ncyte (Nasdaq:INCY) announced that the Japanese Ministry of Health, Labour and Welfare (MHLW) has approved Pemazyre^® (pemigatinib), a selective fibroblast growth factor receptor (FGFR) inhibitor, for the treatment of myeloid/lymphoid neoplasms (MLNs) with FGFR1 fusion (also known as 8p11 myeloproliferative syndrome). MLNs are a rare, aggressive group of cancers characterized by an over-production of myeloid cells, or bone tissue, with the tendency to rapidly progress to an acute myeloid leukemia (AML).

“The MHLW approval of Pemazyre in MLNs is an important step toward potentially providing a therapeutic option for Japanese patients with this rare condition,” said Lothar Finke, M.D., Ph.D., Group Vice President and General Manager, Incyte Asia. “Bringing this first and only approved therapy to MLN patients in Japan demonstrates Incyte’s commitment to finding solutions for critical unmet medical needs regardless of the size of the patient population – as is the case with MLNs, an extremely rare disease that is estimated to affect fewer than 100 patients worldwide.”

The approval was based on data from the Phase 2 FIGHT-203 study, a multicenter open-label, single-arm trial that evaluated the safety and efficacy of Pemazyre in 41 patients in myeloid or lymphoid neoplasms with FGFR1 fusion gene positive who received Pemazyre 13.5 mg orally once daily continuously or intermittently. The primary endpoint, investigator-assessed complete response rate, was 62.5% (95% CI: 45.8 - 77.3). The complete response rate in the continuous dosing population was 66.7% (95% CI: 46.0 - 83.5). The most common adverse reactions observed in patients receiving Pemazyre were hyperphosphatemia (70.7%), alopecia (56.1%), diarrhea (43.9%) and stomatitis (43.9%).

Previously, the MHLW granted Orphan Drug Designation (ODD) for Pemazyre – a designation granted to investigational compounds intended to treat rare diseases that affect fewer than 50,000 people in Japan, and for which there is a high medical need¹. Designated orphan drugs are also eligible for priority review for marketing authorizations to ensure supply to clinical settings at the earliest opportunity¹. The MLN ODD is the second such designation granted to Pemazyre by the MHLW, having also received ODD for cholangiocarcinoma, a type of biliary tract cancer.

MLNs with FGFR1 rearrangement are a form of very rare hematological cancers caused by a chromosomal abnormality (translocation) in which the chromosome breaks where the FGFR1 gene is located (position 11 in the short arm of chromosome 8: location 8p11) and fuses with fragments (genes) of other chromosomes. Various partner genes cause a constitutive activation of the FGFR1 tyrosine kinase, impacting cell proliferation and survival. These cancers are largely divided into two phases according to clinical presentation: the chronic phase, if diagnosed as myeloproliferative disorder or myelodysplastic syndrome, or acute phase, if diagnosed as acute leukemia. The prognosis is unfavorable, and while allogenic hematopoietic stem cell transplant is considered to be the only currently available treatment option that may achieve cure or long-term remission, no standard of care has been established.