On August 26, 2022, the U.S. Food and Drug Administration (FDA) approved pemigatinib (Pemazyre®) for adults with relapsed or refractory myeloid or lymphoid neoplasms (MLNs) with fibroblast growth factor receptor 1 (FGFR1) rearrangement.
Efficacy was evaluated in FIGHT-203 (NCT03011372), a multicenter, open-label, single-arm trial that included 28 patients with relapsed or refractory MLNs with FGFR1 rearrangement. Eligible patients were either not candidates for or had relapsed after allogeneic hematopoietic stem cell transplantation (allo-HSCT) or after a disease-modifying therapy (e.g., chemotherapy). Pemigatinib was administered until patients experienced disease progression or unacceptable toxicity or were able to receive allo-HSCT.
The study patients’ median age was 65 years (range = 39–78), and 68% were White, 64% female, 11% Asian, 3.6% Black or African American, and 3.6% American Indian/Alaska Native. Eighty-eight percent of patients had an ECOG Performance Status Scale score of 0 or 1.
Efficacy was established based on complete response (CR) rates per the response criteria relevant to the morphologic disease type. Of the 18 patients in the chronic phase with or without extramedullary disease (EMD), 14 achieved CR (78%; 95% CI = 52, 94). The median time-to-CR was 104 days (range = 44–435). The median duration was not reached (range = 1+–988+ days). Of the 4 patients in the blast phase with or without EMD, 2 achieved CR (duration = 1+ and 94 days). Of the 3 patients with EMD only, 1 achieved a CR (duration = 64+ days). For all 28 patients (including 3 patients without evidence of morphologic disease), the complete cytogenetic response rate was 79% (n = 22; 95% CI = 59, 92).
The most common adverse reactions reported in at least 20% of patients in the drug’s clinical trial were hyperphosphatemia, nail toxicity, alopecia, stomatitis, diarrhea, dry eye, fatigue, rash abdominal pain, anemia, constipation, dry mouth, epistaxis, serous retinal detachment, extremity pain, decreased appetite, dry skin, dyspepsia, back pain, nausea, blurred vision, peripheral edema, and dizziness.
The most common grade 3 or 4 laboratory abnormalities reported in at least 10% of patients in the clinical trial were decreased phosphate, decreased lymphocytes, decreased leukocytes, decreased platelets, increased alanine aminotransferase, and decreased neutrophils.
The recommended dose of pemigatinib is 13.5 mg orally once daily until patients experience disease progression or unacceptable toxicity.
The application was granted priority review and breakthrough designation. A description of FDA expedited programs is in the Guidance for Industry: Expedited Programs for Serious Conditions-Drugs and Biologics. The application also was granted orphan drug designation.
Healthcare professionals should report all serious adverse events suspected to be associated with the use of any medicine and device to FDA’s MedWatch Reporting System or by calling 800-FDA-1088.