Treatment protocol stratified by the early responses of RUX. All enrolled patients received oral RUX as a frontline therapy, which was dosed depending on the body weight. Corticosteroid was permitted to continue if the patient was receiving it at screening and tapered gradually. Patients with a favorable response remained on RUX monotherapy for 4 weeks. Patients with an unfavorable response proceeded to intensive treatment with RUX and additional therapy. A favorable response was defined as achieving CR; an unfavorable response was defined as no response, disease improvement but not achieving PR, or disease progression at any time during frontline treatment.