Pralsetinib, known by its brand name Gavreto, is a prescription medication used in the treatment of certain cancers. It is a targeted therapy, working as a kinase inhibitor to block specific enzymes that play a role in cell growth and proliferation. This offers a more precise approach to fighting cancer compared to traditional treatments.
Mechanism of Action
Targeted therapies like pralsetinib differ from traditional chemotherapy by focusing on specific molecules involved in cancer growth, rather than broadly attacking fast-growing cells. Pralsetinib functions as a highly selective inhibitor of the RET (rearranged during transfection) receptor tyrosine kinase. The RET gene normally produces a protein involved in cell signaling and development.
However, alterations in the RET gene, such as fusions or mutations, can lead to the production of abnormal RET proteins. These faulty proteins send uncontrolled signals that drive cancer cells to grow and multiply. Pralsetinib works by binding to and blocking these aberrant RET proteins, effectively turning off the growth signals, which helps to slow or stop cancer progression.
Medical Uses
Pralsetinib is approved for treating specific types of cancer in patients with confirmed RET gene alterations. It is used for adults with metastatic RET fusion-positive non-small cell lung cancer (NSCLC).
The medication is also indicated for advanced or metastatic RET-mutant medullary thyroid cancer (MTC) in adults and pediatric patients 12 years of age and older who require systemic therapy. Additionally, it treats advanced or metastatic RET fusion-positive thyroid cancer in adults and pediatric patients 12 years of age and older who require systemic therapy and are radioactive iodine-refractory, if radioactive iodine is appropriate. Patients must undergo specific testing to confirm these RET gene alterations before treatment.
Administration and Dosing
Pralsetinib is an oral medication taken as capsules, typically once daily. It is generally advised to take the dose on an empty stomach, meaning at least one hour before or two hours after a meal. This helps ensure proper absorption of the medication into the body.
A healthcare professional determines the exact dosage, which may be adjusted based on the patient’s individual response to treatment and any side effects that might develop. If a dose is missed on the same day, it should be taken as soon as remembered. If it is close to the time for the next scheduled dose, the missed dose should be skipped, and the regular dosing schedule resumed. Do not take two doses at once.
Potential Side Effects
Patients taking pralsetinib may experience various side effects. Common side effects often include constipation, high blood pressure (hypertension), general fatigue, and musculoskeletal pain.
More serious side effects can also occur during treatment. These include lung problems such as pneumonitis, an inflammation of the lungs that can cause scarring. Liver toxicity is another concern, potentially leading to elevated liver enzymes. Severe high blood pressure can also arise, necessitating close monitoring and management.
Pralsetinib carries a risk of bleeding events, ranging from minor to severe hemorrhages. Patients should report any unusual bruising or bleeding promptly. Other serious but less common effects include wound healing complications, where surgical wounds might heal slowly, and tumor lysis syndrome, which can occur if a large number of cancer cells are rapidly destroyed. Patients should communicate any new or worsening side effects to their healthcare team without delay.
Important Patient Considerations
Before beginning treatment with pralsetinib, patients should have a thorough discussion with their doctor about their complete medical history. It is important to disclose any pre-existing conditions, including a history of lung disease, liver problems, or high blood pressure. Patients should also inform their doctor if they are pregnant, planning to become pregnant, or breastfeeding, as pralsetinib can cause harm to an unborn baby or nursing infant.
Pralsetinib can interact with other medications, potentially affecting its effectiveness or increasing the risk of side effects. Patients should provide their healthcare team with a complete list of all prescription and over-the-counter drugs, as well as any vitamins, herbal remedies, or supplements they are currently taking. Certain medications, such as strong CYP3A4 inhibitors or inducers, may require dose adjustments or avoidance.
Regular monitoring is a necessary part of treatment. Patients will require periodic check-ups, which typically include regular blood pressure measurements to manage hypertension risks. Blood tests will also monitor liver function for any signs of liver toxicity. Adhering to these appointments and tests is important for effective management.