Pemigatinib, known by its brand name Pemazyre, is a targeted cancer therapy that blocks specific proteins contributing to uncontrolled cancer cell growth and spread. This medication focuses on the molecular characteristics of certain tumors.
Cancers Treated by Pemigatinib
Pemigatinib treats specific cancers with particular genetic changes. It is used for cholangiocarcinoma, a bile duct cancer that has spread or cannot be surgically removed, especially when it has a fibroblast growth factor receptor 2 (FGFR2) gene fusion or other rearrangement. A diagnostic test confirms these genetic markers before treatment.
The medication also treats certain myeloproliferative neoplasms (MLNs), a group of blood cancers. It is indicated for MLNs that have relapsed or not responded to previous treatments and involve a fibroblast growth factor receptor 1 (FGFR1) rearrangement.
Understanding How Pemigatinib Works
Pemigatinib targets and inhibits Fibroblast Growth Factor Receptors (FGFRs), proteins on cell surfaces. Normally, FGFRs regulate cell growth, survival, and differentiation. In certain cancers, genetic alterations like fusions or rearrangements cause overactive FGFR signaling.
Overactive FGFRs continuously signal cancer cells to grow and divide. Pemigatinib, a kinase inhibitor, blocks these abnormal FGFRs. This interrupts signaling pathways that drive tumor cell proliferation and survival, slowing or stopping cancer spread.
Dosing and Administration
Pemigatinib is taken orally as a tablet. For cholangiocarcinoma, the typical dosing schedule involves taking 13.5 mg once daily for 14 consecutive days, followed by a 7-day break, completing a 21-day cycle. This cycle is repeated as long as the treatment is beneficial and side effects are manageable.
It is important to take the tablets whole without crushing, chewing, splitting, or dissolving them. The medication can be taken with or without food, but consistency in timing each day is advised. If a dose is missed by four or more hours, or if vomiting occurs after taking a dose, patients should not take an additional dose and should resume with the next scheduled dose.
Potential Side Effects and Management
Pemigatinib can cause various side effects. A frequent one is hyperphosphatemia, an elevated level of phosphate in the blood. This can be managed with dietary changes, like a low-phosphate diet, or with phosphate-lowering medications if levels exceed certain thresholds.
Gastrointestinal issues such as diarrhea, nausea, vomiting, and abdominal pain are also common. These symptoms can often be managed with supportive medications or by adjusting the treatment plan with a healthcare provider. Other common side effects include fatigue, hair loss, dry mouth, dry eyes, and nail changes. Patients should promptly report any visual changes, as eye problems like retinal pigment epithelial detachment (RPED) can occur, requiring ophthalmological evaluation and potential dose adjustments.