Mark Murray
Analyst · JMP Securities. You may begin
Thanks, Pam. And thank you to everyone for joining us on the call today. I'm going to focus my remarks on our key objectives for 2019. Mike Sofia will follow with an update on AB-452 and the HBV RNA destabilizer program. Dave Hastings will then describe our financial results, after which we'll open up this call for Q&A. As you know, we are focused on developing a cure for patients with chronic HBV. We believe this can best be achieved by using a combination regimen of complementary therapeutic agents administered for a finite treatment duration. We believe having control over the discovery and development of these compounds is important. To that end, we have developed a pipeline of diverse proprietary therapeutic agents that target the aspects of chronic HBV infections we believe are the most important, and are therefore the ones we are focused on, including HBV replication, hepatitis B surface antigen expression and immune reawakening. Our two lead compounds, AB-506 and AB-729 have the potential to be used in combination with an approved nucleoside analogue and deliver a meaningful advanced over the current standard of care. AB-506 is our oral capsid inhibitor, it is pan-genotypic, has a favorable PK profile was quite potent, works against nuc resistant variance, is dosed once daily and is complimentary with respect to Hepatitis B surface antigen targeting compound. AB- 506 is now being evaluated in HBV patients in a 28 day daily dosing mono-therapy clinical trial. This trial includes the evaluation of several doses of AB-506. It may include a cohort using AB-506 in combination with the nucleotide analogue. We intend to report top line results of the completed cohorts in this phase 1a/1b study late in the second quarter with full results presented later in the year at an appropriate scientific meeting. We also plan to initiate a phase 2 clinical trial combining AB-506 and a nucleotide analogue in the second half of the year to establish long term safety of AB-506 plus a nuc to support and use of these in future combination trials. Now regarding surface antigen reduction. As I said, in our third quarter call, we confirm that our first generation LNP enabled RNAi agent AB-1467 reduced Hepatitis B surface antigen to very low levels in some patients. We are now focused on our GalNAc conjugated subcutaneously delivered RNAi agent, AB-729. AB-729 applies a single RNAi trigger that spans all of the HBV transcripts, thus reducing all the viral antigens and inhibits HBV replication. This compound employs our proprietary GalNAc Hepatitis targeting technology, which not only allows for subcutaneous dosing but also provides the important benefit of less frequent dosing, potentially once a month dosing. We are currently completing IND enabling studies and believe AB-729 is on track to begin a phase 1a/1b clinical trial in the second quarter of this year. We believe that these two agents, AB- 506 , the capsid inhibitor, which inhibits HBV replication and AB-729, which reduces Hepatitis B surface antigen, will when combined with an approved nuc, have the potential to be an effective well tolerated combination regimen. Provided the mono-therapy trials of AB-506 and AB-729 perceived as expected, we anticipate initiating a phase 2 combination clinical trials with these two agents together with an approved nucleosides in the first half of 2020. I'd now like to move to an update on AB-452, our oral RNAi destabilize, which also targets Hepatitis B surface antigen expression but via a very novel mechanism of action. We’ve opted to delay the initiation of our phase 1a/1b clinical trials in order to evaluate a non-clinical safety finding seen in the longer term safety studies. Since that announcement, we have initiated a number of studies designed to further characterize these findings, the compound itself and its mechanism of action and to determine their proceeding into humans testing with AB-452 as appropriate. These studies are still ongoing and we expect to be able to make a go, no-go decision with respect to AB-452 itself in the second half of the year. In a moment, Mike Sofia will describe some of the activities going on allow us to make this decision. We are often asked if we were being committed the RNA destabilizer program? And the answer is a resounding yes. In addition to AB-452, we have robust lead optimization efforts underway for other distinct compounds with this novel biological activity. We are confident, the RNA destabilizing mechanism we are focused on represents a very relevant and importance of therapeutic target, and success here could be very meaningful for patients and for Arbutus. I'd now like to turn the call over to Mike Sofia. Mike?