8-K: Spero Therapeutics Announces Q4 and Full Year 2024 Results, Provides Business Update

• Spero Therapeutics announced its fourth quarter and full year 2024 financial results and provided a business update on March 27, 2025.
• The company reported a net loss of $(20.9) million for Q4 2024, compared to a net income of $51.2 million for Q4 2023.
• The net loss for the year ended December 31, 2024, was $(68.6) million, compared to a net income of $22.8 million for the year ended December 31, 2023.
• Total revenue for Q4 2024 was $15.0 million, a decrease from $73.5 million in Q4 2023, primarily due to decreased collaboration revenue from agreements with GSK and Pfizer.
• Total revenue for the year ended December 31, 2024, was $48.0 million, compared to $103.8 million for the year ended December 31, 2023.
• Research and development expenses for Q4 2024 were $28.8 million, compared to $16.6 million for the same period in 2023, with full year expenses at $96.8 million compared to $51.4 million in the prior year.
• The increase in R&D expenses was primarily due to increased clinical trial activity related to the PIVOT-PO trial.
• General and administrative expenses for Q4 2024 were $7.1 million, compared to $6.4 million for the same period in 2023.
• As of December 31, 2024, Spero had cash and cash equivalents of $52.9 million.
• The company estimates that its existing cash and cash equivalents, along with earned development milestones from GSK, will fund operating expenses and capital expenditures into Q2 2026.
• Spero expects to complete the interim analysis of the Phase 3 PIVOT-PO clinical trial of tebipenem HBr in Q2 2025.
• The company discontinued the SPR206 program following a pipeline review in Q1 2025.
• Spero is completing analysis of the full data set from the Phase 2 study of SPR720 for treatment of NTM-PD and will determine next steps for the program.

Score: 4

Explanation: The sentiment is neutral to slightly negative. While the company has sufficient cash runway and is progressing with the tebipenem HBr trial, the significant net loss and discontinuation of the SPR206 program weigh negatively on the outlook.

• Spero's existing cash and cash equivalents, along with expected milestone payments from GSK, are projected to fund operations into Q2 2026.
• The Phase 3 PIVOT-PO clinical trial of tebipenem HBr is progressing, with an interim analysis expected in Q2 2025.
• Spero is completing analysis of the Phase 2 study of SPR720 for NTM-PD to determine future steps, indicating a commitment to addressing unmet medical needs.

• Spero reported a net loss of $(20.9) million for Q4 2024 and $(68.6) million for the full year 2024, a significant decrease compared to the previous year's net income.
• Total revenue decreased significantly in Q4 2024 and for the full year, primarily due to reduced collaboration revenue from GSK and Pfizer.
• The company discontinued the SPR206 program following a pipeline review in Q1 2025.
• An interim analysis of a Phase 2a proof-of-concept study for SPR720 did not meet its primary endpoint, leading to suspension of the oral development program for NTM-PD in October 2024.

• The success of tebipenem HBr is dependent on the outcome of the PIVOT-PO trial and regulatory approval, which are subject to uncertainties.
• Spero's reliance on GSK for the development and commercialization of tebipenem HBr introduces risk, as GSK has the discretion to determine whether to continue the trial.
• The company's future success depends on its ability to secure additional funding.
• The company is responding to a Wells Notice from the SEC, related to certain public disclosures from March 31, 2022 up to May 3, 2022.

Spero anticipates that its current cash reserves, combined with milestone payments from GSK, will sustain operations into Q2 2026. The company is focused on the interim analysis of the Phase 3 PIVOT-PO trial for tebipenem HBr and determining the next steps for the SPR720 program.

• Spero is focused on the execution of the tebipenem HBr clinical program, including preparing for the pre-specified interim analysis next quarter, said Esther Rajavelu, Interim President and Chief Executive Officer.
• We believe that, if approved, tebipenem HBr could address a critical unmet need for an oral carbapenem in the treatment of patients with complicated urinary tract infections.
• As previously announced, we are reviewing the comprehensive data we've gathered for SPR720 after suspending development of the oral program for NTM-PD.
• We have decided to discontinue our SPR206 program, following a pipeline review and reprioritization.

Spero Therapeutics is operating in the biopharmaceutical industry, specifically focused on developing treatments for rare diseases and multi-drug resistant bacterial infections. The discontinuation of the SPR206 program reflects the challenges and high attrition rates in drug development. The focus on tebipenem HBr for cUTI aligns with the growing need for novel antibiotics to combat antimicrobial resistance.

• Spero's financial performance, particularly the shift from net income to net loss, is not uncommon for clinical-stage biopharmaceutical companies that rely heavily on milestone payments and partnerships.
• Companies like Achaogen (prior to its bankruptcy) and Nabriva Therapeutics faced similar challenges in commercializing novel antibiotics, highlighting the difficulties in this market.
• The cash runway into Q2 2026 is a critical metric, and investors will likely compare this to other companies in the sector to assess Spero's financial stability.
• The discontinuation of SPR206 is a setback, but pipeline reprioritization is a common practice in the industry to focus resources on the most promising assets.

• Shareholders are impacted by the reported net loss and the discontinuation of the SPR206 program, but may be reassured by the cash runway into Q2 2026.
• Employees may be affected by the pipeline reprioritization and discontinuation of the SPR206 program.
• Patients with cUTI could benefit if tebipenem HBr is approved, providing a new oral treatment option.
• GSK, as a partner, is significantly impacted by the progress of tebipenem HBr and its potential commercialization.

• Complete the pre-specified interim analysis of the Phase 3 PIVOT-PO clinical trial of tebipenem HBr in Q2 2025.
• Complete analysis of the full data set from the Phase 2 study of SPR720 for treatment of NTM-PD and determine next steps for the program.
• Monitor the progress of tebipenem HBr development and potential commercialization by GSK.
• File the Annual Report on Form 10-K with the SEC.

• The leadership changes were implemented as part of the Company's response to a Wells Notice from the Securities and Exchange Commission (the SEC), related to certain public disclosures by the Company from March 31, 2022 up to May 3, 2022.

• March 31, 2022: Start date of SEC investigation period related to public disclosures.
• May 3, 2022: End date of SEC investigation period related to public disclosures.
• October 2024: Company suspended its oral development program for the treatment of NTM-PD, following a planned interim analysis of 16 patients dosed in the Phase 2a proof-of-concept study.
• December 31, 2024: End of fourth quarter and full year 2024 financial reporting period.
• January 10, 2025: Esther Rajavelu appointed as Interim President and CEO.
• March 27, 2025: Date of the press release announcing Q4 and full year 2024 results.
• Q1 2025: SPR206 program discontinued following pipeline review.
• Q2 2025: Expected completion of pre-specified interim analysis of Phase 3 PIVOT-PO clinical trial of tebipenem HBr.
• Q2 2026: Estimated timeframe until which existing cash and cash equivalents, together with earned development milestones from GSK, will be sufficient to fund operating expenses and capital expenditures.