iTeos Reports Topline Interim Results from GALAXIES Lung-201 Study of Belrestotug + Dostarlimab in First-Line, PD-L1 High Non-Small Cell Lung Cancer Patients
Rhea-AI Summary
iTeos Therapeutics (NASDAQ: ITOS) reported disappointing topline results from the GALAXIES Lung-201 Phase 2 study evaluating belrestotug + dostarlimab combination in first-line PD-L1 high non-small cell lung cancer (NSCLC). While the study showed improvements in objective response rate (ORR), it failed to meet criteria for meaningful progression-free survival improvements. Additionally, interim analysis of GALAXIES H&N-202 Phase 2 trial showed below-threshold results in head and neck cancer.
Following these results, iTeos and GSK have decided to terminate the belrestotug development program and end their collaboration. The company is halting all belrestotug-containing cohorts and new enrollment in the GALAXIES Lung-301 Phase 3 trial. iTeos has engaged TD Cowen to explore strategic alternatives to maximize shareholder value.
Positive
- Study showed clinically meaningful improvements in objective response rate (ORR)
- Company maintains a strong balance sheet
- Company taking immediate action to preserve capital
Negative
- Failed to meet criteria for clinically meaningful improvements in progression-free survival
- GALAXIES H&N-202 trial showed below-threshold results in head and neck cancer
- Complete termination of belrestotug development program
- End of collaboration with GSK
- Halting of all ongoing TIGIT studies
Insights
iTeos' lead TIGIT drug fails key lung cancer trial metric, prompting program termination and strategic review of company's future.
This announcement represents a significant setback for iTeos Therapeutics and their immunotherapy program. The Phase 2 GALAXIES Lung-201 study evaluated the combination of belrestotug (a TIGIT inhibitor) with dostarlimab in first-line PD-L1 high non-small cell lung cancer patients. While the combination showed improvement in the primary endpoint of objective response rate (ORR), it critically failed to demonstrate clinically meaningful improvements in progression-free survival (PFS) compared to dostarlimab monotherapy.
The failure in PFS is particularly damaging because this outcome measure is often more predictive of overall survival benefit and regulatory approval than response rates alone. A drug that increases tumor shrinkage (ORR) but doesn't meaningfully delay disease progression offers limited clinical benefit to patients.
Further compounding this negative data, the GALAXIES H&N-202 trial in head and neck cancer showed suboptimal response rates, indicating the mechanism may have limited efficacy across multiple tumor types. The comprehensive termination of the entire belrestotug program (including halting the ongoing Phase 3 GALAXIES Lung-301 trial) signals that both iTeos and GSK see no viable path forward for this agent.
Most significantly, iTeos has initiated a "targeted review of strategic alternatives" and engaged TD Cowen as an advisor. In biotech, this language typically indicates the company is considering major strategic options such as a merger, acquisition, asset sales, or significant restructuring. The CEO's emphasis on "preserving capital" and "maximizing shareholder value" further reinforces that iTeos is pivoting from drug development to company preservation.
The complete absence of discussion about other pipeline assets or development programs in the announcement suggests the company had heavily prioritized the TIGIT program, and alternative clinical candidates may be limited or early-stage. For a clinical-stage biotech company, the termination of a lead program and collaboration with a major partner like GSK represents a fundamental challenge to the business model.
– GALAXIES Lung-201 did not meet established criteria for clinically meaningful improvements in progression free survival
– Based on totality of data, iTeos and GSK have agreed to terminate the belrestotug development program
– iTeos has initiated a targeted review of strategic alternatives to maximize shareholder value
WATERTOWN, Mass. and GOSSELIES, Belgium, May 13, 2025 (GLOBE NEWSWIRE) -- iTeos Therapeutics, Inc. (Nasdaq: ITOS), a clinical-stage biopharmaceutical company pioneering the discovery and development of a new generation of immuno-oncology therapeutics for patients, today reported topline results from an updated interim analysis of GALAXIES Lung-201, the Phase 2 platform study sponsored by iTeos’ development partner GSK assessing the belrestotug + dostarlimab doublet in previously untreated, unresectable, locally advanced or metastatic PD-L1 high non-small cell lung cancer (NSCLC).
The GALAXIES Lung-201 data continued to demonstrate clinically meaningful improvements in the trial’s primary endpoint of objective response rate (ORR), however the analysis did not meet established criteria for clinically meaningful improvements in the secondary endpoint of progression free survival in the belrestotug + dostarlimab combination cohorts versus dostarlimab monotherapy. Additionally, an interim analysis of the GALAXIES H&N-202 Phase 2 trial showed a trend below the meaningful threshold for ORR in the belrestotug combination cohorts vs. dostarlimab monotherapy in PD-L1 positive head and neck squamous cell carcinoma.
Based on these results, iTeos and GSK have made the decision to terminate the belrestotug development program and end the collaboration. All belrestotug-containing cohorts are ending, and any new enrollment in the ongoing GALAXIES Lung-301 Phase 3 trial is ending. GSK is communicating with investigators, institutional review boards, ethics committees, and health authorities about next steps for appropriate management of currently enrolled patients. The Company is taking immediate steps to preserve capital and has initiated a targeted process to identify opportunities that preserve and maximize shareholder value. iTeos has engaged TD Cowen to advise on this process.
“We are truly disappointed by the results from GALAXIES Lung-201,” said Michel Detheux, Ph.D., president and chief executive officer of iTeos. “Following the analysis of the TIGIT data generated to-date with GSK, we have made the mutual decision to discontinue development of all ongoing TIGIT studies. We are grateful to all patients, caregivers, and investigators involved in the GALAXIES studies and believe it is important to share these data with the scientific community at an upcoming medical meeting in order to advance our collective understanding of immuno-oncology and TIGIT.”
“Since founding this company over a decade ago, I could not be prouder of the team we have built, the quality of science produced, and our collective commitment to improving the lives of cancer patients in need. However, given current market conditions and our appreciation of the responsibility to our valued shareholders, we believe the best path forward is to promptly evaluate a full range of strategic alternatives to unlock the value of our assets. With a strong balance sheet and a commitment to disciplined execution, we are well positioned to pursue opportunities that maximize shareholder value,” continued Dr. Detheux.
About iTeos Therapeutics, Inc.
iTeos Therapeutics is a clinical-stage biopharmaceutical company pioneering the discovery and development of a new generation of immuno-oncology therapeutics for patients. iTeos Therapeutics leverages its 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, MA with a research center in Gosselies, Belgium.
About Belrestotug (EOS-448/ GSK4428859A)
Belrestotug is an Fc active human immunoglobulin G1, or IgG1, monoclonal antibody (mAb) targeting T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT), an important inhibitory receptor which contributes to the suppression of adaptive and innate immune responses against cancer. As an optimized high-affinity, potent anti-TIGIT mAb, belrestotug is designed to enhance the antitumor response through a multifaceted immune modulatory mechanism by engaging with TIGIT and FcγR, a key regulator of immune responses which induces cytokine release and antibody dependent cellular cytotoxicity (ADCC).
Forward-Looking Statements
This press release contains forward-looking statements. Any statements that are not solely statements of historical fact are forward-looking statements. Words such as “believe,” “anticipate,” “plan,” “expect,” “will,” “may,” “intend,” “prepare,” “look,” “potential,” “possible” and similar expressions are intended to identify forward-looking statements. These forward-looking statements include statements relating to iTeos’ steps to preserve capital and review and identify opportunities to maximize shareholder value.
These forward-looking statements involve risks and uncertainties, many of which are beyond iTeos’ control. Actual results could materially differ from those stated or implied by these forward-looking statements as a result of such risks and uncertainties. Known risk factors include the following: risks relating to volatility and uncertainty in the capital markets for biotechnology companies; whether iTeos will be able to identify opportunities to maximize shareholder value and whether iTeos will be able to execute on such opportunities on attractive terms or timing, or at all; whether any capital preservation strategies undertaken will be effective; and those risks identified under the heading “Risk Factors” in iTeos’ Annual Report on Form 10-K for the period ended December 31, 2024 filed with the Securities and Exchange Commission (SEC) as well as other SEC filings made by iTeos which you are encouraged to review.
Any of the foregoing risks could materially and adversely affect iTeos’ business, results of operations and the trading price of iTeos’ common stock. We caution investors not to place undue reliance on the forward-looking statements contained in this press release. iTeos does not undertake any obligation to publicly update its forward-looking statements other than as required by law.
For further information, please contact: Investor Contact: Carl Mauch iTeos Therapeutics, Inc. carl.mauch@iteostherapeutics.com Media Contact: media@iteostherapeutics.com
FAQ
What were the results of iTeos Therapeutics' (ITOS) GALAXIES Lung-201 trial?
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What happens to ongoing GALAXIES Lung-301 Phase 3 trial patients?
