Spero Therapeutics

What Spero Therapeutics does

Spero Therapeutics, Inc. is a Cambridge, Massachusetts-based clinical-stage biopharmaceutical company founded in 2013 and listed on NASDAQ (ticker SPRO) since November 2017, focused on developing therapeutics for multidrug-resistant (MDR) bacterial infections and rare infectious diseases. The company's lead asset, Utebzi (tebipenem pivoxil hydrobromide, formerly SPR994), is an oral carbapenem antibiotic that received FDA approval on June 17, 2026 for the treatment of complicated urinary tract infections (cUTIs) including pyelonephritis in adults, becoming the first and only oral carbapenem available in the U.S. The Phase 3 PIVOT-PO trial showed 58.5% clinical success versus 60.2% for IV imipenem-cilastatin. The pipeline additionally includes SPR206, an IV polymyxin derivative for MDR infections that is licensed to Pfizer for development outside the U.S. and Asian territories, and SPR720, an oral candidate for non-tuberculous mycobacterial pulmonary disease with Phase 1 data published.

Spero generates revenue primarily through licensing and collaboration economics rather than direct product sales. In September 2022, GSK acquired near-global rights to tebipenem HBr in exchange for a $66 million upfront payment, up to $750 million in potential milestones, tiered royalties on net sales, and a $9 million equity investment in Spero. Pfizer's 2021 deal for SPR206 provided $40 million in equity and licensing economics for ex-U.S./Asian territories. HealthCare Royalty Partners provided $125 million in revenue-interest financing in 2021, and BARDA's pediatric development contract has a potential value of up to $59.7 million in non-dilutive government funding. FY2025 revenue totaled $66.8 million, driven largely by collaboration milestone and grant recognition including a $25 million milestone from GSK triggered by NDA resubmission in December 2025.

The company operates through a small team of 11-50 employees and runs a partner-driven commercialization model: GSK leads global Utebzi commercialization via established hospital formularies, retail pharmacy networks, and specialty distributors, while Pfizer owns ex-U.S. development rights for SPR206. Headquartered at 675 Massachusetts Avenue in Cambridge, MA, Spero has been recognized multiple times as one of Boston's Best Places to Work by the Boston Business Journal (2020, 2021, 2024) and maintains $56.1 million in cash and equivalents as of Q1 2026 with an operating runway extending into 2028.

Name

Spero Therapeutics

Legal name

Spero Therapeutics, Inc.

Website

https://sperotherapeutics.com

Company type

Public

Founded year

2013

Operating status

Operating

Headcount range

11–50 employees

Short description

Spero Therapeutics is a Cambridge, MA-based biopharmaceutical company developing oral carbapenem antibiotics and other therapeutics for multidrug-resistant bacterial infections, with its lead product Utebzi (tebipenem pivoxil) FDA-approved in June 2026 for complicated urinary tract infections.

Ownership category

akta.pro rank

Product category

Infectious Disease Pharmaceuticals

NAICS

Research and Development in Biotechnology (except Nanobiotechnology) (541714)

SIC

Pharmaceutical Preparations (2834)

akta.pro industry

PRIMARYHLAIAAAG

Infectious Disease & Antimicrobials Pharmaceuticals

Healthcare & Life Sciences/Pharmaceuticals/Branded (Innovator) Pharmaceuticals

SECONDARYHLAIACAF

Pulmonology & Allergy Specialty Pharmaceuticals

Healthcare & Life Sciences/Pharmaceuticals/Specialty Pharmaceuticals

SECONDARYHLAIACAH

Nephrology & Urology Specialty Pharmaceuticals

Healthcare & Life Sciences/Pharmaceuticals/Specialty Pharmaceuticals

Keywords

• Antibiotic drug development
• Multidrug-resistant infection therapies
• Oral carbapenem antibiotics
• Complicated urinary tract infection treatment
• Rare disease pharmaceuticals

Headquarters

HQ city

Cambridge

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Operations, Marketing or Sales, Infrastructure

Revenue model

1. Licensing Royalties from GSK: GSK pays Spero royalties on net sales of Utebzi (tebipenem pivoxil). Royalty structure rewards meaningful cash flow above $750M in annual net sales. Potential royalties of approximately $50 million annually with upside exceeding $100 million if blockbuster status achieved.
2. Licensing Revenue from Pfizer: Pfizer licensed SPR206 for development outside U.S. and Asian territories, with Spero receiving upfront payment and potential milestone payments.
3. BARDA Grant Funding: Biomedical Advanced Research and Development Authority provides funding support for tebipenem pediatric development, totaling up to $59.7 million potential contract value.
4. Revenue Interest Financing: HealthCare Royalty Partners agreement providing upfront funding with potential milestones and royalties based on future revenue from medical products.

Pricing tiers

Go-to-market motion1 record

Distribution channels2 records

Marketing channels4 records

Core offering

Spero Therapeutics is a clinical-stage biopharmaceutical company developing a pipeline of antibacterial and anti-infective medicines. Its lead commercial product is Utebzi (tebipenem pivoxil hydrobromide), the first and only oral carbapenem antibiotic approved in the U.S. for complicated urinary tract infections (cUTIs) including pyelonephritis in adults. The pipeline includes SPR206 (a polymyxin derivative for multi-drug resistant bacterial infections, licensed to Pfizer) and SPR720 (an oral agent for non-tuberculous mycobacterial pulmonary disease).

Product overview

Spero Therapeutics is a clinical-stage biopharmaceutical company developing a pipeline of investigational medicines targeting rare diseases and multidrug-resistant (MDR) bacterial infections. The company's lead product is Utebzi (tebipenem pivoxil hydrobromide), an FDA-approved oral carbapenem antibiotic for complicated urinary tract infections - the first and only oral carbapenem available in the US. The pipeline includes SPR206 (licensed to Pfizer for MDR bacterial infections) and SPR720 (in development for non-tuberculous mycobacterial pulmonary disease). The company operates through partnerships with major pharmaceutical companies including GSK (for tebipenem HBr) and Pfizer (for SPR206), with funding support from government agencies like BARDA.

Differentiator

Problem solved

Functional benefit

Products and services

• Utebzi (tebipenem pivoxil hydrobromide) FDA-approved oral carbapenem antibiotic for treating complicated urinary tract infections (cUTIs) including pyelonephritis in adults. The first and only oral carbapenem approved in the U.S., developed to help patients avoid hospitalizations or transition home after IV therapy. Commercialized globally (outside Japan and certain Asian territories) by GSK under exclusive license.
• SPR206 Investigational intravenous polymyxin derivative drug candidate for the treatment of multi-drug resistant bacterial infections. Licensed to Pfizer for development and commercialization outside of U.S. and Asian territories under a 2021 agreement that included a $40 million equity investment.
• SPR720 Investigational oral drug candidate for the treatment of non-tuberculous mycobacterial (NTM) pulmonary disease. Phase 1 clinical trial results have been published. Remains in clinical-stage development.

Quantifiable outcome

• 58.5% overall success rate vs 60.2% for IV imipenem-cilastatin in PIVOT-PO Phase 3 trial
• +3 more outcomes

Named customers1 record

Segments2 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Four partnerships are on record, tiered flagship, core and minor.

• GSK (GlaxoSmithKline)flagshipOEM/ Whitelabel/ Licensing Partner · 22 September 2022Exclusive global licensing agreement for tebipenem HBr (Utebzi). GSK received rights to commercialize outside Japan and certain Asian territories. Spero received $66 million upfront, potential milestones up to $750 million, tiered royalties, and GSK purchased $9 million in Spero shares. FDA approved Utebzi on June 17, 2026 for cUTI in adults. GSK assumes NDA sponsorship and commercialization responsibilities.
• Pfizer Inc.coreOEM/ Whitelabel/ Licensing Partner · 30 June 2021$40 million equity investment and licensing agreement for SPR206, a drug candidate for multi-drug resistant bacterial infections. Pfizer purchased shares and obtained rights to develop and commercialize SPR206 outside U.S. and Asian territories. Spero uses funds to support clinical pipeline.
• Meiji Seika PharmaminorStrategic or Co-development PartnerStrategic partner with logo displayed on Spero Therapeutics partnerships page; specific collaboration details not detailed in available sources.
• Vertex PharmaceuticalsminorStrategic or Co-development PartnerStrategic partner with logo displayed on Spero Therapeutics partnerships page; specific collaboration details not detailed in available sources.

Scale indicators11 records

Recent moves7 records

Expansion highlights5 records

Direct peers

• Melinta Therapeutics: Melinta Therapeutics is a specialty antibiotics company commercializing drugs for serious bacterial infections, directly comparable as a focused anti-infective pharma with both marketed and development-stage carbapenem/quinolone assets.
• Tetraphase Biosciences: Tetraphase developed eravacycline (Xerava), an IV antibiotic approved for complicated intra-abdominal infections, and was acquired by La Jolla Pharmaceutical — a relevant precedent for a small-cap anti-infective with a single approved asset.
• Paratek Pharmaceuticals: Paratek Pharmaceuticals developed and commercialized omadacycline and tetracycline-class antibiotics, a comparable specialty anti-infective company that navigated similar FDA approval and partnership dynamics.
• Iterum Therapeutics: Iterum Therapeutics is developing oral antibiotics (sulopenem) for complicated urinary tract infections, directly competing with Spero's Utebzi in the same cUTI oral step-down market with similar patient population and prescriber base.
• Nabriva Therapeutics: Nabriva Therapeutics develops antibiotics for community-acquired pneumonia and complicated UTIs, making it a direct peer in the specialty anti-infective space with similar regulatory and commercialization challenges.
• Cidara Therapeutics: Cidara Therapeutics develops anti-infectives including antivirals and antibacterial conjugates, comparable to Spero as a small clinical-stage biopharma focused on novel anti-infective modalities.
• Innoviva Specialty Therapeutics (formerly Entasis/VenatoRx): Innoviva acquired Entasis Therapeutics and VenatoRx, both of which developed novel antibiotics for multi-drug resistant bacterial infections — directly comparable to Spero's SPR206 program targeting the same MDR Gram-negative market.

Broad incumbents

• GSK (GlaxoSmithKline): GSK is Spero's primary commercialization partner (Utebzi global licensee) and a broad incumbent with extensive infectious disease and antibiotics heritage, comparable as the counterparty controlling Utebzi's commercial destiny.
• Pfizer Inc. Pfizer is both an Spero partner (SPR206 licensee, $40M equity investor) and a broad incumbent in the anti-infective space with established carbapenem franchises (meropenem) and large infectious disease R&D infrastructure that could compete in MDR infections.

Emerging players

• BioMarin Pharmaceutical: BioMarin is a rare-disease focused biopharma with a similar small-cap commercial-stage model — relevant as a comp for how a specialty pharma of Spero's size monetizes a single high-need therapy through partnership-driven commercialization.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat4 records

Key risks6 records

Key highlights6 records

Customer concentration

• Xx.com/Spero_Tx
• LinkedInlinkedin.com/company/spero-therapeutics
• Facebookfacebook.com/1604324273181772

Revenue estimate

Valuation estimate

Number of profiles

Profiles11 records

Funding overview

Funding rounds16 records

Investors21 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Spero Therapeutics