On August 26, 2022, the FDA accelerated the approval of pemigatinib (Pemazyre; Incyte), a tyrosine kinase inhibitor, for the treatment of relapsed or refractory myeloid/lymphoid neoplasms (MLNs) with FGFR1 rearrangements in adults. Pemigatinib received a breakthrough therapy designation for this indication.
Pemigatinib was previously approved for unresectable, locally advanced or metastatic cholangiocarcinoma with FGFR2 fusion or other rearrangements.
The new indication was approved based on results of the multicenter, open-label, single-arm FIGHT-203 clinical trial of 28 adults with relapsed or refractory MLNs and FGFR1 rearrangements. Eligible patients were either not candidates for or had disease relapse after undergoing an allogeneic hematopoietic stem-cell transplant or after receiving disease-modifying therapy.
The primary end point was complete response (CR). A total of 14 of the 18 (78%) patients with chronic-phase disease, regardless of extramedullary disease (EMD) status, achieved a CR (95% confidence interval [CI], 52%-94%). The median time to CR was 104 days (range, 44-435 days), and the median duration of response was not reached (range, 1-988 days). Of the 4 patients with blast-phase disease or without EMD, 2 had a CR (lasting 1-94 days), and 1 of the 3 patients with EMD reached a CR (lasting 64 days).
Of all the 28 patients, including 3 patients without morphologic disease, 22 (79%) patients had a complete cytogenetic response (95% CI, 59%-92%).
The most common (≥20%) adverse events 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.