Not yet taking people in United StatesPhase 2

Ublituximab as a possible treatment for Down Syndrome Regression Disorder

Tests ublituximab for Down Syndrome Regression Disorder after earlier treatments.

Key facts

Who runs it: Jonathan Santoro
Where: Los Angeles, United StatesSee the site
Trial code: NCT07812181
Registry title: An Open-Label Phase II Feasibility Study for the Use of Ublituximab in Adults With Down Syndrome Regression Disorder
Status: Not yet recruiting
Phase: Phase 2
People taking part: 20 people, planned
Started: 1 Oct 2026
Expected to end: 1 Dec 2030
Type of study: Interventional
Treatments tested: Ublituximab
Record updated: 23 September 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults with Down syndrome who have Down Syndrome Regression Disorder (DSRD). Their DSRD did not improve enough with first-line treatment.

Age: 18 to 40 years
Sex: All sexes
Disease stage: Possible or probable DSRD based on the 2022 International Consensus Criteria. Down syndrome must be trisomy 21 or translocation type.
Earlier treatment: First-line treatment (for example lorazepam, SSRIs, corticosteroids and/or IVIg) must have given partial response (10-50% improvement) or no response (<10% improvement) after 3 months. No IVIg within 8 weeks and no immunosuppressive drugs within 12 weeks before the start. No prior chemotherapy drugs such as methotrexate or cyclophosphamide.

Main reasons for not taking part

Mosaic Down syndrome, or weight < 40 kg (88 lb)
Pregnancy or breastfeeding, or current or past tobacco smoking
History of cancer, solid organ transplant, moyamoya syndrome or stroke
Serious active or long-term infection, including HBV, HCV, TB or HIV
Serious heart disease, clotting disorder or untreated thyroid disease

The registry criteria, word for word

Show all 34 criteriaShow less

Who can take part

Age 18 to 40 years, inclusive at time of consent
Diagnosis of Down syndrome (trisomy 21 or translocation type)
Diagnosis of possible or probable Down Syndrome Regression Disorder (DSRD) based on 2022 International Consensus Criteria
History of partial response or non-response to first-line treatment (e.g., lorazepam, SSRIs, corticosteroids, and/or IVIg). Partial response = 10-50% improvement, Non-response = <10% improvement, Based on BFCRS or NPI-Q after 3 months of treatment
Ability to attend all study visits with a study partner or legally authorized representative
Study partner willing to comply with all study procedures
Willingness to complete required washout periods for medications that may interfere with the study
Highly effective contraception for reproductive participants and partners of childbearing potential
Study partner/LAR sufficiently proficient in English to complete assessments

Who cannot take part

Use of IVIg within 8 weeks prior to baseline
Use of immunosuppressive drugs within 12 weeks prior to baseline
Prior treatment with anti-CD20 or B-cell therapies within required washout unless B-cell recovery criteria are met
Any prior use of chemotherapeutic agents (e.g., methotrexate, cyclophosphamide)
Receipt of live or live-attenuated vaccines within 4 weeks prior to treatment
Prior neurosurgical intervention (exceptions for longstanding shunts)
Current investigational therapy/prohibited medications
Requirement for B-cell recovery >50 cells/μL after prior anti-CD20 therapy
Mosaic Down syndrome
History of solid organ transplant
Clinically significant cardiac disease, clotting disorder, or other serious medical condition
Active or chronic infection of clinical significance (including HBV, HCV, TB, HIV per protocol criteria)
History of malignancy
Untreated thyroid disease (hypo- or hyperthyroidism)
History of moyamoya syndrome or stroke
Detailed HBV, HCV, and TB criteria
Weight < 40 kg at screening
Pregnancy or breastfeeding
Current or past tobacco smoking
Poor venous access or inability to comply with IV procedures
Other immunosuppressive biologics within 24 months
Recent receipt of blood or plasma products (≤30 days)
Abnormal screening labs indicating unacceptable risk
Wards of the state
Employees or students of Children's Hospital Los Angeles (CHLA)

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

Are you between 18 and 40 years old?

Where in United States

Children's Hospital Los AngelesLos Angeles, United StatesContact: Mariam YousufNot yet recruiting

About the trial

What the trial wants to find out

The goal of this clinical trial is to evaluate whether the monoclonal antibody ublituximab can treat Down Syndrome Regression Disorder (DSRD) by assessing its safety, tolerability, and preliminary efficacy in affected individuals. This study is conducted in adults aged 18-40 years with Down syndrome who have DSRD and have had an inadequate or partial response to first-line therapies.

Read full original descriptionShow less

The main questions it aims to answer are:

* Does ublituximab demonstrate acceptable safety and tolerability, as measured by treatment-emergent adverse events from baseline through Week 24? * Does ublituximab lead to improvement in cognitive, neuropsychiatric, motor, and functional outcomes from baseline to Weeks 12 and 24?

This is a single-arm study, so there is no comparison group.

Participants will:

* Receive two intravenous infusions of ublituximab (150 mg on Day 1 and 450 mg on Day 15) * Attend study visits at Screening, Baseline (Day 1) , Week 2 (Day 15), Week 3, Week 6, Week 12, and Week 24 * Undergo clinical assessments, including neurological and physical exams and safety monitoring labs throughout the study * Complete cognitive, behavioral, and functional evaluations at Baseline, Week 12, and Week 24 * Provide blood samples for safety monitoring and research biomarker analyses

The group in the trial

UblituximabTreatment being tested
Participants assigned to the Ublituximab arm will receive a fixed two-dose intravenous regimen consisting of 150 mg on Day 1 and 450 mg on Day 15. All participants will be followed for 24 weeks with regular safety monitoring, clinical assessments, and evaluation of cognitive, neuropsychiatric, and functional outcomes.