Emerging treatments + myelin repairRegistered study in peopleFirst participant dosed; no results posted

Combined early Phase 1/2a study in people; no results posted

PRO-1562: Progentos reports first participant dosed in an early study of a possible myelin-repair drug

Published by MyelinWatch: 6 Nov 2026

Organisation: Progentos Therapeutics · United States
Study sponsor: Progentos Therapeutics

What happened

On 3 November 2026, Progentos Therapeutics announced that the first participant has been dosed in its Phase 1/2a study of PRO-1562 (NCT07826689), an experimental oral small molecule designed to repair myelin in multiple sclerosis (MS). The company did not give the dosing date or say in which part of the study this happened. It describes the Phase 1 part as placebo-controlled single rising doses in healthy adults at one site in Australia, so the announcement does not show whether that participant received PRO-1562 or placebo. The later Phase 2a part plans six months of once-monthly doses or placebo in adults with relapsing MS and chronic optic neuropathy. The company says that the drug promoted myelin repair in laboratory and animal studies; it reports no human results. The ClinicalTrials.gov record, last updated on 29 September 2026 and checked on 6 November, still shows the study as accepting participants, an estimated October 2026 start and no posted results.

What this means for people with MS

According to the company, this study has started dosing. That does not show that PRO-1562 is safe, that it repairs myelin in people or that it helps people with MS. Laboratory and animal results may not apply to people. The announcement does not establish that the MS part has opened. PRO-1562 is an experimental drug, not an available treatment. The registry lists one site, in Adelaide, Australia, and none in Greece. No established approved treatment in clinical practice has been proven to reliably restore myelin in MS.

About the approach studied in this programme: PRO-1562

PRO-1562 is an experimental oral small molecule studied for a possible effect on myelin repair. The study measures safety, drug exposure and repair-related outcomes. Its exact molecular target is not established by the sources reviewed here; a repair effect remains a study question, not an established action.

Approach source: ClinicalTrials.gov — PRO-1562 study record ↗

What kind of evidence exists?: Official Progentos announcement, with study status from ClinicalTrials.gov
How reliable is this source?: Official Progentos Therapeutics announcement for the first dose; ClinicalTrials.gov for study status and the listed site. The registry has not been updated since 29 September 2026, so it does not separately confirm the first dose. The laboratory and animal statements come from the company and were not checked against published data.

Source: Progentos Therapeutics — official company announcement ↗Source: ClinicalTrials.gov — PRO-1562, NCT07826689 ↗

Research event/source date: 3 Nov 2026
Published by MyelinWatch: 6 Nov 2026
Last substantive MyelinWatch update: 6 Nov 2026

Related substantive developments

Research event/source date: 2 Nov 2026

Emerging treatmentsRegistered study in peopleStudy authorised in Greece; not a result

Phase 3 extension study authorised in Greece; recruitment not yet started

Frexalimab: Greece authorises the long-term Phase 3 extension study

Organisation: Sanofi · France

The EU Clinical Trials Information System (CTIS) shows that Greece authorised Sanofi's Phase 3 extension study LTS18002 (2026-525688-41-00) on 2 November 2026. Denmark, Portugal and Poland authorised it on the same day, after Belgium (30 October 2026) and Austria (1 November 2026); all six countries are listed as authorised with recruitment pending. The record plans 17 participants in Greece and lists four Greek hospitals: AHEPA University General Hospital of Thessaloniki, the University General Hospital of Ioannina, the General University Hospital of Larissa and the 401 General Military Hospital of Athens. The study will look at the long-term safety and tolerability of frexalimab, an experimental antibody, in people with multiple sclerosis (MS). It is open only to people who complete earlier frexalimab studies on the study drug, such as the Phase 3 studies FREXALT and FREVIVA. The estimated EU recruitment start is 15 February 2027.

Published by MyelinWatch: 3 Nov 2026

What this means for people with MS

Authorisation means the study may proceed in Greece; it does not mean that it has started at any Greek hospital, that anyone has received treatment in it, or that frexalimab works. No Phase 3 results are available yet. People who are not already in a frexalimab study cannot join this extension, so it is not a way for other people with MS in Greece to receive frexalimab. Frexalimab is not an available treatment in Greece.

Read the update →Source: EU Clinical Trials Information System (CTIS), European Medicines Agency — official CTIS record ↗Source: ClinicalTrials.gov — FREXALT (NCT06141473), Phase 3, ongoing, not accepting new participants ↗ Source: ClinicalTrials.gov — FREVIVA (NCT06141486), Phase 3, ongoing, not accepting new participants ↗

Research event/source date: 30 Oct 2026

Emerging treatmentsResults from peopleDescriptive observations; causality unproven

Published observational follow-up of 204 people with relapsing MS in Italy and Switzerland, without a comparison group

CladStop: almost four years of follow-up after the two-year cladribine tablet course in 204 people with MS

Organisation: CladStop Study Group (University of Genoa and centres in Italy and Switzerland) · Italy

The CladStop study followed 204 people with relapsing multiple sclerosis (MS) at centres in Italy and Switzerland who had completed the approved two-year course of cladribine tablets. Follow-up started 24 months after the first dose and lasted 44.2 months on average. Over this time, 81 of 204 (39.7%) showed new disease activity (a relapse, new MRI activity or confirmed disability worsening); the estimated share still free of such activity was 82.8% after 12 months, 69.6% after 24 months, 63.3% after 36 months and 56.4% after 48 months. 42 people (20.6%) had a relapse (annualised relapse rate 0.06), 29.9% had new MRI activity and 7.4% had disability worsening confirmed after 6 months. 40.7% started another disease-modifying treatment, most often an anti-CD20 antibody or natalizumab. Adverse events after the course were recorded in 6 people, 2 of them serious (prostate cancer and enteritis).

Published by MyelinWatch: 5 Nov 2026

What this means for people with MS

For people who have finished cladribine tablets, these data describe what happened afterwards in routine care in two countries: disease activity stayed away for years in many people, but not in everyone, and when it returned it was mostly relapses or new MRI lesions rather than disability worsening. Follow-up continued after people started another treatment, so the figures for being free of disease activity also include time on those later treatments; the authors say they describe outcomes after completing cladribine, not the effect of cladribine alone. Among the 121 people who started no further treatment, 70.1% were estimated to be free of disease activity at 48 months, but this group was not chosen at random. The study has no comparison group, so it cannot show that cladribine caused the outcomes or compare it with other treatments; treatment decisions after the course were not random. Safety data came from routine records and stopped when another treatment began, and few people remained in the analysis at 48 months, so the later estimates are less precise. It does not justify a treatment change without review by a neurologist.

Read the update →Source: European Journal of Neurology — peer-reviewed research article ↗Source: PubMed — CladStop extended follow-up, PMID 42963188 ↗ Source: Europe PMC — open-access full text, PMC13722574 ↗

Research event/source date: 30 Oct 2026

Emerging treatmentsRegistered study in peopleStudy authorised in two EU countries; not a result

Phase 3 extension study authorised in two EU countries; recruitment not yet started

Frexalimab: long-term Phase 3 extension study authorised in Belgium and Austria

Organisation: Sanofi · France

The EU Clinical Trials Information System (CTIS) shows that Belgium authorised Sanofi's Phase 3 extension study LTS18002 (2026-525688-41-00) on 30 October 2026 and Austria on 1 November 2026. The study will look at the long-term safety and tolerability of frexalimab, an experimental antibody given into a vein or under the skin, in people with multiple sclerosis (MS). It is open only to people with relapsing MS or non-relapsing secondary progressive MS who complete earlier frexalimab studies on the study drug, including the Phase 3 studies FREXALT and FREVIVA. It plans 1,710 participants in total. Both countries are listed as authorised with recruitment pending; the estimated EU recruitment start is 15 February 2027.

Published by MyelinWatch: 2 Nov 2026

What this means for people with MS

Authorisation means the study may proceed; it does not mean that it has started, that anyone has received treatment in it, or that frexalimab works. No Phase 3 results are available yet. People who are not already in a frexalimab study cannot join this extension. Greece authorised the study later, on 2 November 2026 (see the separate update); frexalimab is not an available treatment in Greece.