Telitacicept’s penetration in SLE and emerging off-label use in lupus nephritis offer an early look at how dual BAFF/APRIL blockade may expand across autoimmune disease.
Telitacicept’s Western story is only beginning. Its story in China is considerably further along.
In June 2025, Vor Bio acquired exclusive rights to develop and commercialize telitacicept outside Greater China, effectively rebuilding its pipeline around a drug that had already accumulated years of clinical and commercial experience in China. Today, telitacicept is approved there across five autoimmune diseases—systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), generalized myasthenia gravis (gMG), Sjögren’s disease (SjD), and IgA nephropathy (IgAN). Vor is now advancing global Phase III programs in gMG and SjD, while RemeGen continues to widen the molecule’s footprint in China.
But one of the more interesting signals may be emerging in a disease for which telitacicept does not have an indication: lupus nephritis (LN).
New Spherix Global Insights research among nephrologists and rheumatologists in China suggests that Tai’ai, the local telitacicept brand, has already established a meaningful off-label role in LN.
That LN use is best understood against telitacicept’s established SLE footprint. SLE provides a labeled base of experience in the same disease continuum: physicians can build familiarity with patient selection, dosing, and the drug’s safety profile before considering it for renal involvement. The commercial implication is that penetration in a broad systemic indication may create a launchpad for adoption in adjacent organ disease.
The China experience therefore offers a class-level lesson. BAFF/APRIL agents may not need to win every indication independently from a standing start; credibility and routine use in one disease can lower the barrier to expansion into closely related settings, even before labels and guidelines catch up.
Off-label use has moved well beyond experimentation
Despite the absence of an LN indication, 63% of surveyed nephrologists and 48% of rheumatologists report having prescribed telitacicept specifically for LN. Among biologic-treated LN patients, telitacicept accounts for 17% of nephrologists’ treatment share and 15% of rheumatologists’—behind Benlysta and rituximab, but substantial for an off-label therapy.
The patient types receiving it are equally telling.
Physicians describe using telitacicept in patients with persistent proteinuria, proliferative LN, and in insufficient response to approved biologic therapies. Rheumatologists also cite steroid reduction as a reason to initiate the drug.
The pattern appears to become more pronounced as renal disease becomes harder to control. In Spherix’s treatment-scenario analysis, Benlysta-based regimens remain common across proteinuria levels, but specialists become more likely to favor telitacicept-based regimens as proteinuria rises.
That does not establish telitacicept’s efficacy in LN; randomized LN-specific evidence is needed to do that. RemeGen has initiated a randomized Phase II study of telitacicept in active LN, but until results are available, the China prescribing data should be understood as a commercial rather than clinical signal. Chinese specialists appear increasingly willing to extrapolate from telitacicept’s SLE evidence, their own clinical experience, and the biology of BAFF/APRIL inhibition when faced with difficult renal disease.
China is testing the portability of the mechanism
That distinction matters because telitacicept is part of a drug class that suddenly looks much more consequential than it did even a few years ago.
BAFF and APRIL are proteins that help B cells and antibody-producing cells survive. Benlysta (belimumab) showed that blocking BAFF can be an effective strategy in lupus. Telitacicept, Vera Therapeutics’ Trutakna (atacicept-vymj), Vertex’s investigational povetacicept, and Aurinia’s investigational aritinercept (formerly AUR200) block both BAFF and APRIL, potentially reaching a broader range of disease-driving cells.
For years, whether dual inhibition would translate into a major drug class remained an open question. In 2026, that question is beginning to look different.
Vera Therapeutics’ Trutakna received FDA accelerated approval for IgAN in July, making it the first approved dual BAFF/APRIL inhibitor in the United States. Vertex’s povetacicept is close behind: its IgAN application has a November 30, 2026 PDUFA date, while Vertex is also developing the drug in primary membranous nephropathy and gMG.
Telitacicept provides a different type of validation. Rather than being defined by one disease, its China experience increasingly resembles a platform across B-cell-mediated autoimmunity.
Five indications are already approved. RemeGen has started a 260-patient Phase III trial in CTD-associated interstitial lung disease, and additional development extends into ocular MG and pediatric disease.
In other words, the class is no longer being tested only on whether suppressing BAFF and APRIL can work. The next question is how broadly the mechanism can travel across immune-mediated diseases.
Vor does not need to recreate the Chinese strategy exactly
Interestingly, Vor has so far resisted simply reproducing RemeGen’s China portfolio in the West.
Its public global development strategy is focused primarily on gMG and SjD, with an ocular MG program planned. That may be strategically sensible. The U.S. lupus market is increasingly competitive, with established BAFF inhibition, type I interferon blockade, B-cell depletion, and numerous late-stage mechanisms competing for position. SjD, by contrast, offers an opportunity to establish telitacicept around a disease in which B-cell biology is central and the treatment landscape is only now beginning to change.
China therefore may be most valuable to Vor not as an exact development blueprint, but as evidence that telitacicept can support something more ambitious than a single-indication franchise.
The off-label LN experience demonstrates physician willingness to use the drug in severe organ disease. The five approved Chinese indications demonstrate breadth. And RemeGen’s ongoing CTD-ILD development could provide another test of whether dual BAFF/APRIL inhibition can extend further into systemic rheumatic disease.
The competitive question is shifting from class validation to differentiation
That creates a different challenge for the companies developing these agents.
In the U.S., Trutakna now has first-mover status in the dual BAFF/APRIL class. Povetacicept is being positioned around monthly administration and potentially differentiated renal efficacy. Telitacicept enters the global race with something its competitors cannot easily recreate: extensive multi-indication clinical experience and an established commercial market in China.
As the class expands, mechanism alone will become less differentiating.
Manufacturers will need to show where each molecule works best, which patients benefit most, how far immunoglobulins can be reduced without compromising safety, and whether benefits extend beyond disease control to steroid reduction, durability, organ protection, and outcomes that matter to patients.
The question for the next several years may therefore be less whether dual BAFF/APRIL inhibition becomes an important therapeutic class than which diseases—and which drug—ultimately define it.