Filgotinib or lanraplenib in moderate to severe cutaneous lupus erythematosus: a phase 2, randomized, double-blind, placebo-controlled study

OBJECTIVES: To explore the safety and efficacy of filgotinib (FIL), a Janus kinase 1 inhibitor, and lanraplenib (LANRA), a spleen kinase inhibitor, in cutaneous lupus erythematosus (CLE). METHODS: This was a phase 2, randomized, double-blind, placebo-controlled, exploratory, proof-of-concept study of LANRA (30 mg), FIL (200 mg) or placebo (PBO) once daily for 12 weeks in patients with active CLE. At week 12, PBO patients were rerandomized 1:1 to receive LANRA or FIL for up to 36 additional weeks. RESULTS: Of 47 randomized patients, 45 were treated (PBO, n = 9; LANRA, n = 19; FIL, n = 17). The primary endpoint [change from baseline in Cutaneous Lupus Erythematosus Disease Area and Severity Index Activity (CLASI-A) score at week 12] was not met. The least squares mean CLASI-A score change from baseline was −5.5 (s.e. 2.56) with PBO, −4.5 (1.91) with LANRA and −8.7 (1.85) with FIL. Numerical differences between FIL and PBO were greater in select subgroups. A ≥5-point improvement in the CLASI-A score at week 12 was achieved by 50.0%, 56.3% and 68.8% in the PBO, LANRA and FIL arms, respectively. A numerically greater proportion of patients in the FIL arm (50%) also achieved ≥50% improvement in the CLASI-A score at week 12 (37.5% PBO, 31.3% LANRA). Most adverse events (AEs) were mild or moderate in severity. Two serious AEs were reported with LANRA and one with FIL. CONCLUSION: The primary endpoint was not met. Select subgroups displayed a numerically greater treatment response to FIL relative to PBO. LANRA and FIL were generally well tolerated. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT03134222