Simon Pimstone
Analyst · William Blair
Thank you, Jodi, and good afternoon, and thank you, everyone, for joining us today. I hope everyone is staying well. At Xenon, despite the ongoing serious second wave of the global COVID-19 pandemic, which is certainly placing pressure on everyone and in particular in clinical recruitment, we continue to progress advancing our proprietary neurology product candidates into mid to late-stage clinical development. We have made important adjustments to our business in order to respond and react to COVID's impact on our business. And with many factors outside of our control, we've been closely assessing the potential impacts of this COVID-19 second wave to our clinical programs, and we'll provide some further updates to program and cash guidance today. I'll be starting by providing a brief status report on each of our proprietary and partnered programs with a focus on XEN1101 and XEN496. First, XEN1101, which is a differentiated next-generation Kv7 potassium channel modulator currently in our Phase II b X-TOLE clinical trial in the U.S., Canada and Europe. Briefly, this trial is a randomized, double-blind, placebo-controlled multicenter study to evaluate the clinical efficacy, safety and tolerability of XEN1101 administered as adjunctive treatment in approximately 300 adult patients with focal epilepsy. The primary end point is the median percent change in monthly focal seizure frequency from baseline compared to treatment period of active versus placebo. Within the X-TOLE study and as many other companies are experiencing, this is an extremely challenging environment in which to provide guidance as COVID-19 is resulting in regular changes in clinic screening and in-patient perspectives on committing to longer-term studies that require monitoring and interaction with medical staff. In the early stages of the COVID-19 pandemic, we experienced a significant decrease in patient screening and randomization. In response, we implemented several risk mitigation strategies that resulted more recently in a positive uptick in patient screening and randomization. We expanded the X-TOLE clinical trial to include a number of new sites in both existing and new jurisdictions, and many of these new sites have recently initiated patient screening. While we are pleased to see more positive trends in enrollment recently, these rates are still short of pre-COVID levels, and we are modeling that patient enrollment will likely continue at this reduced level for the remainder of the year. Therefore, while we believe our presence in multiple jurisdictions with new sites opening will certainly help to mitigate the risks of delay presented by COVID-19, we anticipate that patient randomization will be completed in the first half of 2021. And with an 8-week dosing period and follow-up, we are now guiding that top line data is anticipated in the third quarter of 2021. This guidance is based on the recovery in patient's enrollment rates we have seen over the past few months but with a more cautious outlook for the coming months until we have better visibility into the second wave of the pandemic and its resulting impacts. It is important to emphasize that despite these trying circumstances, we remain confident in the conduct of the study and in the integrity of the data as captured by electronic diary. And we do not believe COVID-19 will have any impact on the final efficacy results of the study. To-date, dropout rates remain lower than modeled, and we continue to see excellent continuation into the open-label portion of the study. Although we are laser-focused on the X-TOLE study, this year we have completed additional primary market research and detailed work around the focal epilepsy market. And we remain very excited about XEN1101 and the role it could play in that focal epilepsy market, with its novel mechanism of action, its PK characteristics and other potentially beneficial pharmaceutical properties, we believe XEN1101 has the potential to be significantly differentiated in the marketplace. We look forward to sharing more of our research with you over the coming months. Next, I'd like to turn to XEN496, which is a Kv7 potassium channel modulator that contains the active pharmaceutical ingredient, ezogabine also known as retigabine, that we have reformulated and are developing as a treatment for a rare pediatric neurodevelopmental disorder called KCNQ2 developmental and epileptic encephalopathy or KCNQ2-DEE, which is a severe pediatric condition for which no medicine has yet been approved. Over the past quarter, we have made considerable progress toward our goal to initiate a Phase III clinical trial examining XEN496 in patients with KCNQ2-DEE. In addition to a Fast Track designation and Orphan Drug Designation for XEN496 for the treatment of KCNQ2-DEE, we received a positive opinion from the EMA, which recommends the granting of an orphan medicinal product designation in Europe for XEN496 for the treatment of KCNQ2-DEE. In addition, the FDA has completed its review of the clinical trial protocol. And based on this, we expect to initiate our Phase III EPIK clinical trial in pediatric patients with KCNQ2-DEE before year-end. This EPIK study is designed as a randomized, double-blind, placebo-controlled parallel group multicenter clinical trial to evaluate the efficacy, safety and tolerability of XEN496 administered as adjunctive treatment in approximately 40 pediatric patients aged one month to less than six years with KCNQ2-DEE. Eligible subjects will be randomized on a 1:1 basis to receive either XEN496 or placebo for approximately 15 weeks, which includes the titration period and a 12-week maintenance period. The primary end point is the percent change from baseline in monthly countable motor seizure frequency during the blinded treatment period as recorded by caregivers in a daily seizure diary. We continue to work closely with the medical community, genetic testing companies and patient advocacy groups to identify potential patients for our EPIK study. This marks an extremely important milestone for Xenon with the first of our proprietary product candidates now poised to enter a Phase III clinical trial and we look forward to initiating the trial before year-end. Turning now to XEN007, with the active ingredient flunarizine, which is a CNS-acting calcium channel modulator that modulates Cav2.1 and T-type calcium channels. The physician-led Phase II proof-of-concept study is examining the potential clinical efficacy, safety and tolerability of XEN007 as an adjunctive treatment in pediatric patients diagnosed with treatment-resistant childhood absence epilepsy or CAE. We continue to work with our collaborators and anticipate that a presentation of interim data collected from a small number of patients initially enrolled is expected to be presented in a poster presentation at AES 2020, the Virtual Annual Meeting of the American Epilepsy Society to be held in December 2020. Due to the impact of COVID-19, we now expect the top line results from a larger data set will be available by the middle of next year. Depending on the final results, CAE may represent a potential orphan indication for future development of XEN007. Turning briefly to our partnered programs, we have an ongoing collaboration with Neurocrine Biosciences to develop treatments for epilepsy. Neurocrine has an exclusive license to XEN901, now known as NBI-921352, a clinical stage selective Nav1.6 sodium channel inhibitor with potential SCN8A developmental and epileptic encephalopathy otherwise known as SCN8A-DEE as well as other forms of epilepsy. We provided an update last month indicating that the FDA had provided feedback on the IND application submitted by Neurocrine in support of a Phase II clinical trial in pediatric SCN8A-DEE patients. As part of its review of the IND, the FDA is requesting additional nonclinical data to support dose justification in this pediatric study. We are supporting Neurocrine as it engages with the FDA to address the feedback received with the goal of initiating a Phase II clinical trial in 2021. In parallel with this interaction, Neurocrine is advancing clinical plans to develop NBI-921352 for the treatment of adult focal epilepsy. Moving now to our partnership with Flexion Therapeutics, who acquired the global rights to develop and commercialize XEN402, an Nav 1.7 inhibitor known as funapide. FX301 consists of XEN402 formulated for extended release from a flexion proprietary thermosensitive hydrogel for administration as a peripheral nerve block for control of post-operative pain. Flexion has made good progress and anticipates filing an IND application in the first half of 2021 to support a proof-of-concept clinical trial in patients undergoing bunionectomy. Results from that trial could potentially be available in late 2021, and we look forward to keeping you updated on this partnered program. At this point, I would like to also take the opportunity to welcome Patrick Machado to Xenon's Board of Directors. Pat brings deep biotech experience and a great track record of strong business leadership having overseen finance, business development and legal functions over more than 20 years of a very impressive career. Many of you may know Pat as the Co-founder and CFO, CBO and later Board Member of Medivation until its acquisition for approximately $14 billion by Pfizer in 2016. More recently, Pat served on the Board of Principia Biopharma, which was recently acquired by Sanofi. I believe Pat will add tremendous value to our Board as we continue to advance multiple mid to late-stage neurology-focused clinical development programs. Before turning the call over to Ian, I'll close by saying that I remain excited and optimistic about the important milestone events ahead for Xenon. I genuinely believe we have one of the most promising epilepsy pipelines currently in development. The clinical programs have been addressed today, but Xenon also has an exciting pipeline of nonclinical programs, which we expect to present in more detail in the future. At this point, I'll ask Ian to recap our financial position and provide some closing commentary before opening up the call to your questions. Thank you. Ian?