The autoimmune B-cell depletion race is getting crowded. CAR-T therapies are showing dramatic results in lupus. Rituximab (CD20) has been around forever. Newer anti-CD19 agents are in the mix.
And a few weeks ago we covered Commit Biologics and their complement-based approach that skips T cells entirely.
So when Hinge Bio announces first patient dosed with HB2198, the question isn’t whether B-cell depletion works in autoimmune disease.
We know it does.
The question is whether hitting CD19 and CD20 simultaneously, with a single molecule, does it better.
That’s the bet. HB2198 is a multispecific antibody built on Hinge Bio’s GEM-DIMER platform. It binds both CD19 and CD20 on B cells and features dual Fc domains that enhance natural killer cell recruitment.
In preclinical work, it achieved B-cell depletion exceeding 99% across both peripheral blood and lymphoid tissues, including durable depletion of memory B cells (the stubborn ones that drive autoimmune relapse).
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The Phase 1 program is running two parallel studies: one in healthy volunteers and one in patients with systemic lupus erythematosus (SLE). That’s a smart design. The healthy volunteer study gives you clean PK/PD data without disease confounders, while the SLE study starts generating efficacy signals early.
The competitive framing actually matters here quite a bit.
The CAR-T approach to autoimmune disease (think Allogene’s recent data) delivers deep responses but comes with manufacturing complexity, cost, and toxicity concerns.
What Hinge Bio is pitching is CAR-T-level B-cell clearance from an off-the-shelf antibody. No apheresis, no lymphodepletion, no hospital stay.
The pedigree behind the platform is worth noting. CSO Daniel Capon co-invented Fc fusion proteins at Genentech, chimeric antigen receptors for T cell therapy at Cell Genesys, and fully human antibodies at Abgenix. He’s been at the structural biology of antibody engineering for decades.
Hinge Bio has raised $66.8 million total, including a Series A’ led by Point72 in early 2025. They also signed a deal with Kyorin Pharmaceutical for Japanese rights: $10 million upfront plus up to $95 million in milestones for SLE alone, with more for additional indications.
If HB2198 can replicate its preclinical B-cell depletion profile in humans, with a clean safety profile, this becomes one of the more compelling autoimmune assets in the clinic.
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