A new clinical trial is evaluating selinexor, a non-JAK inhibitor, as a first-line therapy in myelofibrosis, with a JAK inhibitor added later only if needed. This innovative sequencing challenges the current, long-standing paradigm of initiating all treatments with a JAK inhibitor.
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The field of multiple myeloma has transformed from having few treatments to an abundance of effective drugs. The primary clinical challenge is no longer finding a therapy that works, but rather determining the optimal sequence and combination of available options, highlighting a unique form of market maturity.
A novel trial design used mosinutuzumab monotherapy first in frontline follicular lymphoma, adding lenalidomide only for patients without a complete response. This adaptive approach successfully spared about two-thirds of patients from the added toxicities of lenalidomide while still achieving very high overall efficacy.
Non-covalent BTK inhibitors like pirtobrutinib are currently approved for use after covalent BTK inhibitors fail. Moving them to the frontline setting, as studied in BRUIN-313, disrupts the established treatment pathway and creates uncertainty for managing relapsed disease, as the standard 'next step' is removed.
Clinicians can reassure myelofibrosis patients that the drop in hemoglobin often seen when starting ruxolitinib does not carry the same negative prognostic weight as anemia caused by the disease itself. This distinction is crucial for managing patient expectations and continuing effective therapy despite initial side effects.
A diagnosis of myelofibrosis without a JAK2, CALR, or MPL mutation should be treated as a red flag, not a final diagnosis. It warrants a deeper investigation for alternative causes, such as MDS/MPN overlap syndromes or secondary fibrosis from other conditions like autoimmune disease or hairy cell leukemia.
For myelofibrosis patients with profound splenomegaly but only moderate thrombocytopenia (platelets 50k-100k), fedratinib may be the best frontline option. It is arguably the most potent JAK inhibitor for spleen reduction and is approved for use in patients with platelet counts as low as 50,000.
The development of agents targeting specific mutations like CALR and JAK2V617F marks a move away from the "one size fits all" JAK inhibitor approach. This enables a more personalized, molecularly-driven treatment strategy that was previously not possible for MPN patients.
For myelofibrosis patients with both anemia and splenomegaly, a practical approach is to start with ruxolitinib for its superior symptom control. If the subsequent anemia is not well-tolerated, switching to momelotinib allows for a more informed, personalized decision based on the patient's experience with both agents.
While pirtobrutinib is effective after covalent BTK inhibitors, the reverse is unproven. Starting with pirtobrutinib frontline raises a critical unanswered question about whether patients will still respond to older covalent inhibitors, complicating sequencing decisions, especially for younger patients.
Clinicians are hesitant to use newer, potentially safer non-covalent BTK inhibitors before established covalent inhibitors. While it's known that non-covalents work after covalents fail, the reverse is unproven, creating a one-way treatment path that reserves these newer agents for later lines of therapy.
