Alpine Immune Sciences Shares Updated Clinical Data from Povetacicept in IgA Nephropathy

Alpine Immune Sciences, Inc. (NASDAQ: ALPN), a leading clinical-stage immunotherapy company focused on developing innovative treatments for autoimmune and inflammatory diseases, today shared updated clinical data for povetacicept in IgA nephropathy (IgAN) which will be presented as a late breaking poster at the World Congress of Nephrology (WCN) April 13-16, 2024 in Buenos Aires, Argentina.

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Figure 1. Povetacicept is Associated with Clinically Meaningful UPCR Reductions, Stable eGFR in IgA Nephropathy, and Reductions in Gd-IgA1 and Gd-IgA1/C3 Ratio (Graphic: Business Wire)

Povetacicept is a potent dual antagonist of the BAFF (B cell activating factor) and APRIL (a proliferation inducing ligand) cytokines, which play key roles in pathogenesis of multiple autoimmune diseases via their roles in the activation, differentiation and/or survival of B cells, particularly antibody-secreting cells, as well as T cells and innate immune cells. RUBY-3 is a multiple ascending dose, multi-cohort, open label, phase 1b/2a study of povetacicept in autoimmune glomerulonephritis, including IgA nephropathy, where povetacicept is administered subcutaneously (SC) once every four weeks.

Key Highlights Include:

• As of March 01, 2024, 41 patients with IgAN had received povetacicept 80 or 240 mg subcutaneously every 4 weeks. Treatment with povetacicept 80 mg SC Q4W has been associated with a clinically meaningful improvement in proteinuria, with a 64.1% reduction from baseline in urine protein to creatinine ratio (UPCR; n=6) at 36 weeks, associated with stable renal function as assessed by estimated glomerular filtration rate (eGFR). At this same time, 4/6 (67%) had achieved remission, as defined as UPCR < 0.5 g/g, ≥50% reduction in UPCR from baseline, and stable renal function (≤ 25% reduction in eGFR from baseline).
• Resolution of hematuria, as defined as negative or trace/small hematuria in patients with non-negative/trace hematuria at baseline, was achieved in all (100%) patients with data available at 36 or more weeks (N=4).
• Treatment with povetacicept 240 mg SC Q4W has been associated with similar improvements in proteinuria, stable renal function, and remission, based on initial data through 12 (13 patients) and 24 (2 patients) weeks.
• Treatment with both doses was associated with significant reductions in the key disease-related biomarker Gd-IgA1, with the 80 mg dose achieving a 68.9% reduction at 40 weeks, and the 240 mg dose achieving a 78.6% reduction at 20 weeks. Both doses achieved reductions in IgA/C3 and Gd-IgA1/C3 ratios, which are additional severity and prognostic biomarkers in IgAN.
• Both doses have been well tolerated in IgAN, with no instances of IgG < 3 g/L and no severe infections.

“These updated findings for povetacicept are highly promising and continue to support the potential for the program as an important new therapy in IgA nephropathy,” noted Jonathan Barratt, M.D., the Mayer Professor of Renal Medicine and Honorary Consultant Nephrologist and IgA Nephropathy Rare Disease Group Lead, University of Leicester. “The marked and clinically meaningful improvement in UPCR and stable eGFR observed with a monthly dosing regimen at 36 weeks are particularly impressive, as are the deep reductions in Gd-IgA1, a key disease-related biomarker, and resolution of hematuria in patients. The lack of serious adverse events with longer duration of treatment and higher dose is also notable and, together with povetacicept’s disease modifying potential and substantial patient experience, strongly supports the rapid advancement of povetacicept into a pivotal study for IgA nephropathy.”