The U.S. Food and Drug Administration granted accelerated approval to Trutakna last month based on its ability to reduce proteinuria, a key marker of kidney damage in IgAN. However, newly released regulatory documents suggest the therapy may also contribute to stabilizing kidney function over time, potentially strengthening its competitive position in an increasingly crowded treatment landscape.

Data from the pivotal Phase 3 ORIGIN 3 trial, detailed in the FDA’s Summary Basis for Approval, indicate that patients receiving Trutakna experienced sustained stabilization of estimated glomerular filtration rate (eGFR) through 52 weeks. eGFR is widely used to assess how well the kidneys filter waste from the blood and is considered an important indicator of long-term kidney health.

Analysts at Guggenheim Securities described the observed eGFR trends as noteworthy, highlighting the relative stability of kidney function over the one-year study period. Nevertheless, the FDA emphasized that the available evidence was not sufficient to draw firm conclusions about Trutakna’s effect on long-term kidney outcomes. The agency noted that the approval decision relied primarily on proteinuria reduction rather than direct proof of kidney function preservation.

Researchers and analysts cautioned that the eGFR findings were based on a relatively limited patient population. More comprehensive results from the ORIGIN 3 study are expected to be presented at a scientific meeting later this year, which could provide greater clarity regarding the drug’s renal benefits.

According to Jefferies analysts, Trutakna’s kidney function profile shares several similarities with that observed for Voyxact. Both therapies appeared to produce an early increase in eGFR during the first few weeks of treatment, followed by a generally stable trajectory over time. Jefferies reported that Trutakna’s performance compared favorably with Voyxact through 52 weeks and that longer-term datasets extending to 60 and 72 weeks, although involving fewer participants, continued to suggest sustained kidney function stabilization.

The findings are significant because Voyxact had recently gained attention after Otsuka reported data suggesting the therapy could slow the decline of kidney function in IgAN patients. At the time, some analysts viewed those results as a potential differentiator in the market, with RBC Capital Markets noting that clear eGFR stabilization had rarely been demonstrated in a placebo-controlled setting.

That perception prompted some investors to question whether Trutakna could compete effectively against Voyxact. The newly disclosed eGFR data may help alleviate those concerns. Analysts now suggest that Trutakna’s long-term kidney function profile could ultimately resemble that of its rival, reducing the likelihood that Voyxact will maintain a unique advantage on that metric alone.

Beyond its competition with Voyxact, Trutakna is also entering a market that includes Novartis’ Fabhalta, another IgAN therapy. Fabhalta initially received accelerated approval in August 2024 and recently secured full FDA approval, further intensifying competition among treatments aimed at slowing disease progression and preserving kidney health in patients with IgA nephropathy.

While additional long-term evidence will be needed to confirm Trutakna’s renal benefits, the emerging eGFR data suggest that the drug may offer more than proteinuria reduction, positioning it as a potentially important new option for patients with IgAN.