Spero Therapeutics, Inc. Q4 FY2024 earnings call

• Spero is a clinical stage biopharmaceutical focused on rare diseases and multidrug-resistant infections. Tebipenem HBr is in Phase 3 PIVOT-PO trial; interim analysis expected in Q2 2025. - SPR720 Phase IIa trial for NTM-PD didn't meet primary endpoint, had dose-limiting grade 3 hepatotoxicity in high-dose cohort. - Discontinued development of SPR206. - Esther reviewed financials, noting cash position and expense details.

For the fourth quarter of 2024, total revenue was $15 million compared to $73.5 million in the fourth quarter of 2023. Full year 2024 revenue was $48 million versus $103.8 million in 2023. R&D expenses in Q4 2024 were $28.8 million vs $16.6 million in 2023; full year R&D 2024 was $97 million vs $51.4 million in 2023. G&A expenses in Q4 2024 were $7.1 million vs $6.4 million in 2023; full year G&A 2024 was $23.7 million vs $25.6 million in 2023. The company reported a net loss of $20.7 million for Q4 2024 and $68.4 million for the full year 2024.

• Existing cash and cash equivalents plus remaining GSK milestone funds will fund operations into Q2 2026. - Look forward to Q2 2025 interim analysis of tebipenem HBr Phase 3 trial.

• Forward-looking statements involve risks; detailed risks in SEC filings.

Q: Does the tebipenem trial get unblinded if the interim is successful?

A: If the interim is successful, managed by independent data monitoring committee; management team will be unblinded if IDMC recommends stopping trial or enrollment.

Q: What are potential paths forward for SPR720 and when to expect an update?

A: First step is to complete data analysis of full 25 patients dosed in trial; once data is analyzed, will determine next steps, which may include reformulation strategy.