Bill Rote
Analyst · William Blair. Your line is open
Thanks Steve. Let me start by covering our most recent development milestone related to sparsentan. As of last week, we completed positive interactions with both the FDA and EMA on our program for IgA nephropathy. As Steve mentioned, the key conclusion from our meetings is that the feedback from both agencies supports moving sparsentan directly into a single Phase 3 study. In broad strokes, we expect the trial in IgA nephropathy to be similar to the recently initiated DUPLEX study with endpoints evaluating proteinuria and EGFR. We would also expect the patient numbers and study duration to be similar, but not exactly the same. We are currently working to harmonize our protocol by incorporating all of the feedback to guide our clinical activity. Alongside the efforts to finalize protocol, our project team is working closely with our CRO and investigators to get this important study up and running. On our current path, we would expect to initiate enrollment in the fourth quarter of this year. At that time, we'll be in a position to share more about the study protocol specifics and timelines. We also recently increased momentum in our FSGS efforts with the initiation of our Phase 3 DUPLEX study last month. DUPLEX is an innovative clinical trial that builds upon the promising results from our Phase 2 DUET study, and positions us to potentially gain approval in the US and Europe. We are excited to see new sites opening each week and taking steps to initiate enrollment of FSGS patients. DUPLEX is expected to enroll a total of approximately 300 patients with FSGS across estimated sites 150 around the globe. All patients in the study will randomize one to one to receive either sparsentan or the active-control irbesartan. Most notably the trial design provides for an interim assessment measuring modified partial remission of proteinuria in approximately 190 patients after they've received treatment for 36 weeks. Achieving modified partial remission of proteinuria is defined as obtaining a urine protein to creatinine ratio of less than or equal to 1.5 gram per gram and greater than 40% reduction in proteinuria from baseline. As many of you recall, this is the same endpoint in which we saw a statistically significant difference between this sparsentan and treatment group and the irbesartan group after 8 weeks of treatment in the DUET study. We expect that the successful achievement of this proteinuria endpoint and the interim analysis of DUPLEX will serve as the basis for subpart H accelerated approval of sparsentan in the United States and conditional marketing authorization consideration in Europe. Based on our current enrollment estimates top-line data from our interim assessment is expected to be available in the second half of 2018. The confirmatory portion of the study will evaluate the primary endpoint, which is the change in slope of estimated glomerular filtration rate or EGFR measured in approximately 300 patients after 108 weeks of treatment. Given the promising results seen on the modified partial remission endpoint in our Phase 2 study and a similar patient population expected, we have a high degree of confidence in the outcome of the DUPLEX study and we look forward to continuing to enroll towards our key milestones. Overall, we are pleased by the progress made to advance sparsentan in two registration enabling studies by the end of 2018, and we look forward to sharing more in the coming quarters. Our lead program fosmetpantotenate for the treatment of PKAN continues to progress in the pivotal port study. As Steve mentioned earlier, we recently met the study's initial adult enrollment milestone to trigger the first data safety monitoring board review, and reaching that milestone we anticipate opening the study to pediatric enrollment shortly after the DSMB meeting later this month. The great work by our clinical and medical teams initiating additional sites and driving awareness of the study is resulting in an uptick in patient enrollment. During the first quarter, we also opened key European centers which are already having an encouraging impact on study enrollment. Importantly, we remain on track to complete enrollment of all patients in this study around year-end or early 2019 which would enable a top-line read out sometime in the second half of 2019. Finally, I will take a minute to touch on CNSA-001, an orally bioavailable proprietary form of sepiapterin for Phenylketonuria or PKU. This is being developed in conjunction with CNSA Pharmaceuticals through our option and joint development agreement that we announced in January. I'm very pleased with the collaboration between our team and our partners to further advance this candidate, which has the opportunity to make a meaningful difference for PKU patients. The single ascending dose portion of the Phase I study is completed and the multiple ascending dose segments has initiated. Importantly, the Phase 2 proof-of-concept study remains on track to initiate in the coming months. The envision study is a crossover design evaluating multiple doses of CNSA-001 versus the current standard of care in patients with PKU. We continue to expect data readout from the Phase 2 study by early 2019. As we've mentioned previously, if the results from the proof-of-concept study are positive, and we then choose to exercise our option to acquire CNSA, we would anticipate moving quickly into a pivotal Phase 3 study in 2019. Overall, I'm delighted with the advancement across our development portfolio to start the year. Our performance has put us on track for three Phase 3 programs enrolling first in class molecules by the end of this year, and potentially a fourth pivotal studies starting 2019. Let me now turn the call over Neil for his operational update. Neil?