Rallybio

RLYB116

RLYB116 Program

Stage
Phase 1
Indication
Complement-mediated diseases, including PNH, gMG, and APS
Approach
Novel antibody mimetic fusion protein designed to inhibit Complement Factor 5 (C5)
Mode of Administration
Subcutaneous injection

Complement Dysregulation

The complement system plays a central role in innate immunity, as well as in shaping adaptive immune responses. Dysregulation of the complement pathway has been linked to a broad range of diseases, including paroxysmal nocturnal hemoglobinuria (PNH), antiphospholipid syndrome (APS), and generalized myasthenia gravis (gMG), reinforcing its importance as a target for therapeutic intervention. 

RLYB116 is a novel, innovative, once-weekly, small volume, subcutaneously injected C5 inhibitor designed to meet patient demand for a convenient, self-administered at-home solution. RLYB116 is an antibody mimetic fusion protein composed of two linked components: 

  • An Affibody® molecule with high affinity for C5, thereby inhibiting terminal complement activation, and 
  • Albumod™ technology that enables binding to serum albumin for the potential of an extended plasma half-life and broad tissue distribution 

C5: A Proven Target in Complement Dysregulation

Complement-Figure
“RLYB116 presents a unique opportunity for the Rallybio team to utilize its deep experience in successfully designing, developing, and delivering complement inhibitors for patients with rare diseases.”
—Steve Ryder, M.D., Chief Medical Officer