ITeos Therapeutics

What ITeos Therapeutics does

iTeos Therapeutics was a clinical-stage biotechnology company specializing in tumor immunology and immuno-oncology drug discovery, founded in 2011 and headquartered in the Cambridge/Watertown, Massachusetts area. The company's scientific focus was on developing anti-TIGIT antibodies and other candidates designed to modulate the tumor microenvironment and enhance anti-tumor immune responses. Its lead asset was belrestotug, an anti-TIGIT antibody being co-developed with GSK until May 2025, alongside an earlier-stage pipeline targeting complementary immune checkpoint and tumor microenvironment mechanisms. The company had no approved products and no product revenue throughout its operating history.

iTeos's business model was that of a traditional clinical-stage biotech: it did not sell commercial products, did not operate recurring software or services revenue, and instead funded operations through successive private and public equity rounds (including a 2020 IPO under the ticker ITOS on NASDAQ) and through collaboration income from pharmaceutical partners, principally GSK. Pricing and commercialization infrastructure were not applicable because no candidate reached approval.

In 2025, iTeos entered a sharp negative trajectory: belrestotug failed in Phase II, GSK terminated the partnership in May 2025, and the company entered a definitive merger agreement on July 21, 2025 to be acquired by Concentra Biosciences for approximately $10.047 per share in cash plus a contingent value right, with closing anticipated in Q3 2025. The acquisition effectively ends iTeos as an independent operating company and removes any standalone expansion path for the remaining pipeline.

Name

ITeos Therapeutics

Legal name

iTeos Therapeutics

Website

https://iteostherapeutics.com

Company type

Private

Founded year

2011

Operating status

Acquired

Headcount range

101–250 employees

Short description

iTeos Therapeutics is a clinical-stage immuno-oncology biotech developing anti-TIGIT antibodies, notably belrestotug with GSK, and is now being acquired by Concentra Biosciences following its lead candidate's Phase II failure.

Ownership category

akta.pro rank

Product category

Immuno-oncology Therapeutics

NAICS

Research and Development in Biotechnology (except Nanobiotechnology) (541714), Biological Product (except Diagnostic) Manufacturing (325414)

SIC

Biological Products, (No Disgnostic Substances) (2836)

akta.pro primary industry

Target Identification & Validation Platforms (omics-driven, chemoproteomics, genetic validation) (HLAAAIAI)

akta.pro secondary industries

In Vivo Discovery & Translational Models Platforms (humanized models, PK/PD, efficacy) (HLAAAIAK), Protein Engineering & Directed Evolution Platforms (enzyme/therapeutic protein optimization) (HLAAAIAC)

Keywords

• Immuno-oncology therapeutics
• Cancer immunotherapy
• Anti-TIGIT antibodies
• Tumor microenvironment targeting
• Clinical-stage biotechnology

Headquarters

HQ city

Cambridge

HQ country

United States

HQ region

North America

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Personnel, Technology or R&D, Operations

Core offering

ITeos Therapeutics was a clinical-stage biotechnology company that discovered and developed immuno-oncology drug candidates, with its pipeline focused on anti-TIGIT antibodies and other agents designed to modulate the tumor microenvironment and enhance immune-mediated cancer cell killing. The company's lead candidate, belrestotug, was co-developed under a partnership with GSK before that collaboration was terminated in 2025.

Differentiator

Problem solved

Functional benefit

Products and services

• Belrestotug (anti-TIGIT antibody candidate) Clinical-stage anti-TIGIT antibody immunotherapy candidate developed for the treatment of cancer, intended for global development and commercialization through a partnership with GSK before that partnership was terminated in May 2025 following a failed Phase II trial.

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature2 records

Partnerships

One partnership is on record.

• GSKcoreStrategic or Co-development Partner · 1 May 2025GSK terminated its belrestotug partnership with iTeos in May 2025, leading to the biotech's closure. The partnership was focused on belrestotug development in the immuno-oncology space.

Scale indicators3 records

Recent moves4 records

Expansion highlights2 records

Emerging players

• Surface Oncology (acquired by Coherus BioSciences): Was a clinical-stage immuno-oncology company with anti-TIGIT (SRF388 targeting IL-27) and tumor-microenvironment programs; was acquired by Coherus. Directly relevant precedent for clinical-stage I/O biotechs navigating acquisition outcomes.
• Werewolf Therapeutics: Clinical-stage oncology biotech developing INDUKINE-based tumor-selective immunotherapies. Comparable as an emerging immuno-oncology company pursuing novel immune-engagement mechanisms in the tumor microenvironment.
• Mereo BioPharma: Clinical-stage oncology and rare-disease company with immuno-oncology programs. Comparable as a small-cap clinical biotech with oncology focus, similar headcount scale, and similar dependence on partner-led development.

Broad incumbents

• Bristol Myers Squibb: Major immuno-oncology incumbent (Opdivo, Yervoy) with active TIGIT pathway interest and substantially greater R&D and commercialization resources than iTeos.
• Genentech (Roche): Develops tiragolumab, the leading clinical-stage anti-TIGIT antibody, in combination with atezolizumab across multiple tumor types. Broad incumbent competitor in the TIGIT checkpoint space where iTeos's belrestotug was positioned.
• Merck & Co. Developed vibostolimab (anti-TIGIT) in combination with pembrolizumab. Direct large-pharma competitor in anti-TIGIT combinations, with substantially greater capital and clinical-development resources.
• AstraZeneca: Has pursued anti-TIGIT programs and broad immuno-oncology combinations, representing a major competitor in the I/O landscape where iTeos was positioned.

Regional players

• Akeso Biopharma: China-based biotech that developed ivonescimab, a first-in-class PD-1/VEGF bispecific that has shown competitive readouts against TIGIT-pathway combos. Adjacent competitor in the immuno-oncology combination space where iTeos was positioned.

Direct peers

• Arcus Biosciences: Clinical-stage immuno-oncology company developing anti-TIGIT antibody domvanalimab (in combination with anti-PD-1) — a directly competing anti-TIGIT approach to iTeos's belrestotug, with similar target profile and combination development strategy.
• Compugen: Clinical-stage immuno-oncology company with anti-TIGIT antibody COM902 and a computational target-discovery platform that parallels iTeos's approach to identifying novel immune checkpoints in the tumor microenvironment.

Market position

Strengths3 records

Weaknesses5 records

Competitive moat2 records

Key risks6 records

Key highlights5 records

Customer concentration

• Xx.com/iTeosTx
• LinkedInlinkedin.com/company/iteos-therapeutics-sa

Revenue estimate

Valuation estimate

Number of profiles

Profiles4 records

Funding overview

Funding rounds9 records

Investors17 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 ITeos Therapeutics