Spero Therapeutics Reports $68.6 Million Net Loss for 2024, Decreased Collaboration Revenue

Spero Therapeutics, a clinical-stage biopharmaceutical company, reported a net loss of $68.6 million for the year ended December 31, 2024, compared to a net income of $22.8 million in 2023. This significant decrease is primarily attributable to a reduction in collaboration revenue from $103.8 million in 2023 to $48.0 million in 2024, offset by an increase in research and development expenses from $51.4 million to $96.8 million. Grant revenue increased from $7.0 million to $20.6 million during the same period. The company attributes the increase in research and development expenses to increased clinical activities related to its Phase 3 clinical trial of tebipenem HBr, which commenced in the fourth quarter of 2023.

Significant changes in the company's financial performance compared to the previous fiscal year include the aforementioned net loss versus net income, the decrease in collaboration revenue, and the increase in research and development expenses. The decrease in collaboration revenue is largely due to a decrease in milestone payments received under the GSK License Agreement. The company also reported restructuring expenses of $0.9 million in 2024 related to a workforce reduction of approximately 39%, and an impairment of long-term assets of $5.3 million in 2023. The company's cash and cash equivalents decreased from $76.3 million to $52.9 million during the year.

Strategic developments during the fiscal year included the initiation of a Phase 3 clinical trial for tebipenem HBr in December 2023, and the suspension of development activities for the oral SPR720 program in October 2024 due to the Phase 2a clinical trial not meeting its primary endpoint. In March 2025, the company announced it was discontinuing development of SPR206. The company also amended its GSK License Agreement multiple times during the year, resulting in milestone payments totaling $118.8 million. The company's employee headcount was 32 as of December 31, 2024.

Key operational developments included the commencement of enrollment in the pivotal Phase 3 clinical trial for tebipenem HBr, and the completion of the Phase 2a clinical trial for SPR720. The company's most advanced product candidate, tebipenem HBr, is being developed in partnership with GSK, which holds exclusive rights to develop and commercialize the product in most territories. The company's financial statements include an auditor's report expressing substantial doubt about the company's ability to continue as a going concern due to its history of losses and need for additional funding.

The company's outlook indicates a continued need for substantial additional funding to support its operations and product development. The company plans to prioritize advancing the Phase 3 clinical trial for tebipenem HBr and completing analysis of data from the SPR720 trial. The company acknowledges substantial doubt about its ability to continue as a going concern without securing additional capital. The company is exploring various options for securing additional funding, including equity or debt financings and new collaborations.