Upadacitinib, a selective <scp>JAK1</scp> inhibitor, for the treatment of steroid refractory chronic graft‐versus‐host disease: A multicentre real‐world study

Graft-versus-host disease (GVHD) remains an important cause of morbidity and mortality after allo-HSCT. Upadacitinib is a selective JAK1 inhibitor. This study investigated the clinical outcomes of upadacitinib in patients with steroid refractory (SR) chronic graft-versus-host disease (cGVHD). Thirty-two patients with steroid refractory cGVHD (SR-cGVHD) who received upadacitinib treatment were enrolled from three hospitals in China. The overall response rates (ORRs) at 24 weeks and at any time were 81.3% (complete response [CR] rate: 21.9%; partial response [PR] rate: 59.4%) and 84.4% (CR rate: 21.9%; PR rate: 62.5%) respectively. In particular, the cutaneous-specific ORRs at week 24 and at any time were 84.4% (CR rate: 40.6%, PR rate: 43.8%) and 87.6% (CR rate: 43.8%; PR rate: 43.8%) respectively. The rates of infection and haematological toxicity were 18.75% and 6.25%, and two patients (6.25%) experienced grade III adverse events after upadacitinib treatment. One patient died from relapse, and no patient died from non-relapse mortality. The 1-year probabilities of overall survival, failure-free survival and disease-free survival after upadacitinib were 96.6%, 64.9% and 83.1% respectively. In summary, upadacitinib may be an effective and safe treatment for SR-cGVHD.