Rineterkib

Ruxolitinib, a Janus kinase (JAK)1/JAK2 inhibitor, is the standard of care for symptomatic patients with myelofibrosis (MF). However, ∼70% of patients discontinue ruxolitinib after ∼5 years, a third of whom report suboptimal splenic response. ADORE was a phase 1b/2 study with an innovative open platform design that assessed the safety, efficacy, and pharmacokinetics of novel compounds in combination with ruxolitinib in patients with MF who had a suboptimal response to ruxolitinib alone. A total of 44 patients were enrolled in part 1 of the study of ruxolitinib in combination with siremadlin, rineterkib, sabatolimab, crizanlizumab, or NIS793. Most patients were allocated to receive ruxolitinib plus siremadlin (N = 23). The most frequent adverse events with siremadlin were gastrointestinal (nausea and diarrhea) and hematological (thrombocytopenia, anemia, and neutropenia). Siremadlin 30 mg orally once daily on days 1 to 5 of a 28-day cycle was selected as the recommended phase 2 dose. The most robust spleen volume reduction (SVR) at 24 weeks was observed with ruxolitinib plus siremadlin 30 mg. Reductions in percent JAK2V617F allele burden at week 24 were observed, notably in several patients with SVR. An increase in growth differentiation factor 15 protein levels in patients receiving siremadlin demonstrated the on-target modulation of downstream p53 targets. Overall, available data from ADORE suggest the feasibility and benefits of combining novel agents with ruxolitinib in patients with suboptimal response to ruxolitinib alone. This trial was registered at www.clinicaltrials.gov as #NCT04097821.