Spero Therapeutics, Inc. SEC filings SPRO
Spero Therapeutics, Inc. has 515 filings in SEC EDGAR's recent list, going back to Mar 21, 2017. Its latest annual report, Form ARS, was filed on Apr 27, 2026 for the period ended Dec 31, 2025. The latest quarterly report (Form 10-Q) was filed on Aug 12, 2026, covering the quarter ended Jun 30, 2026. The most recent current report (Form 8-K) was filed on Oct 27, 2026 (officer or director change). The company's fiscal year ends on December 31.
| Form | Description | Filed | Period |
|---|---|---|---|
| S-8 | Employee stock plan registration | Oct 28, 2026 | — |
| S-3 | Shelf registration | Aug 28, 2026 | — |
| S-8 | Employee stock plan registration | Jun 23, 2026 | — |
| S-8 | Employee stock plan registration | Aug 12, 2025 | — |
| S-8 | Employee stock plan registration | Aug 5, 2024 | — |
| S-3 | Shelf registration | Mar 15, 2024 | — |
| S-8 | Employee stock plan registration | Mar 15, 2024 | — |
| S-8 | Employee stock plan registration | Nov 13, 2023 | — |
| S-8 | Employee stock plan registration | Nov 13, 2023 | — |
| S-8 | Employee stock plan registration | Aug 10, 2023 | — |
| S-8 | Employee stock plan registration | Mar 30, 2023 | — |
| S-8 | Employee stock plan registration | Nov 14, 2022 | — |
| S-8 | Employee stock plan registration | Sep 20, 2021 | — |
| S-8 | Employee stock plan registration | Mar 11, 2021 | — |
| S-3 | Shelf registration | Mar 11, 2021 | — |
| 424B5 | Prospectus supplement | Nov 13, 2020 | — |
| 424B5 | Prospectus supplement | Sep 14, 2020 | — |
| 424B5 | Prospectus supplement | Sep 9, 2020 | — |
| S-8 | Employee stock plan registration | Aug 6, 2020 | — |
| S-8 | Employee stock plan registration | Mar 19, 2020 | — |
| 424B5 | Prospectus supplement | Feb 11, 2020 | — |
| 424B5 | Prospectus supplement | Jun 14, 2019 | — |
| S-8 | Employee stock plan registration | Mar 14, 2019 | — |
| S-8 | Employee stock plan registration | Mar 14, 2019 | — |
| S-3 | Shelf registration | Dec 3, 2018 | — |
| 424B4 | Prospectus | Jul 13, 2018 | — |
| S-1/A | Amended registration statement | Jul 11, 2018 | — |
| S-1 | Registration statement | Jul 9, 2018 | — |
| S-8 | Employee stock plan registration | Dec 14, 2017 | — |
| 424B4 | Prospectus | Nov 2, 2017 | — |
| S-1/A | Amended registration statement | Oct 23, 2017 | — |
| S-1 | Registration statement | Oct 6, 2017 | — |
Showing 32 filings. 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.
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Company profile
- Industry
- Pharmaceutical Preparations (SIC 2834)
- Listed as
- SPRO (Nasdaq)
- Fiscal year ends
- December 31
- Incorporated in
- DE
- Headquarters
- Cambridge, MA
- SEC filer status
- Non-accelerated filer, Smaller reporting company
- SEC CIK
- 1701108
- Former names
- Spero Therapeutics, LLC (until Mar 21, 2017)
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Source: SEC EDGAR filings. This is company-reported data, not investment advice.