INmune Bio Inc. Announces New Preclinical Data at AACR 2026 Demonstrating INB03 (XPro1595) Overcomes Resistance and Reduces Metastases in HER2-Positive Breast Cancer Models

Rhea-AI Summary

INmune Bio (NASDAQ: INMB) reported preclinical AACR 2026 data showing that INB03 (XPro1595), a dominant-negative soluble TNF inhibitor, enhanced the anti-tumor activity of TKIs lapatinib and tucatinib and reduced metastases in HER2-positive breast cancer models.

Key findings include statistically superior inhibition of cell proliferation and migration (p < 0.05 to p < 0.0001), slowed tumor growth in mouse models, and reduced brain, lung, and liver metastases; poster available April 21, 2026.

Positive

• Statistically superior inhibition of proliferation/migration (p < 0.05 to p < 0.0001)
• INB03 + TKI combinations slowed tumor growth in JIMT-1 mouse models
• Significant reduction of metastases to brain, lung, and liver (ex‑vivo IVIS)
• Tucatinib lung metastases effect further enhanced (p < 0.05 to p < 0.0001)
• AACR poster presentation on April 21, 2026

Negative

• Data are preclinical only (in vitro and mouse models), not clinical efficacy in humans
• No reported clinical trial dates, safety, or survival outcomes for patients yet
• Findings limited to specific cell lines (JIMT-1 and JIMT-1 Br3-luc) and nude mice

Argus Apr 16 session

+1.52% close to close Open Argus

Details

News Market Reaction – INMB

On Apr 16, the day this news came out, INMB closed 1.52% above the previous close.

Data tracked by StockTitan Argus for the Apr 16 session.

Key Figures

INB03 dose: 10 µg/mL Lapatinib dose: 1 µM Tucatinib dose: 10 µM +5 more

INB03 dose

10 µg/mL

In vitro combination with TKIs in HER2+ JIMT-1 models

Lapatinib dose

1 µM

Tyrosine kinase inhibitor combined with INB03 in vitro

Tucatinib dose

10 µM

Tyrosine kinase inhibitor combined with INB03 in vitro

P-value range (in vitro)

p < 0.05 to p < 0.0001

Superior inhibition of proliferation and migration vs TKIs alone

Metastasis reduction

Brain, lung, liver metastases reduced

INB03 plus TKIs in HER2-positive breast cancer models

Price change

4.76%

24h move prior to article publication

52-week high

11.64

Pre-news 52-week high price

Short interest

15.56%

Short interest as of latest risk context

Historical Context

5 past events · Latest: Mar 30

5 events

1. Mar 30

   Earnings and update

   24h Move

   -0.9%

   2025 financial results and business update with pipeline and runway details.

2. Mar 24

   Earnings scheduling

   24h Move

   -4.8%

   Announcement of upcoming year-end 2025 results call and webcast.

3. Mar 19

   Alzheimer’s trial focus

   24h Move

   -1.6%

   MINDFuL trial highlighted at AD/PD 2026 with efficacy signals in subgroup.

4. Feb 23

   Alzheimer’s webinar

   24h Move

   -3.8%

   Webinar announcement on XPro1595 registrational strategy in early Alzheimer’s.

5. Feb 19

   RDEB data webinar

   24h Move

   -2.2%

   Upcoming webinar to present new CORDStrom Phase III data in RDEB.

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Key Terms

tyrosine kinase inhibitors, HER2-positive, soluble TNF, metastases, +4 more

8 terms

tyrosine kinase inhibitors medical

"Soluble TNF blockade overcomes tyrosine kinase inhibitors resistance in HER2-positive..."

Drugs that block specific enzymes called tyrosine kinases, which act like on/off switches in cells and help control growth and division; by turning those switches off, these medicines can slow or stop the growth of cancers and some non-cancer conditions. They matter to investors because clinical trial outcomes, regulatory approvals, patent protection and competition determine sales potential and risk—think of them as targeted tools whose success can sharply change a drugmaker’s future revenue.

HER2-positive medical

"overcomes tyrosine kinase inhibitors resistance in HER2-positive breast cancer"

HER2-positive describes cancer cells that have too many copies of the HER2 gene or make too much of the HER2 protein, which acts like an overactive growth switch that drives tumor growth. For investors, HER2 status matters because it determines whether patients can receive specific, often expensive targeted therapies and diagnostic tests, so trial results, approvals, or competing drugs tied to HER2 can strongly affect drug sales and company value.

soluble TNF medical

"a first-in-class dominant-negative soluble TNF (sTNF) inhibitor"

Soluble TNF is the circulating form of tumor necrosis factor, a small signaling protein the immune system uses to call cells to action during inflammation. It matters to investors because levels of soluble TNF can serve as a measurable marker of disease activity and because many drugs aim to block it; changes in test results, trial outcomes or regulatory status for TNF-targeting therapies can directly affect a company’s value.

metastases medical

"reducing metastatic spread to the brain, lungs, and liver in HER2-positive breast cancer models"

Metastases are secondary tumors that form when cancer cells break away from the original tumor and establish new growths in other organs or tissues, like seeds scattering from a plant and taking root elsewhere. For investors, metastases matter because they usually make a disease harder and more expensive to treat, influence patient outcomes and survival, and can affect the size and urgency of the market for therapies, clinical trial design, regulatory review, and reimbursement decisions.

dominant-negative medical

"a first-in-class dominant-negative soluble TNF (sTNF) inhibitor"

A dominant-negative is a mutated form of a protein that not only fails to do its normal job but also blocks the normal version from working, like a broken cog that jams a machine. Investors should care because dominant-negative mutations can drive disease, change how well drugs work, and create both challenges and opportunities for therapies and diagnostics, affecting clinical outcomes, development costs, and market potential.

nude mice medical

"In female nude mice bearing JIMT-1 or JIMT-1 Br3-luc tumors"

Nude mice are specially bred, hairless laboratory mice with a severely weakened immune system that allows human cells or tissues to be implanted and grow without being rejected. For investors, they act like a controlled test garden for early-stage drug or therapy experiments—helping researchers show whether a candidate can affect human tumors or tissues before moving into costly human trials, but their results are suggestive rather than definitive.

IVIS luminescence imaging medical

"quantified by ex-vivo IVIS luminescence imaging"

A laboratory imaging technique that uses sensitive cameras and light-producing markers to noninvasively visualize biological processes inside living small animals or cell samples. Think of it like a night-vision camera that lets researchers watch tumors grow, drugs reach their targets, or genes turn on and off in real time without surgery. For investors, it matters because clear, early visual evidence from these tests can speed development decisions, reduce costly failures, and de-risk preclinical stages of therapeutics or diagnostics.

MUC4 medical

"selective sTNF neutralization with INB03 down-regulates MUC4, a protein that shields the HER2 molecule"

MUC4 is a human gene that produces a large sugar-coated protein on cell surfaces, acting like a protective coating and a cellular “name tag” that helps cells interact with their surroundings. Investors watch MUC4 because changes in its levels or structure can signal disease, guide diagnostic tests, or serve as a drug target; treatments or tests tied to MUC4 can affect clinical trial outcomes, regulatory approvals, and potential market value.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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BOCA RATON, Fla., April 16, 2026 (GLOBE NEWSWIRE) -- INmune Bio Inc. (NASDAQ: INMB) (the “Company”), a clinical-stage biotechnology company focused on developing therapies that harness the patient’s innate immune system, today announces new preclinical data for INB03 (XPro1595 for oncology).  The data will be presented at the American Association for Cancer Research (AACR) Annual Meeting 2026 in San Diego on April 17-22.

The poster, titled, “Soluble TNF blockade overcomes tyrosine kinase inhibitors resistance in HER2-positive breast cancer,” details how INB03 (“XPro™”), a first-in-class dominant-negative soluble TNF (sTNF) inhibitor, significantly enhances the anti-tumor activity of the tyrosine kinase inhibitors (TKIs) lapatinib and tucatinib while reducing metastatic spread to the brain, lungs, and liver in HER2-positive breast cancer models.  It was authored by collaborators from the Instituto de Biología y Medicina Experimental (IBYME-CONICET) in Buenos Aires, Argentina.

Key Scientific Findings:

• Overcoming Resistance in Vitro: The combination of INB03 (10 µg/mL) with either lapatinib (1 µM) or tucatinib (10 µM) produced statistically superior inhibition of cell proliferation and migration in both HER2+ JIMT-1 and brain-metastatic JIMT-1 Br3-luc cell lines compared to TKIs alone (p < 0.05 to p < 0.0001).
• Enhanced Tumor Control In Vivo: In female nude mice bearing JIMT-1 or JIMT-1 Br3-luc tumors, INB03 + TKI combinations markedly slowed tumor growth compared to TKIs alone.
• Reduction of Metastatic Spread:  The addition of INB03 significantly reduced the incidence of metastases to brain, lung, and liver (quantified by ex-vivo IVIS luminescence imaging).  Notably, it further enhanced tucatinib’s effect on lung metastases (p < 0.05 to p < 0.0001).
• Mechanism of Action: These results support prior research showing that selective sTNF neutralization with INB03 down-regulates MUC4, a protein that shields the HER2 molecule and prevents therapies from binding effectively.

“These results build on our prior work showing that selective sTNF neutralization with INB03 down-regulates MUC4, restoring sensitivity to HER2-targeted therapies,” said Roxana Schillaci, Ph.D., lead investigator. “The ability of INB03 to overcome TKI resistance and limit metastatic dissemination, including to the brain, highlights its potential to address key unmet needs in advanced HER2-positive breast cancer.”

David Moss, CEO of INmune Bio, added, “INB03 continues to demonstrate broad therapeutic potential across solid tumors by targeting the soluble TNF pathway. These AACR data reinforce our confidence in advancing INB03 combinations in the clinic for patients who have developed resistance to standard TKIs or who are at high risk for brain metastases.”

The poster will be available for viewing during the AACR 2026 meeting on April 21st.

About XPro™ (INB03)

XPro™ is a next-generation inhibitor of tumor necrosis factor (TNF) that is currently in clinical trial and acts differently than currently available TNF inhibitors in that it neutralizes soluble TNF (sTNF), without affecting trans-membrane TNF (tmTNF) or TNF receptors. XPro™ could have potential substantial beneficial effects in patients with neurologic disease by decreasing neuroinflammation. For more information about the importance of targeting neuroinflammation in the brain to improve cognitive function and restore neuronal communication visit this section of INmune Bio’s website. 

About INmune Bio Inc.

INmune Bio Inc. is a publicly traded (NASDAQ: INMB), clinical-stage biotechnology company focused on developing treatments that target the innate immune system to fight disease. INmune Bio has three product platforms: (1) CORDStrom™, a proprietary pooled, allogeneic, human umbilical cord-derived mesenchymal Stromal/Stem cell (hucMSCs) platform that recently completed a blinded randomized trial in recessive dystrophic epidermolysis bullosa; (2) XPro™, a Dominant-Negative Tumor Necrosis Factor (DN-TNF) product platform designed to selectively neutralize soluble TNF, a key driver of inflammation and innate immune dysfunction; and (3) INKmune®, a cell-based medicine designed to prime a patient’s natural killer cells to eliminate minimal residual disease in patients with cancer.  To learn more, please visit www.inmunebio.com.

Forward Looking Statements

Clinical trials are in early stages and there is no assurance that any specific outcome will be achieved. Any statements contained in this press release related to the development or commercialization of product candidates and other business and financial matters, including without limitation, trial results and data, including trial results, timing of key milestones, future plans or expectations, and the prospects for receiving regulatory approval or commercializing or selling any product or drug candidates, may constitute forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. Any forward-looking statements contained herein are based on current expectations but are subject to several risks and uncertainties. Actual results and the timing of certain events and circumstances may differ materially from those described by the forward-looking statements because of these risks and uncertainties. CORDstrom™, XPro1595™ (XPro™, pegipanermin), and INKmune®™ have either finished clinical trials, are still in clinical trials or are preparing to start clinical trials and have not been approved by the US Food and Drug Administration (FDA), the UK MHRA or any regulatory body and there cannot be any assurance that they will be approved by the FDA, the UK MHRA or any regulatory body or that any specific results will be achieved. The factors that could cause actual future results to differ materially from current expectations include, but are not limited to, risks and uncertainties relating to the Company’s ability to produce more drug for clinical trials; the availability of substantial additional funding for the Company to continue its operations and to conduct research and development, clinical studies and future product commercialization; and the Company’s business, research, product development, regulatory approval, marketing and distribution plans and strategies. These and other factors are identified and described in more detail in the Company’s filings with the Securities and Exchange Commission, including the Company’s Annual Report on Form 10-K, the Company’s Quarterly Reports on Form 10-Q and the Company’s Current Reports on Form 8-K. The Company assumes no obligation to update any forward-looking statements to reflect any event or circumstance that may arise after the date of this release.

INmune Bio Contacts:

David Moss 
Chief Executive Officer 
(561) 710-0512 
info@inmunebio.com

Daniel Carlson 
Head of Investor Relations 
(415) 509-4590 
dcarlson@inmunebio.com

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What did INmune Bio (INMB) announce at AACR 2026 about INB03 on April 16, 2026?

INmune Bio announced new preclinical AACR data showing INB03 enhanced TKI activity and reduced metastases. According to the company, the poster reports improved inhibition in HER2+ cell lines, slowed tumor growth in mice, and reduced brain, lung, and liver metastases.

How does INB03 (XPro1595) affect resistance to TKIs in HER2-positive breast cancer models?

INB03 restored sensitivity to TKIs by down-regulating MUC4 and improving drug binding. According to the company, selective sTNF neutralization with INB03 reduced MUC4, yielding statistically superior inhibition of proliferation and migration versus TKIs alone.

What experimental models were used for the INB03 preclinical results presented at AACR 2026?

The study used HER2+ JIMT-1 and brain-metastatic JIMT-1 Br3-luc cell lines and female nude mice bearing these tumors. According to the company, results include in vitro proliferation/migration assays and ex‑vivo IVIS quantification of metastases in mice.

Did the AACR 2026 data show INB03 reduces metastases for INMB's therapy combinations?

Yes — INB03 addition significantly reduced incidence of brain, lung, and liver metastases in mouse models. According to the company, ex‑vivo IVIS imaging quantified the reduction and showed enhanced effect with tucatinib on lung metastases (p < 0.05 to p < 0.0001).

Will INmune Bio (INMB) move INB03 into clinical trials for HER2+ breast cancer after AACR 2026?

The company said the AACR data reinforce confidence to advance INB03 combinations in the clinic, but no clinical trial start dates or protocols were disclosed. According to the company, these are supportive preclinical data rather than clinical results.