Lead program: Phase II

Clexio Biosciences

Data updated June 26, 2026

2 Drug Candidates1 Trial

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.

Pipeline Intelligence

Developer Momentum

Programme tracker

Active candidates: 2
Active programmes: 2
Lead stage: Phase II
Forecast coverage: 2 of 2

Latest sourced update

ClinicalTrials.gov NCT06340958 - SOLEO Phase 2 CLE-100 MDD Study

Jun 23, 2026 - Registry update - ClinicalTrials.gov - CLE-100 (Oral Esketamine)

Next known catalyst

Phase II topline

Q3 2026 - CLE-100 (Oral Esketamine) / CLE-100 Phase 2 Programme (MDD) - Confidence: 45%

2 sources0 pipeline-linked trials0 pipeline-linked papers1 Phase II1 Phase I

Development Programmes

CLE-100 (Oral Esketamine)

Esketamine

Phase II

Major Depressive Disorder (MDD)Treatment-Resistant Depression (TRD)

CLE-100 is an oral esketamine tablet being developed as an adjunctive treatment for adults with major depressive disorder who have inadequate response to standard antidepressants. SOLEO Phase 2 (NCT06340958) is now completed on ClinicalTrials.gov, with 99 actual participants and the registry last updated on 2026-06-23; no public topline release was found in this pass.

Programme Tracker

Major Depressive Disorder (MDD)

Primary: US (FDA)

Phase IIActive

Forecast

Phase II topline - Likely: Q3 2026

SOLEO Phase 2 (NCT06340958) is completed on ClinicalTrials.gov. The registry lists 99 actual participants, actual primary completion in June 2025, actual study completion in November 2025, and a last update posted on 2026-06-23. No public topline results release was found in this pass.

Milestones

Phase II started

Completed

Actual: Jun 1, 2024

SOLEO Phase 2 (NCT06340958) initiated; oral esketamine adjunct to antidepressants; US multi-centre

Why it matters: SOLEO is designed to generate registration-enabling efficacy data for oral esketamine as an adjunct to standard antidepressants — the same patient population as Spravato but with the convenience of oral dosing. Success would address the major commercial limitation of intranasal esketamine (clinic-only administration).

Watch next: SOLEO primary endpoint results (HAM-D change from baseline at 4 weeks)

ClinicalTrials.gov NCT06340958 - SOLEO Phase 2 CLE-100 MDD Study(Registry update)[Verified]

Phase II topline

Planned

Actual: Oct 1, 2023 - Likely: Q3 2026

CLEO Phase 2 (NCT04103892) results presented at ASCP: 130 subjects randomised across 32 US sites; safety profile confirmed; post-acute COVID subgroup showed promising efficacy signal

Why it matters: CLE-100 is an oral esketamine (S-ketamine) formulation designed for once-daily home dosing — bypassing the intranasal/IV administration burden of Spravato. CLEO safety data enables the SOLEO Phase 2b with a larger sample and primary efficacy endpoint.

Recorded Events

Jun 1, 2024: Phase II started

Oct 1, 2023: Phase II topline

Evidence Links

ClinicalTrials.gov NCT06340958 - SOLEO Phase 2 CLE-100 MDD Study

Registry update - ClinicalTrials.gov - Jun 23, 2026 - Verified

Registry last update posted 2026-06-23; status completed with 99 actual participants, actual primary completion 2025-06-06, and actual study completion 2025-11-25.

CLE-905 (M1/M4 Muscarinic Agonist)

Phase I

Schizophrenia

Programme Tracker

Schizophrenia

Primary: US (FDA)

Phase IActive

Forecast

Phase I topline - Likely: Q4 2026

Licensed/spun out to Syremis Therapeutics. Fierce Biotech reported Syremis launched on 2025-12-18 with a $165M Series A and ST-905/CLE-905 in Phase 1 development for schizophrenia and other neuropsychiatric conditions; Syremis also lists ST-905 as a potent M1/M4 preferential muscarinic agonist.

Milestones

Licensing deal

Completed

Actual: Jun 1, 2024

CLE-905 spun out to Syremis Therapeutics (Q2 2024); renamed ST-905 at Syremis

Why it matters: CLE-905 is a potent dual M1/M4 preferential muscarinic agonist for schizophrenia — the same validated mechanism as KarXT/Cobenfy (FDA-approved 2024). Syremis was founded by former Karuna Therapeutics team members (who developed KarXT), giving ST-905/CLE-905 the highest-possible team pedigree for this mechanism.

Syremis launches with $165M Series A to advance ST-905/CLE-905(News / media)[Verified]

Funding milestone

Completed

Actual: Dec 1, 2025

Syremis Therapeutics raises $165M Series A (December 2025)

Why it matters: $165M Series A led by former Karuna leadership validates ST-905's potential to compete with or improve upon KarXT in the schizophrenia market. Clexio retains value from this spinout through equity/milestone payments.

Watch next: Syremis Phase 1 FIH results for ST-905; Clexio CLE-905 internal Phase 1 timeline

Syremis launches with $165M Series A to advance ST-905/CLE-905(News / media)[Verified]

Recorded Events

Dec 1, 2025: Funding milestone

Jun 1, 2024: Licensing deal