Stock Markets January 28, 2026

GRI Bio Shares Jump After RNA-Sequencing Shows Drug Hits IPF Disease Pathways

New Phase 2a gene-expression results point to impacts on lung injury and fibrosis biology; stock surges in premarket trade

By Nina Shah GRI
GRI Bio Shares Jump After RNA-Sequencing Shows Drug Hits IPF Disease Pathways
GRI

GRI Bio Inc reported additional RNA-sequencing evidence from its Phase 2a trial of GRI-0621 in idiopathic pulmonary fibrosis (IPF) showing significant changes in genes tied to lung injury, myofibroblast activation, and fibrosis progression versus placebo. The company says the pattern of gene expression supports mechanisms consistent with fibrosis resolution and activation of tissue repair, and the announcement sent the stock up 37.6% in premarket trading.

Key Points

  • GRI Bio reported RNA-sequencing data from its Phase 2a IPF trial showing significant gene-expression improvements tied to lung injury, myofibroblast activation, and fibrosis progression - impacts biotech and healthcare sectors.
  • Company asserts GRI-0621 targets core IPF biology and supports mechanisms consistent with fibrosis resolution and active tissue repair - relevant to clinical development and investor assessment in biotech markets.
  • Phase 2a previously met its primary endpoint for safety and tolerability and showed secondary signals including FVC outcomes; twice as many treated subjects experienced no FVC decline at 12 weeks versus standard of care.

GRI Bio Inc (NASDAQ:GRI) saw its shares climb sharply in premarket trading Wednesday after the company released further genetic data from its Phase 2a clinical trial of GRI-0621 for idiopathic pulmonary fibrosis (IPF).

The newly disclosed RNA-sequencing results showed statistically significant improvements across sets of genes associated with lung injury, myofibroblast activation, and progression of fibrosis when compared with placebo. According to the company, these gene-expression changes are aligned with earlier biomarker, functional, and clinical signals observed in the same study.


Findings and interpretation

GRI Bio reported that the differential gene expression indicates GRI-0621 engages core aspects of IPF biology. The company described links between the affected genes and central disease drivers, interpreting the pattern as consistent with fibrosis resolution and active tissue repair rather than solely slowing disease progression.

Specifically, the firm highlighted gene-expression shifts consistent with basement membrane repair and transitions of epithelial cells in treated participants versus placebo, which the company characterized as hallmarks of lung regeneration.


Clinical context and study endpoints

The Phase 2a trial previously met its primary endpoint, demonstrating favorable safety and tolerability. The study also achieved multiple secondary endpoints the company says are indicative of disease-modifying activity. Additionally, the trial showed improvements in forced vital capacity (FVC): twice as many subjects receiving GRI-0621 experienced no decline in FVC at 12 weeks compared with those receiving standard of care alone.

GRI Bio indicated it plans to submit the newly reported gene-expression findings for presentation at a major medical conference.


Company comment

Marc Hertz, the company's chief executive officer, commented on the data: "The data from the Phase 2a study exceed our expectations. Across gene expression, serum biomarkers, immune profiles and lung function, we see a remarkably consistent picture emerge. GRI-0621 appears to suppress ongoing injury, reduce fibrosis, and activate mechanisms associated with rebuilding damaged lung tissue."


Market reaction

The disclosure of the new RNA-sequencing results corresponded with a 37.6% increase in GRI Bio's stock in premarket trading on Wednesday.

While the company interprets the gene-expression profile as supporting regeneration of lung architecture, the reported findings stem from the Phase 2a dataset and will be included in planned scientific presentation materials.

Risks

  • The reported results are derived from a Phase 2a study, meaning the dataset is early-stage and will require further validation in later clinical trials - this uncertainty affects biotech and healthcare investors.
  • The gene expression findings are newly reported and are slated for submission to a major medical conference, indicating they have not yet undergone broader scientific presentation or external scrutiny - this creates short-term informational uncertainty in markets.
  • The stock reaction occurred in premarket trading and reflects immediate market sentiment to the release; such volatility can pose near-term market risk for investors in the healthcare and biotechnology sectors.

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