This phase II trial tests the effect of mirdametinib in treating patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) that has come back after a period of improvement (relapsed) or that has not responded to previous treatment (refractory). Mirdametinib, a methyl ethyl ketone (MEK) inhibitor, works by blocking the action of an abnormal protein that signals cancer cells to multiply. This may help slow or stop the spread of cancer cells. Giving mirdametinib may be effective in treating patients with relapsed or refractory CLL or SLL.
Patients must have histologically or cytologically confirmed CLL or small lymphocytic lymphoma (SLL), as documented by a history at some point in time of an absolute peripheral blood B cell count > 5000/mcL with a monoclonal B cell population coexpressing CD19, CD5, and CD23, or if CD23 negative, then documentation of the absence of t(11;14) or cyclin D1 overexpression. Alternatively, patients with lymphadenopathy in the absence of circulating disease will also be eligible for this study if lymph node biopsy or bone marrow biopsy has established the diagnosis of CLL with the above immunophenotype
Massive or progressive splenomegaly; OR
Massive lymph nodes, nodal clusters, or progressive lymphadenopathy; OR
Grade 2 or 3 fatigue; OR
Patients who have not recovered from adverse events due to prior anti-cancer therapy (i.e., have residual toxicities > grade 1) with the exception of alopecia
Patients who are receiving any other investigational agents
History of allergic reactions attributed to compounds of similar chemical or biologic composition to mirdametinib
Patients with concurrent administration of strong inhibitors and inducers of P-glycoprotein (P-g)p or breast cancer specific resistance protein (BCRP). If discontinuation of the medication is appropriate, a washout duration of approximately 3 to 5 half-lives is recommended prior to the first dose of mirdametinib