Spero Therapeutics, Inc. 8-K

What Happened

• Spero Therapeutics, Inc. (SPRO) announced its financial results for the fourth quarter and full year ended December 31, 2025 in a press release dated March 26, 2026. The company furnished that press release as Exhibit 99.1 to a Current Report on Form 8-K (Item 2.02: Results of Operations and Financial Condition).

Key Details

• Filing date: March 26, 2026 (Form 8-K reporting results).
• Reporting period: Quarter and full year ended December 31, 2025.
• Disclosure format: Press release furnished as Exhibit 99.1 to the 8-K.
• The Form 8-K also includes interactive XBRL cover page data (Exhibit 101).

Why It Matters

• This 8-K signals that Spero has publicly reported its latest quarterly and annual operating and financial results, which investors can review to assess recent revenue, expenses, cash position, and trends. Because the press release is furnished (not filed), investors should read the full release and any accompanying financial statements or filings for detailed figures and management commentary before making investment decisions.