Simon Pimstone
Analyst · Stifel
Thank you, Jodi, and good afternoon, everyone. 2019 was an exciting and transformative year for Xenon. We made significant progress within our clinical stage programs and entered into important collaborations. As a result, we have a strong balance sheet to support the development plans for our proprietary programs driving them towards critical data inflection points and resources devoted to furthering our preclinical innovative R&D efforts. Today, I'll provide an overview of each of our proprietary clinical stage programs, including XEN1101, 496 and 007 as well as our earlier-stage discovery work and partnered programs in order to highlight some of the important milestone events anticipated this year. Obviously, top of mind for businesses is the current uncertainty related to the potential impact of COVID-19. Depending upon the locations of outbreaks, recruitment in clinical trials, transportation of drug products, patients travel to sites, physicians participation in investigator meetings, medical meetings, and additional factors in our business could all be affected. It's too early to predict the scope or nature of the impact from COVID-19, but we will continue to monitor the issue closely, and we'll communicate any material changes in our business should these occur. I will start my update with XEN1101, which is a differentiated next-generation Kv7 potassium channel modulator being developed for the treatment of adult focal epilepsy and potentially other neurological disorders. Patient enrollment for our XEN1101 Phase IIb clinical trial is ongoing in the United States, Canada and Europe. The trial is a randomized, double-blind, placebo-controlled multicenter study to evaluate the clinical efficacy, safety and tolerability of XEN1101 administered as adjuvant therapy treatment in approximately 300 adult patients with focal epilepsy. The primary endpoint is the median percent change in monthly focal seizure frequency from baseline compared to treatment period of active versus placebo. The long-term 6- and 9-month toxicology studies, which were recently completed, support the ongoing advancement of patients into the 12-month open-label extension stage of the ongoing Phase IIb clinical trial. Key opinion leaders and investigators are supportive of the Kv7 mechanism of action in epilepsy and feedback from sites to date has been positive. If approved, XEN1101 could represent an only drug in class and support refractory epilepsy patients who are seeking effective anti-seizure medications. As we've guided previously, depending upon the rate of enrollment, top line results are anticipated in the second half of 2020. One pending decision is whether or not we opt to conduct an interim analysis. By way of background, we have made certain statistical modeling assumptions on tolerability and potential dropouts from the study. Depending on the dropout rate data, which we have access to on a blinded basis, we can choose to have a third-party statistician review unblinded data and provide guidance on resizing or reallocating to different treatment arms or doses to ensure power is maintained. We expect to make a decision on the interim analysis in the near term. Given its unique mechanism of action, we also continue to explore potential indications for XEN1101 outside of epilepsy, and there are a number of indications, which we are actively exploring. We look forward to keeping you updated as these plans develop in the coming months. Also, within our portfolio of proprietary epilepsy products, XEN496 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 characterized by multiple daily refractory seizures presenting within the first week of life. A recent epidemiological study from Europe, examining the incidence and phenotypes of childhood-onset genetic epilepsies, reports the incidence of KCNQ2-DEE as approximately 1 per 17,000 live births, which can be compared to the 1 per 12,200 live births estimated for Dravet syndrome. There is a strong genetic rationale to suggest that ezogabine may be efficacious as a treatment for KCNQ2-DEE. This is further supported by non-controlled clinical studies as well as anecdotal parental and physician feedback, suggesting that XEN496 may be well tolerated and reduced seizure burden with potential to improve development and cognition in this rare pediatric population. We recently presented data in December at the AES meeting, a survey of patients and caregivers in the KCNQ2-DEE community, which provided feedback consistent with the Millichap and Olson clinical case reports and added further strong support for our rationale to develop XEN496 for this rare pediatric developmental epilepsy disorder. The FDA has granted Xenon orphan drug designation for XEN496 as a treatment for KCNQ2-DEE. In response to our pre-IND briefing package that included our proposal to study XEN496 in infants and children with KCNQ2-DEE, the FDA supported our proposed safety monitoring plans, including long-term follow-up to monitor potential side effects and indicated that a single small pivotal trial could sufficient provided the study shows evidence of a clinically meaningful benefit in patients with KCNQ2-DEE. The in vitro and in vivo testing done to date demonstrates that XEN496 acts as an immediate release drug, has similar pharmacokinetics to what was observed with the ezogabine tablets, and has compatibility with common feeding devices used in pediatric dosing such as baby bottles and NG tubes. We presented all of these significant CMC advances at the AES meeting in December. Stability studies for XEN496 are ongoing, and no issues have been encountered to date. Late last year, we filed an IND application with the FDA related to a pharmacokinetic, or PK study, testing XEN496, our proprietary pediatric formulation of ezogabine in healthy adult volunteers. In January this year, we received permission to proceed with the study, which is now ongoing. All subjects have completed dosing in the PK study, and we expect to have these PK data later this quarter. In parallel, feedback from correspondence with the FDA regarding the Phase III clinical design is expected early in the second quarter of this year with the anticipated start of a Phase III clinical trial in KCNQ2-DEE in 2020. Although the protocol is still being finalized, at a high level, the trial design includes a randomized, placebo-controlled trial using seizure frequency as the primary endpoint with both dose titration and maintenance phases. We have selected a CRO and began work in preparation for the Phase III trial with site selection underway. In addition, our clinical development team is planning for regulatory submissions outside of the U.S. and select European jurisdictions following the receipt of FDA feedback in order to support the broader clinical development of XEN496. Turning now to Xen007, active ingredient of which is flunarizine, which is a CNS acting calcium channel modulator, it modulates CAV 2.1 and T-type calcium channels. Other reported mechanisms include dopamine, histamine and serotonin inhibition. We are considering various development strategies for XEN007 and have entered into key exclusive licensing agreements in order to access regulatory files and drug product manufacturing, both of which may enable advanced clinical development of XEN007. The FDA granted orphan drug designation for the treatment of hemiplegic migraine with XEN007, and granted ODD and a rare pediatric disease, or RPD designation, for the treatment of alternating hemiplegia of childhood with XEN007. During our analysis of potential neurological indications, we identified childhood absence epilepsy, or CAE, as a potential indication for XEN007. 007 has demonstrated efficacy in preclinical models of absence seizures, and flunarizine has been shown to be well tolerated clinically. To provide a bit more background on CAE, approximately 10% of seizures in children with epilepsy are typical absence seizures. Age of onset ranges from 3 to 13 years, with a peak of 6 to 7 years. Absence seizures can have a significant impact on quality of life. Episodes of unconsciousness may occur at any time and usually without warning. Affected children need to take precautions to prevent injury during absence periods, and should refrain from activities that will put them at risk if seizures occurred. Often, school staff members are the first to notice the recurrent episodes of absence seizures, and treatment is generally initiated because of the adverse impact on learning. A physician-led Phase II proof-of-concept study is now ongoing to examine the potential clinical efficacy, safety and tolerability of XEN007 as an adjunctive treatment in pediatric patients diagnosed with treatment-resistant childhood absence epilepsy. It is anticipated that the study will enroll up to approximately 20 patients with CAE in an open-label manner after failing standard of care because of lack of efficacy or because of adverse events. Results from this Phase II study are expected in 2020. Results from the CAE study will help shape our development strategy for XEN007, and may represent a potential orphan indication for future development of XEN007. Just briefly, I would like to also highlight that we continue to make an exciting progress in our early-stage discovery work. Our deep knowledge of the genetics of channelopathies, combined with our proprietary biology and medicinal chemistry know-how, have positioned Xenon as a leader in small molecule ion channel drug discovery. A robust pipeline of early-stage preclinical candidates encompasses our work related to a number of sodium and potassium channel targets. For example, our preclinical data suggests that a highly selective small molecule potentiator of Nav1.1 could potentially address the underlying cause of Dravet syndrome using a precision medicine approach, and may have utility in other neurological indications where interneuron excitability is impaired. We intend to build upon this promising work and expect to highlight this exciting and novel preclinical work as it matures. We also presented some of our preclinical Nav1.1 potentiated data at AES in December and the poster is on our website. Turning now to our partnered programs. We have an ongoing collaboration with Neurocrine Biosciences to develop novel sodium channel inhibitors as treatments for epilepsy. As announced in December last year, Neurocrine has an exclusive license to XEN901, now known as NBI-921352, a clinical stage selective Nav1.6 sodium channel inhibitor as well as novel selective Nav1.6 inhibitors in JUUL Nav1.2/1.6 inhibitors that are in preclinical development. The agreement also included a multiyear research collaboration to discover, identify and develop additional novel NAV1.6 and Nav1.2/1.6 inhibitors. We believe that this collaboration with Neurocrine was a thoughtful and strategic decision, allowing us to invest in and maximize the potential of the later stage potassium channel assets in our pipeline while still ensuring there is significant investment in the XEN901 and next-generation selective sodium channel programs. Both Xenon and Neurocrine have a keen interest in precision medicine therapies and our combined expertise in neuroscience and ion channel modulation represents a powerful partnership. Neurocrine has indicated a strong interest in addressing the unmet medical needs of patients with SCN8A-DEE, a rare, extremely severe single-gene epilepsy caused by mutations in the SCN8A gene that result in a gain of function in the Nav1.7 -- sorry, the Nav1.6 sodium channel. SCN8A-DEE typically presents with seizure onset between birth and 18 months of age. Most children diagnosed with SCN8A-DEE have seizures that can occur multiple times a day and often difficult to treat. Neurocrine plans to conduct a placebo-controlled study with NBI-921352 and anticipates filing an IND application with the FDA in mid-2020 in order to start a Phase II clinical trial in SCN8A-DEE patients in the second half of 2020. We are eligible to receive up to $25 million upon the FDA acceptance of an IND. In addition, Neurocrine has also indicated that NBI-921352 may have potential in a range of seizure disorders, including adult focal epilepsy. Moving now to our partnership with Flexion Therapeutics, which has global rights to develop and commercialize FX301, formerly XEN402, and Nav1.7 inhibitor. Flexion's preclinical FX301 program consists of XEN402 formulated for extended-release from a thermo-sensitive hydrogel. The initial development of FX301 is intended to support administration as a peripheral nerve block for control of postoperative pain. Flexion has indicated that it anticipates initiating FX301 clinical trials in 2021. I believe that Xenon currently is one of the most exciting epilepsy pipeline that's currently in development and strong relationships with our valued collaborators. Bolstered by a healthy balance sheet, we are entering a data-rich period with the expectation that a number of our product candidates will enter mid- to late-stage clinical trials or generate important clinical data in 2020. At this point, I'll ask Ian to recap our financial position and to provide some closing commentary before opening up the call to your questions. Ian?