GRI Bio Announces Additional Positive Data from Phase 2a Study in Idiopathic Pulmonary Fibrosis, Strengthening Clinical Proof-of-Concept for GRI-0621

Rhea-AI Summary

GRI Bio (NASDAQ: GRI) reported positive Phase 2a flow cytometry data for GRI-0621 in idiopathic pulmonary fibrosis (IPF). After 12 weeks, treated subjects showed iNKT inhibition, increased TCR expression, higher anti-fibrotic IFN-γ and reductions in IL-4, IL-13, IL-17A, IL-22 and TGF-β in BAL and PBMC samples versus baseline or placebo.

The randomized, double-blind 2:1 study enrolled 35 subjects (4.5mg daily or placebo) with an 8-subject BAL sub-study. The trial met its primary safety/tolerability endpoint and reported exploratory signals of collagen turnover, lung repair and more subjects with no FVC decline at 12 weeks versus standard of care. Company completed a December 2025 public offering and reports stockholders' equity above the Nasdaq $2.5M minimum.

Positive

• Primary safety and tolerability endpoint met at 12 weeks
• Biomarker shift: IFN-γ increased; TGF-β reduced in BAL and PBMC
• Exploratory pulmonary signal: twice as many subjects with no FVC decline vs standard of care at 12 weeks

Negative

• Small overall sample size: 35 subjects randomized 2:1
• BAL immunology sub-study limited to 8 subjects
• Short treatment duration: efficacy signals reported at 12 weeks only

News Market Reaction

-4.70% 1.6x vol

27 alerts

-4.70% News Effect

+33.0% Peak Tracked

-33.3% Trough Tracked

-$149K Valuation Impact

$3M Market Cap

1.6x Rel. Volume

On the day this news was published, GRI declined 4.70%, reflecting a moderate negative market reaction. Argus tracked a peak move of +33.0% during that session. Argus tracked a trough of -33.3% from its starting point during tracking. Our momentum scanner triggered 27 alerts that day, indicating elevated trading interest and price volatility. This price movement removed approximately $149K from the company's valuation, bringing the market cap to $3M at that time. Trading volume was above average at 1.6x the daily average, suggesting increased trading activity.

Data tracked by StockTitan Argus on the day of publication.

Key Figures

Phase 2a enrollment: 35 subjects Treatment duration: 12 weeks Dose: 4.5mg +5 more

8 metrics

Phase 2a enrollment 35 subjects Randomized 2:1 to GRI-0621 4.5mg or placebo

Treatment duration 12 weeks Once-daily oral GRI-0621 vs placebo

Dose 4.5mg GRI-0621 once-daily oral regimen

BAL sub-study size 8 subjects Immune cell analysis in bronchoalveolar lavage fluid

Prior tazarotene exposure Over 1,700 patients Oral tazarotene safety experience up to 52 weeks

Trial identifier NCT06331624 Phase 2a GRI-0621-IPF-02 IPF study on clinicaltrials.gov

Nasdaq equity minimum $2.5 million Stockholders’ equity requirement the company believes it exceeds

Standard of care duration 12 weeks Comparison against placebo plus standard of care

Market Reality Check

Price: $0.2379 Vol: Volume 1,139,336 is below...

low vol

$0.2379 Last Close

Volume Volume 1,139,336 is below 20-day average 5,015,071 (relative volume 0.23x). low

Technical Price 0.298 is trading below the 200-day MA at 1.66, reflecting a longer-term downtrend.

Peers on Argus

GRI is down 1.29% while close biotech peers show mixed moves: ADTX -6.62%, TTNP ...

GRI is down 1.29% while close biotech peers show mixed moves: ADTX -6.62%, TTNP -3.96%, APVO +12.01%, PALI +0.75%, XBIO +1.43%. No coordinated sector direction is evident.

Historical Context

5 past events · Latest: Dec 12 (Negative)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Dec 12	Equity offering close	Negative	-10.0%	Closing of $8M public offering with Series F warrants and dilution impact.
Dec 11	Equity offering pricing	Negative	-56.5%	Pricing of $8M best-efforts offering of shares and Series F warrants.
Dec 10	Phase 2a topline data	Positive	-12.9%	Phase 2a IPF trial met primary safety endpoint with favorable biomarker shifts.
Sep 11	Interim clinical update	Positive	+31.4%	6‑week interim IPF data showing no FVC decline and anti-fibrotic biomarkers.
Sep 03	Conference participation	Neutral	+4.3%	Announcement of presentation at H.C. Wainwright global investment conference.

Pattern Detected

Positive clinical updates have sometimes led to sharp gains but also notable selloffs, while equity offerings have generally aligned with negative price reactions.

Recent Company History

Over the last six months, GRI Bio has focused on advancing GRI-0621 in IPF while repeatedly accessing capital markets. A Sept 11, 2025 6‑week interim update drove a 31.41% gain, but the positive Phase 2a topline on Dec 10, 2025 coincided with a -12.95% move. Subsequent best-efforts offerings priced and closed on Dec 11–12, 2025 raised about $8M and were followed by further declines. Today’s additional mechanistic Phase 2a data extends that clinical narrative against a backdrop of dilution and balance-sheet repair.

Market Pulse Summary

This announcement adds detailed immune-profiling results to earlier Phase 2a data, showing GRI-0621’...

Analysis

This announcement adds detailed immune-profiling results to earlier Phase 2a data, showing GRI-0621’s effect on iNKT cells, cytokines, and fibrotic pathways in IPF over 12 weeks in 35 subjects. It reinforces signals of fibrosis resolution and lung function support, while management notes improved stockholders’ equity above the $2.5 million Nasdaq minimum after a recent financing. Investors may watch for larger trials, durability of FVC trends, and future capital needs.

Key Terms

idiopathic pulmonary fibrosis, bronchoalveolar lavage, peripheral blood mononuclear cells, flow cytometry, +4 more

8 terms

idiopathic pulmonary fibrosis medical

"Phase 2a GRI-0621-IPF-02 clinical trial evaluating GRI-0621 for the treatment of Idiopathic Pulmonary Fibrosis"

Idiopathic pulmonary fibrosis is a chronic lung disease in which the air‑carrying tissue becomes progressively thickened and scarred for no identifiable reason, making the lungs stiff and less able to move oxygen—similar to a sponge that hardens and loses its pores. It matters to investors because it is life‑limiting with limited effective treatments, so clinical trial outcomes, regulatory approvals, pricing and reimbursement decisions can strongly affect the commercial value of therapies and the financial prospects of companies developing treatments.

bronchoalveolar lavage medical

"Immune cell samples from lung bronchoalveolar lavage (BAL) fluid and peripheral blood"

A bronchoalveolar lavage is a medical procedure that rinses a small area of the lung with fluid and then collects that fluid for analysis, like flushing and examining the inside of a pipe to see what’s inside. Investors care because results can reveal infection, inflammation, or drug-related lung effects that influence clinical trial outcomes, regulatory decisions and market perception of respiratory therapies or safety profile of systemic drugs.

peripheral blood mononuclear cells medical

"bronchoalveolar lavage (BAL) fluid and peripheral blood mononuclear cells (PBMC) demonstrated iNKT inhibition"

Peripheral blood mononuclear cells (PBMCs) are a mixed group of immune cells—like white blood cells—drawn from a blood sample that researchers use to study immune response, test vaccines, or develop cell-based therapies. They matter to investors because results derived from PBMC tests can indicate whether a drug or therapy is engaging the immune system as intended, much like a car’s dashboard lights reveal how well the engine components are working.

flow cytometry medical

"announced positive flow cytometry data from the Phase 2a GRI-0621-IPF-02 clinical trial"

A laboratory method that uses lasers and sensors to count and analyze individual cells or tiny particles as they flow past a detector, like a high‑speed supermarket scanner that reads barcodes on each item. Investors care because flow cytometry is widely used in drug development, diagnostics and manufacturing quality control; demand for the instruments, reagents and services can signal progress in clinical programs, recurring revenue streams and adoption of new therapies or tests.

interferon-gamma medical

"producing more anti-fibrotic interferon-gamma (IFN-γ) and less pro-fibrotic interleukin-4"

Interferon-gamma is an immune signaling protein produced by certain white blood cells that helps coordinate the body’s defense against infections and abnormal cells; think of it as a coach that tells other immune cells when and how to act. It matters to investors because drugs, diagnostics, or safety findings involving interferon-gamma can change clinical trial results, regulatory decisions, and market potential for therapies, which in turn can affect a company’s valuation and stock performance.

transforming growth factor-beta medical

"IL-22, and transforming growth factor-beta (TGF-β). Chronically activated iNKT cells"

Transforming growth factor-beta (TGF-β) is a naturally occurring signaling protein that helps control cell growth, inflammation and tissue repair, acting like a traffic cop that tells cells when to divide, change form or calm down. It matters to investors because drugs that block or boost TGF-β can treat cancers, fibrotic diseases and immune disorders, affecting clinical trial outcomes, regulatory risk and the commercial potential of biopharma assets.

forced vital capacity medical

"exploratory endpoints demonstrating increased forced vital capacity (FVC) with twice as many subjects"

The amount of air a person can forcefully breathe out after taking the deepest breath possible; think of it as how much air you can squeeze out of a balloon in one hard blow. It matters to investors because it’s a common, objective measure used in clinical trials and patient monitoring for respiratory drugs, devices and treatments—changes in this number can signal whether a therapy works, affecting regulatory approval, sales and company value.

pharmacokinetics medical

"assessment of the pharmacokinetics (PK) of GRI-0621 at the week 12 visit of treatment"

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.

AI-generated analysis. Not financial advice.

New immune profiling data confirms disease-modifying mechanism, reinforces earlier signals of fibrosis resolution, lung repair, and improved lung function

LA JOLLA, CA, Jan. 08, 2026 (GLOBE NEWSWIRE) -- GRI Bio, Inc. (NASDAQ: GRI) (“GRI Bio” or the “Company”), a biotechnology company advancing an innovative pipeline of immune cell modulators for the treatment of inflammatory, fibrotic and autoimmune diseases, today announced positive flow cytometry data from the Phase 2a GRI-0621-IPF-02 clinical trial evaluating GRI-0621 for the treatment of Idiopathic Pulmonary Fibrosis (“IPF”). Immune cell samples from lung bronchoalveolar lavage (BAL) fluid and peripheral blood mononuclear cells (PBMC) demonstrated iNKT inhibition and a clear immunomodulatory shift towards an anti-fibrotic profile, producing more anti-fibrotic interferon-gamma (IFN-γ) and less pro-fibrotic interleukin-4 (IL-4), IL-13, IL-17A, IL-22, and transforming growth factor-beta (TGF-β).

Chronically activated iNKT cells downregulate the expression of their T cell receptor (TCR). GRI-0621-treated subjects demonstrated increased TCR expression after 12 weeks of treatment compared with baseline or placebo-treated subjects receiving standard of care. T cell subsets demonstrated increased type I-associated cytokines (IFN-γ) and reduced type 2 (IL-4 and IL-13) and type 3-associated cytokines (IL-17A and IL-22) in both BAL and PBMC samples. Similarly, TGF-β was observed to be reduced after 12 weeks of GRI-0621 treatment in T cell subsets (e.g. Treg and Treg-like), B cells, monocytes, macrophages and neutrophils in BAL and PBMC samples compared to baseline or placebo-treated subjects receiving standard of care.

“There remains a tremendous unmet need for safe, tolerable, and truly effective treatments for patients suffering from IPF,” said Marc Hertz, PhD, Chief Executive Officer of GRI Bio. “GRI-0621 continues to demonstrate a compelling profile, combining favorable safety and tolerability with a dual mechanism of action as both an immunomodulator and an anti-fibrotic agent.”

“Our Phase 2a study was intentionally designed to assess a broad range of clinical, biomarker, and mechanistic endpoints,” Dr. Hertz continued. “The immune cell data announced today are highly consistent with our earlier findings on collagen turnover, lung tissue repair, and improvements in pulmonary function, further strengthening the overall clinical proof-of-concept for GRI-0621.”

The Company previously reported that the study met its primary endpoint, demonstrating a safety and tolerability profile differentiated from that of existing treatment options. The study also met secondary endpoints suggestive of disease-modifying activity, reversal of fibrosis and inducement of a lung repair mechanism, as well as exploratory endpoints demonstrating increased forced vital capacity (FVC) with twice as many subjects observed to have no decline in FVC compared to standard of care alone at 12 weeks of treatment.

The Phase 2a, randomized, double-blind, multinational, multi-center, placebo-controlled, parallel-design, 2-arm study enrolled 35 subjects with IPF who were randomized in a 2:1 ratio for GRI-0621 4.5mg or a placebo. GRI-0621 dose of 4.5mg was compared with a dose of placebo following once daily oral administration for 12 weeks. Concurrently, a sub-study examined the number and activity of immune cells in bronchoalveolar lavage (“BAL”) fluid in 8 subjects (across various centers). The primary endpoint for the Phase 2a study was safety and tolerability of oral GRI-0621 as assessed by clinical labs, vital signs and adverse events after 12 weeks of treatment. Secondary endpoints were baseline changes in serum biomarkers collected at week 6 and week 12; an assessment of the pharmacokinetics (PK) of GRI-0621 at the week 12 visit of treatment (steady state); and a determination of the pharmacodynamic activity of oral GRI-0621 as measured by inhibition of immune cell activation in blood after 6 weeks and 12 weeks, and from BAL fluid after 12 weeks of treatment in the sub-study. Additional exploratory endpoints for the study included assessment of the effect of GRI-0621 on pulmonary function at baseline and after 6 weeks and 12 weeks of treatment and flow cytometry and differential gene expression at various time points. These results show that GRI-0621’s receptor selectivity is consistent with the toxicity profile observed in earlier studies evaluating oral tazarotene in over 1,700 patients treated for up to 52 weeks.

For more information about the Phase 2a study, please visit clinicaltrials.gov and reference identifier NCT06331624.

The Company also previously announced that it successfully completed a public offering in early December 2025. As a result of this offering and as of the date of this press release, the Company believes its stockholders’ equity is in excess of the minimum $2.5 million Nasdaq requirement.

About GRI Bio, Inc.

GRI Bio is a clinical-stage biopharmaceutical company focused on fundamentally changing the way inflammatory, fibrotic and autoimmune diseases are treated. GRI Bio’s therapies are designed to target the activity of Natural Killer T (“NKT”) cells, which are key regulators earlier in the inflammatory cascade, to interrupt disease progression and restore the immune system to homeostasis. NKT cells are innate-like T cells that share properties of both NK and T cells and are a functional link between the innate and adaptive immune responses. Type I invariant NKT (“iNKT”) cells play a critical role in propagating the injury, inflammatory response, and fibrosis observed in inflammatory and fibrotic indications. GRI Bio’s lead program, GRI-0621, is an RARβγ agonist shown to inhibit the activity of key immune cells, like iNKT cell activity, and is being developed as a novel oral therapeutic for the treatment of idiopathic pulmonary fibrosis, a serious disease with significant unmet need. The Company is also developing a pipeline of novel type 2 diverse NKT (“dNKT”) agonists for the treatment of systemic lupus erythematosus. Additionally, with a library of over 500 proprietary compounds, GRI Bio has the ability to fuel a growing pipeline.

Forward-Looking Statements

This press release contains “forward-looking statements” within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements may be identified by the use of words such as “anticipate,” “believe,” “contemplate,” “could,” “estimate,” “expect,” “intend,” “seek,” “may,” “might,” “plan,” “potential,” “predict,” “project,” “target,” “aim,” “should,” “will,” “would,” or the negative of these words or other similar expressions. These forward-looking statements are based on the Company’s current beliefs and expectations. Forward-looking statements include, but are not limited to, statements regarding: the Company’s expectations with respect to development and commercialization of the Company’s product candidates, the timing of initiation or completion of clinical trials and availability of resulting data, the potential benefits and impact of the Company’s clinical trials and product candidates and any implication that the data or results observed in preclinical trials or earlier studies, topline or interim data or trials will be indicative of results of later studies or clinical trials or final data, that final data will be indicative of a proof-of-concept, the Company’s beliefs and expectations regarding potential shareholder value and future financial performance, the Company’s beliefs and estimates about its cash and available resources and its ability to fund its planned operations through any particular date, the Company’s beliefs about the timing and outcome of regulatory approvals and potential regulatory approval pathways, the Company’s expected milestones future milestones, and the Company’s beliefs and expectations regarding the sufficiency of its existing cash and cash equivalents to fund its planned operations, its ability to raise additional funds, which may not be available to the Company on acceptable terms, or at all, and capital expenditure requirements. Actual results may differ from the forward-looking statements expressed by the Company in this press release and consequently, you should not rely on these forward-looking statements as predictions of future events. These forward-looking statements are subject to inherent uncertainties, risks and assumptions that are difficult to predict, including, without limitation: (1) the inability to maintain the listing of the Company’s common stock on The Nasdaq Capital Market and to comply with applicable listing requirements, including as a result of the Staff’s potential determination that the Company does not satisfy the Nasdaq’s stockholder equity requirements for which the Company received notice in November 2025 and any failure of the Company to comply with Nasdaq’s $1.00 “minimum bid price rule”; (2) changes in applicable laws or regulations; (3) the inability of the Company to raise financing in the future; (4) the success, cost and timing of the Company’s product development activities; (5) the inability of the Company to obtain and maintain regulatory clearance or approval for its respective products, and any related restrictions and limitations of any cleared or approved product; (6) the inability of the Company to identify, in-license or acquire additional technology; (7) the inability of the Company to compete with other companies currently marketing or engaged in the development of products and services that the Company is currently developing; (8) the size and growth potential of the markets for the Company’s products and services, and their respective ability to serve those markets, either alone or in partnership with others; (9) that later data or clinical trials may be inconsistent with or contrary to data and observations to date, including that later data may not indicate a proof-of-concept or patient benefit; (10) inaccuracy in the Company’s estimates regarding expenses, future revenue, capital requirements and needs for and the ability to obtain additional financing; (11) the Company’s ability to protect and enforce its intellectual property portfolio, including any newly issued patents and its ability to obtain any expected patent term extensions, adjustments, exclusivities or disclaimers; and (12) other risks and uncertainties indicated from time to time in the Company’s filings with the U.S. Securities and Exchange Commission (the “SEC”), including the risks and uncertainties described in the “Risk Factors” section of the Company’s most recent Annual Report on Form 10-K filed with the SEC on March 14, 2025 and subsequently filed reports. Forward-looking statements contained in this announcement are made as of this date, and the Company undertakes no duty to update such information except as required under applicable law.

Investor Contact:
JTC Team, LLC
Jenene Thomas
(908) 824-0775
GRI@jtcir.com

FAQ

What did GRI Bio announce about GRI-0621 results in IPF on January 8, 2026?

GRI Bio announced Phase 2a flow cytometry data showing iNKT inhibition, increased TCR expression and shifts toward anti-fibrotic cytokines after 12 weeks.

How many patients were enrolled in the GRI-0621 Phase 2a IPF trial (NASDAQ: GRI)?

The randomized, double-blind study enrolled 35 subjects, randomized 2:1 to GRI-0621 4.5mg or placebo.

Did the GRI-0621 Phase 2a study meet its primary endpoint?

Yes; the primary endpoint of safety and tolerability at 12 weeks was reported as met.

What clinical signals were reported for lung function in the GRI-0621 trial?

Exploratory endpoints showed increased markers of lung repair and twice as many subjects with no decline in FVC at 12 weeks versus standard of care.

How large was the bronchoalveolar lavage (BAL) immunology sub-study for GRI-0621?

The BAL sub-study examined immune cells in 8 subjects across study centers after 12 weeks of treatment.

Does GRI Bio have sufficient Nasdaq equity after the December 2025 offering?

GRI Bio stated that following its December 2025 public offering it believes stockholders' equity is in excess of the $2.5 million Nasdaq requirement.