Clexio Biosciences

Clexio Biosciences is a private Israeli clinical-stage CNS company founded in 2018 by Teva Pharmaceuticals R&D veterans. Their lead programme CLE-100 is a once-daily oral tablet formulation of esketamine for MDD — distinguished from the FDA-approved Spravato (intranasal, in-clinic) by enabling outpatient, at-home use. Phase 2 CLEO study results showed a promising safety profile and encouraging efficacy specifically in post-COVID MDD subgroups; the Phase 2 SOLEO study (NCT06340958, higher dose, stricter treatment-resistance criteria) enrolled first patients April 2024 and reached 50% enrollment by December 2024. CLE-100 holds multiple US method-of-use patents (2024). In December 2025, Clexio spun out its muscarinic agonist programme (CLE-905) into a new entity, Syremis Therapeutics, which raised $165M Series A co-led by Dexcel Pharma and Third Rock Ventures. Co-founders Kogan, Levy, and Kagan simultaneously lead Syremis; Clexio continues independently with CLE-100 and preclinical CLE-043.