A Phase II Trial of the MEK Inhibitor Mirdametinib in Histiocytic Disorders
The purpose of this study is to see if treatment with mirdametinib in patients with Langerhans cell histiocytosis (LCH) or other histiocytic disorders will be better than current treatments and with fewer side effects.
• Subjects must be ≥ 2 years of age AND have a diagnosis of a histiocytic disorder that requires systemic therapy
‣ If patient has had a diagnostic biopsy, biopsy must be reviewed and confirmed by CCHMC pathologist as feasible
⁃ If patient has had a biopsy but has not had molecular testing done, must have tissue available for mutational analysis
⁃ If patient has isolated pituitary/CNS disease or situations where biopsy is not feasible, positive ddPCR blood test for mutation associated with histiocytic neoplasm with clinical features of histiocytosis is sufficient
• Must have measurable disease on PET scan or brain MRI
• Subjects must demonstrate adequate organ function as defined:
‣ Renal: maximum serum creatinine 2x the upper limit of normal (ULN) OR a creatinine clearance or radioisotope GFR ≥ 70ml/min/1.73 m2
⁃ Liver: ALT ≤ 3x ULN AND normal INR (≤ 1.5)
⁃ Hematologic: Hematology: Albumin ≥ 2.8 g/dL; Absolute neutrophil count ≥ 1.5 x 109/L; Platelets ≥ 100 x 109/L; Hemoglobin ≥ 9.0 g/dL
⁃ Patients with organ function abnormalities outside of these thresholds deemed to be the result of histiocytic disease will be considered eligible