Patterns of Care for Older Patients With Myelofibrosis: A Population-based Study

Methodological challenges in the development of endpoints for myelofibrosis clinical trials

Myelofibrosis is a myeloid neoplasm characterised by the presence of JAK2, CALR, or MPL mutations (with a 90% mutation frequency) and trilineage myeloid proliferation with prominent megakaryocyte atypia. People with myelofibrosis have a lower survival rate and poorer quality of life than healthy individuals. Therapy for myelofibrosis uses Janus kinase inhibitors, which reduce splenomegaly and alleviate symptoms. Regulatory approvals for Janus kinase inhibitors have focused on this dual endpoint. In this Viewpoint, we discuss the validity of using spleen reduction as a surrogate endpoint for the disease-modifying activity of candidate drugs for myelofibrosis. We suggest alternative endpoints addressing unmet patient needs, including progression-free survival and overall survival. Moreover, we highlight the importance of selecting a core set of crucial outcomes with which we can individualise clinical decision making and standardise reporting of clinical trials results. We propose selecting patient-reported outcomes and anaemia response. We also suggest integrating economic considerations in the process of evaluating new drugs for myelofibrosis.

Real-World Electronic Medical Records Data Identify Risk Factors for Myelofibrosis and Can Be Used to Validate Established Prognostic Scores

Myelofibrosis (MF) is a myeloproliferative neoplasia arising de novo as primary myelofibrosis (PMF) or secondary to polycythemia vera or essential thrombocythemia. Patients experience a high symptom burden and a marked reduction in life expectancy. Despite progress in molecular understanding and treatment, the clinical and prognostic heterogeneity of MF complicates treatment decisions. The International Prognostic Scoring System (IPSS) integrates clinical factors for risk stratification in MF. This study leverages the TriNetX database with more than 64,000 MF patients to assess the impact of accessible parameters on survival and complicating events, including AML transformation, cachexia, increased systemic inflammation, thrombosis and hemorrhage. Age over 65 years correlated with increased risks of death, AML transformation, thrombosis and hemorrhage. Anemia (Hb < 10 g/dL), leukocytosis (>25 × 103/µL) and thrombocytopenia (<150 × 103/µL) reduced survival and increased risks across all assessed events. Monocytosis is associated with decreased survival, whereas eosinophilia and basophilia were linked to improved survival. Further, as proof of concept for the applicability of TriNetX for clinical scores, we devised a simplified IPSS, and confirmed its value in predicting outcomes. This comprehensive study underscores the importance of age, anemia, leukocytosis and thrombocytopenia in predicting disease trajectory and contributes to refining prognostic models, addressing the challenges posed by the disease's heterogeneity.

OUP accepted manuscript

Background

This study analyses treatment patterns, health care resource utilization (HCRU), and costs in patients with myelofibrosis (MF) and a subgroup treated with ruxolitinib (RUX).

Materials and Methods

Treatment patterns, all-cause and MF-related HCRU, and costs were analyzed in adults with MF with continuous enrollment in a commercial or the Medicare Advantage health plan in the pre-index period, defined as the 12 months immediately prior to the index date (date of primary or secondary MF diagnosis), and the post-index period, defined as ≥6 months following the index date. In a subgroup analysis, outcomes were analyzed in patients treated with optimal RUX (OPT RUX, ≥30 mg) and suboptimal RUX (SUB RUX, <30 mg) in the pre-index RUX period, defined as the 3 months immediately prior to the index RUX date (first date for an RUX claim), and the post-index RUX period, defined as ≥6 months following the index RUX date.

Results

Of 2830 patients with an MF diagnosis, 1191 met eligibility requirements. The median age of patients was 72 years, 54% were male, and comorbidities were frequent. Sixty percent of patients received ≥1 line of therapy (LOT), of which 46% (n = 331) had ≥2 LOTs during the post-index MF period. Costs increased considerably 6-month pre-index to 6-month post-index (all-cause: cause ($24,216 to $48,966) and MF-related ($16,502 to $39,383), driven by inpatient stays and pharmacy costs. In the subgroup analysis, patients treated with RUX (n = 495) experienced significant disease burden and high costs, regardless of dose. A shorter duration of therapy and a higher rate of discontinuation were observed in patients treated with SUB RUX (n = 191) versus OPT RUX (n = 304).

Conclusion

These findings suggest a significant disease and economic impacts associated with MF patients that persists with RUX therapy, highlighting the need for additional therapeutic options for MF.