Single Ascending Dose Study of HB2198 in Healthy Participants

A Phase 1, Randomized, Double Blinded, Placebo Controlled Dose Escalating Single Ascending Dose Study of HB2198, a Tetravalent Bispecific Anti CD19/CD20 Antibody With Dual Fc Domains, in Healthy Participants

Phase 1, single center, randomized, double blind, placebo controlled SAD study assessing safety, tolerability, PK, PD, and immunogenicity of HB2198 after a single IV infusion in healthy adults. Four dose levels will be explored with sentinel participants per cohort. Approximately 32 participants (6 HB2198:2 placebo per cohort) will be followed for ~2 months, with extended follow up if B-cell counts remain suppressed.

Study Overview

• Status: Recruiting
• Conditions: Healthy Volunteer
• Intervention / Treatment: Drug: Placebo comparator: HB2198 Diluent; Drug: HB2198, a Tetravalent Bispecific Anti-CD19/CD20 Antibody with Dual Fc Domains

Detailed Description

HB2198 is a tetravalent bispecific antiCD19/CD20 antibody engineered with dual Fc domains (S239D/I332E) to enhance FcγR engagement. Cohorts (n=8 each) receive a single IV dose of HB2198 or placebo under double blind conditions; 2 sentinels (1 active, 1 placebo) are dosed ≥48 h before the remaining 6 participants. Safety/PK/PD and immunogenicity are characterized through Day 28 and to Month 2, including B-cell depletion kinetics, lymphocyte phenotyping, cytokines, quantitative immunoglobulins, and ADAs.

• Study Type: Interventional
• Enrollment (Estimated): 32
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Joshua Pelham; Phone Number: 1-415-378-4738; Email: joshua.pelham@hingebio.com
• Study Contact Backup: Name: Kristen Quigley; Email: kristen.quigley@hingebio.com

Study Locations

• Australia
  • Victoria
    • Bayswater, Victoria, Australia, 3153
      • Recruiting
      • Veritus Research

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 18-55 years; Healthy Adults
• IgG ≥ 600 mg/dL
• Peripheral B cell count within lab normal range
• Negative pregnancy test (WOCBP) and protocol specified contraception
• Confinement from Day -1 through ≥24 h after Day 1 dosing
• Informed consent

Exclusion Criteria:

• Clinically significant disease that could affect safety or data
• Hypogammaglobulinemia; active/recent significant infection
• Chronic antivirals/antimicrobials
• Recent major surgery; live vaccine <30 days (inactivated ≥14 days before Day 1 recommended)
• Positive TB screen without treatment
• HBV DNA+ or HCV RNA+; HIV+
• Pregnancy/breastfeeding
• Planned conception or gamete donation within 6 months post dose

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: HB2198, a Tetravalent Bispecific Anti-CD19/CD20 Antibody with Dual Fc Domains; HB2198, a Tetravalent Bispecific Anti-CD19/CD20 Antibody with Dual Fc Domains administered via IV infusion on Day 1. There are 4 planned dose levels: 0.001 mg/kg → 0.1 mg/kg.	Drug: Placebo comparator: HB2198 Diluent; HB2198 Diluent: single IV infusion
Placebo Comparator: HB2198 Diluent (IV); HB2198 Diluent administered via IV infusion on Day 1	Drug: HB2198, a Tetravalent Bispecific Anti-CD19/CD20 Antibody with Dual Fc Domains; Drug: HB2198, a Tetravalent Bispecific Anti-CD19/CD20 Antibody with Dual Fc Domains administered via IV infusion on Day 1.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety and Tolerability	Incidence/severity of AEs and SAEs (CTCAE v5.0)	Time Frame: Day 1 to Day 28; may extend to Month 2
Dose Limiting Toxicities (DLTs)	DLT's as defined within the protocol.	Day 1 through Day 28

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To characterize the pharmacokinetic (PK) profile of HB2198	Area under the concentration versus time curve (AUC)	Day 1 to Month 2
To characterize the pharmacokinetic (PK) profile of HB2198	Maximum drug concentration (Cmax)	Day 1 to Month 2
To characterize the pharmacokinetic (PK) profile of HB2198	Time to maximum plasma concentration (tmax)	Day 1 to Month 2
To characterize the pharmacokinetic (PK) profile of HB2198:	Area Under the Curve to last measurable concentration (AUClast)	Day 1 to Month 2
To evaluate the development of anti-drug antibodies (ADAs)	ADA incidence	Day 1 to Month 2
To evaluate B-cell depletion and other pharmacodynamic changes	B-cell depletion and subsets; duration; change in total immunoglobulins; cytokines/CRP and other biomarkers.	Day 1 to Month 2

Collaborators and Investigators

• Sponsor: Hinge Bio

Study record dates

Study Major Dates

• Study Start (Actual): March 19, 2026
• Primary Completion (Estimated): August 14, 2026
• Study Completion (Estimated): August 21, 2026

Study Registration Dates

• First Submitted: February 18, 2026
• First Submitted That Met QC Criteria: February 23, 2026
• First Posted (Actual): February 27, 2026

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 7, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: HB2198-002

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: This is still being actively discussed. A decision will be made during the course of the study.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No