Equillium Announces First Subject Dosed in Phase 1 Clinical Trial of EQ504

The Phase 1 study will test once-daily oral doses ranging from 0.1–3.0 mg in approximately 70 healthy subjects.

Rhea-AI Summary

Equillium (Nasdaq: EQ) has dosed the first subject in Australia in its Phase 1 clinical trial of investigational EQ504.

The randomized, double-blind, placebo-controlled study will evaluate safety, tolerability, drug exposure and biological activity in approximately 70 healthy subjects. Equillium expects topline proof-of-mechanism data in Q2 2027 and, subject to supportive results, anticipates starting a placebo-controlled ulcerative colitis study in the second half of 2027.

First dosing triggered a milestone under the August 2025 equity private placement. The closing is expected later today, with approximately $20.0 million in gross proceeds from common shares and pre-funded warrants, bringing total placement proceeds to approximately $50 million. With these proceeds, Equillium expects cash and cash equivalents to fund currently planned operations into 2029.

5 points · 1 major

MixediHow this balance works

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It reads the document as published, with the same rules for every company, and it does not look at what the market expected or at how the stock traded, so a point can be objectively good on a day the stock falls.

Rhea-AI Sentiment measures something else, the tone of the wording.

How the balance worksHow Sentiment works

2 major · 4 points

Hollow bars mark forward-looking points. How the balance works

Positive

• Major point. Forward-looking: it has not happened yet and may not happen.Milestone financing is expected to raise approximately $20.0 million in additional gross proceeds. 26% of market cap
• Moderate point. Forward-looking: it has not happened yet and may not happen.Topline proof-of-mechanism data are anticipated in Q2 2027.
• Moderate point. Forward-looking: it has not happened yet and may not happen.Cash and cash equivalents, including milestone proceeds, are expected to fund currently planned operations into 2029.
• Minor pointFirst subject dosed advances EQ504 into Phase 1 clinical testing in Australia.
• Minor point. Forward-looking: it has not happened yet and may not happen.Equillium anticipates a placebo-controlled ulcerative colitis study in the second half of 2027, subject to supportive Phase 1 data.

Negative

• Major point. Forward-looking: it has not happened yet and may not happen.Expected issuance of 14,957,260 common shares at $0.57 per share adds dilution.
• Major point. Forward-looking: it has not happened yet and may not happen.Expected issuance of 20,130,457 pre-funded warrants at $0.5669 each adds potential share dilution.
• Moderate point. Forward-looking: it has not happened yet and may not happen.The milestone financing closing remains anticipated, with completion expected later today.
• Minor point. Forward-looking: it has not happened yet and may not happen.The planned ulcerative colitis study depends on supportive topline Phase 1 data.

News Explained

The expected closing would bring Equillium about $20 million and issue 14,957,260 common shares plus 20,130,457 pre-funded warrants; the issued shares reduce existing holders’ ownership percentages, while warrants can add shares if exercised.

Key Figures

Additional private placement funding: $20 million Common shares: 14,957,260 shares at $0.57 per share Pre-funded warrants: 20,130,457 warrants at $0.5669 each +4 more

Additional private placement funding

$20 million

Anticipated milestone closing

Common shares

14,957,260 shares at $0.57 per share

Expected issuance at the milestone closing

Pre-funded warrants

20,130,457 warrants at $0.5669 each

Expected issuance at the milestone closing

Phase 1 topline data

Q2 2027

Anticipated proof-of-mechanism data

Healthy subjects

Approximately 70

EQ504 Phase 1 trial

Dose range

0.1–3.0 mg

Once-daily oral doses in the Phase 1 trial

Planned operations runway

Into 2029

Cash and cash equivalents expected to fund currently planned operations

Previous Clinical trial Reports

1 past event · Latest: Oct 05

Same Type 1 event

1. Oct 05

   trial clearance

   24h Move

   -2.1%

   Australian clearance authorized the EQ504 Phase 1 study; dosing was expected in early November.

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

Key Terms

pharmacokinetics, pharmacodynamics, pre-funded warrants, aryl hydrocarbon receptor

4 terms

pharmacokinetics medical

"evaluate safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD)"

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

"evaluate safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD)"

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.

pre-funded warrants financial

"or pre-funded warrants in lieu thereof"

Pre-funded warrants are financial instruments that give investors the right to purchase a company's stock at a set price, but with most or all of the purchase price paid upfront. They function like a coupon or gift card for stock, allowing investors to buy shares later at a fixed price, which can be beneficial if they want to avoid future price increases. This makes them important for investors seeking flexibility and certainty in their investment plans.

aryl hydrocarbon receptor medical

"an investigational oral, colon-targeted aryl hydrocarbon receptor (AhR) modulator"

Aryl hydrocarbon receptor (AHR) is a protein inside cells that detects certain environmental chemicals and helps turn genes on or off in response, like a smoke alarm that triggers specific reactions. It matters to investors because AHR influences how the body handles toxins and can be a target or safety concern in drug development, environmental liability assessment, and biomarker-driven regulatory decisions that affect company value.

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Topline Phase 1 proof-of-mechanism data anticipated in Q2 2027

Randomized, double-blind, placebo-controlled study will evaluate safety, tolerability, PK and PD of EQ504

Triggers Milestone Closing of $20 million in additional funding under previously announced equity private placement agreement; cash expected to fund currently planned operations into 2029

LA JOLLA, Calif., Oct. 26, 2026 (GLOBE NEWSWIRE) -- Equillium, Inc. (Nasdaq: EQ), a biotechnology innovator developing novel therapies to treat severe autoimmune and inflammatory disorders, today announced that the first subject has been dosed in Australia in its Phase 1 clinical trial of EQ504, an investigational oral, colon-targeted aryl hydrocarbon receptor (AhR) modulator being developed for the treatment of serious inflammatory diseases (the Milestone Event). In connection with the occurrence of the Milestone Event, the Company also announced the anticipated milestone closing under its August 2025 equity private placement of an additional $20 million of shares of its common stock, or pre-funded warrants in lieu thereof (the Milestone Closing), which is expected to occur later today.

“Dosing the first participant in our Phase 1 trial marks an important milestone as we advance EQ504, our differentiated, oral, colon-targeted AhR modulator, into clinical development,” said Bruce Steel, Chief Executive Officer of Equillium. “We believe EQ504's locally acting and non-immunosuppressive approach has the potential to address important unmet medical needs in ulcerative colitis and other serious inflammatory diseases. The Phase 1 trial is designed to evaluate safety and tolerability, as well as characterize EQ504’s pharmacokinetic and pharmacodynamic profile to assess proof of mechanism. Subject to supportive topline Phase 1 data, expected in Q2 2027, we anticipate initiating a placebo-controlled proof-of-concept study in patients with moderately to severely active ulcerative colitis in the second half of 2027.”

The Phase 1 trial (NCT07869225), being conducted in Australia, is a randomized, double-blind, placebo-controlled, single-center study designed to evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of EQ504 in approximately 70 healthy subjects exploring once-daily oral doses ranging from 0.1–3.0 mg. The study consists of a single ascending dose portion evaluating escalating oral doses of EQ504 across five sequential cohorts, and a multiple ascending dose (MAD) portion evaluating once-daily oral dosing over 10 days across three cohorts.

The MAD portion will also evaluate EQ504's pharmacodynamic activity through multiple gastrointestinal (GI) mucosal biopsies, including measurement of cytochrome P450 1A1 (CYP1A1) expression, a biomarker of AhR pathway activation. These assessments are designed to provide early clinical evidence of localized target engagement and biological activity in the GI tract, supporting EQ504's differentiated, colon-targeted approach. An optional food-effect cohort will examine whether food affects EQ504 exposure.

Milestone Closing of $20 Million Under the August 2025 Equity Private Placement

At the Milestone Closing, investors are expected to purchase and the Company expects to issue and sell 14,957,260 shares of common stock at a purchase price of $0.57 per share and 20,130,457 pre-funded warrants to purchase common stock at a purchase price of $0.5669 per pre-funded warrant, for aggregate gross proceeds of approximately $20.0 million, bringing the total equity private placement proceeds to approximately $50 million. With the proceeds from the Milestone Closing, the Company expects its cash and cash equivalents to be sufficient to fund its currently planned operations into 2029.

The offer and sale of the foregoing securities were made in a transaction not involving a public offering and have not been registered under the Securities Act of 1933, as amended (the “Securities Act”), or any applicable state securities laws. Accordingly, the securities may not be reoffered or resold in the United States except pursuant to an effective registration statement or an applicable exemption from the registration requirements of the Securities Act and such applicable state securities laws. The investors have been granted customary resale Form S-3 registration rights for the shares of common stock issued to them in the financing.

This press release shall not constitute an offer to sell, or a solicitation of an offer to buy, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

About EQ504
EQ504 is an investigational potent and selective aryl hydrocarbon receptor (AhR) modulator with a multi-modal, non-immunosuppressive mechanism of action designed to be 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. For ulcerative colitis, EQ504 is formulated as an oral, colon-targeted delayed-release drug product. Equillium is also evaluating the potential of EQ504 for additional indications, including inflammatory lung diseases through inhaled formulations.

About Equillium
Equillium is a biotechnology innovator with a mission to develop highly impactful therapies to treat severe autoimmune and inflammatory disorders.
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”, “will”, “designed to” 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 reporting data from a Phase 1 study of EQ504; the potential benefits of EQ504; the anticipated initiation of a placebo-controlled proof-of-concept study in patients with ulcerative colitis; the expected Milestone Closing for the additional $20 million tranche under Equillium’s 2025 equity private placement, including receipt of the Price Threshold Waiver; the expected use of proceeds from the private placement; and Equillium’s expectations that its financial position and cash runway will fund currently planned operations into 2029. 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; 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; risks involving the expected Milestone Closing, including the occurrence and anticipated time and the impact the sale will have on the Company’s stock price; 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.

Investor Contact
PJ Kelleher
LifeSci Advisors, LLC
+1-617-430-7579
pkelleher@lifesciadvisors.com

FAQ

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

When does Equillium expect EQ504 Phase 1 results?

Equillium anticipates topline Phase 1 proof-of-mechanism data in Q2 2027. The randomized, double-blind, placebo-controlled study will evaluate safety, tolerability, drug exposure and biological activity in approximately 70 healthy subjects.

How much funding does EQ504 first dosing trigger for Equillium?

The dosing milestone triggers an anticipated closing for approximately $20.0 million in gross proceeds under Equillium's August 2025 equity private placement. The closing is expected later today and would bring total placement proceeds to approximately $50 million.

How will Equillium's EQ504 Phase 1 trial measure biological activity?

The multiple ascending dose portion will assess biological activity through gastrointestinal mucosal biopsies, including measurement of CYP1A1 expression, a marker of AhR pathway activation. This portion evaluates once-daily oral dosing over 10 days across three cohorts.