Phase 2 Study on the Pharmacokinetics and Safety of RLYB212 in Pregnant Women at Higher Risk for HPA-1a Alloimmunization
← catalyst calendarSponsored by Rallybio (industry) · RLYB — their whole pipeline →.
Phase
Phase 2
Status
Terminated
Study type
Interventional
Design
Na · None · Prevention
Enrollment
1actual
Sites
3
Countries
Netherlands, Norway, Sweden
Every value on this page is a field the sponsor filed with ClinicalTrials.gov, reproduced. Dates are their own estimates, revised as a study runs, unless the registry marks them actual. sources →
Source: ClinicalTrials.gov, retrieved 2026-08-19
Why the sponsor stopped it
This study was terminated early by the sponsor due to insufficient drug exposure to achieve the intended therapeutic effect.
As filed on the registry record, in the sponsor's own words.
Dates
each axis at the precision it was filed, with the registry's own basis| Date | Filed | Basis | What it is |
|---|---|---|---|
| Start | 2024-11-21 | actual | When the study began enrolling |
| Primary completion | 2025-10-01 | actual | The date the last participant is measured for the primary outcome — the readout window |
| Study completion | 2025-10-01 | actual | The whole study's end, after follow-up |
| First posted | 2024-05-30 | actual | When this record first appeared on the registry |
| Results posted | 2026-03-06 | actual | When the sponsor posted results to the registry |
| Record updated | 2026-03-06 | actual | The sponsor's own last edit to this record — every projection above is as current as this date |
What it studies
Condition
- Fetal and Neonatal Alloimmune Thrombocytopenia
Intervention
- Drug: Anti-(integrin beta-3) human monoclonal antibody — also filed as RLYB212
Primary outcomes
what the primary-completion date above is the date OFNumber of Participants With Treatment Related Adverse Events as Defined by CTCAE 5.0
measured Approx. Gestational Week (GW) <16, 16, 18, 20, 24, 26, 28, 30, 32, 34, 36, 38; at birth (~40), Post Partum (PP) Week 4, 10 week
Maternal Exposure to RLYB212 as Measured in Serum
measured Approx. GW 16, 18, 20, 24, 26, 28, 30, 32, 34, 36, 38, at birth (~40), PP Week 4
Posted documents
hosted by the registry — we link, never re-serveStudy Protocolposted 2024-10-14 · 1.1 MB · Prot_000.pdf
Statistical Analysis Planposted 2025-09-08 · 1.1 MB · SAP_001.pdf
Permalink · RLYB's whole pipeline · Catalyst calendar · Every registered study · What changed