One Diagnosis, Different Diseases: Is TLR7/8 Inhibition the Future of Lupus Treatment? Save

We call it systemic lupus erythematosus (SLE), but are we really treating one disease? Increasingly, I wonder whether grouping biologically distinct patients under one diagnosis is limiting our ability to treat them effectively.

Two abstracts at ACR Convergence 2026 highlight the promise of targeting Toll-like receptors 7 and 8 (TLR7/8). Abstract 0045 investigated KBD051, a selective oral TLR7/8 antagonist demonstrating prolonged pharmacodynamic activity and efficacy in preclinical lupus models. Abstract 0054 examined BMS-905, an afimetoran analog, demonstrating transcriptional reprogramming of renal inflammation in murine SLE.

What excites me most is the mechanism.

TLR7 and TLR8 are closely related endosomal RNA sensors, but their cellular distributions differ. TLR7 is particularly important in plasmacytoid dendritic cells and B cells, whereas TLR8 is predominantly expressed in monocytes, myeloid dendritic cells, and neutrophils. These antagonists target both receptors while sparing TLR9, another endosomal nucleic acid sensor.

Unlike anifrolumab, which blocks downstream type I interferon signaling, TLR7/8 inhibition intervenes upstream, potentially interrupting interferon production, NF-κB-driven inflammation, autoreactive B-cell activation, and TLR-associated glucocorticoid resistance simultaneously.

We now know that rare patients develop monogenic lupus from gain-of-function mutations in TLR7, demonstrating that this pathway can directly drive disease. But what about patients without these mutations whose lupus is predominantly TLR7-driven? Or patients whose disease is driven by EBV-positive autoreactive B cells?

Imagine if we could identify each patient’s dominant pathogenic mechanism and select treatment accordingly, rather than relying primarily on clinical manifestations.

The phase 2 WILLOW trial of enpatoran offers an important reality check. Although it missed its primary endpoint, interferon pathway suppression and encouraging secondary outcomes suggest biological activity. Perhaps patient selection matters as much as drug selection.

Of course, KBD051 and BMS-905 remain preclinical, and translating pathway inhibition into meaningful clinical benefit is far from guaranteed.

Still, these findings make me optimistic about where rheumatology is heading. Rather than searching for one increasingly powerful treatment for everyone with lupus, perhaps we should be developing therapies alongside biomarkers that identify who will benefit.

The future of SLE treatment may depend less on what we call the disease and more on understanding what is driving it in each patient.

References

Morand EF, Dall'Era M, Sanchez-Guerrero J, et al. Enpatoran, a toll-like receptor 7/8 inhibitor, in moderate-to-severe systemic lupus erythematosus: findings from Cohort B of a multicentre, international, double-blind, placebo-controlled dose-finding phase 2 trial. Lancet. 2026;407:1809–1824.

Brown GJ, Cañete PF, Wang H, et al. TLR7 gain-of-function genetic variation causes human lupus. Nature. 2022;605:349–356. 

Younis et al. EBV-positive autoreactive B-cell findings in SLE. Science Translational Medicine. 2025. PMID: 41223250.