Notice of Proposed Sale · 144
X4 Pharmaceuticals, Inc.
XFORNASDAQEQUITYCurrent
Notice of Proposed Sale
Structured filing — 144
primary_doc.xml
Notice of proposed sale. The proposed amounts below do not establish that a sale occurred.
Proposed-sale notice
- Issuer
- X4 Pharmaceuticals, Inc
- Issuer CIK
- 0001501697
- SEC file number
- 001-38295
- Phone
- 508-633-4447
- Person for whose account securities are to be sold
- David Kirske
- Relationships to issuer
- Officer
- Street
- 61 NORTH BEACON STREET
- Street (continued)
- 4TH FLOOR
- City
- BOSTON
- State / country code
- MA
- Postal code
- 02134
Securities proposed for sale
| Security | Proposed units | Aggregate market value | Units outstanding | Approximate sale date | Exchange | Broker / market maker |
|---|---|---|---|---|---|---|
| Common Stock | 11,767 | 33,658.47 | 99,146,743 | 10/01/2026 | NASDAQ | Morgan Stanley Smith Barney LLC |
Broker / market maker — proposed row 1, entry 1
- Name
- Morgan Stanley Smith Barney LLC
- Street
- New York Plaza, 38th Floor
- City
- New York
- State / country code
- NY
- Postal code
- 10004
Acquisition of securities to be sold
| Security | Acquired | Nature of acquisition | Acquired from | Amount acquired | Gift transaction | Payment date | Nature of payment |
|---|---|---|---|---|---|---|---|
| Common Stock | 09/30/2026 | Restricted Stock Unit Vesting | Issuer | 32,209 | N | 09/30/2026 | Compensation |
Prior-sale reporting
- Nothing to report for the preceding three months
- Y
Remarks
Represents the number of shares required to be sold by the Reporting Person to cover the tax withholding obligation in connection with the settlement of vested restricted stock units. This sale is mandated by the Issuer's election under its equity incentive plans to require the Reporting Person to fund this tax withholding obligation by completing a "sell to cover" transaction with a brokerage firm designated by the Issuer. This sale does not represent a discretionary trade by the Reporting Person.
Notice signature
- Notice date
- 10/01/2026
- Signed
- /s/ Mitch Buckley as attorney-in-fact for David Kirske
Company context
X4 is delivering progress for patients by developing and commercializing innovative therapies for those with rare hematology diseases and significant unmet needs. Leveraging expertise in CXCR4, X4 has successfully developed mavorixafor, an orally available CXCR4 antagonist that is currently being marketed in the U.S. as XOLREMDI® in its first indication. The company is also evaluating additional uses of mavorixafor and is conducting a global, pivotal Phase 3 clinical trial (4WARD) in people with certain