Spero Therapeutics 2025 Q3 Earnings Narrowed Losses and Cautious Regulatory Outlook

Spero Therapeutics (SPRO) reported Q3 2025 earnings on November 14, 2025, with a narrowed net loss of $7.38 million (56.9% improvement YoY) and GAAP EPS of -$0.13, surpassing estimates. The company maintained cash runway into 2028 and highlighted progress in tebipenem HBr regulatory submissions.

Revenue

Spero Therapeutics’ Q3 2025 revenue fell 59.6% to $5.44 million, driven by reduced collaboration revenue with GSK and lower grant income. Grant revenue contributed $2.39 million, while collaboration revenue from related parties totaled $3.05 million. The decline reflects ongoing challenges in monetizing its pipeline.

Earnings/Net Income

The company narrowed its net loss to $7.38 million in Q3 2025, a 56.9% reduction from $17.15 million in Q3 2024. Per-share losses improved to -$0.13 from -$0.32, a 59.4% improvement. Despite progress, Spero has posted losses for nine consecutive years, underscoring persistent financial pressures.

Price Action

SPRO shares edged up 0.84% on the latest trading day but declined 2.03% for the week and 3.21% month-to-date, reflecting mixed investor sentiment.

Post-Earnings Price Action Review

A strategy of buying SPRO shares on earnings dates and holding for 30 days yielded a 23.4% cumulative return over three years, outperforming the SPY ETF’s 16.2%. This suggests SPRO’s stock has historically reacted positively to earnings events, though recent volatility complicates short-term outlooks.

CEO Commentary

CEO Esther Rajavelu emphasized the PIVOT-PO Phase 3 trial results for tebipenem HBr, presented at IDWeek 2025, and collaboration with GSK to submit data to the FDA by year-end. While acknowledging the discontinuation of the SPR720 program, she expressed cautious optimism about regulatory approval by H2 2026, balancing progress with inherent risks.

Guidance

Spero expects cash reserves of $48.6 million as of September 30, 2025, to fund operations through 2028. R&D expenses dropped to $8.6 million in Q3 2025 from $26.9 million in Q3 2024, aligning with reduced financial burn. The company projects GSK’s FDA filing for tebipenem HBr in Q4 2025 and a regulatory decision by H2 2026.

Additional News

1. CEO Insider Transaction: Esther Rajavelu surrendered 40,270 shares to cover tax obligations, reducing her direct holdings to 869,450 shares.

2. PIVOT-PO Trial Milestone: Results for tebipenem HBr were presented at IDWeek 2025, with GSK planning an FDA filing in Q4 2025.

3. Analyst Price Target: A median 12-month price target of $5.00 reflects 46.8% upside from November 12’s closing price of $2.66, despite a “hold” consensus rating.