---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-118882"
form_type: "8-K"
ticker: "SPRO"
cik: "0001701108"
company_name: "Spero Therapeutics, Inc."
filed_at: "2025-05-13T23:59:59+00:00"
generated_at: "2026-05-21T16:31:31.894962+00:00"
event_type: "earnings"
sentiment: "negative"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Spero Q1 loss $13.9M, revenue $5.9M; appoints new CEO, tebipenem trial interim on track

## Summary
- Net loss $13.9M ($0.25/share) vs $12.7M loss in Q1 2024; revenue $5.9M down from $9.3M.
- Cash $48.9M plus $23.75M earned GSK milestone payments provides runway into Q2 2026.
- Esther Rajavelu appointed President & CEO effective May 2, 2025; continues as CFO & Treasurer.
- Phase 3 PIVOT-PO interim analysis for tebipenem HBr expected Q2 2025; SPR720 program suspended after missing endpoint.

## SEC filing metadata
- accession: 0001193125-25-118882
- form_type: 8-K
- ticker: SPRO
- cik: 0001701108
- company_name: Spero Therapeutics, Inc.
- filed_at: 2025-05-13T23:59:59+00:00
- event_type: earnings
- sentiment: negative
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 2.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1701108/000119312525118882/0001193125-25-118882-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1701108/000119312525118882/d918635d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-118882
- JSON: https://secwatch.observer/filing/0001193125-25-118882.json
- Plain text: https://secwatch.observer/filing/0001193125-25-118882.txt

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