Spero Therapeutics

SPROPhase 3

Boston, United StatesFounded 2013sperotherapeutics.com

Founded in 2013, Spero Therapeutics is dedicated to pioneering differentiated medicines for patients with rare diseases and serious bacterial infections, particularly addressing the global crisis of antibiotic resistance. Its most advanced program, tebipenem HBr, achieved a pivotal milestone in May 2025 with the Phase 3 PIVOT-PO trial stopping early for efficacy in cUTI. The company operates with a partnership-centric model, collaborating with government agencies, academic institutions, and pharmaceutical companies to maximize the impact of its innovative therapies.

Market Cap

$133.5M

Founded

2013

Focus

Small Molecules

SPRO · Stock Price

USD 2.375.78 (-70.92%)

Historical price data

AI Company Overview

Technology Platform

Focus on developing and in-licensing novel therapeutic candidates, particularly oral formulations of potent antibiotic classes and treatments for rare diseases, leveraging a partnership-centric model for research and development.

Pipeline Snapshot

22 drugs in pipeline, 2 in Phase 3

Drug	Indication	Stage
TBPM-PI-HBr + Ertapenem + Dummy Infusion + Dummy tablets	Complicated Urinary Tract Infection	Phase 3
TBP-PI-HBr + Imipenem-cilastatin + Dummy Infusion + Dummy Tablets	Urinary Tract Infection	Phase 3
Placebo + SPR720 500 mg + SPR720 1000 mg	Nontuberculous Mycobacterial Pulmonary Disease (NTM-PD)	Phase 2
SPR720 + Placebo + Open-label Standard of Care	Mycobacterium Avium Complex	Phase 2
TBPM-PI-HBr	Healthy Volunteers	Phase 1

Funding History

Total raised: $255M

Series C$80MRock Springs CapitalJun 15, 2018

IPO$75MUndisclosedNov 9, 2017

Series B$70MSR OneMar 15, 2017

Series A$30MAtlas VentureJan 15, 2015

Opportunities

The primary near-term opportunity is the potential approval and commercialization of tebipenem HBr as the first oral carbapenem for cUTI in the US, which could capture significant market share by enabling outpatient treatment.

Long-term opportunities include expanding the tebipenem HBr label to other infections, in-licensing new candidates in adjacent rare disease areas, and leveraging the company's partnership model to build a broader portfolio.

Risk Factors

Key risks include regulatory hurdles for tebipenem HBr, the inherent commercial challenges of launching a new antibiotic (pricing, stewardship), and the company's heavy reliance on this single late-stage asset for value creation.

Financial sustainability remains a concern as a pre-revenue company dependent on capital markets and partnerships.

Competitive Landscape

Tebipenem HBr's main competitors are intravenous carbapenems and other broad-spectrum IV antibiotics for cUTI. Its primary differentiation is its oral formulation, which offers a potential paradigm shift to outpatient therapy. In the broader landscape, Spero competes with other biotechs and large pharma companies developing novel antibiotics and rare disease therapies, where success depends on clinical efficacy, safety, and strategic partnerships.