Data demonstrates that NKT cells are activated in airways in IPF patients and inhibition of type 1 invariant NKT (iNKT) cell activity can ameliorate bleomycin-induced pulmonary fibrosis in mice

Compared to controls, mice treated with GRI-0621 showed histological improvement in fibrotic lesion in the lung; Inhibition of iNKT activity led to a decrease in fibrosis score and total lung inflammation

Company advancing Phase 2a biomarker study of GRI-0621 in patients with IPF with interim data expected Q3 2024 and topline data in Q4 2024

LA JOLLA, CA, July 02, 2024 — 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 announced the publication of positive preclinical data demonstrating its lead program GRI-0621 reduces the important inflammatory and fibrotic drivers in Idiopathic Pulmonary Fibrosis (IPF). The manuscript titled, "Type 1 invariant natural killer T cells drive lung fibrosis¹," has been published in the American Journal of Respiratory and Critical Care Medicine.

"There remains a significant unmet need with no existing therapeutic solutions that halt disease progression of fibrotic diseases such as IPF. We are encouraged by our growing body of promising data demonstrating the potential of GRI-0621 for the treatment of IPF," Marc Hertz, PhD, Chief Executive Officer of GRI Bio. "Supported by the data we've seen to date, our team continues to make solid progress in the advancement of our lead program, GRI-0621 and look forward to announcing interim data and topline data from our Phase 2a biomarker study in the third and fourth quarters of this year, respectively."

Natural Killer T (NKT) cells are a group of innate-like T cells which express NK cell receptors and antigen T cell receptors (TCR). NKT cells become rapidly activated following either TCR recognition of CD1d-bound lipid antigen or following inflammatory cytokine-activation. NKT cells produce type 1, 2 or 3 cytokines; NKT1 produce IFN-γ, whereas NKT2 secrete IL-4, IL-5, and IL-13, and NKT17 secrete IL-17A and IL-22. NKT cells have diverse functions bridging adaptive and innate immune responses. iNKT cells are tissue-resident and enriched in peripheral tissues, such as the lung.

To investigate the role of pulmonary NKT populations in IPF, the Company utilized the murine bleomycin model of pulmonary fibrosis.

Key Highlights

• Compared to controls, mice treated with GRI-0621 showed reduced fibrosis and immunopathology.
• Inhibition of iNKT activity led to a decrease in fibrosis score and total lung inflammation.
• GRI-0621 treated mice had reduced numbers of neutrophils and lymphocytes.
• Levels of the pro-fibrotic factor TGF-β were significantly decreased in GRI-0621-treated group in comparison to the untreated group. Similarly, VCAM-1 levels were also decreased in GRI-0621-treated group.

IPF is a rare chronic progressive pulmonary disease with abnormal scarring of the lung blocking the movement of oxygen into the bloodstream. The architectural destruction of the lung results in breathlessness, significant decline in quality of life and an average untreated survival of 3.5 years from diagnosis. Currently available treatments for IPF are limited with only two approved drugs that come with significant side-effects, limited compliance and no impact on survival².

GRI Bio is currently advancing its lead program GRI-0621, a small molecule RAR-βɣ dual agonist candidate that inhibits the activity of human iNKT cells, in a Phase 2a, randomized, double-blind, multi-center, placebo-controlled, parallel-design, 2-arm study for the treatment of IPF. Interim data from the Phase 2a biomarker study is expected in the third quarter of 2024 and topline results are expected in the fourth quarter of 2024.

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 NKT 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 stakeholder value and future financial performance, the Company's beliefs about the timing and outcome of regulatory approvals and potential regulatory approval pathways, the Company's expected milestones for 2024, and the Company's beliefs and expectations regarding the sufficiency of its existing cash and cash equivalents to fund its operating expenses 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 Nasdaq 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 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) 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 28, 2024 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
(833) 475-8247
GRI@jtcir.com

¹https://doi.org/10.1164/rccm.202402-0288LE
² T. M. Maher et al., Global incidence and prevalence of idiopathic pulmonary fibrosis. Respir Res 22, 197 (2021)