What evolving risk definitions, shifting treatment expectations, and B cell immunomodulation mean for drug developers
IgA nephropathy (IgAN) is no longer a niche renal indication defined by slow progress and limited treatment options. The combination of evolving clinical guidelines, a maturing late-stage pipeline, and changing physician expectations is fundamentally reshaping how this market is viewed and how opportunity is defined.
At REACH Market Research, we recently released an updated MarketVue® (U.S.) IgA Nephropathy report to help drug developers and brand teams understand where the market is headed next. What emerged from our physician research is not just incremental change, but a structural shift in how IgAN is risk-stratified and treated and how current drug classes are viewed.
Below, we outline the themes shaping the next phase of IgAN, alongside some of the key strategic questions addressed in REACH’s MarketVue® (U.S.) IgA Nephropathy report for drug developers navigating a more competitive landscape.
The Definition of “High Risk” Is Expanding
One of the most consequential developments in IgAN is the broadening of the definition of patients considered at high risk of progression. While updated clinical guidelines have begun to reflect this evolution, real-world practice has already moved ahead.
Physicians are increasingly identifying a larger share of patients as candidates for immune-active therapy, often earlier in the disease course than in the past. This shift is materially changing the size, timing, and composition of the treatable population.
Key question:
How are nephrologists defining “high-risk” IgAN in practice, and what does this mean for the commercially actionable patient population?
Proteinuria Reduction Is No Longer Enough
For years, proteinuria reduction served as a primary benchmark for success in IgAN. Today, that bar has moved.
As multiple therapies demonstrate comparable effects on proteinuria, physicians are increasingly focused on whether a treatment can meaningfully alter disease trajectory over time. Long-term kidney function preservation and durability of response are becoming central to how value is defined.
Key questions:
What outcomes are now considered “table stakes” versus truly differentiating in IgAN?
How are expectations shifting toward disease modification rather than short-term control?
A Meaningful Unmet Need Persists Despite Optimized Care
Despite advances in supportive care and the availability of branded therapies, a substantial subset of IgAN patients remains inadequately controlled. These patients continue to progress, prompting physicians to consider add-on strategies, switching, or later-line options.
This persistent unmet need represents a critical area of opportunity for both in-market and emerging therapies.
Key question:
How large is the population of patients who remain uncontrolled despite optimized current treatment, and how are physicians prioritizing them for next-line therapy?
The IgAN Treatment Flow Is Becoming More Complex
The traditional, linear view of IgAN treatment is giving way to a more nuanced and segmented reality. As patients move beyond supportive care, physicians are no longer thinking only in terms of “next line,” but in terms of which therapy best fits which patient profile. Indeed, REACH’s research shows that distinct patient archetypes are emerging for current IgAN therapies, which has implications for how current therapies are used and how emerging therapies will fit into the treatment algorithm.
Key questions:
What does the real-world IgAN treatment flow look like today and where do Calliditas’ Tarpeyo, Tavere’s Filspari, Novartis’ Vanrafia and Fabhalta, and Otsuka’s Voyxact sit within it? What is the patient archetype for each of these drug classes?
Why B Cell Targeting Is the Next Competitive Battleground
Perhaps the most forward-looking shift in IgAN is the growing role of immunomodulation, particularly therapies targeting B cell pathways such as APRIL and/or BAFF.
As patients escalate beyond foundational/supportive care, B cell-targeted therapies are increasingly viewed as a logical and potentially earlier intervention. Early experience with first-in-class sibeprenlimab is already shaping physician expectations for this category, with important implications for emerging competitors, including Vera’s atacicept and Vertex’s povetacicept.
Key questions:
How is Otsuka’s sibeprenlimab being used today, and what does this signal for the broader APRIL/BAFF class?
How will B cell-targeted therapies ultimately need to differentiate themselves as intraclass competition quickly increases?
What This Means for Drug Developers
Taken together, these shifts point to an IgAN market that is becoming larger, more competitive, and more demanding. Success will increasingly depend on clear patient segmentation, thoughtful positioning within a fragmented treatment paradigm, and compelling evidence of long-term value.
REACH’s MarketVue® (U.S.) IgA Nephropathy report was developed to help biopharma teams navigate this complexity with fresh, timely physician insights.
Interested in exploring these questions in depth?
Learn more about the MarketVue® (U.S.) IgA Nephropathy report or request access below.