Janux Therapeutics Announces First Patient Dosed in Phase 1 Study of JANX011

Key Terms

cd19 medical

CD19 is a protein found on the surface of most B cells, a type of immune cell; think of it as a distinctive nametag that helps identify and track these cells. It matters to investors because many cancer and autoimmune treatments, diagnostics, and lab tests are designed to target or detect CD19—so advances, approvals, or setbacks in CD19‑focused therapies can directly affect drug pipelines, regulatory value, and potential revenue for healthcare companies.

bispecific medical

A bispecific molecule is a therapeutic designed to bind two different biological targets at once — imagine a two-headed key that fits two locks simultaneously. For investors, bispecific therapies matter because that dual-action can make a treatment more effective or selective, potentially improving clinical results, altering safety profiles, and creating a stronger commercial edge; those factors directly affect development risk, regulatory chances, and future revenue prospects.

adaptive immune response modulator (arm) medical

An adaptive immune response modulator (ARM) is a drug or therapy designed to adjust how the body's adaptive immune system — the part that learns, targets, and remembers specific threats — reacts to disease or treatment, much like tuning an orchestra so instruments play the right notes. For investors, ARMs matter because they can enable more precise treatments with fewer side effects, create large commercial opportunities in areas like autoimmune disease and cancer, and materially affect a company’s clinical and regulatory risk profile and valuation.

t-cell engagers medical

T-cell engagers are engineered proteins that act like microscopic matchmakers, physically bringing a patient’s immune T cells into close contact with diseased cells so the immune system can recognize and kill them. Investors track them because they represent a promising class of therapies that can drive strong clinical benefits and commercial value if trials succeed, but they also carry development, safety and regulatory risks that can rapidly change a company’s market outlook.

lymphodepletion medical

Lymphodepletion is a short medical treatment that lowers a patient’s lymphocytes, the immune cells that can interfere with certain cell-based therapies, to create a more supportive environment for the new therapy to work. Think of it like clearing a crowded garden bed before planting seeds: by temporarily reducing competing cells, the engineered therapy can take hold more effectively. Investors watch lymphodepletion because it affects clinical trial results, safety profiles, treatment adoption, and overall commercial potential.

cytokine release syndrome medical

An intense immune overreaction in which the body's defense system releases a large surge of signaling proteins, causing fever, low blood pressure, breathing trouble or organ stress; imagine the immune system's alarm going into overdrive and flooding the body with emergency responders. Investors care because this side effect can slow or block regulatory approval, increase clinical trial costs and liabilities, limit how widely a therapy can be used, and therefore affect a drug's market value and sales potential.

pharmacokinetics medical

Pharmacokinetics is the study of how a substance, such as a drug or chemical, moves through and is processed by the body over time. It tracks how it is absorbed, distributed, broken down, and eventually eliminated. For investors, understanding pharmacokinetics helps gauge the effectiveness, safety, and potential risks of new medications or treatments, which can influence a company’s success and valuation in the healthcare industry.

pharmacodynamics medical

Pharmacodynamics is how a drug actually affects the body — the strength, type and duration of its effects and the relationship between dose and response. Think of it like how turning a thermostat changes room temperature: it shows what the drug does and how much is needed to get the desired effect. Investors care because these properties drive clinical success, dosing convenience, safety profile and competitive advantage, all of which influence commercial potential and regulatory approval.

SAN DIEGO--(BUSINESS WIRE)-- Janux Therapeutics, Inc. (Nasdaq: JANX) (Janux), a clinical-stage biopharmaceutical company developing a broad pipeline of novel immunotherapies, today announced that the first participant has been dosed in a Phase 1 clinical study of JANX011, a CD19-targeted bispecific engineered using the company’s proprietary Adaptive Immune Response Modulator (ARM) platform. JANX011 is being developed for autoimmune diseases and is designed to enable deep and durable immune reset through targeted depletion of CD19-expressing B cells in blood and tissue.

JANX011 is the first clinical candidate from Janux’s proprietary ARM platform, which is designed to deliver sustained target B-cell depletion by harnessing an adaptive-like immune response while improving the safety and convenience of immune-engaging therapies. Unlike conventional T-cell engagers, which typically require repeated dosing to maintain B-cell depletion, ARM molecules are engineered to drive controlled T-cell expansion while target cells are present, followed by contraction after target cell elimination. This response is designed to enable deep tissue-level target cell clearance without the need for lymphodepletion or pre-conditioning. In preclinical studies, a single, subcutaneous dose of JANX011 demonstrated deep and durable B-cell depletion in both blood and tissue compartments along with prolonged memory B-cell reset. Across a greater than 100-fold preclinical dose range, cytokine levels remained low, supporting a wide safety window and reduced risk of cytokine release syndrome while maintaining ongoing target cell depletion.

“Dosing the first participant with JANX011 marks an important milestone for Janux and the first clinical evaluation of our ARM platform,” said David Campbell, Ph.D., President and CEO, Janux Therapeutics. “While JANX011 is initially being developed for autoimmune diseases, the differentiated immune profile of the ARM platform may also have broader implications across CD19-expressing diseases, including hematologic malignancies.”

“Based on compelling preclinical data, we believe JANX011 has the potential to achieve pharmacodynamic effects comparable to those seen with CAR-T therapies, including stable immune cell population changes and reductions in autoantibody drivers of disease, while offering the safety, convenience, and re-dosing flexibility required for autoimmune patients,” said Tommy DiRaimondo, Ph.D., Chief Scientific Officer and Co-founder.

The Phase 1 study (NCT07291323) is an open-label, dose-escalation trial designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of JANX011 in healthy adult volunteers. The study is intended to characterize key immune effects, including B-cell depletion, memory B-cell reset, T-cell expansion, and cytokine release risk. The study is expected to generate early pharmacodynamic insights to inform dose selection and prioritization of autoimmune indications for subsequent clinical development.

About Janux Therapeutics

Janux is a clinical-stage biopharmaceutical company developing a broad pipeline of novel immunotherapies by applying its proprietary technology to its Tumor Activated T Cell Engager (TRACTr), Tumor Activated Immunomodulator (TRACIr), and Adaptive Immune Response Modulator (ARM) platforms. Janux’s first clinical candidate, JANX007, is a TRACTr that targets prostate-specific membrane antigen (PSMA) and is being investigated in a Phase 1 clinical trial in adult patients with mCRPC. Janux’s second clinical candidate, JANX008, is a TRACTr that targets epidermal growth factor receptor (EGFR) and is being studied in a Phase 1 clinical trial for the treatment of multiple solid tumors. Janux is also advancing its first ARM platform clinical candidate, JANX011, a CD19-ARM for the potential treatment of autoimmune diseases in a Phase 1 study in healthy adult volunteers. Janux continues to generate a number of additional TRACTr, TRACIr, and ARM programs for potential future development. For more information, please visit www.januxrx.com and follow us on LinkedIn.

Forward-Looking Statements

This news release contains certain forward-looking statements that involve risks and uncertainties that could cause actual results to be materially different from historical results or from any future results expressed or implied by such forward-looking statements. Such forward-looking statements include statements regarding, among other things, Janux’s ability to bring new treatments to cancer patients in need, expectations regarding the timing, scope and results of Janux’s development activities, including its ongoing and planned preclinical studies and clinical trials, the potential benefits of Janux’s product candidates and platform technologies, and expectations regarding the use of Janux’s platform technologies to generate novel product candidates. Factors that may cause actual results to differ materially include the risk that interim results of a clinical trial are not necessarily indicative of final results and one or more of the clinical outcomes may materially change as patient enrollment continues, following more comprehensive reviews of the data and as more patient data becomes available, including the risk that unconfirmed responses may not ultimately result in confirmed responses to treatment after follow-up evaluations, the risk that compounds that appear promising in early research do not demonstrate safety and/or efficacy in later preclinical studies or clinical trials, the risk that Janux may not obtain approval to market its product candidates, uncertainties associated with performing clinical trials, regulatory filings and applications, risks associated with reliance on third parties to successfully conduct clinical trials, the risks associated with reliance on outside financing to meet capital requirements, and other risks associated with the process of discovering, developing and commercializing drugs that are safe and effective for use as human therapeutics, and in the endeavor of building a business around such drugs. You are urged to consider statements that include the words “may,” “will,” “would,” “could,” “should,” “believes,” “estimates,” “projects,” “promise,” “potential,” “expects,” “plans,” “anticipates,” “intends,” “continues,” “designed,” “goal,” or the negative of those words or other comparable words to be uncertain and forward-looking. For a further list and description of the risks and uncertainties Janux faces, please refer to Janux’s periodic and other filings with the Securities and Exchange Commission, which are available at www.sec.gov. Such forward-looking statements are current only as of the date they are made, and Janux assumes no obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

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Source: Janux Therapeutics