[FORM 10-K Filing Information](index=1&type=section&id=FORM%2010-K) This section details **X4 Pharmaceuticals, Inc.'s** identification, incorporation, executive offices, **Nasdaq** listing, and **SEC** filing classifications for the fiscal year ended **December 31, 2021** [Registrant Information](index=1&type=section&id=Registrant%20Information) This section provides key identification details for **X4 Pharmaceuticals, Inc.**, including its incorporation state, principal executive offices, telephone number, and **SEC** filing particulars for the fiscal year ended **December 31, 2021**. The company is registered on **The Nasdaq Stock Market LLC** under the symbol **XFOR** and is classified as a non-accelerated filer, smaller reporting company, and emerging growth company - Registrant: **X4 PHARMACEUTICALS, INC.**[2](index=2&type=chunk) - Incorporation: **Delaware**[2](index=2&type=chunk) - Principal Executive Offices: **61 North Beacon Street, 4th Floor, Boston, Massachusetts**[2](index=2&type=chunk) SEC Filing Classifications | Classification | Status | | :--------------- | :----- | | **Well-known seasoned issuer** | No | | **Required to file reports** | Yes | | **Filed all reports (preceding 12 months)** | Yes | | **Submitted Interactive Data File (preceding 12 months)** | Yes | | **Large Accelerated Filer** | No | | **Accelerated Filer** | No | | **Non-accelerated filer** | Yes | | **Smaller reporting company** | Yes | | **Emerging growth company** | Yes | - **Market Value of Voting Common Stock** (non-affiliates, **June 30, 2021**): Approximately **$158 million**[4](index=4&type=chunk) - **Shares of Common Stock Outstanding** (**March 14, 2022**): **30,809,376 shares**[5](index=5&type=chunk) [Documents Incorporated by Reference](index=1&type=section&id=DOCUMENTS%20INCORPORATED%20BY%20REFERENCE) Portions of the registrant's definitive proxy statement for its **2022 Annual Meeting of Stockholders** are incorporated by reference into **Part III** of this **Annual Report on Form 10-K** - Portions of the **2022 Proxy Statement** for the **Annual Meeting of Stockholders** are incorporated by reference into **Part III** of this **Form 10-K**[7](index=7&type=chunk) [Cautionary Note Regarding Forward-Looking Statements](index=3&type=section&id=CAUTIONARY%20NOTE%20REGARDING%20FORWARD-LOOKING%20STATEMENTS) This section advises investors on the inherent risks and uncertainties associated with forward-looking statements in the **Annual Report**, emphasizing that actual results may differ materially from projections [Nature of Forward-Looking Statements](index=3&type=section&id=Nature%20of%20Forward-Looking%20Statements) This section highlights that the **Annual Report** contains forward-looking statements, identifiable by specific terminology, which are based on expectations, assumptions, estimates, and projections. These statements are not guarantees of future results and involve substantial risks and uncertainties, with actual results potentially differing materially - The **Annual Report** contains forward-looking statements identified by terms such as 'may,' 'should,' 'expects,' 'intends,' 'plans,' 'anticipates,' 'believes,' 'estimates,' 'predicts,' 'potential,' 'continue' or negatives thereof[12](index=12&type=chunk) - These statements are based on expectations, assumptions, estimates, and projections, are not guarantees of future results, and involve substantial risks and uncertainty[12](index=12&type=chunk) [Key Risks and Uncertainties](index=3&type=section&id=Key%20Risks%20and%20Uncertainties) Forward-looking statements are subject to numerous known and unknown risks, including those detailed in the '**Risk Factors**' section. These risks encompass the timing and results of clinical trials for **mavorixafor** (**WHIM**, **Waldenström's**, **SCN**), the impact of the **COVID-19 pandemic** on operations and trials, regulatory approval processes, commercialization strategies, intellectual property protection, and financial needs - Timing, progress, and results of current trials of **mavorixafor** (**Phase 3** for **WHIM syndrome**, **Phase 1b** for **Waldenström's macroglobulinemia**, **Phase 1b** for severe congenital **Neutropenia** (**SCN**) and chronic neutropenia disorders)[12](index=12&type=chunk) - Initiation, timing, design, progress, and results of current and future preclinical studies and clinical trials of **X4P-002** and **X4P-003**[12](index=12&type=chunk) - Impact of the ongoing **COVID-19 pandemic** on business, operations, strategy, goals, and anticipated timelines, including diversion of healthcare resources and interruption of clinical trial activities[12](index=12&type=chunk) - Ability to obtain and maintain regulatory approval for product candidates and related restrictions[12](index=12&type=chunk) - Plans to research, develop, manufacture, and commercialize product candidates[12](index=12&type=chunk) - Timing of regulatory filings and developments in the **U.S.** and other countries[12](index=12&type=chunk) - Size and growth potential of markets for product candidates and market acceptance[12](index=12&type=chunk) - Benefits of **FDA** and **European Commission** designations (**Fast Track**, **Orphan Drug**, **Breakthrough Therapy**)[13](index=13&type=chunk) - Commercialization, marketing, and manufacturing capabilities and strategy[13](index=13&type=chunk) - Ability to attract and retain qualified employees and key personnel[13](index=13&type=chunk) - Competitive position and industry developments[13](index=13&type=chunk) - Expectations regarding intellectual property protection, future operations, financial position, revenues, costs, expenses, capital requirements, and need for additional financing[13](index=13&type=chunk) - Plans to in-license, acquire, develop, and commercialize additional product candidates[13](index=13&type=chunk) - Impact of laws and regulations[13](index=13&type=chunk) - Strategies, prospects, plans, expectations, or objectives[13](index=13&type=chunk) [Disclaimer and Obligation](index=5&type=section&id=Disclaimer%20and%20Obligation) Investors are advised not to rely on forward-looking statements as guarantees of future performance, and the company undertakes no obligation to publicly update these statements unless required by law - Investors should not rely on forward-looking statements as representing the company's views as of any date subsequent to the report date[14](index=14&type=chunk) - The company undertakes no obligation to publicly update any forward-looking statements, except as required by law[14](index=14&type=chunk) [PART I](index=6&type=section&id=PART%20I) [Item 1. Business](index=6&type=section&id=Item%201.%20BUSINESS) **X4 Pharmaceuticals, Inc.** is a late-stage clinical biopharmaceutical company focused on rare diseases, particularly those involving immune system dysfunction. Its lead product candidate, **mavorixafor**, a **CXCR4 inhibitor**, is in **Phase 3** trials for **WHIM syndrome** and **Phase 1b** trials for chronic neutropenia and **Waldenström's macroglobulinemia**. The company aims to commercialize **mavorixafor**, expand its pipeline with earlier-stage candidates (**X4P-002**, **X4P-003**), and pursue strategic collaborations - **X4 Pharmaceuticals** is a late-stage clinical biopharmaceutical company focused on rare diseases, initially immune system dysfunction[18](index=18&type=chunk) - Lead product candidate, **mavorixafor**, is a **first-in-class**, small molecule **CXCR4 inhibitor**, developed as a **once-daily oral therapy**[18](index=18&type=chunk) - **Mavorixafor** is in a global **Phase 3 clinical trial** for **WHIM syndrome**, and **Phase 1b clinical trials** for chronic neutropenia and **Waldenström's macroglobulinemia**[19](index=19&type=chunk) [Overview](index=6&type=section&id=Overview) **X4 Pharmaceuticals** is a late-stage clinical biopharmaceutical company developing **mavorixafor**, a **CXCR4 inhibitor**, for rare diseases like **WHIM syndrome**, chronic neutropenia, and **Waldenström's macroglobulinemia**. The **Phase 3** trial for **WHIM syndrome** completed enrollment in **Q3 2021**, with top-line data expected in **Q4 2022**. **Mavorixafor** has received **Breakthrough Therapy**, **Fast Track**, and **Rare Pediatric Designations** from the **FDA** for **WHIM syndrome**, with an **NDA** submission anticipated in **H2 2023**. The company estimates a higher prevalence of **WHIM syndrome** in the **U.S.** (**1,000 to 3,500+ patients**) than previously thought, supported by new mutation identification - **Mavorixafor** is a **first-in-class**, small molecule inhibitor of the chemokine receptor **CXCR4**, developed as a **once-daily oral therapy** for rare diseases, including primary immunodeficiencies (**PIDs**) and certain cancers[18](index=18&type=chunk) - Global **Phase 3 clinical trial** for **WHIM syndrome** completed enrollment in **Q3 2021** (**31 patients**), with **top-line data expected Q4 2022**[20](index=20&type=chunk) - **Mavorixafor** received **FDA Breakthrough Therapy**, **Fast Track**, and **Rare Pediatric Designations** for **WHIM syndrome**, potentially leading to accelerated review[20](index=20&type=chunk) - Anticipated **New Drug Application (NDA) submission** to **FDA** in **H2 2023** for **WHIM syndrome** (ages **12+**)[20](index=20&type=chunk) - Prevalence of **WHIM syndrome** in the **U.S.** is estimated to be **1,000 to 3,500+ patients**, significantly higher than previous registries, supported by market research and identification of a new **D84H mutation**[21](index=21&type=chunk) - Additional data from **Phase 1b clinical trials** in chronic neutropenia and **Waldenström's** expected by **Q3 2022** and **H2 2022**, respectively[22](index=22&type=chunk) [Our Strategy

Investor Presentation March 2022 Forward-Looking Statements 2 This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. These statements may be identified by the words "may," "will," "could," "would," "should," "expect," "plan," "anticipate," "intend," "believe," "estimate," "predict," "project," "potential," "continue," "target," or other similar terms or expressions that concern X4's expectations, strategy, plans, or inten ...

Mavorixafor's Potential & Target Diseases - Mavorixafor, a Phase 3 candidate, is being advanced to potentially treat over 30,000 patients in the US and EU markets across multiple indications[7] - The company is targeting 1,000-3,700 U S WHIM syndrome patients, 2,000-3,000 U S Waldenström's Macroglobulinemia patients, and 5,000-10,000 U S Chronic Neutropenia patients[10] - The global G-CSF market for all uses is over $4 billion, with the U S market for severe chronic neutropenia estimated at $120-460 million[57] Clinical Trial Updates & Data - Top-line data from the Phase 3 trial in WHIM syndrome is expected in 4Q 2022, with a potential NDA filing in 1Q 2023[7, 98] - Initial data from the Phase 1b trial in Chronic Neutropenia and additional data in Waldenström's Macroglobulinemia are expected in 4Q 2021[7, 98] - Phase 2 trial in WHIM syndrome demonstrated a 6-fold increase in TATANC and over 80% reduction in annualized infection rates[37] Pipeline & Expansion - A new molecule (X4P-002) is expected to enter the clinic in 2H 2022 for oncology indications, targeting other leukemias and lymphomas which is >25,000[7, 10] - The company anticipates additional data at all doses and initial response data (OR, MR) for Waldenström's Macroglobulinemia in 4Q 2021[92] - Newly identified D84H CXCR4 mutation suggests additional ~1,250-2,500 WHIM patients[49] Financial Status - The company had $78 million in cash and equivalents as of September 30, 2021, expected to fund operations into Q4 2022, excluding $19.5 million in net proceeds from equity sale in November 2021[100, 101, 105]

X4 Pharmaceuticals, Inc. (NASDAQ:XFOR) Q3 2021 Earnings Conference Call November 4, 2021 9:05 AM ET Company Participants Dan Ferry - LifeSci Advisors Paula Ragan - Chief Executive Officer Adam Mostafa - Chief Financial Officer Art Taveras - Chief Scientific Officer Diego Cadavid - Chief Medical Officer Conference Call Participants Zegbeh Jallah - ROTH Capital Leland Gershell - Oppenheimer Marc Frahm - Cowen & Company Stephen Willey - Stifel Operator Greetings and welcome to X4 Pharmaceuticals Third Quarter ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 _____________________________________________________________________________________ FORM 10-Q _____________________________________________________________________________________ (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2021 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the trans ...

| --- | --- | --- | --- | |--------------------------------------------------------------------------------------------------------------------------------|-------|-------|-------| | | | | | | | | | | | Developing treatments | | | | | designed to have a clear and profound impact for patients with rare diseases, including WHIM syndrome and uncommon cancers | | | | | September 2021 Investor Deck | | | | | | | | | Forward-Looking Statements 2 This presentation contains forward-looking statements within the mea ...

X4 Pharmaceuticals, Inc. (NASDAQ:XFOR) Q2 2021 Earnings Conference Call August 3, 2021 8:30 AM ET Company Participants Carey Gallant - Investor Relations, LifeSci Advisors Paula Ragan - Chief Executive Officer Adam Mostafa - Chief Financial Officer Art Taveras - Chief Scientific Officer Conference Call Participants Trevor Allred - Oppenheimer RK - H.C. Wainwright Zegbeh Jallah - ROTH Capital Partners Mayank Mamtani - B. Riley Financial Ben Shim - Canaccord. Operator Greetings, and welcome to X4 Pharmaceutic ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 _____________________________________________________________________________________ FORM 10-Q _____________________________________________________________________________________ (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2021 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition ...

X4 Pharmaceuticals, Inc. (NASDAQ:XFOR) Q1 2021 Earnings Conference Call May 6, 2021 8:30 AM ET Company Participants Daniel Ferry - LifeSci Advisors Paula Ragan - CEO Adam Mostafa - CFO Art Taveras - Chief Scientific Officer Diego Cadavid - Chief Medical Officer Conference Call Participants Stephen Willey - Stifel Marc Frahm - Cowen Swayampakula Ramakanth - H.C. Wainwright Sahil Kazmi - B. Riley FBR Arlinda Lee - Canaccord Genuity Operator Greetings and welcome to X4 Pharmaceuticals First Quarter Financial a ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 _____________________________________________________________________________________ FORM 10-Q _____________________________________________________________________________________ (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2021 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transitio ...