Bill Sheridan
Analyst · JMP Securities. You may proceed with your question
Thanks, Charlie, and good morning. I'd like to start by taking a moment to share why targeting Factor D with BCX9930 is such a promising approach for diseases involved in the alternative pathway of complement.First Factor D is required for the alternative pathway to work. That means that doses of 9930 that block Factor D will succeed in inhibiting the alternative pathway, independent of the particular disease setting. And Factor D as a target is the same PNH as it is in nephritis and other alternative pathway diseases. So proof-of-concept in PNH provides proof-of-concept for other diseases of the alternative pathway, not just PNH. Next, Factor D levels as lowest of any complement pathway enzyme. This means that you need less drug to inhibit it compared to other complement targets.On top of that, Factor D levels do not increase with inflammatory illnesses. So the dose does not need to be changed when patients get illnesses like influenza. Lastly, in contrast to other complement enzymes, Factor D has a unique structure and bicruciates scientist have been able to design inhibitors like 9930 that intrinsically have better specificity against other serine proteases. This leads to a lower likelihood of off-target effects and, therefore, a better safety margin.Considering the attractiveness of Factor D as a target, we were very excited to announce today that we have started our PNH proof-of-concept study with 9930. In PNH, our goal is to develop an oral monotherapy with excellent efficacy, whether or not patients in PNH have ever been treated with the C5 inhibitor.Just recently, I returned from an advisory meeting with top world experts in PNH and diseases of complement, where we discussed the profile of 9930, favorable preclinical pharmacokinetics and pharmacodynamics with large safety margins and in healthy subjects, linear and dose proportional exposure and outstanding PD profile and safe dosing to high exposures.I was excited about the prospects for 9930 before the meeting, but based on the experts, strongly positive assessment and their confidence in 9930 being successful in PNH, I'm even more enthusiastic now. What these experts expect to see is that an oral potent Factor D inhibitor with great exposure like 9930 will be superior to C5 inhibitors.To summarize their advice, for this drug it is just a matter of achieving and maintaining adequate drug levels. We're excited that the proof-of-concept study has now started and look forward to seeing evidence of proof-of-concept in the second quarter. Because PNH is such a rare disease, we designed the proof-of-concept study to step through dose ranging as quickly as feasible, as shown in the study scheme on Slide 30.Subjects in the first cohort will receive 50 milligrams twice a day for 14 days then 100 milligrams twice a day for 14 days for a total of 28 days. Subjects in the second cohort, the planned dose regimen is 200 milligrams twice daily for 14 days, followed by 400 milligrams twice daily for 14 days. Twice a day treatment will continue for subjects who showed benefits, such as improvement in LDH levels or hemoglobin.We are enrolling two – patients of two types, one, patients who are not taking a C5 inhibitor, for these patients, 9930 will be their only treatment; and two, patients who have had a poor response to a C5 inhibitor, but are still on treatment. For those patients, 9930 will be added to continued C5 inhibitor.The first patients enrolled in the proof-of-concept study have been treatment naïve patients with a goal of monotherapy for 9930 data from treatment naive subjects is our first priority. Because PNH patients are very sick and 9930 could provide benefit to them, the protocol allows any patient with a benign rash to continue dosing.We and the expert advisers that I discussed before, expect that any benign rash events will resolve quickly and amount to a temporary and one-time occurs. As you may recall, this is what we saw in the healthy subjects we dosed through in the med portion of the trial.We are looking for and expect to see clinical activity with improvement from baseline in LDH level and hemoglobin. Hematologists have learned that this type of clinical laboratory evidence of efficacy in PNH, even when seen in just a handful of patients is very compelling.But our goal for this program is much broader than PNH. The alternative pathway of complement is the same, no matter the disease. So – and this is very important, and it's worth repeating and was reinforced for us by the key opinion leaders in the space, if we demonstrate proof-of-concept in PNH, that an Oral Factor D inhibitor can suppress complement, this result is directly applicable to many other alternative pathway diseases, such as a set of rare kidney diseases, including dense deposit disease, C3 glomerulonephritis and primary membranous nephropathy, which currently have no approved treatments and also acquired hemolytic uremic syndrome.So following our proof-of-concept data in PNH, we intend to advance this program in both PNH and other complement-mediated diseases. We have a very strong scientific and clinical basis to expect excellent results from our proof-of-concept study, and very much look forward to reporting data in the second quarter.