Bortezomib, known by its brand name Velcade, is a targeted therapy drug used in cancer treatment. It is designed to interfere with specific processes inside cancer cells, unlike traditional chemotherapy that affects all rapidly dividing cells. This medication is prescribed for adults to treat certain blood cancers and is classified as a first-generation proteasome inhibitor. It can be used alone or with other anti-cancer drugs.
Medical Uses of Bortezomib
Bortezomib is primarily used to treat two types of blood cancer: multiple myeloma and mantle cell lymphoma (MCL). Multiple myeloma is a cancer of plasma cells, a type of white blood cell in the bone marrow. In this condition, abnormal plasma cells are produced, which can crowd out healthy blood cells.
The drug is approved for treating multiple myeloma in previously untreated patients and in those whose cancer has worsened after at least one prior therapy.
Mantle cell lymphoma is a rare non-Hodgkin lymphoma starting in lymphocytes. In MCL, abnormal lymphocytes interfere with healthy blood cell production. Bortezomib is used for previously untreated adults with MCL who are not eligible for a blood stem-cell transplant.
Mechanism of Action
Bortezomib is a proteasome inhibitor, targeting a cellular component called the proteasome. Proteasomes act as the cell’s recycling system, breaking down and removing unnecessary or damaged proteins to allow for normal cell function. By blocking proteasomes, bortezomib disrupts this waste-management process.
This blockage causes unwanted proteins to accumulate inside the cancer cell, which becomes toxic. This buildup disrupts multiple signaling pathways and triggers programmed cell death, known as apoptosis. Cancer cells are more susceptible to proteasome inhibition than normal cells, allowing the drug to selectively target them.
Studies have shown that bortezomib can improve progression-free survival in patients with multiple myeloma, especially when used with other therapies. The drug’s ability to induce cell death through this pathway makes it an effective treatment for these malignancies.
Administration and Dosing
Bortezomib is administered by a healthcare professional in a hospital or clinic. It can be given as a subcutaneous injection under the skin in the thigh or abdomen, or as an intravenous injection into a vein. The choice of administration route depends on the treatment plan and patient factors.
Treatment is organized into cycles, involving drug administration on specific days followed by a rest period. A common schedule for the drug used alone involves injections twice a week for two weeks, followed by a 10-day rest period, completing a 21-day cycle. Patients may undergo several cycles depending on their condition and response to treatment.
The dose is calculated based on the patient’s body surface area, which considers both height and weight. The prescribed dose and number of cycles can vary if bortezomib is given with other cancer drugs. A physician determines the final dosing and schedule.
Common Side Effects and Management
A frequently reported side effect is peripheral neuropathy, which is nerve damage that can cause numbness, tingling, weakness, or pain in the hands and feet. If neuropathy develops, a doctor may adjust the dose or change the administration from intravenous to subcutaneous to reduce its severity.
Gastrointestinal problems are common, including nausea, diarrhea, vomiting, and constipation. These symptoms can be managed with medications, dietary adjustments, and other supportive care.
Fatigue and weakness are also prevalent side effects that can impact daily life. Scheduling rest and prioritizing activities can help manage energy levels during treatment.
Bortezomib can impact blood cell counts, causing thrombocytopenia (low platelets), which increases the risk of bleeding and bruising. It can also lead to low white blood cell counts, increasing infection susceptibility. Regular blood tests are performed to monitor these levels, and treatment may be paused or the dose adjusted if they become unsafe.
Serious Health Warnings
Bortezomib can be associated with severe health complications requiring immediate medical attention. Heart problems, including the development or worsening of heart failure, can occur. Symptoms like shortness of breath, swelling in the ankles or feet, or a rapid heartbeat should be reported to a healthcare provider immediately.
Serious lung conditions, such as acute respiratory distress syndrome, have been reported. Any new or worsening cough, shortness of breath, or difficulty breathing should be evaluated by a doctor.
Liver problems can also arise and may be detected through blood tests. Symptoms such as yellowing of the skin or eyes, or pain in the upper right abdomen, warrant immediate medical consultation.
Two other rare but serious conditions are tumor lysis syndrome (TLS) and posterior reversible encephalopathy syndrome (PRES). TLS is a metabolic complication from the rapid death of cancer cells, while PRES is a neurological disorder causing headaches, seizures, and vision loss. Both are medical emergencies requiring urgent treatment.