Phase II study of the JAK kinase inhibitor ruxolitinib in patients with refractory leukemias, including post myeloproliferative neoplasms (MPN) acute myeloid leukemia (AML)
Mené sur 38 patients atteints d'une leucémie réfractaire ou récidivante (âge médian : 69 ans), cet essai de phase II évalue la toxicité et l'efficacité du ruxolitinib, un inhibiteur sélectif de JAK
We conducted a phase II study of ruxolitinib in patients with relapsed/refractory leukemias. Patients with acceptable performance status (0-2), adequate organ function and no active infection, received ruxolitinib 25 mg orally twice a day for four weeks (1 cycle). Response was assessed after every 2 cycles of treatment and patients who completed 2 cycles were allowed to continue treatment until disease progression. Dose escalation to 50 mg twice daily was permitted in patients demonstrating a benefit. Thirty-eight patients, with a median age of 69 (range, 45-88), were treated. The median number of prior therapies was 2 (range, 1-6). Twelve patients had JAK2V617F mutation. Patients received a median of 2 cycles of therapy (range, 1-22). Three of 18 patients with post-MPN AML showed a significant response; two achieved complete remission (CR) and one achieved a CR with insufficient recovery of blood counts (CRi). The responding patients with palpable spleens also had significant reductions in spleen size. Overall, ruxolitinib was very well tolerated with only 4 patients having grade 3 or higher toxicity. Ruxolitinib has modest anti-leukemic activity as a single agent, particularly in patients with post-MPN AML. The study was registered at www.ClinicalTrials.gov as NCT00674479.