US-based Alpine Immune Sciences has initiated dosing in the second IgA nephropathy (IgAN) cohort using 240mg povetacicept (ALPN-303) in the Phase Ib/IIa RUBY-3 study to treat autoimmune glomerulonephritis.

Dosing is initiated based on the positive data from the first IgAN dose cohort which received 80mg povetacicept subcutaneously once every four weeks.

The Safety Monitoring Committee reviewed the data and found it to be safe and well-tolerated.

No severe adverse events and instances of hypersensitivity or administration-related reactions were observed with repeat povetacicept dosing in the first cohort.

In addition, there were no events of hypogammaglobulinemia (IgG < 3g/L).

Alpine Research and Development head and president Stanford Peng said: “We are encouraged by this first in-disease experience with the lowest dose level of povetacicept in this study, confirming its initial safety and pharmacodynamic activity during multiple dose administration.

“We look forward to providing more detailed clinical updates later this year in appropriate scientific forums.”

The company started enrolling patients for the second cohort in its open label, multi-cohort, multiple ascending dose study.

The study is also intended to treat patients with primary membranous nephropathy, and lupus nephritis. They will receive povetacicept subcutaneously for up to 48 weeks.

Key endpoints of the study include proteinuria, renal response, eGFR, and disease-related autoantibodies.

Povetacicept is a dual antagonist of the B cell activating factor (BAFF) and a proliferation inducing ligand (APRIL) cytokines.

Greater potency of povetacicept was demonstrated in preclinical studies against wild-type TACI-based comparators and other inhibitors of BAFF and/or APRIL alone.

Povetacicept is also in development for treating systemic lupus erythematosus, and autoimmune cytopenias.