GRI Bio’s GRI-0621 Demonstrates Encouraging Safety Results at Planned Interim 6-Week Analysis in Ongoing Phase 2a Study in Idiopathic Pulmonary Fibrosis (“IPF”)

Rhea-AI Summary

GRI Bio (NASDAQ: GRI) has reported positive interim safety results from its Phase 2a study of GRI-0621, a RAR-βɣ dual agonist for treating Idiopathic Pulmonary Fibrosis (IPF). The Independent Data Monitoring Committee (IDMC) found no safety concerns in the first 24 patients after 6 weeks of treatment and recommended continuing the study.

The trial involves approximately 36 subjects randomized in a 2:1 ratio, receiving either 4.5mg GRI-0621 or placebo daily for 12 weeks. The drug demonstrated favorable safety profiles with no adverse events related to hyperlipidemia. The company expects to report 6-week interim biomarker data in July 2025 and topline results in Q3 2025.

Positive

• None.

Negative

• Early-stage trial with efficacy data still pending
• Small patient population size of only 36 subjects
• Final results not expected until Q3 2025

Insights

Biotech Clinical Trial Analyst

GRI Bio's positive interim safety data for GRI-0621 in IPF patients supports continued development with upcoming efficacy readouts expected soon.

GRI Bio has announced encouraging safety results from their planned 6-week interim analysis of GRI-0621 in a Phase 2a study for Idiopathic Pulmonary Fibrosis (IPF). The Independent Data Monitoring Committee (IDMC) recommended continuing the study as planned after reviewing data from the first 24 patients, finding no safety concerns with the 4.5mg once-daily oral dose.

Particularly noteworthy is the absence of hyperlipidemia side effects, with no clinically meaningful changes in HDL, LDL, or triglyceride levels. This favorable lipid profile is significant because it differentiates GRI-0621 from other retinoid-based therapies that often cause problematic lipid abnormalities. The safety profile appears consistent with earlier clinical experience with oral tazarotene (the active metabolite of GRI-0621) in over 1,700 patients treated for up to 52 weeks.

For context, IPF represents a substantial unmet medical need. The disease is characterized by progressive scarring of lung tissue, leading to respiratory failure. The two currently approved treatments (nintedanib and pirfenidone) have significant tolerability issues and don't improve survival, creating a clear opportunity for better-tolerated alternatives like GRI-0621.

Investors should note the upcoming catalysts: 6-week interim biomarker data expected in July 2025 and topline data in Q3 2025. While these safety results are encouraging, the biomarker data will provide the first signals of potential efficacy in this indication. The study's design includes multiple secondary endpoints examining serum biomarkers and pharmacodynamic activity of GRI-0621 in inhibiting iNKT cell activation, which is the drug's proposed mechanism of action in reducing inflammation and fibrosis.

The Independent Data Monitoring Committee (“IDMC”) has recommended to continue the study as planned as there are no safety concerns demonstrated in the data reviewed

Interim results to date demonstrate GRI-0621 to be safe and well-tolerated in the first 24 patients evaluated

6-week interim biomarker data (n=24) expected in July 2025 and topline data expected in Q3 2025

Currently available treatments for IPF are limited to only two approved drugs that come with significant side-effects, limited patient compliance and no impact on survival

LA JOLLA, CA, June 26, 2025 (GLOBE NEWSWIRE) -- GRI Bio, Inc. (NASDAQ: GRI) (“GRI Bio” or the “Company”), a biotechnology company advancing an innovative pipeline of Natural Killer T (“NKT”) cell modulators for the treatment of inflammatory, fibrotic and autoimmune diseases, today reported positive 6-week interim safety results from its ongoing Phase 2a study evaluating GRI-0621 for the treatment of IPF.

GRI-0621 is the Company’s small molecule RAR-βɣ dual agonist that inhibits the activity of human Type 1 Invariant NKT (“iNKT”) cells. In preliminary clinical trials to date and previous clinical trials with the oral formulation, GRI-0621 has been shown to improve fibrosis in multiple disease models and improve liver function tests and other markers of inflammation and injury in patients.

The pre-planned interim analysis for 6-week safety results from the ongoing Phase 2a biomarker study demonstrated GRI-0621 (4.5mg orally once daily) to be safe and well-tolerated in the first 24 patients evaluated per protocol. There were no adverse events associated with hyperlipidemia, as assessed by LDL, HDL and triglyceride (“TG”) levels in the 24 patients assessed at the 6-week visit. There were no clinically meaningful changes in HDL, LDL or TG levels in patients receiving GRI-0621, consistent with the safety data reported after the first 12 subjects completed 2-weeks of treatment, and all subjects remained within protocol accepted ranges. The interim analysis committee recommended the study should continue as planned. The interim 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.

Marc Hertz, PhD, Chief Executive Officer of GRI Bio commented, “We are happy to report the IDMC confirmed no safety concerns in the first 24 subjects evaluated after 6-weeks of treatment, building upon the 2-week safety data reported earlier and adding to the large safety data available for oral tazarotene. We are encouraged by the consistent safety data and early anti-fibrotic trends previously reported and remain on track to report 6-week interim biomarker data in the coming weeks followed by topline data expected in the third quarter of this year.”

The Phase 2a, randomized, double-blind, multi-center, placebo-controlled, parallel-design, 2-arm study is enrolling approximately 36 subjects with IPF. Subjects are being randomized in a 2:1 ratio for GRI-0621 4.5mg or a placebo. GRI-0621 dose of 4.5mg is being compared with a dose of placebo following once daily oral administration for 12 weeks. Concurrently, a sub-study is examining the number and activity of NKT cells in bronchoalveolar lavage (“BAL”) fluid for up to 12 eligible subjects (across various centers). The primary endpoint for the study is safety and tolerability of oral GRI-0621 as assessed by clinical labs, vital signs and adverse events after 12 weeks of treatment. Secondary endpoints are 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 iNKT cell activation in blood after 6 weeks and 12 weeks, and from BAL fluid after 12 weeks of treatment in a sub-study. Additional exploratory endpoints for the study are to assess 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.

The Company expects to report 6-week interim biomarker data in July 2025. Topline results from the Phase 2a biomarker study are expected in the third quarter of 2025.

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

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 inhibitor of 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 or trials will be indicative of results of later studies or clinical trials, the Company’s beliefs and expectations regarding potential shareholder value, 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, and the Company’s expected milestones in 2025. 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; (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 product candidates, and any related restrictions and limitations of any cleared or approved product candidates; (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) the failure to achieve any milestones or receive any milestone payments under any agreements; (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 (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. In particular, the data discussed in this release is interim data and additional study and additional favorable results will be needed for development of GRI-0621 to continue; this interim data may not be indicative of later or final data for this trial. 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 were the safety results of GRI Bio's Phase 2a trial for GRI-0621 in IPF treatment?

The 6-week interim analysis showed GRI-0621 to be safe and well-tolerated in the first 24 patients, with no adverse events related to hyperlipidemia and no clinically meaningful changes in HDL, LDL, or triglyceride levels.

How many patients are enrolled in GRI Bio's Phase 2a IPF trial?

The trial is enrolling approximately 36 subjects with IPF, randomized in a 2:1 ratio to receive either GRI-0621 4.5mg or placebo.

When will GRI Bio (NASDAQ: GRI) report the full results of the GRI-0621 Phase 2a trial?

GRI Bio expects to report 6-week interim biomarker data in July 2025 and topline results in the third quarter of 2025.

What are the primary and secondary endpoints of GRI Bio's Phase 2a IPF trial?

The primary endpoint is safety and tolerability after 12 weeks. Secondary endpoints include changes in serum biomarkers, pharmacokinetics assessment, and pharmacodynamic activity measurement through iNKT cell activation.

What advantages could GRI-0621 have over current IPF treatments?

Current IPF treatments are limited to only two approved drugs that have significant side-effects and limited patient compliance. GRI-0621 is showing a favorable safety profile, potentially offering an advantage over existing treatments.