---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-280518"
form_type: "8-K"
ticker: "SPRO"
cik: "0001701108"
company_name: "Spero Therapeutics, Inc."
filed_at: "2025-11-13T23:59:59+00:00"
generated_at: "2026-05-16T20:27:56.065239+00:00"
event_type: "earnings"
sentiment: "neutral"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Spero Therapeutics Q3 net loss narrows to $7.4M; GSK plans FDA filing for tebipenem HBr in Q4 2025

## Summary
- Net loss of $7.4M ($0.13 EPS) vs $17.1M ($0.32 EPS) in Q3 2024; revenue $5.4M, down from $13.5M.
- Cash and equivalents $48.6M as of Sep 30, 2025; company expects funding into 2028.
- Phase 3 PIVOT-PO trial of tebipenem HBr met primary endpoint; GSK to submit NDA to FDA in Q4 2025 with decision expected 2H 2026.
- SPR720 program for NTM pulmonary disease discontinued in Q3 2025 after Phase 2a/1 data review.
- R&D expenses fell to $8.6M from $26.9M due to lower PIVOT-PO and SPR720 costs.

## SEC filing metadata
- accession: 0001193125-25-280518
- form_type: 8-K
- ticker: SPRO
- cik: 0001701108
- company_name: Spero Therapeutics, Inc.
- filed_at: 2025-11-13T23:59:59+00:00
- event_type: earnings
- sentiment: neutral
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 2.02, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1701108/000119312525280518/0001193125-25-280518-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1701108/000119312525280518/d44321d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-280518
- JSON: https://secwatch.observer/filing/0001193125-25-280518.json
- Plain text: https://secwatch.observer/filing/0001193125-25-280518.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.