A first-in-class JAK/ROCK inhibitor, rovadicitinib, for glucocorticoid-refractory or -dependent chronic GVHD

Rovadicitinib (TQ05105) is a novel, oral dual Janus kinase 1/2 and rho-associated coiled-coil-containing protein kinase-1/2 inhibitor targeting inflammatory and fibrotic components of chronic graft-versus-host disease (cGVHD). This phase 1b/2a, multicenter, open-label study enrolled patients with moderate or severe glucocorticoid-refractory or -dependent cGVHD to evaluate the safety and efficacy of rovadicitinib. The study followed a 3+3 design with 2 escalating doses (rovadicitinib 10 and 15 mg twice daily) and a dose expansion cohort. Primary end points included safety and recommended phase 2 dose (RP2D); the best overall response (BOR) was the key secondary end point. A total of 44 patients were enrolled (29 at 10 mg, 15 at 15 mg twice daily). Rovadicitinib was well tolerated without dose-limiting toxicity at both dosages, and no rovadicitinib-related adverse events (AEs) led to discontinuation. The most prevalent hematological AE was anemia (38.6%), with grade ≥3 of 4.6%. The RP2D was 10 mg twice daily. The BOR was 86.4% (95% confidence interval [CI], 72.6-94.8), with no difference between the 2 dosage cohorts. Besides, BOR was 72.7% in the steroid-refractory cohort and 90.9% in the steroid-dependent cohort. All affected organs exhibited responses regardless of prior therapy. The failure-free survival rate was 85.2% (95% CI, 64.5-94.3) at 12 months. Rovadicitinib reduced corticosteroid doses in 88.6% of patients and improved cGVHD symptoms in 59.1%. Rovadicitinib has favorable tolerability and notable clinical response rates, ameliorating the quality of life and reducing corticosteroid dose requirements in patients with glucocorticoid-refractory or -dependent cGVHD. This trial was registered at www.ClinicalTrials.gov as #NCT04944043.