X4 Pharmaceuticals, Inc.

Greetings, and welcome to X4 Pharmaceutical's Third Quarter Financial and Operating Results Conference Call. At this time, all participants are in a listen-only mode. A question-and-answer session will follow the formal presentation. As a reminder, this conference call is being recorded. It is now my pleasure to introduce your host, Dr. Glenn Shulman, Head of Investor Relations. Please begin.

Thank you, Operator, and good morning, everyone. Presenting on today's call will be X4's chief executive officer, Dr. Paula Reagan, and the company's chief financial officer, Adam Mustafa. Following some prepared remarks by each, we will then open the call to your questions, where we'll also be joined by our chief scientific officer, Art Tavares, chief medical officer, Diego Karavid, and chief operating officer, Mary Dubeyasi. As a reminder on today's call, X4 will be making forward-looking statements regarding regulatory and product development plans, as well as research activities. These statements are subject to risks and uncertainties that may cause actual risks to differ from those forecasted. A description of these risks can be found in X4's most recent filings with the SEC, including our Form 10-K being filed today. And now I'd like to turn the call over to Paula Regan, President and CEO. Paula?

Thanks, Glenn, and thank you, everyone, for joining us on the call this morning. Before we get started, I did want to officially introduce our new Vice President of Investor Relations and Corporate Communications, Glenn Schulman, who you just heard from. He has a Master's in Public Health and a PharmD and an extensive public life sciences company experience leading successful investor relations and corporate communications teams and programs. Glenn joined us in mid-November and has been a great addition to the team. Welcome, Glenn. 2021 was an important year for X4, a year of execution across our multiple ongoing clinical trials and significant progress in advancing our lead candidate, Maverick Sephora, closer to patients in need. And importantly, we expect 2022 to be a pivotal year for the company, a year of clinical results that will shape the future of X4 for years to come. During 2021, not only did we complete enrollment in the pivotal Phase III trial of Maverick's 4 and WIM syndrome for the 4-WIM trial, but we also enrolled enough patients in our two earlier stage trials to achieve proof of concept for Maverick's 4 and 2 additional rare disease indications with many thousands of patients that had great medical need for additional treatments, chronic neutropenia and Waldstrom's macroglobulinemia. 31 adults and pediatric patients have been enrolled in the 4WIM trial, which was originally designed to enroll 18 to 28 patients. As you know, this clinical trial is evaluating the safety and efficacy of a single daily oral dose of maverixifor in patients with WIM syndrome, a rare genetic immunodeficiency disorder caused by gain-of-function mutations to the CXCR4 receptor. The disease is characterized by HPV-associated warts, hypogamyloglobulinemia, multiple types of infections, and myelocathexis, which causes leukopenia and neutropenia in most patients, reducing the body's ability to mount a healthy immune response. Results from the ongoing open-label extension of our Phase II clinical trial of Mavericks IV and WIM patients continues to support this indication, with data showing durable increases in neutrophils, lymphocytes, and monocytes, decreased frequency severity and duration of infections, fewer hospital doctor visits, and sustained improvement in warts. Mavericks 4 continued to be well-tolerated over a median treatment duration of almost 150 weeks. We continue to anticipate top-line data from the 4-WIM trial in the fourth quarter of 2022. We ended last year with our largest-ever presence at a scientific meeting the annual meeting of the American Society of Hematology, or ASH, and we held a company virtual seminar immediately following with several key thought leaders in the industry. Our posters and abstracts at the ASH meeting contained a broad array of both clinical and scientific data, data that we believe not only further establishes X4 as a leader in the CXCR4-related research space, but also supports the broadening scope of the clinical potential of Maverick Sephora due to its ability to selectively inhibit CXCR4. At the meeting, we shared data demonstrating the effect of Maverick Sephora across multiple disease states, multiple cell types, and over chronic periods of dosing. One of our posters showed for the first time that Maverick Sephora is able to raise total counts of all the key white blood cells necessary to mount an appropriate immune response across a wide spectrum of diseases over both short- and long-term treatment periods. Data were presented from ongoing clinical trials in Waldenstrom's macroglobulinemia, clear cell renal cell carcinoma, WIM syndrome, and for the first time, early data from our ongoing Phase Ib trial in patients with chronic neutropenia. These data demonstrated that Mavarixifor broadly increased white blood cells and neutrophil counts, anywhere from two to six-fold, across all indications, as well as in healthy subjects. Early data from our Phase Ib clinical trial in chronic neutropenia mirrored these results, with demonstrated elevations in white blood cells and absolute neutrophil, lymphocyte, and monocyte counts across the first four patients enrolled in the trial. As a reminder, chronic neutropenia refers to a condition of sustained or recurrent abnormally low neutrocell counts, lasting at least three months. It's estimated that six in 10,000 people have chronic neutropenia, which can be present in a variety of severities, mild, moderate, or severe, and can increase the risk of serious and recurrent infections in patients. Enrollment in our Phase 1b trial continues with additional data expected in the second or third quarter of 2022. It was a compelling set of consistent responses, irrespective of disease state and irrespective of CXCR4 mutation status. And in aggregate, have encouraged us to think much more broadly about how Maverick Sport could impact larger numbers of patients with primary immunodeficiencies, whether caused by CXCR4 mutations, as in the case of Lyme syndrome, or via antagonism of the wild-type CXCR4 signaling pathway and many other cellular immunodeficiencies. We also presented results from our ongoing Phase 1B clinical trial in people with Waldstrom's macroglobulinemia, a rare B-cell lymphoma. At low 200 milligram and mid-level 400 milligram dosing of Mavarixifor combined with the BTK inhibitor and Brutinib, the median treatment duration of 272 days. As a reminder, the Phase 1B trial is designed to demonstrate safety, dose, and elucidate proof of concept of maverick support in people with Waldenstroms with significant unmet needs resulting from mutations to both their MYD88 and CXVR4 genes. The data showed a 100% overall response rate in the 10 evaluable double mutation patients, sustained decrease in serum IgM levels, and a trend towards normalization of hemoglobin levels. We also announced this morning that 600 mg dose of Maverick Zephyr was cleared of the ongoing study. All eligible patients in cohorts A and B, or the low and mid-level cohorts, are now being dose escalated to receive 600 mg of Maverick Zephyr once daily in combination with ibrutinib. We expect to report updated data from this trial during the second half of the year. At ASH last December, we also announced that our research efforts had led to the discovery of several novel WIM-causing CXDR4 mutations, the incidence of which further strengthens our confidence that there are more than 3,500 WIM patients in the US alone. More detailed data on one of these mutations, the D84H mutation, was just presented at the American Academy of Allergy, Asthma, and Immunology or Quad AI meeting in late February. The poster for this is available on our website. Looking forward, our participation at major medical conferences continues in 2022, where we are working hard to educate the medical community and raise awareness of WIM. At the upcoming 2022 Clinical Immunology Society, or CIS, conference, we will present for the first time another recently identified novel WIM variant, the S341Y variation. This, combined with the D84H mutation, are just two of the many novel WIM variants that have been sequenced, characterized, and published into the literature, stemming from our world-class research center in Vienna. Next month at the AACR conference, our preclinical team will be presenting new data demonstrating the additive to synergistic activity of Maverick Spore when combined with any BTK inhibitor including zanubrutinib and abrutinib. With that update complete, I would like to take a little time today to share some insights in our commercial approach as we near our first phase 3 clinical data in Maverick 4 for the treatment of limb syndrome. The first is our early engagement with patient communities through patient advocacy. Patient voices are at the center of all decisions we make at X4. Early in the Maverick 4 clinical development process, we appointed a vice president of patient advocacy who engaged with patient advocacy groups long before entering the Phase III trial, which enabled us to understand the diverse disease journeys and unmet needs of our patients. We have worked closely with patient advocacy groups all along to develop disease awareness materials and other resources to help educate on testing resources, disease presentation, access to medical experts and treatment options available or in clinical development. The second is our educational support and access to genetic testing to improve diagnosis. As you likely know, diagnosis and patient identification are the main challenges for rare disease. Due to the heterogeneous symptom presentation and lack of physician awareness, Lyme syndrome is often difficult to diagnose. This leads to long diagnosis journeys and delayed access to the symptomatic treatments of the current standard of care. People with WHIM syndrome often visit numerous medical specialties before being diagnosed. As we've discussed previously, we sponsor a no-charge genetic testing and counseling program, TaskForward, for individuals who might carry mutations associated with congenital neutropenia, including WHIM syndromes, aid in patient identification and to help bring patients one step closer to an accurate diagnosis. We also employ the use of artificial intelligence and machine learning tools to enhance our understanding of the prevalence and burden of disease. Women thought to be underdiagnosed due to the absence of an international classification of disease or ICD-10 code, as well as inconsistent coding for key symptoms. we have utilized artificial intelligence and machine learning platforms to identify patients with WIM lookalike clinical phenotypes that might have been previously undiagnosed due to inconsistent symptom presentation. As we talked about last year, this space of WIM is like a puzzle, but with our ongoing research and that of the physician, scientists, and patient communities, there's increasing clarity as the understanding of the disease continues to evolve as is often the case with many rare diseases. We have also assembled a strong medical affairs team. Building a specialized team geared towards physician education and creating partnerships to increase awareness of limb syndrome is a critical bridge to achieving our goals. Collectively, we feel passionately about empowering medical professionals and their patients to understand their unique journeys so that they can get answers and find available treatments. Lastly, and as we just mentioned, we continue to conduct research on the underlying genetics of WHIM. We have built strong in-house research programs that leverage world-class collaborations to advance bench-to-bedside research. By continuing to establish correlations between clinical presentation and new genetic variants associated to WHIM, we can improve our ability to identify undiagnosed patients including those who may potentially benefit from Maverick support treatment in the event it gains approval. Of course, building a sustainable rare disease business is not solely rooted in supporting patients and physicians. There's much more needed beyond that that we need to deliver on, and we are well on our way. We have made great progress in adding leadership to the company with our VP of U.S. Commercial and our new board director, both with significant life science commercialization experience. More key hires, including a chief commercial officer, are slated for 2022. In terms of our ultimate commercial product, we have taken the appropriate steps in terms of registration and validation batches to support our NDA filing and are advancing our work to support Mavericks for its future commercial trade dress and third-party logistics providers to enable a successful U.S. launch. Finally and importantly, given the disease-modifying impact that Mavericks 4 may have on this rare WIMP syndrome population, we are engaging payers with research and education in the U.S. and key European territories. All of these platforms and initiatives are working in concert to enable us to be ready to deliver our patients in the event of our first approval. With that update, I now turn it over to Adam to discuss results for the quarter before we open up the call for questions. Adam?