X4 Pharmaceuticals, Inc.

Greetings, and welcome to X4 Pharmaceuticals' first 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. To ask a question during the session, you'll need to press star 1 on your telephone. As a reminder, this conference call is being recorded. If you require any further assistance, please press star 0. It is now my pleasure to introduce your host, Dan Ferry of LifeSci Advisors. Please begin.

Thank you, operator, and good morning, everyone. Thanks for joining us. Presenting on today's call will be XFOR's Chief Executive Officer, Dr. Paula Regan, and the company's Chief Financial Officer, Adam Mostafa. Following prepared remarks by each, we will open the call to your questions. And we'll be joined by Dr. Diego Cadavid, Chief Medical Officer, Art Tavares, Chief Scientific Officer, and Mary DiBiase, Senior Vice President, technical operations, and quality. As a reminder on today's call, the company 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 results to differ from those forecasted. A description of these risks can be found in X4's most recent filings with the SEC. I would now like to turn the call over to Paul Regan.

Thanks, Dan, and thank you, everyone, for joining us on the call this morning. Let me start by saying that we could not be more pleased with our accomplishments so far this year. We have achieved significant progress in our Maverick X4 clinical programs and successfully completed a $55 million at-the-market pipe financing that included participation from leading biotech investors, both new to X4, as well as from existing investors. We believe this demonstrates a strong level of investor conviction in the clinical and commercial potential of Maverick Zephyr while also extending our expected cash runway into late 2022 and supporting our additional pipeline programs. As mentioned on our last call, the pace of enrollment in our key clinical programs has ramped up significantly since last year. Specifically, we now expect to be able to announce an important enrollment update in our Phase III trial in WIM syndrome in mid-2021. As a reminder, WIM is a rare inherited primary immunodeficiency disease caused by gain-of-function CXCR4 mutations that prevent healthy immune cell trafficking and effective immunosurveillance. Most patients with WIM disease have lifelong neutropenia and lymphopenia, that can result in a variety of serious chronic infections across multiple organ systems, HPV-associated lesions and increased cancer risk, and other serious life-impacting morbidities. Mavericks 4 is our first-in-class small molecule antagonist of the CXTR4 receptor that we believe has the potential to be the first disease-modifying therapy for the more than 3,500 potential diagnosed and undiagnosed WIM patients in the U.S. The 4WIM Phase III trial is a global, randomized, placebo-controlled, double-blinded, multi-center study designed to evaluate the safety and efficacy of Mavericks A4 over a course of 52 weeks in approximately 18 to 28 genetically confirmed WIM patients. The Phase III primary efficacy endpoint, called time above threshold for absolute neutrophil count, or TAT-ANC, compares the level of circulating neutrophils relative to a clinically meaningful threshold in response to Mavericks 4 treatment versus placebo. As you may recall from our Phase 2 study and published in the journal Blood in 2020, Mavericks 4 demonstrated greater than a 600% increase in time above threshold for neutrophil counts at our selected Phase 3 dose as compared to the lower doses treated for WIM patients. which gives us deep confidence in the potential success of our phase three study. Secondary endpoints include infection rates, warp burden, and assessment of immune system function and quality of life among others. At our current rate of enrollment, we continue to expect top line data from this phase three trial in 2022. We also continue to expect to report new data from the open label extension of our phase two clinical trial and WHIM later this year. We expect these data will continue to provide us insights regarding the long-term safety and durability of chronic Mavericks 4 treatments. Additionally, we anticipate several scientific publications that further support Mavericks 4's mechanism of action and potential for disease modification, as well as demonstrate its breadth of activity across the spectrum of WIM genotypes. Finally, we look forward to sharing new information regarding our additional WIM prevalence research later this year. In addition to our WHIM program, we continue to make good progress in our Phase 1b trial for the treatment of Waldenstrom's macroglobulinemia, a rare form of non-Hodgkin's lymphoma. As a reminder, this Phase 1b study is a multicenter, open-label, dose escalation clinical trial that is expected to enroll approximately 12 to 18 patients. We are very excited to have recently received notice of acceptance of our Phase 1B trial abstracts for a poster presentation at this year's Annual Congress of the European Hematology Association, or EHA, that will be taking place virtually from June 9th to June 17th. The abstract and poster will focus on initial clinical data from the ongoing Phase 1B trial of Maverick Sephora at the study's low and mid doses in combination with ibrutinib and the subset of Waldenstrom's macroglobulinemia patients harboring both the MYD88 and CXCR4 mutations. In addition to safety, pharmacokinetics, and pharmacodynamic markers, the initial data set will evaluate changes in serum immunoglobulin M, or IgM, and blood hemoglobin levels. It is well established that reductions in IgM levels and increases in hemoglobin levels correlate favorably with clinical responses for the treatment in Waldenstrom's patients. Later this year, we expect that the study will mature further such that we should be able to present data sets regarding the determination of the final dose selection for further study and assessment of major response rates, as well as ongoing safety across a range of doses. So as you can see, 2021 has been quite productive for us to date, and we're looking forward to a steady flow of value-adding data presentations and business milestones throughout the rest of the year. With that update, I will now turn the call over to Adam to discuss our results for the quarter and our recent financing announcements. Adam?