day 14 and 28. Results from this 28-day healthy volunteer trial will be submitted along with additional data from the Phase Ia/Ib clinical trial for presentation at an appropriate scientific meeting later this year.We also plan on dosing AB-506 to additional cohorts at different doses with or without a nucleoside analog. We intend to review data from the healthy volunteer 28-day clinical trial and final data from the Phase Ia/Ib trial is expected in the first half of 2020, before we move forward with the our plans for an AB-506, AB-729 and nucleoside analog proof-of-concept Phase II clinical trial in subjects with chronic hepatitis B.But just to recap, provided both AB-506 and AB-729 progress as expected, we anticipate moving into the combination proof-of-concept Phase II clinical trial in chronic hepatitis B subjects in the second half of 2020.We continue to believe the combination of AB-729 and AB-506 with their distinct mechanisms of action have the potential to result in profound inhibition of HBV replication in conjunction with a reduction in S-antigen level, and that this combination will enable a reawakening of the patient's immune system.We also believe that these combined effects should lead to significantly higher rates of sustained S-antigen loss than the current standard of care after a yet-to-be-established finite dosing period.That being said, I'll now hand over the call to Dave Hastings for his summary of our most recent financial results.