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Emerging treatmentsResults from peopleInfection safety signal in adults aged 55 and older; observational association

Published retrospective cohort study in adults aged 55 years and older with multiple sclerosis

Ocrelizumab and infection risk from age 55: a cohort study

Published by MyelinWatch:

Organisation
Massachusetts General Hospital
Funder
Genentech

What happened

Published on 24 September 2026, this Massachusetts General Hospital study examined 1,600 adults aged 55 years or older with multiple sclerosis (MS): 800 who received at least 600 mg of intravenous ocrelizumab and 800 who had never received a B-cell-depleting treatment. Using person-time and adjustment for measured group differences, the researchers found higher rates in the ocrelizumab group for infection-related hospitalization (incidence rate ratio 1.67; 95% confidence interval 1.15–2.43) and infections overall (1.42; 95% confidence interval 1.20–1.68).

What this means for people with MS

This safety signal can inform a discussion with a treating neurologist about individual infection risk and monitoring. It does not prove that ocrelizumab caused the difference or predict an individual's risk. The groups differed in age and follow-up (median 3.5 versus 8.2 years), and the retrospective records may capture infections differently because treatment recipients had more structured clinical contact. Treatment selection, missing disability data, and possible immortal-time bias also limit causal interpretation. This study does not test MS efficacy, support changing treatment without clinical review, or establish Greek availability or reimbursement.

What kind of evidence exists?
Peer-reviewed, single-center observational study of electronic health records; 800 ocrelizumab recipients and 800 adults never exposed to B-cell-depleting treatment
How reliable is this source?
The Lancet Regional Health – Americas, original peer-reviewed article (PMID 42834886; DOI 10.1016/j.lana.2026.101640). Single-center retrospective evidence; investigator-initiated Genentech funding, with no funder role reported by the authors. Substantial missing disability measurements and possible selection, ascertainment, and immortal-time biases.
Source: The Lancet Regional Health – Americas — peer-reviewed research article ↗Source: PubMed — PMID 42834886 ↗ Source: The Lancet Regional Health – Americas — DOI 10.1016/j.lana.2026.101640 ↗
Research event/source date
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Related substantive developments

Research event/source date:
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:

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:
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:

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.

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:
Emerging treatmentsResults from peopleSubgroup finding: significant in Hispanic or Latino participants, not significant in Black participants

Post hoc analysis of two completed Phase 3 trials in relapsing MS

OPERA trials: post hoc look at disability worsening in Black and Hispanic or Latino participants

Organisation: Keck School of Medicine, University of Southern California, with Genentech and Roche · United States

Researchers led by the University of Southern California, with authors from Genentech, Roche and other US centres, re-analysed the OPERA I and II trials, which compared ocrelizumab with interferon beta-1a for two years in relapsing multiple sclerosis (MS). In the interferon group, non-Hispanic Black and Hispanic or Latino participants had a higher risk of disability worsening confirmed after 24 weeks, measured with a combined (composite) disability measure, than non-Hispanic White participants (hazard ratio 3.0 and 2.3). Non-Hispanic Black and Hispanic or Latino participants also had more CD19-positive B cells at the start. In 1,138 participants who consented to genetic analysis, higher African or Americas genetic ancestry was also linked to higher risk. Ocrelizumab lowered B cells in all groups. Compared with interferon, it lowered the risk of this composite disability worsening in Hispanic or Latino participants (hazard ratio 0.38; 95% confidence interval 0.20–0.72). In the 65 Black participants the estimate also pointed to lower risk (hazard ratio 0.41), but the 95% confidence interval of 0.13–1.29 includes no difference, so the result is not statistically significant.

Published by MyelinWatch:

What this means for people with MS

This is not a new treatment or a new approval: ocrelizumab is already an approved MS treatment. The analysis was done after the trials ended, in small subgroups (only 65 Black participants), using self-reported race and ethnicity; it cannot show why risk differed and does not change treatment guidance. The authors conclude that ocrelizumab reduced risk regardless of race or ethnicity, but for Black participants the study alone does not establish this. It does not establish availability or reimbursement in Greece or support changing an individual treatment without a neurologist.

Read the update →Source: Multiple Sclerosis Journal (SAGE) — peer-reviewed primary article ↗Source: Multiple Sclerosis Journal — DOI 10.1177/13524585261496124 ↗ Source: ClinicalTrials.gov — OPERA I (NCT01247324), completed with posted results ↗ Source: ClinicalTrials.gov — OPERA II (NCT01412333), completed with posted results ↗