Atacicept Accelerated Approval: Surrogate-Endpoint Win in Crowded IgAN Field Masks Hard-Outcome Gap

Vera's Trutakna Receives Accelerated FDA Approval for IgAN

Vera Therapeutics' atacicept, marketed as Trutakna, has received accelerated FDA approval for adults with primary IgA nephropathy (IgAN) who are at risk of disease progression. This approval was based on an interim analysis from the Phase 3 ORIGIN 3 trial, which showed a 46% reduction from baseline in proteinuria, a key disease biomarker, and a 42% reduction compared to placebo at 36 weeks. Trutakna is the first medicine for IgAN to target both BAFF and APRIL, positioning it in a competitive market against existing and upcoming therapies.

• Vera Therapeutics secured accelerated FDA approval for Trutakna (atacicept) for adults with primary IgA nephropathy at risk of disease progression. Analysts noted the "clean label" and broad approval without limitations on proteinuria levels or mention of neutralizing antibodies, providing a competitive advantage over existing rivals like Otsuka's Voyxact by accessing a broader patient population.
• The approval was supported by interim data from the ongoing Phase 3 ORIGIN 3 trial, demonstrating significant efficacy with a 46% reduction from baseline in proteinuria and a 42% reduction compared to placebo at 36 weeks. While this data underpinned the accelerated approval, Vera is required to confirm long-term clinical benefit, specifically slowing kidney function decline, with full results from ORIGIN 3 expected in the third quarter.
• Trutakna is distinguished by its dual mechanism of action, targeting both B cell activating factor (BAFF) and A Proliferation Inducing Ligand (APRIL), which are crucial for immune cell survival and maturation, leading to decreased abnormal IgA antibody production. This unique approach positions Trutakna in a competitive landscape alongside Otsuka’s Voyxact and Novartis’ Fabhalta, with Vertex Pharmaceuticals also having a candidate, povetacicept, under FDA review.

Trutakna's Accelerated Approval and ORIGIN 3 Efficacy

Recent clinical investigation in primary IgA nephropathy has generated robust data across multiple study designs, from phase 3 randomized controlled trials to retrospective multicenter cohorts. The findings collectively underscore meaningful advances in proteinuria reduction and eGFR preservation, alongside an evolving understanding of the comparative safety profiles of emerging targeted therapies.

• TELIGAN Trial (telitacicept; NCT05799287): This phase 3, multicenter, double-blind, randomized, placebo-controlled trial enrolled 318 adults with biopsy-proven IgAN and persistent proteinuria ≥1.0 g/day despite optimized supportive care. Patients received subcutaneous telitacicept 240 mg once weekly versus placebo (1:1). At week 39, telitacicept produced a −58.9% reduction in 24-hour urinary protein-to-creatinine ratio versus −8.8% with placebo (relative difference −55.0%; 95% CI: −61.3 to −47.6; P<0.001). eGFR change was −1.0% (95% CI: −3.2 to 1.2) with telitacicept versus −7.7% (95% CI: −9.9 to −5.4) with placebo. Although overall adverse events were more frequent with telitacicept (89.3% vs. 78.6%), serious adverse events were notably lower (2.5% vs. 8.2%), with no unexpected safety signals.

• Telitacicept Combination Therapy Study (telitacicept ± glucocorticoid/mycophenolate mofetil): This retrospective multicenter cohort enrolled 256 adults with biopsy-proven IgAN (eGFR ≥30 mL/min/1.73 m²; proteinuria ≥0.75 g/day) comparing telitacicept monotherapy (n=125) to telitacicept plus glucocorticoid/mycophenolate mofetil (GM; n=131) over 9 months. The combination arm demonstrated significantly greater proteinuria reduction (−1.32 vs. −0.94 g/day; P<0.001), a favorable eGFR slope (+2.74 vs. −0.56 mL/min/1.73 m²/year; P=0.014), higher complete remission (54.2% vs. 40.8%; P=0.005), and higher overall remission rates (78.6% vs. 70.4%; P=0.014). Multivariable Cox regression confirmed an adjusted HR of 2.18 (95% CI: 1.46–3.22; P<0.001) for complete remission with combination therapy. Overall adverse events were higher in the combination arm (28.2% vs. 11.2%), though no serious adverse events were reported in either group.

• Budesonide EC versus Telitacicept Comparative Study (budesonide EC vs. telitacicept): This single-center retrospective cohort at Henan Provincial People's Hospital enrolled 95 adults with biopsy-proven IgAN (budesonide EC n=46; telitacicept n=49) from January 2022 to December 2025, with 6 months of follow-up. The treatment effect on proteinuria reduction was significantly modified by baseline proteinuria level (interaction P=0.003), with telitacicept demonstrating greater relative benefit at mild-to-moderate baseline proteinuria. Budesonide EC was associated with higher mean eGFR during follow-up in the primary model (β=4.090 mL/min/1.73 m²; P=0.018), though this association attenuated and lost statistical significance in the propensity score-matched cohort (β=5.022 mL/min/1.73 m²; P=0.085).

• Bortezomib Pilot Study (bortezomib): This open-label, prospective, uncontrolled trial enrolled 16 adults with biopsy-confirmed IgAN, proteinuria >1.5 g/day, and eGFR ≥30 mL/min/1.73 m² despite optimized management. Patients received 4–8 doses of intravenous bortezomib at 1.1–1.3 mg/m² per dose. At 12 months, proteinuria decreased by 44.67% from a baseline of 2.719 g/24h, with ≥50% proteinuria reduction achieved in 43.75% of patients and complete remission in 6.25%. At 24 months, mean proteinuria was 1.411 g/24h (48.09% reduction), with an annual eGFR slope of −4.275 mL/min/1.73 m². No serious treatment-related adverse events were reported.

• Meta-Analysis of Phase 2b/3 Trials (multiple drug classes): A systematic review and meta-analysis of 14 randomized, placebo-controlled multicenter trials searched through May 2025 evaluated four drug classes. Proteinuria reduction varied significantly by class (P-heterogeneity <0.001): corticosteroids −51%, B-cell modulating agents −45%, complement inhibitors −35%, and non-immunological therapies −34%. eGFR slope benefits over a minimum of 12 months also differed by class (P-heterogeneity=0.03): B-cell modulating agents achieved the greatest absolute benefit at 4.3 mL/min/1.73 m²/year (−73% relative), followed by corticosteroids at 2.3 mL/min/1.73 m²/year (−52% relative) and non-immunological therapies at 1.1 mL/min/1.73 m²/year (−28% relative). Corticosteroids, particularly at higher doses, carried the highest risk of serious adverse events; other drug classes were generally well tolerated.

Navigating the Evolving IgAN Treatment Landscape

The treatment landscape for primary IgA nephropathy (IgAN) has undergone a profound transformation over the past five years, shifting decisively away from broad immunosuppression and supportive care toward mechanistically targeted, disease-modifying therapies. This evolution has been driven in part by sobering epidemiological data: the UK RaDaR registry cohort of 2,299 adults demonstrated a median kidney survival of only 11.4 years (95% CI 10.5–12.5), with 50% of patients reaching kidney failure or death during a median follow-up of 5.9 years. Critically, even patients historically considered low-risk — those with time-averaged proteinuria below 0.88 g/g — experienced kidney failure rates approaching 20–30% within 10 years, reinforcing the urgency for effective intervention. Each 10% reduction in time-averaged proteinuria was associated with a hazard ratio of 0.89 (95% CI 0.87–0.92) for kidney failure or death, establishing proteinuria reduction as a validated surrogate endpoint and anchoring the design of subsequent trials. Against this backdrop, three novel agents — nefecon (targeted-release budesonide, marketed as Tarpeyo), sparsentan, and iptacopan — have received regulatory approval, marking a turning point in the therapeutic standard of care.

Clinical trial data across multiple mechanistic classes have now substantiated the efficacy of targeted approaches. In the ALIGN trial, the endothelin receptor type A antagonist atrasentan, evaluated in 404 participants over 132 weeks, demonstrated a total eGFR slope difference of 1.4 mL/min/1.73 m²/year (95% CI 0.5–2.3) versus placebo, with a notably amplified benefit of 9.1 mL/min/1.73 m² (95% CI 3.0–15.2) in the SGLT2 inhibitor co-treatment stratum. A phase 2 trial of SC0062, a selective endothelin receptor type A antagonist, in 131 patients demonstrated dose-dependent, placebo-corrected reductions in UPCR reaching −51.6% (95% CI −64.2 to −34.6) at 24 weeks with the 20 mg dose, without increased peripheral edema at higher doses. In the complement pathway space, cemdisiran — an RNA interference therapeutic targeting hepatic complement component 5 — achieved a placebo-adjusted geometric mean reduction in 24-hour UPCR of −37.4% at week 32 in a phase 2 study, alongside a 98.7% mean decrease in serum C5. A 2025 meta-analysis of 25 studies further contextualized these findings: complement pathway inhibitors demonstrated superior eGFR preservation of +5.8 mL/min/1.73 m²/year (95% CI 2.4–9.2), while systemic corticosteroids, though showing hard outcome benefits (HR 0.37, 95% CI 0.26–0.52), carried the highest adverse event risk (RR 3.28, 95% CI 2.11–5.09).

The most recent wave of development has centered on B-cell and plasma-cell-directed strategies targeting the APRIL and BAFF cytokine axes, which are central to pathogenic galactose-deficient IgA1 (Gd-IgA1) production. The phase 3 VISIONARY trial evaluated sibeprenlimab, a selective APRIL inhibitor, in 510 patients across 31 countries — the largest IgAN trial conducted to date — with patients receiving subcutaneous sibeprenlimab 400 mg or placebo every four weeks for 26 doses against a background of near-universal RASi use (97.8%) and substantial SGLT2 inhibitor co-administration (45.1%). In parallel, the phase 3 TELIGAN trial of telitacicept, a fusion protein neutralizing both BAFF and APRIL, reported a 58.9% reduction in 24-hour urinary protein-to-creatinine ratio at week 39 versus −8.8% with placebo (relative difference −55.0%, 95% CI −61.3 to −47.6; P<0.001), accompanied by an eGFR change of −1.0% versus −7.7% in the placebo arm, and a lower rate of serious adverse events (2.5% vs. 8.2%). The meta-analytic projection of B-cell/plasma-cell-targeted therapies yielded a proteinuria reduction of −34.0% (95% CI −45.7 to −22.3%) and a projected hard-outcome HR of 0.38, pending longer-term validation. Collectively, these data position the field at an inflection point, with emerging frameworks for biomarker-guided, combination, and precision-stratified treatment regimens poised to further individualize therapeutic decision-making.

Trutakna's Dual-Targeting MoA and Competitive Edge

Atacicept's dual inhibition of BLyS (BAFF) and APRIL via its TACI-Ig fusion protein architecture distinguishes it within a competitive landscape of B-cell–targeting biologics. Several agents sharing this mechanistic axis — either as dual BAFF/APRIL inhibitors or selective BAFF antagonists — are under investigation or have completed trials across overlapping autoimmune indications, including SLE and IgA nephropathy. The intervention models span Phase I through Phase III, with trial designs ranging from dose-escalating placebo-controlled studies to large randomised multicentre RCTs.

Trutakna's Accelerated Approval: Reshaping IgA Nephropathy Treatment

The recent accelerated FDA approval of atacicept (Trutakna) for adults with primary IgA nephropathy (IgAN) marks a pivotal moment for a patient population facing a progressive and often debilitating kidney disease. IgAN, the most common primary glomerulopathy worldwide, frequently leads to kidney failure, yet specific effective treatments have historically been scarce, with management largely relying on supportive care. This approval introduces a novel therapeutic approach, as atacicept is the first medicine to simultaneously inhibit both B-lymphocyte stimulator (BAFF) and a proliferation-inducing ligand (APRIL), two cytokines critically involved in the B-cell dysregulation and pathogenic IgA1 production central to IgAN.

The clinical data supporting this approval are compelling, with an interim analysis from the Phase 3 ORIGIN 3 trial demonstrating a substantial 46% reduction in proteinuria from baseline, and a 42% reduction compared to placebo at 36 weeks. This significant reduction in a key disease biomarker, coupled with evidence of eGFR stabilization in earlier studies, suggests that atacicept may offer true disease modification rather than merely symptom management. This positions the drug as a potential game-changer, offering a targeted intervention that addresses the underlying immunopathogenesis of IgAN.

However, the path forward is not without considerations. As an accelerated approval, it is predicated on a surrogate endpoint, necessitating confirmatory trials to unequivocally demonstrate long-term benefits in preserving kidney function and delaying end-stage kidney disease. Failure to meet these endpoints could impact its long-term market presence. Furthermore, the drug's mechanism of reducing immunoglobulin levels, while therapeutic, also carries a risk of increased susceptibility to infections, a concern highlighted by past clinical trial experiences in other autoimmune conditions. Vigilant patient monitoring will be crucial. The IgAN treatment landscape is also rapidly evolving, with other BAFF/APRIL inhibitors and complement pathway modulators in development, signaling a competitive environment. Despite these challenges, atacicept's entry represents a significant step towards precision medicine in nephrology, offering a new horizon for improved renal outcomes and long-term disease control for patients with IgAN.