X4 Pharmaceuticals, Inc SEC filings XFOR
X4 Pharmaceuticals, Inc has 818 filings in SEC EDGAR's recent list, going back to Sep 24, 2010. Its latest annual report, Form ARS, was filed on Mar 20, 2026 for the period ended Dec 31, 2025. The latest quarterly report (Form 10-Q) was filed on Nov 4, 2026, covering the quarter ended Sep 30, 2026. The most recent current report (Form 8-K) was filed on Oct 29, 2026 (other events). The company's fiscal year ends on December 31.
| Form | Description | Filed | Period |
|---|---|---|---|
| 10-Q | Quarterly report | Nov 4, 2026 | Sep 30, 2026 |
| 8-K |
Current report
Other events
|
Oct 29, 2026 | Oct 29, 2026 |
| 8-K |
Current report
Material agreement, Agreement ended, New debt, Unregistered share sale, Regulation FD disclosure
|
Oct 8, 2026 | Oct 7, 2026 |
| 8-K |
Current report
Other events
|
Sep 9, 2026 | Sep 8, 2026 |
| 8-K |
Current report
Other events
|
Sep 8, 2026 | Sep 8, 2026 |
| 10-Q | Quarterly report | Aug 6, 2026 | Jun 30, 2026 |
| 8-K |
Current report
Officer or director change, Regulation FD disclosure
|
Jul 1, 2026 | Jun 30, 2026 |
| EFFECT | Filing | May 14, 2026 | — |
| 8-K/A |
Amended current report
Officer or director change, Shareholder vote results
|
May 13, 2026 | May 11, 2026 |
| 8-K |
Current report
Officer or director change, Shareholder vote results
|
May 12, 2026 | May 11, 2026 |
| CORRESP | Letter to the SEC | May 12, 2026 | — |
| UPLOAD | Letter from the SEC | May 11, 2026 | — |
| S-3 | Shelf registration | May 6, 2026 | — |
| 10-Q | Quarterly report | May 6, 2026 | Mar 31, 2026 |
| ARS | Annual report to shareholders | Mar 20, 2026 | Dec 31, 2025 |
| DEFA14A | Additional proxy material | Mar 20, 2026 | — |
| DEF 14A | Proxy statement | Mar 20, 2026 | Mar 20, 2026 |
| S-8 | Employee stock plan registration | Mar 18, 2026 | — |
| 10-K | Annual report | Mar 17, 2026 | Dec 31, 2025 |
| 10-Q | Quarterly report | Nov 5, 2025 | Sep 30, 2025 |
| 8-K |
Current report
Results of operations
|
Nov 5, 2025 | Nov 5, 2025 |
| 8-K |
Current report
Material agreement
|
Oct 27, 2025 | Oct 23, 2025 |
| 424B5 | Prospectus supplement | Oct 24, 2025 | — |
| 424B5 | Prospectus supplement | Oct 23, 2025 | — |
| 424B3 | Prospectus | Sep 18, 2025 | — |
| EFFECT | Filing | Sep 17, 2025 | — |
| 8-K |
Current report
Exit or restructuring costs, Officer or director change, Regulation FD disclosure
|
Sep 17, 2025 | Sep 15, 2025 |
| CORRESP | Letter to the SEC | Sep 15, 2025 | — |
| UPLOAD | Letter from the SEC | Sep 15, 2025 | — |
| S-3 | Shelf registration | Sep 10, 2025 | — |
| S-8 | Employee stock plan registration | Sep 10, 2025 | — |
| D | Filing | Aug 25, 2025 | — |
| 8-K |
Current report
Officer or director change
|
Aug 25, 2025 | Aug 22, 2025 |
| 8-K |
Current report
Material agreement, Unregistered share sale, Other events
|
Aug 13, 2025 | Aug 12, 2025 |
| 8-K |
Current report
Material agreement, Unregistered share sale, Officer or director change, Other events
|
Aug 12, 2025 | Aug 11, 2025 |
| 10-Q | Quarterly report | Aug 8, 2025 | Jun 30, 2025 |
| 8-K |
Current report
Material agreement
|
Jun 23, 2025 | Jun 23, 2025 |
| 424B5 | Prospectus supplement | Jun 23, 2025 | — |
| 8-K |
Current report
Shareholder vote results
|
Jun 11, 2025 | Jun 11, 2025 |
| 10-Q | Quarterly report | May 1, 2025 | Mar 31, 2025 |
| 8-K |
Current report
Results of operations, Regulation FD disclosure
|
May 1, 2025 | May 1, 2025 |
| DEF 14A | Proxy statement | Apr 25, 2025 | Apr 25, 2025 |
| DEFA14A | Additional proxy material | Apr 25, 2025 | — |
| 8-K |
Current report
Bylaw or fiscal year change, Other events
|
Apr 24, 2025 | Apr 24, 2025 |
| 8-K |
Current report
Shareholder vote results
|
Apr 18, 2025 | Apr 17, 2025 |
| S-8 | Employee stock plan registration | Mar 26, 2025 | — |
| 10-K | Annual report | Mar 26, 2025 | Dec 31, 2024 |
| 8-K |
Current report
Results of operations
|
Mar 25, 2025 | Mar 25, 2025 |
| DEF 14A | Proxy statement | Mar 24, 2025 | Mar 24, 2025 |
| PRE 14A | Preliminary proxy statement | Mar 14, 2025 | Mar 14, 2025 |
| 8-K |
Current report
Other events
|
Mar 3, 2025 | Mar 3, 2025 |
| 8-K |
Current report
Exit or restructuring costs, Regulation FD disclosure
|
Feb 6, 2025 | Feb 6, 2025 |
| S-8 | Employee stock plan registration | Jan 16, 2025 | — |
| 8-K |
Current report
Material agreement, Regulation FD disclosure
|
Jan 13, 2025 | Jan 13, 2025 |
| UPLOAD | Letter from the SEC | Jan 7, 2025 | — |
| CORRESP | Letter to the SEC | Dec 23, 2024 | — |
| UPLOAD | Letter from the SEC | Dec 13, 2024 | — |
| 10-Q | Quarterly report | Nov 13, 2024 | Sep 30, 2024 |
| 8-K |
Current report
Regulation FD disclosure, Other events
|
Nov 13, 2024 | Nov 13, 2024 |
| 8-K |
Current report
Results of operations
|
Nov 13, 2024 | Nov 13, 2024 |
| S-8 | Employee stock plan registration | Oct 4, 2024 | — |
| 8-K |
Current report
Listing notice
|
Aug 16, 2024 | Aug 13, 2024 |
| 8-K |
Current report
Regulation FD disclosure
|
Aug 9, 2024 | Aug 8, 2024 |
| 10-Q | Quarterly report | Aug 8, 2024 | Jun 30, 2024 |
| 8-K |
Current report
Results of operations
|
Aug 8, 2024 | Aug 8, 2024 |
| 8-K |
Current report
Regulation FD disclosure
|
Jul 19, 2024 | Jul 19, 2024 |
| 8-K |
Current report
Regulation FD disclosure, Other events
|
Jun 27, 2024 | Jun 27, 2024 |
| 8-K |
Current report
Shareholder vote results
|
Jun 11, 2024 | Jun 10, 2024 |
| 8-K |
Current report
Regulation FD disclosure
|
May 22, 2024 | May 22, 2024 |
| 8-K |
Current report
Material agreement, Acquisition or sale of assets, Officer or director change, Regulation FD disclosure, Other events
|
May 9, 2024 | May 8, 2024 |
| 10-Q | Quarterly report | May 7, 2024 | Mar 31, 2024 |
| 8-K |
Current report
Results of operations
|
May 7, 2024 | May 7, 2024 |
| ARS | Annual report to shareholders | Apr 29, 2024 | Dec 31, 2023 |
| DEFA14A | Additional proxy material | Apr 29, 2024 | — |
| DEF 14A | Proxy statement | Apr 29, 2024 | Apr 29, 2024 |
| 8-K |
Current report
Regulation FD disclosure, Other events
|
Apr 29, 2024 | Apr 29, 2024 |
| 8-K |
Current report
Regulation FD disclosure, Other events
|
Apr 29, 2024 | Apr 29, 2024 |
| 8-K |
Current report
Other events
|
Apr 5, 2024 | Apr 5, 2024 |
| 8-K |
Current report
Regulation FD disclosure
|
Apr 1, 2024 | Apr 1, 2024 |
| 10-K | Annual report | Mar 21, 2024 | Dec 31, 2023 |
| 8-K |
Current report
Results of operations
|
Mar 21, 2024 | Mar 21, 2024 |
| S-8 | Employee stock plan registration | Jan 25, 2024 | — |
| 8-K |
Current report
Regulation FD disclosure
|
Jan 8, 2024 | Jan 8, 2024 |
| 8-K |
Current report
Regulation FD disclosure
|
Nov 27, 2023 | Nov 27, 2023 |
| 8-K |
Current report
Listing notice
|
Nov 14, 2023 | Nov 13, 2023 |
| 10-Q | Quarterly report | Nov 9, 2023 | Sep 30, 2023 |
| 8-K |
Current report
Results of operations
|
Nov 9, 2023 | Nov 9, 2023 |
| 8-K |
Current report
Other events
|
Oct 31, 2023 | Oct 31, 2023 |
| 8-K |
Current report
Officer or director change, Regulation FD disclosure
|
Oct 18, 2023 | Oct 16, 2023 |
| 8-K |
Current report
Other events
|
Sep 5, 2023 | Sep 5, 2023 |
| EFFECT | Filing | Aug 24, 2023 | — |
| CORRESP | Letter to the SEC | Aug 22, 2023 | — |
| UPLOAD | Letter from the SEC | Aug 21, 2023 | — |
| S-3 | Shelf registration | Aug 14, 2023 | — |
| S-8 | Employee stock plan registration | Aug 14, 2023 | — |
| 10-Q | Quarterly report | Aug 10, 2023 | Jun 30, 2023 |
| 8-K |
Current report
Results of operations
|
Aug 10, 2023 | Aug 10, 2023 |
| 8-K |
Current report
Material agreement, New debt, Regulation FD disclosure
|
Aug 3, 2023 | Aug 2, 2023 |
| 424B3 | Prospectus | Jun 21, 2023 | — |
| EFFECT | Filing | Jun 20, 2023 | — |
| CORRESP | Letter to the SEC | Jun 16, 2023 | — |
| UPLOAD | Letter from the SEC | Jun 16, 2023 | — |
| 8-K |
Current report
Shareholder vote results
|
Jun 15, 2023 | Jun 13, 2023 |
| S-3 | Shelf registration | Jun 9, 2023 | — |
| D | Filing | Jun 1, 2023 | — |
| 8-K |
Current report
Regulation FD disclosure
|
Jun 1, 2023 | Jun 1, 2023 |
| 8-K |
Current report
Material agreement, Unregistered share sale, Regulation FD disclosure, Other events
|
May 16, 2023 | May 15, 2023 |
| 10-Q | Quarterly report | May 4, 2023 | Mar 31, 2023 |
| 8-K |
Current report
Regulation FD disclosure
|
May 4, 2023 | May 4, 2023 |
| 8-K |
Current report
Results of operations
|
May 4, 2023 | May 4, 2023 |
| 8-K |
Current report
Acquisition or sale of assets
|
May 4, 2023 | May 4, 2023 |
| DEFA14A | Additional proxy material | Apr 27, 2023 | — |
| ARS | Annual report to shareholders | Apr 25, 2023 | Dec 31, 2022 |
| DEFA14A | Additional proxy material | Apr 25, 2023 | — |
| DEF 14A | Proxy statement | Apr 25, 2023 | Apr 25, 2023 |
| 8-K |
Current report
Regulation FD disclosure
|
Mar 21, 2023 | Mar 21, 2023 |
| 10-K | Annual report | Mar 21, 2023 | Dec 31, 2022 |
| 8-K |
Current report
Results of operations
|
Mar 21, 2023 | Mar 21, 2023 |
| 8-K |
Current report
Other events
|
Mar 10, 2023 | Mar 10, 2023 |
| S-8 | Employee stock plan registration | Jan 20, 2023 | — |
| 8-K |
Current report
Material agreement, New debt
|
Jan 6, 2023 | Jan 6, 2023 |
| 8-K |
Current report
Regulation FD disclosure
|
Jan 5, 2023 | Jan 5, 2023 |
| 8-K |
Current report
Officer or director change
|
Dec 23, 2022 | Dec 20, 2022 |
| 8-K |
Current report
Material agreement, Other events
|
Dec 9, 2022 | Dec 6, 2022 |
| 424B5 | Prospectus supplement | Dec 9, 2022 | — |
| 424B5 | Prospectus supplement | Dec 7, 2022 | — |
| 8-K |
Current report
Regulation FD disclosure, Other events
|
Nov 29, 2022 | Nov 29, 2022 |
| 8-K |
Current report
Officer or director change
|
Nov 9, 2022 | Nov 7, 2022 |
| 10-Q | Quarterly report | Nov 3, 2022 | Sep 30, 2022 |
| 8-K |
Current report
Results of operations, Other events
|
Nov 3, 2022 | Nov 3, 2022 |
| 8-K |
Current report
Regulation FD disclosure, Other events
|
Oct 4, 2022 | Oct 4, 2022 |
| 8-K |
Current report
Regulation FD disclosure, Other events
|
Sep 27, 2022 | Sep 27, 2022 |
| 8-K |
Current report
Change to shareholder rights, Bylaw or fiscal year change, Shareholder vote results
|
Sep 1, 2022 | Sep 1, 2022 |
| DEF 14A | Proxy statement | Aug 11, 2022 | Sep 1, 2022 |
| EFFECT | Filing | Aug 5, 2022 | — |
| 424B3 | Prospectus | Aug 5, 2022 | — |
| 8-K |
Current report
Regulation FD disclosure
|
Aug 5, 2022 | Aug 5, 2022 |
| 10-Q | Quarterly report | Aug 4, 2022 | Jun 30, 2022 |
| 8-K |
Current report
Results of operations
|
Aug 4, 2022 | Aug 4, 2022 |
| CORRESP | Letter to the SEC | Aug 3, 2022 | — |
| UPLOAD | Letter from the SEC | Aug 2, 2022 | — |
| PRE 14A | Preliminary proxy statement | Aug 1, 2022 | Sep 1, 2022 |
| S-3 | Shelf registration | Jul 29, 2022 | — |
| 8-K |
Current report
Officer or director change
|
Jul 29, 2022 | Jul 25, 2022 |
| 424B3 | Prospectus | Jul 29, 2022 | — |
| D | Filing | Jul 19, 2022 | — |
| 8-K |
Current report
Material agreement, New debt, Unregistered share sale, Other events
|
Jul 1, 2022 | Jun 30, 2022 |
| 8-K |
Current report
Shareholder vote results
|
Jun 7, 2022 | Jun 6, 2022 |
| 8-K |
Current report
Regulation FD disclosure, Other events
|
May 20, 2022 | May 20, 2022 |
| EFFECT | Filing | May 13, 2022 | — |
| 10-Q | Quarterly report | May 12, 2022 | Mar 31, 2022 |
| CORRESP | Letter to the SEC | May 12, 2022 | — |
| 8-K |
Current report
Results of operations, Regulation FD disclosure
|
May 12, 2022 | May 12, 2022 |
| UPLOAD | Letter from the SEC | Apr 28, 2022 | — |
| DEFA14A | Additional proxy material | Apr 25, 2022 | — |
| DEF 14A | Proxy statement | Apr 25, 2022 | Jun 6, 2022 |
| S-3 | Shelf registration | Apr 22, 2022 | — |
| 424B5 | Prospectus supplement | Mar 22, 2022 | — |
| 10-K | Annual report | Mar 17, 2022 | Dec 31, 2021 |
| 8-K |
Current report
Results of operations, Regulation FD disclosure
|
Mar 17, 2022 | Mar 17, 2022 |
| S-8 | Employee stock plan registration | Mar 10, 2022 | — |
| 8-K |
Current report
Material agreement, Unregistered share sale, Other events
|
Mar 3, 2022 | Mar 3, 2022 |
| 8-K |
Current report
Material agreement, New debt
|
Feb 9, 2022 | Feb 9, 2022 |
| 8-K/A |
Amended current report
Results of operations, Regulation FD disclosure, Other events
|
Jan 26, 2022 | Jan 25, 2022 |
| 8-K |
Current report
Results of operations, Regulation FD disclosure, Other events
|
Jan 25, 2022 | Jan 25, 2022 |
| 8-K |
Current report
Material agreement
|
Jan 14, 2022 | Jan 14, 2022 |
| 424B5 | Prospectus supplement | Jan 14, 2022 | — |
| 8-K |
Current report
Agreement ended
|
Jan 14, 2022 | Jan 13, 2022 |
| 424B3 | Prospectus | Jan 4, 2022 | — |
| EFFECT | Filing | Jan 3, 2022 | — |
| CORRESP | Letter to the SEC | Dec 30, 2021 | — |
| UPLOAD | Letter from the SEC | Dec 29, 2021 | — |
| S-3 | Shelf registration | Dec 23, 2021 | — |
| 8-K |
Current report
Regulation FD disclosure, Other events
|
Dec 13, 2021 | Dec 13, 2021 |
| 8-K |
Current report
Regulation FD disclosure, Other events
|
Nov 15, 2021 | Nov 15, 2021 |
| 8-K |
Current report
Officer or director change
|
Nov 12, 2021 | Nov 11, 2021 |
| 8-K |
Current report
Material agreement, Unregistered share sale
|
Nov 5, 2021 | Nov 5, 2021 |
| 10-Q | Quarterly report | Nov 4, 2021 | Sep 30, 2021 |
| 8-K |
Current report
Results of operations
|
Nov 4, 2021 | Nov 4, 2021 |
| 8-K |
Current report
Officer or director change
|
Oct 19, 2021 | Oct 14, 2021 |
| 8-K |
Current report
Officer or director change
|
Sep 10, 2021 | Sep 10, 2021 |
| 8-K |
Current report
Regulation FD disclosure
|
Aug 6, 2021 | Aug 6, 2021 |
| 10-Q | Quarterly report | Aug 3, 2021 | Jun 30, 2021 |
| 8-K |
Current report
Results of operations
|
Aug 3, 2021 | Aug 3, 2021 |
| 8-K |
Current report
Other events
|
Jul 23, 2021 | Jul 20, 2021 |
| 8-K |
Current report
Other events
|
Jul 15, 2021 | Jul 15, 2021 |
| 424B3 | Prospectus | Jul 12, 2021 | — |
| EFFECT | Filing | Jul 9, 2021 | — |
| CORRESP | Letter to the SEC | Jul 7, 2021 | — |
| UPLOAD | Letter from the SEC | Jul 2, 2021 | — |
| 8-K |
Current report
Regulation FD disclosure, Other events
|
Jun 28, 2021 | Jun 28, 2021 |
| S-3 | Shelf registration | Jun 25, 2021 | — |
| 8-K |
Current report
Other events
|
Jun 11, 2021 | Jun 11, 2021 |
| 8-K |
Current report
Shareholder vote results, Other events
|
Jun 7, 2021 | Jun 7, 2021 |
| 8-K |
Current report
Results of operations
|
May 6, 2021 | May 6, 2021 |
| 10-Q | Quarterly report | May 6, 2021 | Mar 31, 2021 |
| DEFA14A | Additional proxy material | Apr 20, 2021 | — |
| DEF 14A | Proxy statement | Apr 20, 2021 | Dec 31, 2020 |
| 8-K |
Current report
Regulation FD disclosure
|
Apr 9, 2021 | Apr 9, 2021 |
| S-8 | Employee stock plan registration | Mar 23, 2021 | — |
Showing 200 filings, the most recent 200. Main filings leave out insider and ownership forms such as Form 4; choose a type above to see them. Each form opens on SEC.gov. Older filings are on SEC EDGAR.
New to this? Read What Are SEC Filings? 10-K, 10-Q, 8-K and Other Forms Explained.
Company profile
- Industry
- Biological Products, (No Diagnostic Substances) (SIC 2836)
- Listed as
- XFOR (Nasdaq)
- Fiscal year ends
- December 31
- Incorporated in
- DE
- Headquarters
- Boston, MA
- SEC filer status
- Non-accelerated filer, Smaller reporting company
- SEC CIK
- 1501697
- Former names
- Arsanis, Inc. (until Mar 13, 2019)
Other Biological Products, (No Diagnostic Substances) companies
- Amgen Inc AMGN
- Gilead Sciences, Inc. GILD
- Moderna, Inc. MRNA
- Argenx SE ARGX
- Revolution Medicines, Inc. RVMD
- Biogen Inc. BIIB
- BioNTech SE BNTX
- Exelixis, Inc. EXEL
All 182 Biological Products, (No Diagnostic Substances) companies
Source: SEC EDGAR filings. This is company-reported data, not investment advice.