Iteos Therapeutics Stock Price, News & Analysis

iTeos Therapeutics, Inc. (ITOS) is a clinical-stage biopharmaceutical company focused on the discovery and development of a new generation of immuno-oncology therapeutics for patients. The company states that it leverages a deep understanding of tumor immunology and immunosuppressive pathways to design novel product candidates with the potential to restore the immune response against cancer. iTeos Therapeutics is headquartered in Watertown, Massachusetts, with a research center in Gosselies, Belgium.

According to company disclosures, iTeos’ pipeline has included multiple clinical-stage programs targeting novel, validated immunosuppressive pathways, including the TIGIT/CD226 axis and the adenosine pathway. Over time, the company has described three main clinical-stage programs and additional preclinical efforts aimed at modulating the tumor microenvironment and overcoming resistance to existing cancer therapies.

Immuno-oncology focus and scientific approach

iTeos Therapeutics describes itself as a clinical-stage biopharmaceutical company pioneering the discovery and development of immuno-oncology therapeutics. Its research strategy centers on immunosuppressive pathways in the tumor microenvironment, with the goal of restoring or enhancing antitumor immune responses. The company has highlighted its expertise in tumor immunology and immunosuppressive mechanisms as the foundation for its product design.

Public communications from iTeos emphasize programs directed at targets such as TIGIT, equilibrative nucleoside transporter 1 (ENT1), and triggering receptor expressed on myeloid cells 2 (TREM2), as well as work on phosphatases PTPN1/2. These targets are presented by the company as relevant to immune suppression, T cell and B cell function, and the behavior of tumor-associated macrophages.

Key product candidates and programs

Based on company announcements, iTeos’ pipeline has included the following notable product candidates and programs:

• Belrestotug (EOS-448/GSK4428859A): An Fc-active human IgG1 monoclonal antibody targeting TIGIT. iTeos describes TIGIT as an inhibitory receptor that contributes to suppression of adaptive and innate immune responses against cancer. Belrestotug is designed to engage TIGIT and FcγR, with the company stating that this may induce cytokine release and antibody-dependent cellular cytotoxicity (ADCC). Belrestotug has been evaluated in collaboration with GSK in multiple clinical trials, including Phase 2 and Phase 3 studies in first-line PD-L1 high non-small cell lung cancer (NSCLC) and PD-L1 positive recurrent/metastatic head and neck squamous cell carcinoma (HNSCC). In 2025, iTeos and GSK agreed to terminate the belrestotug development program following interim data from the GALAXIES Lung-201 and GALAXIES H&N-202 studies that did not meet certain progression-free survival or response thresholds.
• EOS-984: Described by the company as a potential first-in-class small molecule targeting equilibrative nucleoside transporter 1 (ENT1). iTeos states that EOS-984 is designed to inhibit the immunosuppressive activity of adenosine and restore immune cell proliferation, with the potential to reverse adenosine’s effects on T and B cells. EOS-984 has been in Phase 1 development, including combination studies with pembrolizumab in advanced malignancies.
• EOS-215: A monoclonal antibody that antagonizes TREM2. iTeos describes EOS-215 as a potential best-in-class anti-TREM2 antibody designed to block ligand binding and switch off tumor growth and survival promoting activities of tumor resident macrophages. Preclinical data cited by the company indicate effects on macrophage function and T cell activation, and EOS-215 has advanced through IND-enabling studies and into early clinical development.
• Inupadenant (EOS-850): A small molecule antagonist targeting adenosine A2A receptor (A2AR). iTeos has characterized inupadenant as a next-generation A2AR antagonist optimized for potency, A2AR selectivity, and activity at high adenosine concentrations, with an insurmountable profile. The candidate has been evaluated in Phase 2 settings, including in combination with carboplatin/pemetrexed in metastatic NSCLC. The company has reported that inupadenant was deprioritized to focus resources on other programs.
• PTPN1/2 inhibitor program: iTeos has reported the development of a novel small molecule inhibiting PTPN1/2, phosphatases described as negative regulators of cytokine signaling and T cell receptor signaling. Company communications indicate that inhibiting PTPN1/2 may sensitize cancer and immune cells to interferon gamma (IFNγ), reshape the tumor microenvironment, and trigger antitumor immune responses.

Clinical development and collaborations

iTeos has pursued a range of clinical trials to evaluate its candidates in oncology indications. For belrestotug, the company and its development partner GSK have run multiple studies, including:

• GALAXIES Lung-301: A randomized, double-blind Phase 3 study assessing belrestotug plus dostarlimab versus placebo plus pembrolizumab in first-line advanced, unresectable, or metastatic PD-L1 high NSCLC.
• GALAXIES Lung-201: An open-label Phase 2 platform study assessing belrestotug plus dostarlimab and a triplet including GSK’s investigational anti-CD96 antibody nelistotug in first-line advanced/metastatic PD-L1 high NSCLC.
• GALAXIES H&N-202: A Phase 2 platform study in PD-L1 positive recurrent/metastatic HNSCC, evaluating belrestotug-based combinations.
• TIG-006 HNSCC: A study assessing belrestotug plus dostarlimab in first-line PD-L1 positive advanced/metastatic HNSCC.

In May 2025, iTeos reported that GALAXIES Lung-201 did not meet established criteria for clinically meaningful improvements in progression-free survival in the belrestotug plus dostarlimab cohorts versus dostarlimab monotherapy, and that interim analysis of GALAXIES H&N-202 showed a trend below a meaningful threshold for objective response rate. Based on the totality of data, iTeos and GSK decided to terminate the belrestotug development program and end their collaboration on that candidate.

Strategic review, wind-down, and acquisition

In May 2025, iTeos announced that its Board of Directors intended to wind down operations as part of a review of strategic alternatives aimed at maximizing shareholder value. The company stated that it would wind down clinical and operational activities and focus on leveraging its cash balance and potential proceeds from asset sales, including EOS-984, EOS-215, and a preclinical obesity program targeting ENT1.

On July 18, 2025, iTeos entered into an Agreement and Plan of Merger with Concentra Biosciences, LLC and a Concentra subsidiary. The transaction provided for a tender offer to acquire all outstanding shares of iTeos common stock for cash plus a contingent value right (CVR) tied to net cash and potential proceeds from dispositions of specified product candidates and programs. According to a Form 8-K filed on August 29, 2025, the tender offer was completed and a subsequent merger was effected under Delaware law, with iTeos becoming a wholly owned subsidiary of Concentra. The company reported that its shares were suspended from trading on Nasdaq and that a Form 25 would be filed to remove the listing and registration.

On August 29, 2025, Nasdaq filed a Form 25 to remove iTeos Therapeutics, Inc. from listing on The Nasdaq Stock Market LLC. On September 8, 2025, iTeos filed a Form 15 to terminate registration of its common stock under Section 12(g) of the Securities Exchange Act of 1934 and to suspend its reporting obligations under Sections 13 and 15(d). These filings indicate that ITOS is no longer listed on Nasdaq and that the company has deregistered its common stock with the SEC.

Regulatory status and historical trading

Before its acquisition by Concentra Biosciences, iTeos Therapeutics, Inc. was listed on The Nasdaq Global Market under the ticker symbol ITOS, with its common stock registered under Section 12(b) of the Exchange Act. Following completion of the tender offer and merger in August 2025, the company requested suspension of trading and delisting of its shares, and Nasdaq filed Form 25 to remove the listing and registration. The subsequent Form 15 filing by iTeos terminated registration under Section 12(g) and suspended periodic reporting obligations.

As a result, ITOS now represents a former Nasdaq-listed security associated with a company that has been acquired and is no longer an independent public reporting issuer. Any remaining references to ITOS as a trading symbol typically relate to historical information and not to ongoing public trading on a national securities exchange.

Company history and geographic footprint

Public descriptions of iTeos indicate that the company began operations in 2012 and has maintained a presence in both the United States and Belgium. The company is based in Watertown, Massachusetts, and has a research center in Gosselies, Belgium. Earlier descriptions also note that iTeos was founded and supported in part by investments from the Ludwig Institute for Cancer Research, the Walloon region of Belgium, and the European Fund for Economic and Regional Development.

Over more than a decade, iTeos has presented itself as focused on cancer immunotherapy, including IDO1 inhibition, adenosine pathway modulation, TIGIT-targeted antibodies, ENT1 inhibition, TREM2-targeted antibodies, and PTPN1/2 inhibition. Its later-stage development has centered on immuno-oncology combinations in NSCLC and HNSCC and on early-stage programs designed to reprogram the tumor microenvironment.

Implications for investors and researchers

Because iTeos Therapeutics, Inc. has been acquired by Concentra Biosciences and its common stock has been delisted and deregistered, ITOS functions primarily as a historical reference for investors and researchers reviewing past clinical programs, strategic decisions, and regulatory filings. The contingent value rights associated with the acquisition, as described in company filings, relate to net cash in excess of a specified threshold and to potential proceeds from dispositions of certain product candidates and programs within a defined period after the merger.

For those analyzing the history of immuno-oncology development, iTeos provides an example of a clinical-stage biopharmaceutical company that advanced multiple candidates targeting distinct immunosuppressive pathways, entered into major collaborations, and ultimately chose to wind down operations and pursue an acquisition following key clinical readouts and a strategic review.