What is Temsirolimus?

Temsirolimus is an intravenous medication administered to slow the progression of renal cell carcinoma (RCC), a common form of kidney cancer. The drug is usually given to patients once a week at a hospital or specialty cancer center until their symptoms subside. Temsirolimus has proven very effective in managing RCC, and many patients are able to avoid undergoing chemotherapy, radiation treatments, or kidney transplants. Since the drug can have negative side effects or react adversely with other medications, doctors take care when deciding if it is the best treatment option for specific patients.

RCC is generally a fast-growing cancer due to its ability to engage in efficient cell replication and quickly build blood vessels to feed the tumor. Kinase enzymes present in cancerous cells activate a chemical signal, called vascular endothelial growth factor (VEGF), that leads to the production of new blood vessels. Temsirolimus works by inhibiting the action of kinase enzymes, reducing their ability to activate VEGF. As a result, a tumor cannot continue to grow or spread as efficiently. In addition, ongoing treatments with temsirolimus can actually shrink an existing tumor over time.

A doctor usually administers temsirolimus directly into a vein in the arm, a process that takes about one hour. Over the course of the infusion, about 25 milligrams of the drug enter the bloodstream and travel to the tumor. Most patients receive infusions once a week indefinitely, or until doctors determine the cancer has moved into remission.

Mild side effects are common with temsirolimus use, as the drug can also inhibit the activity of healthy cells in the kidneys and bloodstream. Patients may experience loss of appetite, nausea, vomiting, and stomach pain shortly after receiving a dose of temsirolimus. Some people have chest pains and shortness of breath that worsen after physical activity. If a patient is allergic to temsirolimus, he or she may experience a severe skin rash, airway constriction, and heart complications that need to be addressed in an emergency room. Additionally, drugs used to control high blood pressure, insulin levels, or seizures may lead to adverse drug reactions if they are present in the body during temsirolimus infusions.

Most people do not experience severe side effects after receiving the drug, as their doctors take extensive precautions to avoid health problems. During treatment, doctors and nurses carefully monitor blood pressure and blood glucose levels to prevent possible complications. With regular treatments and frequent checkups with RCC specialists, many patients begin to recover from their symptoms within a few months.