Spero Therapeutics Reports Significant Revenue Decline and Strategic Restructuring in Q3 2025

Spero Therapeutics, Inc. reported a significant decline in financial performance for the third quarter of 2025, with total revenues of $5.4 million, down from $13.5 million in the same period last year. The decrease was primarily driven by a reduction in grant revenue, which fell to $2.4 million from $5.7 million, and collaboration revenue from related parties, which decreased to $3.0 million from $7.8 million. For the nine months ended September 30, 2025, total revenues were $25.5 million, compared to $32.9 million for the same period in 2024. The company reported a net loss of $7.4 million for the quarter, an improvement from a net loss of $17.1 million in the prior year, and a net loss of $22.9 million for the nine-month period, compared to $47.7 million in 2024.

The company's financial position has also changed significantly, with total assets decreasing to $54.2 million as of September 30, 2025, down from $110.5 million at the end of 2024. Cash and cash equivalents were reported at $48.6 million, a decrease from $52.9 million at the end of the previous fiscal year. Current liabilities also saw a reduction, totaling $13.6 million compared to $49.1 million at the end of 2024, reflecting a strategic effort to manage expenses and liabilities. The accumulated deficit increased to $482.6 million, indicating ongoing challenges in achieving profitability.

Strategically, Spero Therapeutics has made significant changes to its development pipeline. The company announced the successful completion of the Phase 3 PIVOT-PO trial for its lead product candidate, tebipenem HBr, which met its primary endpoint and was stopped early for efficacy. This trial's results are expected to be submitted to the FDA in the fourth quarter of 2025. However, the company has ceased development of two other candidates, SPR206 and SPR720, as part of a reprioritization of its programs. This decision reflects a focus on completing obligations under the GSK License Agreement, which includes potential milestone payments and royalties based on future sales of tebipenem HBr.

Operationally, Spero Therapeutics has undergone restructuring to reduce costs, resulting in a reduction of its workforce and a recorded restructuring expense of $1.1 million. The company has also recognized an impairment charge of $0.6 million related to its right-of-use asset. As of September 30, 2025, the company had 56.3 million shares outstanding, an increase from 54.6 million shares at the end of 2024, reflecting ongoing stock-based compensation activities.

Looking ahead, Spero Therapeutics anticipates continued operating losses as it focuses on the development and commercialization of tebipenem HBr. The company expects its current cash reserves will be sufficient to fund operations into 2028, contingent on the successful completion of clinical activities and the management of expenses. However, Spero acknowledges the need for additional funding to support ongoing operations and potential growth strategies, which may include equity offerings, debt financing, or collaborations. The company remains committed to navigating the complexities of the biotechnology landscape while striving to bring its innovative therapies to market.