Equillium Announces New Aryl Hydrocarbon Receptor Modulator Program EQ504

EQ504 targets the aryl hydrocarbon receptor, a clinically validated pathway in the treatment of both skin and gastrointestinal diseases

EQ504 has a unique, multi-modal, non-immunosuppressive mechanism of action that is complementary to other immuno-inflammatory therapeutics

EQ504 data to be presented in three poster presentations next week at the annual meeting of the American Association of Immunologists (AAI)

Equillium, Inc. (NASDAQ:EQ), a clinical-stage biotechnology company leveraging a deep understanding of immunobiology to develop novel therapeutics to treat severe autoimmune and inflammatory disorders, today announced the advancement of a novel and potent aryl hydrocarbon receptor (AhR) modulator (EQ504), which was acquired through the acquisition of Ariagen, a biotechnology company that was majority owned by Equillium's largest investor, Decheng Capital. AhR is critical to barrier organ tissue physiology and immunology, where it maintains barrier function, promotes tissue repair and regeneration, and regulates resident immune cells and anti-inflammatory responses. Modulation of AhR is a clinically validated pathway in the treatment of both skin and gastrointestinal diseases demonstrating high levels of clinical efficacy.

"We're excited to announce the addition of this promising AhR modulator, representing a target of high strategic interest, to our portfolio of differentiated immunology assets," said Bruce Steel, chief executive officer at Equillium. "Decheng had been looking for a team to advance development of this asset and believe Equillium is an excellent fit based on our immunology expertise and development capabilities. Aligning both parties' interests the program was acquired on favorable terms – there was no upfront payment and milestone payments commence upon FDA approval."

"Decades of research has identified the AhR pathway as an important physiological regulator of immune homeostasis in barrier tissues," said Francisco J. Quintana, Ph.D., Professor of Neurology at the Ann Romney Center for Neurologic Diseases, at Brigham and Women's Hospital, Harvard Medical School. "Unique to AhR is that its activation can promote both barrier function and anti-inflammatory pathways highlighting it as an attractive therapeutic target. Indeed, the first AhR-activating drug tapinarof (VTAMA®) was recently approved for the treatment of psoriasis and atopic dermatitis while clinical trials are underway to evaluate the effects of AhR modulators in other inflammatory diseases."

Despite a paradigm shift in our understanding of modulating AhR and the growing level of clinical validation, drug development efforts have been hampered by lack of suitable clinical development candidates. EQ504 is a potent and selective AhR modulator with excellent drug-like properties making it amenable to be formulated for targeted, local delivery such as enteric coating for the treatment of ulcerative colitis or inhaled formulations for the treatment of inflammatory lung diseases.

"There is significant clinical evidence that AhR modulators are impactful in treating gastrointestinal inflammation where they can resolve inflammation and promote mucosal healing. We believe EQ504 may represent a powerful monotherapy or combination approach to treating ulcerative colitis, where poor mucosal healing limits the majority of patients achieving full clinical remission," said Dr. Stephen Connelly, chief scientific officer at Equillium. "Subject to additional capital, we plan to initiate a phase 1 study to demonstrate targeted proof of mechanism."

Additional data will be presented next week at the annual meeting of the American Association of Immunologists (AAI) in Honolulu, Hawaii.

About EQ504

EQ504 is a potent and selective AhR modulator with a unique, multi-modal, non-immunosuppressive mechanism of action that is complementary to other inflammation and immunology agents. AhR is critical to barrier organ tissue physiology and immunology, maintaining barrier function and promoting tissue repair and regeneration, while regulating resident immune cells with anti-inflammatory responses. EQ504 has excellent drug-like properties making it amenable to be formulated for targeted, local delivery such as enteric coating for the treatment of ulcerative colitis or inhaled formulations for the treatment of inflammatory lung diseases.

About Equillium

Equillium is a clinical-stage biotechnology company leveraging a deep understanding of immunobiology to develop novel therapeutics to treat severe autoimmune and inflammatory disorders with high unmet medical need. The company's pipeline consists of several novel immunomodulatory assets and product platform targeting immuno-inflammatory pathways.

For more information, visit www.equilliumbio.com.

Forward Looking Statements

Statements contained in this press release regarding matters that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements may be identified by the use of words such as "anticipate", "believe", "could", "continue", "expect", "estimate", "may", "plan", "outlook", "future", "potential" and "project" and other similar expressions that predict or indicate future events or trends or that are not statements of historical matters. These statements include, but are not limited to, statements regarding Equillium's plans and strategies with respect to developing EQ504, including the initiation of clinical studies and the reporting of data therefrom; the expected timeline for initiating and reporting data from a Phase 1 study of EQ504; the ability to raise additional capital to fund development of EQ504; and the potential benefits of EQ504. Because such statements are subject to risks and uncertainties, many of which are outside of Equillium's control, actual results may differ materially from those expressed or implied by such forward-looking statements. Risks that contribute to the uncertain nature of the forward-looking statements include: Equillium's ability to execute its plans and strategies; Equillium's ability to continue as a going concern; risks related to performing clinical and pre-clinical studies; whether the results from clinical and pre-clinical studies will validate and support the safety and efficacy of Equillium's product candidates; changes in the competitive landscape; and Equillium's ability to raise sufficient financing, which may not be available on acceptable terms or at all, to advance EQ504 and fund Equillium's strategic plans. These and other risks and uncertainties are described more fully under the caption "Risk Factors" and elsewhere in Equillium's filings and reports, which may be accessed for free by visiting the Securities and Exchange Commission's website and on Equillium's website under the heading "Investors." Investors should take such risks into account and should not rely on forward-looking statements when making investment decisions. All forward-looking statements contained in this press release speak only as of the date on which they were made. Equillium undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made, except as required by law.

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