November 2022: Pemigatinib (Pemazyre, Incyte Corporation) has been licenced by the Food and Drug Administration for use in people with relapsed or refractory myeloid/lymphoid neoplasms (MLNs) that have an altered fibroblast growth factor receptor 1 (FGFR1).
FIGHT-203 (NCT03011372), a multicenter open-label, single-arm trial with 28 patients who had relapsed or refractory MLNs with FGFR1 rearrangement, evaluated effectiveness. Patients who met the criteria for eligibility were either ineligible for or had relapsed following allogeneic hematopoietic stem cell transplantation (allo-HSCT) or a disease-modifying treatment (e.g., chemotherapy). Pemigatinib was given until the disease progressed, the toxicity became intolerable, or the patients could receive allo-HSCT.
Selected demographics and baseline characteristics included the following: 64% female; 68% white; 3.6% black or African American; 11% Asian; 3.6% American Indian/Alaska Native; and 88% ECOG performance status of 0 or 1. The median age was 65 years (range, 39 to 78); 3.6% black or African American; 68% white; and 68% white.
Based on complete response (CR) rates that met the response criteria specific to the kind of morphologic illness, efficacy was determined. 14 out of the 18 patients with extramedullary disease (EMD) and chronic phase in the marrow (78%; 95% CI: 52, 94) obtained complete remission (CR). The average number of days to CR was 104. (range, 44 to 435). The median time (from 1+ to 988+ days) was not attained. Two of the four patients who had blast phase in the marrow with or without EMD (duration: 1+ and 94 days) were in remission. One of the three patients who had EMD alone experienced a CR (lasting 64+ days). The full cytogenetic response rate for all 28 patients—including 3 without morphologic disease—was 79% (22/28; 95% CI: 59, 92).
Hyperphosphatemia, nail toxicity, alopecia, stomatitis, diarrhoea, dry eye, fatigue, rash, anaemia, constipation, dry mouth, epistaxis, serous retinal detachment, extremity pain, decreased appetite, dry skin, dyspepsia, back pain, nausea, blurred vision, peripheral edoema, and dizziness were the most frequent (20%) adverse reactions experienced by patients.
Reduced phosphate, reduced lymphocytes, reduced leukocytes, reduced platelets, elevated alanine aminotransferase, and reduced neutrophils were the most prevalent Grade 3 or 4 laboratory abnormalities (10%).
It is advised to take 13.5 mg of pemigatinib once daily until the disease progresses or there is intolerable toxicity.