FDA OKs First Targeted Agent, Pemigatinib, for Rare Blood Cancer FDA OKs First Targeted Agent, Pemigatinib, for Rare Blood Cancer

The US Food and Drug Administration (FDA) has approved pemigatinib (Pemazyre), a selective fibroblast growth factor receptor inhibitor, for adults with relapsed or refractory myeloid/lymphoid neoplasms with FGFR1 rearrangement.

The approval follows priority review of a supplemental New Drug Application submitted by the drug maker, Incyte, and marks the second indication for pemigatinib. The drug previously received accelerated FDA approval in 2020 for adults with previously treated, unresectable locally advanced or metastatic cholangiocarcinoma with FGFR2 fusion or other rearrangement.

Myeloid/lymphoid neoplasms (MLNs) with FGFR1 rearrangement are rare and aggressive blood cancers that affect fewer than 1 in 100,000 people in the US, the company explains in a press release, noting that the pemigatinib is the first and only available targeted treatment for this condition.

“The approval of Pemazyre represents an important treatment advancement for people living with MLNs with FGFR1 rearrangement who currently have limited treatment options,” Incyte’s CEO Hervé Hoppenot, says in the press release.

The FDA’s decision was based on data from the multicenter, open-label, phase 2 FIGHT-203 study of 28 patients with relapsed or refractory MLNs with FGFR1 rearrangement who relapsed after allogeneic hematopoietic stem cell transplantation (HSCT) or after a disease-modifying therapy, or who were not a candidate for those treatments. Interim study results were published in the journal Blood last November.

According to Incyte, the final results showed an overall complete response rate of 79%. Among 18 patients with chronic phase involvement of the bone marrow with or without extramedullary disease, 78% achieved a complete response. In addition, 2 of 4 patients with blast phase in the marrow with or without extramedullary disease achieved a complete response, as did 1 of 3 patients with only extramedullary disease.

The high rate of complete responses in these patients “is clinically meaningful, especially in light of the lack of these specific responses with existing first-line treatments,” principal investigator Srdan Verstovsek, MD, PhD, of the University of Texas MD Anderson Cancer Center, Houston, says in the release.

The study participants received pemigatinib 13.5 mg once daily in 21-day cycles, either on a continuous schedule or on an intermittent schedule with 14 days on, 7 days off, until disease progression or unacceptable toxicity, or until patients were eligible to receive allogeneic HSCT.

The continuous dosing schedule is the approved recommended starting dosage for use in patients with MLNs with FGFR1 rearrangement.

Common adverse events included hyperphosphatemia (74%), nail toxicity (62%), alopecia (59%), stomatitis (53%), diarrhea (50%), dry eye (50%), fatigue (44%), rash (35%), abdominal pain (35%), anemia (35%), constipation (32%), and xerostomia/dry mouth (32%). In 20 patients receiving the recommended continuous dose, adverse reactions requiring dosage interruption occurred in 80% of patients.

Incyte encourages reporting of negative side effects to MedWatch or by calling 1-800-FDA-1088 or the company at 1-855-463-3463.

Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape, MDedge, and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at  sworcester@mdedge.com  or on Twitter:  @SW_MedReporter

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