Patients with myelofibrosis (MF) who were relapsed or refractory, or intolerant to Ruxolitinib, have limited effective treatment options, and the outcome after discontinuation of Ruxolitinib is poor. Rovadicitinib (TQ05105) is a first-in-class, oral, small-molecule Janus kinase (JAK)/Rho-associated kinase (ROCK) inhibitor. Rovadicitinib has demonstrated significant clinical benefits in MF patients for spleen responses and reduced symptom burden. Here, we report safety and efficacy from a single-arm, multicenter, open-label, phase Ib study evaluating Rovadicitinib in MF patients resistant or intolerant to prior Ruxolitinib (NCT06388759). Between August 1, 2022, and September 05, 2023, patients were assessed for eligibility, and 9 patients were enrolled. The median duration of prior Ruxolitinib exposure was 40.6 months. At a median Rovadicitinib exposure of 12.5 months, the most common grade ≥3 treatment-emergent adverse event was thrombocytopenia (33.3 %). No report of a bleeding event and only one of 9 patients (11.1 %) permanently discontinued Rovadicitinib treatment. The spleen volume response rate (≥35 % spleen volume decrease from baseline to end of cycle 6 [EOC6]) was 25.0 %. Symptom response rate (≥50 % reduction from baseline to EOC6 in total symptom score on the modified Myelofibrosis Symptom Assessment Form) was 37.5 %. This study suggests that patients with MF who are intolerant or resistant to Ruxolitinib or other JAK inhibitors might achieve significant clinical benefit after treatment with Rovadicitinib. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT06388759.