Spero Therapeutics, Inc.
Spero Therapeutics, Inc. is a U.S.-based clinical-stage biopharmaceutical company focused on developing novel treatments for rare diseases and multidrug-resistant bacterial infections. Its pipeline has included tebipenem HBr, SPR720, and SPR206, with development activities supported through collaborations and government funding arrangements.
Fiscal year 2025 · change from previous year
Development 2020–2025
Business
Share of revenueOral broad-spectrum carbapenem candidate for complicated urinary tract infections and pyelonephritis.
Revenue recognized under license and development agreements with partners such as GSK and Pfizer.
Oral investigational therapy for nontuberculous mycobacterial pulmonary disease.
Investigational anti-infective program for multidrug-resistant bacterial infections.
Products
Reported · share of revenue- Collaboration Revenue Related Party70.4 %
- Collaboration Revenue18.8 %
- Grant Revenue10.8 %
Source: 10-K FY2025, revenue the company reports per product line (SEC XBRL). Shares are of the lines shown and add up to 100 %.
Customers
Spero’s direct commercial customers are not yet established because it is still a clinical-stage company. Its economic counterparties are primarily pharmaceutical partners, government agencies, and future healthcare payors and hospitals that would influence adoption if a product is approved.
Partners such as GSK and Pfizer support development programs and share in the economics of selected assets.
Agencies such as NIAID support preclinical and clinical development through awards and contracts.
Potential future buyers for tebipenem HBr if approved for inpatient or bundled-payment settings.
They determine coverage and reimbursement levels that affect future adoption and pricing.
Prescribers who would use the company’s anti-infective products for resistant infections.
Strategy
Spero’s strategy is centered on advancing tebipenem HBr through late-stage development and regulatory filing while preserving optionality for its earlier programs. The company also relies on collaborations, government awards, and licensing arrangements to fund development until product sales, if any, become available.
This asset is the main value driver and the most advanced program in the pipeline.
The company depends on non-product revenue until commercialization is possible.
Earlier-stage programs may still create value if a viable path forward is found.
Geography
Spero is headquartered in the United States and conducts development activities through a U.S.-based biopharmaceutical platform. Its supply chain and manufacturing network rely on third-party contract manufacturers in Asia, including facilities in Taiwan, while commercialization and reimbursement considerations are relevant in the U.S. and abroad.
Risks
Spero is highly dependent on the success of a small number of development assets, especially tebipenem HBr and its GSK collaboration. Clinical, regulatory, reimbursement, manufacturing, and funding risks are all material because the company does not yet generate product sales.
- Concentration in tebipenem HBr and GSK collaborationImpact: HighLikelihood: High
The business is substantially dependent on one late-stage program and one major partner.
Exposure: Pipeline concentration
- Clinical development failureImpact: HighLikelihood: High
Drug candidates may not meet endpoints, show safety issues, or fail to gain approval.
Exposure: Phase 3 and regulatory pathway
- Manufacturing and supply chain disruptionImpact: HighLikelihood: High
The company relies on a small number of third-party manufacturers and one raw-material supplier.
Exposure: Asia/Taiwan supply chain
- Financing riskImpact: HighLikelihood: High
The company expects to need external funding until product sales are established.
Exposure - Reimbursement and pricing pressureImpact: MediumLikelihood: Medium
Hospital bundled payments and payor controls can limit uptake and pricing power.
Exposure: U.S. and international commercialization
Accounting
Judgemental itemsRevenue depends on service periods and contract terms, which can shift timing between quarters.
Impact: GSK and Pfizer agreements
Award-based revenue is tied to eligible costs and contract milestones rather than product sales.
Impact: NIAID and other awards
Right-of-use assets may require impairment when sublease or facility assumptions change.
Impact: Reported operating expense and asset values
A meaningful portion of operating expense includes equity-based pay for R&D and administrative staff.
Impact: Operating loss and dilution analysis
Cash balances and vendor payables denominated in foreign currencies create gains or losses.
Impact: Other income (expense), net
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Last updated: 24/09/2026