BACKGROUND: Myelofibrosis (MF) significantly impacts patients' overall survival (OS) and quality of life (QOL). This prospective study analyzed ruxolitinib dosing patterns and associated clinical outcomes in patients with MF over 12 months.

METHODS: ROMEI, a multicenter, observational, ongoing study, enrolled 508 adult patients with MF treated with ruxolitinib. For the current interim analysis, eligible patients with baseline platelet values were categorized into two groups based on ruxolitinib starting dosage: as expected (AsEx, n = 174) and lower than expected (LtEx, n = 132); ruxolitinib dose changes, interruptions and time to permanent discontinuation were analyzed, along with symptoms response, health-related QOL scores, spleen response, OS, and safety.

RESULTS: Forty-three percent of patients started at a lower-than-expected dose. Both groups showed reduction in average daily ruxolitinib doses over 12 months. Symptoms response rate was similar in both groups at week 48 (40.8% AsEx vs 40.9% LtEx). The AsEx group demonstrated higher spleen response rates at both 24 weeks (50.0% vs 30.2%) and 48 weeks (57.7% vs 45.8%) with a shorter median time to first response (3.3 vs 11.1 months, p = .019) when compared to the LtEx group. Both groups showed upward trends in health-related QOL values. Estimated median OS was not reached for the AsEx group versus 4.7 years in the LtEx group (p = .014). Adverse events were reported in 87.4% and 84.9% of patients in the AsEx and LtEx groups, respectively.

CONCLUSIONS: The ROMEI study demonstrated the importance of optimal ruxolitinib dosage in patients with MF for maximum effectiveness and improved OS, with manageable safety.