GRI Bio, Inc. announced the initiation of patient enrollment in the Phase 2a biomarker study evaluating GRI-0621 for the treatment of IPF. Patient dosing is expected imminently. Interim data from the Phase 2a biomarker study is expected in the first half of 2024 and topline results are expected in the second half of 2024.

GRI is developing and repurposing GRI-0621, a type 1 invariant NKT (iNKT) antagonist, as a once-daily oral capsule for the treatment of IPF with the potential to expand into additional fibrotic indications. The Phase 2a, randomized, double-blind, multi-center, placebo-controlled, parallel-design, 2-arm study will enroll approximately 36 subjects with IPF whom will be randomized in a 2:1 ratio for GRI-0621 4.5mg or a placebo. GRI-0621 dose of 4.5mg will be compared with a dose of placebo following once daily oral administration for 12 weeks.

Concurrently, a sub-study will examine the number and activity of NKT cells in bronchoalveolar lavage (BAL) fluid for up to 12 eligible subjects (across various centers). An interim analysis will be performed when 24 subjects (of which approximately 8 will be placebo subjects) complete 6 weeks of treatment. 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. An additional exploratory endpoint for the study is to assess the effect of GRI-0621 on pulmonary function at baseline and after 6 weeks and 12 weeks of treatment.