– ALPN-303 dose-dependently reduces serum galactose-deficient IgA1 (Gd-IgA1), a pivotal molecule implicated in the pathogenesis of IgA nephropathy (IgAN) –

Data further supports best-in-class profile and initiation of glomerulonephritis (GN) basket clinical trial –

SEATTLE, WA, USA I November 03, 2022 IAlpine Immune Sciences, Inc. (NASDAQ: ALPN), a leading clinical-stage immunotherapy company focused on developing innovative treatments for autoimmune and inflammatory diseases, today presented a poster at the American Society of Nephrology Kidney Week 2022 Meeting highlighting updated clinical data from RUBY-1, a phase 1 healthy volunteer (HV) study of ALPN-303, a dual B cell cytokine antagonist being developed for multiple B cell and/or autoantibody-related diseases.


  • ALPN-303 has been well tolerated as single intravenous or subcutaneous (SC) doses of up to 960 mg in adult HV’s and exhibits dose-related pharmacokinetic and on-target pharmacodynamic effects.
  • ALPN-303 maintains target coverage of free APRIL for 2-3 and ≥4 weeks with 80 and 240 mg, respectively, corresponding to reductions in serum Ig and antibody-secreting cells (CD38hi plasmablasts/plasma cells). In addition, ALPN-303 also dose-dependently reduces serum Gd-IgA1 by up to 60%, 4 weeks after a single dose.
  • These data support dose regimens of 80-240 mg SC every 4 weeks in future glomerulonephritis studies.

“The new data importantly indicate that ALPN-303 also reduces Gd-IgA1, an important effector molecule and/or biomarker in IgAN, similar to the previously disclosed effects on serum immunoglobulins and antibody-secreting cells,” said Stanford Peng, MD PhD, Alpine’s President and Head of R&D. “This is important for us because it is the first clinical disease-related biomarker data with ALPN-303, complementing the promising preclinical in vivo data in glomerulonephritis disease models, and providing further rationale for the clinical development of ALPN-303 in IgAN and other autoantibody-related GNs such as lupus nephritis and primary membranous nephropathy.”

Poster Title: Phase 1 Study in Healthy Adults of the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of ALPN-303, a Dual BAFF/APRIL Antagonist for the Treatment of Autoimmune Glomerulonephritides (GN)
Poster Number: TH-PO499

About ALPN-303 and the RUBY-1 Study

ALPN-303 is a dual antagonist of the BAFF (B cell activating factor) and APRIL (a proliferation inducing ligand) cytokines, which play key roles in the activation and survival of B cells. Based upon an engineered TACI (transmembrane activator and CAML interactor) domain, ALPN-303 exhibits greater potency in preclinical studies versus wild-type TACI-based comparators, as well as other inhibitors of BAFF and/or APRIL alone. ALPN-303 is in development for multiple B cell and/or autoantibody-related diseases, such as systemic lupus erythematosus, glomerulonephritides, and autoimmune cytopenias.

RUBY-1 (NCT05034484) is a phase 1, randomized, placebo-controlled study in healthy adult volunteers designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of single doses of intravenously and subcutaneously administered ALPN-303. Initial data show ALPN-303 to be well tolerated up to 960 mg with dose-dependent pharmacokinetics and reductions in circulating immunoglobulins, galactose-deficient IgA1 and antibody-secreting cells, supporting the use of a once every four-week dose regimen for subsequent studies.

About Alpine Immune Sciences

Alpine Immune Sciences is committed to leading a new wave of immune therapeutics. With world-class research and development capabilities, a highly productive scientific platform, and a proven management team, Alpine is seeking to create first- or best-in-class multifunctional immunotherapies via unique protein engineering technologies to improve patients’ lives. Alpine has entered into strategic collaborations with leading global biopharmaceutical companies and has a diverse pipeline of clinical and preclinical candidates in development. For more information, visit www.alpineimmunesciences.com. Follow @AlpineImmuneSci on Twitter and LinkedIn.

SOURCE: Alpine Immune Sciences