## Protocol Section
### Identification Module
**NCT ID:** NCT06435845

**Brief Title:** Phase 2 Study on the Pharmacokinetics and Safety of RLYB212 in Pregnant Women at Higher Risk for HPA-1a Alloimmunization

**Official Title:** A Phase 2, Multicenter, Open-label Study to Evaluate the Pharmacokinetics and Safety of RLYB212 in Pregnant Women at Higher Risk for HPA-1a Alloimmunization

#### Organization Study ID Info
**ID:** IPA2202
#### Organization
**Class:** INDUSTRY
**Full Name:** Rallybio IPA, LLC
#### Secondary ID Infos
**ID:** 2024-512651-20-00
**Type:** CTIS
### Status Module
#### Completion Date
**Date:** 2027-05

**Type:** ESTIMATED

#### Expanded Access Info
#### Last Update Post Date
**Date:** 2024-05-30

**Type:** ACTUAL

**Last Update Submit Date:** 2024-05-24

**Overall Status:** NOT_YET_RECRUITING

#### Primary Completion Date
**Date:** 2027-05

**Type:** ESTIMATED

#### Start Date
**Date:** 2024-09

**Type:** ESTIMATED

**Status Verified Date:** 2024-05

#### Study First Post Date
**Date:** 2024-05-30
**Type:** ACTUAL
**Study First Submit Date:** 2024-05-21
**Study First Submit QC Date:** 2024-05-24
### Sponsor Collaborators Module

#### Lead Sponsor

**Class:** INDUSTRY

**Name:** Rallybio IPA, LLC

#### Responsible Party

**Type:** SPONSOR

### Oversight Module

**Is FDA Regulated Device:** False

**Is FDA Regulated Drug:** True

**Is US Export:** True

### Description Module

**Brief Summary:** The purpose of this Phase 2 study is to assess the pharmacokinetics (PK) and safety of RLYB212 in HPA-1b/b pregnant women at higher risk for HPA-1a alloimmunization and FNAIT.

**Detailed Description:** This study is a single-arm, open-label, multicenter study of RLYB212 in HPA-1b/b pregnant participants at higher risk for the occurrence of HPA-1a alloimmunization and FNAIT. A laboratory testing paradigm will be applied at screening to identify women at higher risk for HPA-1a alloimmunization. Study IPA2202 is comprised of three phases: a two-part screening phase, an antenatal treatment phase, and a postpartum follow-up phase. Study duration for each participant is anticipated to be \~44 weeks, inclusive of the screening visits through the Week 10 postpartum visit.

### Conditions Module

**Conditions:**

- Fetal and Neonatal Alloimmune Thrombocytopenia

### Design Module

#### Design Info

**Allocation:** NA

**Intervention Model:** SINGLE_GROUP

##### Masking Info

**Masking:** NONE

**Primary Purpose:** PREVENTION

#### Enrollment Info

**Count:** 8

**Type:** ESTIMATED

**Phases:**

- PHASE2

**Study Type:** INTERVENTIONAL

### Arms Interventions Module

#### Arm Group 1

**Description:** RLYB212 Subcutaneous injection

**Intervention Names:**

- Drug: Anti-(integrin beta-3) human monoclonal antibody

**Label:** RLYB212

**Type:** EXPERIMENTAL

### Interventions

#### Intervention 1

**Arm Group Labels:**

- RLYB212

**Description:** human monoclonal anti-human platelet antigen (HPA)-1a immunoglobulin G antibody

**Name:** Anti-(integrin beta-3) human monoclonal antibody

**Other Names:**

- RLYB212

**Type:** DRUG

### Outcomes Module

#### Primary Outcomes

**Measure:** Number of Participants with treatment related adverse events as defined by CTCAE 5.0

**Time Frame:** 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

**Measure:** Maternal exposure to RLYB212 as measured in serum

**Time Frame:** Approx. GW 16, 18, 20, 24, 26, 28, 30, 32, 34, 36, 38, at birth (~40), PP Week 4

#### Secondary Outcomes

**Measure:** Neonatal exposure to RLYB212 as measured in cord blood

**Time Frame:** At birth (~GW 40)

**Measure:** Number of HPA-1a positive neonates with treatment related adverse events as defined by CTCAE v5.0

**Time Frame:** At birth (~GW 40), Approx. PP Week 4

**Measure:** Anti-RLYB212 antibodies as measured in serum

**Time Frame:** Approx. GW 16, 20, 24, 28, 32, 36, at birth (~40), PP Week 4

**Measure:** Pregnancy Outcomes: incidence of live births, spontaneous abortions, elective abortions, still births or premature births

**Time Frame:** At birth (~GW 40)

**Measure:** Frequency of Neonatal Thrombocytopenia as measured by platelet count within 72 hours of delivery

**Time Frame:** At birth (~GW 40)

**Measure:** Frequency of HPA-1a Alloimmunization as measured by anti-HPA-1a alloantibodies

**Time Frame:** Approx. PP Week 10

**Measure:** Neonatal Outcomes: general health and overall status as defined by absolute values and percentiles

**Time Frame:** 4-6 weeks following delivery

### Eligibility Module

**Eligibility Criteria:** Inclusion Criteria:

Pregnant women who present at Gestational Week 6 or after and confirmed to be: HPA-1b/b (HPA-1a negative), HLA-DRB3\*01:01 positive, Anti-HPA-1a alloantibody negative, Carrying an HPA-1a/b (HPA-1a positive) fetus

Exclusion Criteria:

* Prior history of HPA-1a related fetal and neonatal alloimmune thrombocytopenia
* Multiple pregnancy (more than 1 fetus)
* Prior history of platelet transfusion or other blood transfusions
* Known sensitivity and/or immediate hypersensitivity to any components of RLYB212 or its formulation
* Any co-morbid medical or obstetric condition(s), laboratory abnormality, concomitant treatment, or other reason that, in the investigator's opinion, could adversely affect the safety of the participant and/or fetus, impair the assessment of study results, or preclude compliance with the study

**Gender Based:** True

**Gender Description:** Pregnant women

**Maximum Age:** 45 Years

**Minimum Age:** 18 Years

**Sex:** FEMALE

**Standard Ages:**

- ADULT

### Contacts Locations Module

#### Central Contacts

**Contact 1:**

**Email:** clinicaltrials@rallybio.com

**Name:** Chief Medical Officer

**Phone:** 2038593820

**Phone Ext:** 1

**Role:** CONTACT

### IPD Sharing Statement Module

**IPD Sharing:** NO

## Derived Section

### Condition Browse Module - Ancestors

- ID: D000001791

- Term: Blood Platelet Disorders

- ID: D000006402

- Term: Hematologic Diseases

- ID: D000095542

- Term: Cytopenia

- ID: D000007232

- Term: Infant, Newborn, Diseases

### Condition Browse Module - Browse Branches

- Abbrev: BC15

- Name: Blood and Lymph Conditions

- Abbrev: All

- Name: All Conditions

- Abbrev: BC16

- Name: Diseases and Abnormalities at or Before Birth

- Abbrev: Rare

- Name: Rare Diseases

### Condition Browse Module - Browse Leaves

- ID: M16680

- Name: Thrombocytopenia

- Relevance: HIGH

- As Found: Thrombocytopenia

- ID: M27571

- Name: Thrombocytopenia, Neonatal Alloimmune

- Relevance: HIGH

- As Found: Neonatal Alloimmune Thrombocytopenia

- ID: M5072

- Name: Blood Platelet Disorders

- Relevance: LOW

- As Found: Unknown

- ID: M9490

- Name: Hematologic Diseases

- Relevance: LOW

- As Found: Unknown

- ID: M3170

- Name: Cytopenia

- Relevance: LOW

- As Found: Unknown

- ID: M10276

- Name: Infant, Newborn, Diseases

- Relevance: LOW

- As Found: Unknown

- ID: T2298

- Name: Fetal and Neonatal Alloimmune Thrombocytopenia

- Relevance: HIGH

- As Found: Fetal and Neonatal Alloimmune Thrombocytopenia

### Condition Browse Module - Meshes

- ID: D000013921

- Term: Thrombocytopenia

- ID: D000054098

- Term: Thrombocytopenia, Neonatal Alloimmune

### Intervention Browse Module - Ancestors

- ID: D000007155

- Term: Immunologic Factors

- ID: D000045505

- Term: Physiological Effects of Drugs

### Intervention Browse Module - Browse Branches

- Abbrev: All

- Name: All Drugs and Chemicals

### Intervention Browse Module - Browse Leaves

- ID: M4225

- Name: Antibodies

- Relevance: HIGH

- As Found: Given

- ID: M4230

- Name: Antibodies, Monoclonal

- Relevance: HIGH

- As Found: Chemotherapy

- ID: M10184

- Name: Immunoglobulins

- Relevance: LOW

- As Found: Unknown

- ID: M10122

- Name: Immunoglobulin G

- Relevance: LOW

- As Found: Unknown

- ID: M19117

- Name: Immunoglobulins, Intravenous

- Relevance: LOW

- As Found: Unknown

- ID: M10201

- Name: Immunologic Factors

- Relevance: LOW

- As Found: Unknown

### Intervention Browse Module - Meshes

- ID: D000000906

- Term: Antibodies

- ID: D000000911

- Term: Antibodies, Monoclonal

### Misc Info Module

- Version Holder: 2024-05-31
