The DHELIVER/HEP102 study is a multicenter, interventional, double-blind, randomized, placebo-controlled trial designed to assess the efficacy of HepaStem® in 100 patients with acute-on-chronic liver failure (ACLF) grade 1 or 2. Patients with grade 1 or 2 ACLF will be eligible to screen for participation in the trial and will be randomized across two treatment arms: patients receiving two weekly intravenous infusions of HepaStem® and patients receiving placebo. The primary outcome measure is overall survival at 90 days post-first infusion. Secondary outcome measures include transplant-free survival at 90 days post-first infusion, at day 90 while free of ACLF, at day 90 with MELD-Na score < 15, and assessment of hepatic function parameters and prognostic scores