First peer-reviewed publication of chemotherapy-resistant gamma-delta T cells (DeltEx Drug Resistant Immunotherapy or DRI) clinical results in newly diagnosed glioblastoma

Repeat-dose patients achieved median progression-free survival (mPFS) of 16.1 months, more than double the ~6.9-month standard of care benchmark, with no dose-limiting toxicities (DLTs)

NEW YORK, July 09, 2026 (GLOBE NEWSWIRE) -- IN8bio, Inc. (NASDAQ:INAB), a clinical-stage biopharmaceutical company developing innovative gamma-delta (γδ) T cell therapies and T cell engagers for cancer and autoimmune diseases, today announced the publication of peer-reviewed clinical data from its Phase 1 trial of INB-200 in The Journal of Clinical Oncology (JCO), one of the most prestigious oncology journals.

The publication, titled: "Intracranial injection of ex vivo expanded and activated gamma-delta T cells engineered with a MGMT-expressing lentivector in patients with primary glioblastoma," reports results from the first-in-human study of an autologous, genetically modified γδ T cell therapy. The expanded, activated γδ T cells are engineered to be resistant to chemotherapy (DeltEx DRI) and delivered intracranially in combination with standard of care (SOC) temozolomide chemotherapy (TMZ).

The Phase 1 trial is a frequency-escalation study of DeltEx DRI in GBM patients in combination with the SOC Stupp regimen (surgical resection followed by chemoradiation and maintenance chemotherapy). A total of 13 patients were enrolled and treated across three cohorts with subjects in their respective cohorts receiving 1, 3, or up to 6 doses of DeltEx DRI in 28-day cycles during maintenance chemotherapy. Evaluations included the safety and feasibility of repeated intracranial administration during maintenance chemotherapy.

GBM is the most common malignant primary brain tumor in adults and one of the most aggressive and difficult cancers to treat, with overall survival of only ~11 months and a five-year survival of ~5%. Despite overall advances across numerous cancer therapies, survival in GBM has been almost unchanged in more than 20 years with no new drug approvals and only a single device approval. Recurrence is nearly universal with GBM patients facing rapid decline, very limited treatment options, and poor outcomes.

In the Phase 1 study, DeltEx DRI in combination with SOC demonstrated a well-tolerated safety profile with no DLTs, no cytokine release syndrome (CRS), and no immune effector cell-associated neurotoxicity (ICANS) observed. The therapy also showed compelling signals of clinical activity. Across all 13 treated patients, mPFS was 9.9 months, and a 43.5% improvement over the 6.9 months typically reported with SOC alone. The results were most striking in repeat-dose patients (those receiving 3 to 6 doses) where mPFS reached 16.1 months, more than double the SOC benchmark. Overall survival (OS) was equally notable: median OS in repeat-dose patients was 19.5 months, compared to a historical SOC mOS of approximately 14.6 months in this patient population.

"These peer-reviewed results validate the scientific foundation of our DeltEx platform and highlight the transformative potential of γδ T cells in treating solid tumors," said William Ho, Chief Executive Officer and Co-founder of IN8bio. "Glioblastoma remains one of the most devastating cancers, and patients urgently need new treatment options. By enabling immune cells to remain active alongside conventional chemotherapy and delivering them directly to the tumor, DeltEx DRI is designed to drive meaningful synergies, improve patient outcomes, and change the treatment paradigm for this disease."

"Publication in The Journal of Clinical Oncology represents a significant milestone for this program and for the broader effort to bring effective immunotherapies to patients with glioblastoma," said Burt Nabors, M.D., Professor of Neurology, Director of Neuro-Oncology at the O’Neal Comprehensive Cancer Center at the University of Alabama at Birmingham, and lead investigator of the study. "This trial demonstrates that intracranial delivery of chemotherapy-resistant γδ T cells is feasible and well tolerated. The encouraging signals of prolonged disease control and absence of immune-mediated toxicity, particularly with repeated dosing, provide a compelling rationale for continued clinical development of this novel therapeutic approach."

Despite aggressive SOC treatment, residual tumor cells persist in nearly all GBM patients, a key reason the disease remains almost universally fatal. The DeltEx DRI technology directly addresses this challenge: γδ T cells are engineered to resist being killed by the chemotherapy that is administered concurrently, then delivered intracranially to the tumor site, where they can attack residual cancer cells and potentially achieve deeper, more durable tumor responses. These JCO-published results offer meaningful evidence that this strategy can extend disease control in these patients with significant unmet need and support its continued advancement as a potential new treatment paradigm for solid tumors. IN8bio expects to provide additional updates to the DeltEx DRI program in newly diagnosed GBM later this year.

About INB-200 and INB-400 (DeltEx^™ Drug Resistant Immunotherapy)

INB-200 and INB-400 are an autologous, genetically modified gamma-delta T cell therapy engineered with an MGMT-expressing lentivector designed to resist alkylating chemotherapy. The therapy is administered intracranially and is intended to work in combination with temozolomide to target residual tumor cells, enhance immune activation, and prolong disease control in patients with glioblastoma.

About IN8bio

IN8bio is a clinical-stage biopharmaceutical company developing γδ T cell and γδ T cell engager (TCE) product candidates to address unmet medical needs. γδ T cells are a specialized population of T cells that possess unique properties, including the ability to differentiate between healthy and diseased tissue. The Company’s pipeline is anchored by INB-600, a novel γδ T cell engager platform with potential applications across oncology and autoimmune indications. IN8bio is also advancing INB-100, an allogeneic γδ T cell candidate for adult patients with high-risk leukemias undergoing haploidentical stem cell transplantation, and INB-200/400, an autologous genetically modified γδ T cell candidate for newly diagnosed glioblastoma (GBM). For more information about IN8bio, visit www.IN8bio.com.

Forward-Looking Statements

This press release may contain forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as "aims," "anticipates," "believes," "could," "estimates," "expects," "forecasts," "goal," "intends," "may," "plans," "possible," "potential," "seeks," "will" and variations of these words or similar expressions that are intended to identify forward-looking statements, although not all forward-looking statements contain these words. Forward-looking statements in this press release include, but are not limited to, statements regarding: the therapeutic potential of IN8bio’s product candidates; the potential of DeltEx DRI γδ T cell therapy to improve outcomes in patients with newly diagnosed glioblastoma; IN8bio’s ability to achieve anticipated milestones, including continued clinical development and regulatory engagement; and other statements that are not historical fact. IN8bio may not actually achieve the plans, intentions or expectations disclosed in these forward-looking statements, and you should not place undue reliance on these forward-looking statements. Actual results or events could differ materially from those anticipated as a result of various factors, including: risks to clinical trial progress, patient enrollment and follow-up; uncertainties inherent in the initiation and completion of clinical trials; whether outcomes from prior studies will be predictive of future clinical results; and other important factors described in greater detail in the section entitled "Risk Factors" in IN8bio’s most recent filings with the Securities and Exchange Commission (SEC). Any forward-looking statements contained in this press release speak only as of the date hereof, and IN8bio expressly disclaims any obligation to update any forward-looking statements contained herein, except as otherwise required by law.

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