Balversa (erdafitinib) is a kinase inhibitor that may be a treatment option for adult patients with certain forms of locally advanced or metastatic bladder cancer.1 It is recommended for use in select cases that have:
- Susceptible fibroblast growth factor receptor FGFR3 or FGFR2 genetic alterations, and
- Gotten worse during or after treatment with certain chemotherapy that contains platinum
What is an FGFR inhibitor?
Erdafitinib is an oral pan-fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitor. FGFRs are a family of receptor tyrosine kinases which may be genetically altered in certain cases of bladder cancer, and treatments that target these genetic alterations can help treat bladder cancer in some patients.1
How does erdafitinib work?
FGFR, fibroblast growth factor receptors, are thought to have a role in cancer growth and development in some types of cancer cells. Erdafitinib, an FGFR kinase inhibitor, blocks the action of FGFR. This could slow down or stop tumor cells dependent on this growth factor to replicate. Around 20% of recurring or refractory bladder cancers have the FGFR mutation which may respond to treatment with an FGFR inhibitor.1,2
What are the possible side effects of erdafitinib?
The most common side effects of erdafitinib include:1
- Change in kidney or liver function
- Constipation or diarrhea
- Dry mouth and/or mouth sores
- Stomach pain, nausea, decreased appetite
- Increased levels of phosphate or decreased levels of sodium in the blood
- Changes in nail appearance
- Dry skin, dry eyes
- Low red blood cell counts (anemia)
- Hair loss
- Muscle pain
- Hand-foot syndrome: the swelling, peeling, redness, or tenderness of the hands and feet
If you are pregnant, plan to become pregnant, or are breastfeeding or plan to breastfeed, talk with your doctor. Erdafitinib can cause harm to a developing fetus and should not be taken by women who are pregnant. While taking erdafitinib, males with female partners who can become pregnant, and females who can become pregnant, should both use contraceptives during treatment and for a period of time after completing treatment (patients should discuss appropriate birth control methods, and how long they need to use them, with their doctor). Females should not breastfeed during erdafitinib treatment and for a period of time following the final dose (patients should discuss breastfeeding considerations with their doctor).
This is not an exhaustive list of all potential side effects of erdafitinib. Talk to your healthcare provider or pharmacist for further information.
Things to know about erdafitinib
Erdafitinib is the first FGFR kinase inhibitor to receive US FDA approval.3 When the FDA approved erdafitinib, it simultaneously approved a companion diagnostic tool to help identify the subgroup of people most likely to benefit from the drug. That’s designed to create a more personalized treatment approach.3
The diagnostic kit is QIAGEN therascreen®. It detects the presence of FGFR in tumor tissue of people with metastatic urothelial cancer. If present, the patient may be a candidate for treatment with erdafitinib.1-3
Erdafitinib and eye problems
Erdafitinib can cause ocular disorders (problems with your eyes), including central serous retinopathy (CSR) that’s characterized by retinal pigment epithelial detachment (RPED) resulting in visual field defects.1,3 Monthly eye exams should be performed during the first 4 months of treatment with erdafitinib, and every 3 months afterward. Eye exams should include evaluation of visual acuity- how well you see at various distances, a slit lamp examination- a microscope with a bright light used to look at different structures at the front of and inside the eye, fundoscopy- a magnifying lens and light used to examine the fundus of the eye including the back of the inside of the eye, the retina and optic nerve, and OCT optical coherence tomography- a non-invasive diagnostic technique to look at the retina. Talk to your healthcare provider immediately if you notice changes in vision.
Erdafitinib can also cause hyperphosphatemia, an abnormally high serum phosphate concentration (greater than 4.5 mg/dL). It can be caused by increased phosphate intake, decreased phosphate excretion, or associated with an underlying disease such as bladder cancer that can have increased phosphate values.1
Patients taking erdafitinib should talk to their doctor about any other medications (prescription and over-the-counter), herbal remedies, and any supplements they are taking, as well as any other health conditions. Patients should take their medication as prescribed by their doctor. Patients should talk to their doctor if they have any questions, or if they have questions regarding their erdafitinib regimen.