Table 4.

Open questions and future priorities with novel agents in primary eosinophilic neoplasms

• Need for response criteria for MLN with eosinophilia and tyrosine kinase gene fusions

• Increasing diagnostic recognition of MLN with eosinophilia and tyrosine kinase gene fusions given the availability of targeted therapies

• How do we incorporate standard cytogenetic/FISH and molecular monitoring of tyrosine kinase fusion genes into clinical decision-making?

• Harmonization of molecular monitoring techniques for tyrosine kinase fusion genes

• What is the optimal induction and maintenance dosing of tyrosine kinase inhibitors in specific MLN with eosinophilia and tyrosine kinase gene fusions?

• What are the best predictors of treatment-free remission in PDGFRA- and PDGFRB-rearranged MLN treated with imatinib?

• In FGFR1-rearranged MLN, is pemigatinib monotherapy sufficient for chronic phase disease, and what is the role of lineage-specific induction chemotherapy ± pemigatinib in blast phase disease?

• How do we incorporate small-molecule inhibitors of MLN tyrosine kinase gene fusions as a cytoreduction strategy before transplant?

• What is the role of pemigatinib and other tyrosine kinase inhibitors posttransplant to minimize disease relapse?

• Unmet therapeutic need in CEL: evaluate HMAs and other therapies (eg, venetoclax) in the context of clinical trials