Spero Therapeutics (SPRO) investor relations material

Executive summary

• Focus shifted to tebipenem HBr after ceasing development of SPR720 and SPR206; business now highly dependent on tebipenem HBr and collaboration with GSK.

• Pivotal Phase 3 PIVOT-PO trial for tebipenem HBr met its primary endpoint, showing non-inferiority to IV imipenem-cilastatin, and was stopped early for efficacy; results presented at IDWeek 2025.

• GSK, the development partner, plans to submit an FDA filing for tebipenem HBr in Q4 2025, with a regulatory decision expected in 2H 2026.

• Accumulated deficit reached $482.6 million as of September 30, 2025; cash and cash equivalents were $48.6 million.

• Restructuring in late 2024 reduced workforce and costs, with $1.1 million in related expenses recognized by Q3 2025.

Financial highlights

• Total revenue for Q3 2025 was $5.4 million, down from $13.5 million in Q3 2024, mainly due to lower collaboration and grant revenue.

• Net loss for Q3 2025 was $7.4 million, improved from $17.1 million in Q3 2024; net loss for the nine months was $22.9 million, improved from $47.7 million in the prior year.

• Research and development expenses for the nine months ended September 30, 2025, were $32.9 million, down from $67.9 million in 2024, reflecting reduced clinical activity and SPR720 program costs.

• General and administrative expenses for the nine months were $16.9 million, flat year-over-year; Q3 2025 expenses decreased to $4.2 million from $5.2 million year-over-year.

• Cash and cash equivalents at September 30, 2025: $48.6 million.

Outlook and guidance

• Cash runway expected to fund operations and capital expenditures into 2028, assuming current plans and no major changes.

• Additional funding will be required beyond this period or if operating plans change; options include equity, debt, collaborations, or further cost reductions.

• Focus remains on completing obligations under the GSK License Agreement and supporting FDA submission for tebipenem HBr.

• Anticipates FDA submission for tebipenem HBr in Q4 2025 and regulatory decision in 2H 2026.