Avastin

Avastin is the brand name for a chemotherapy drug called bevacizumab. It is manufactured by Genentech and is approved for treatment of several types of cancer.  Avastin is one of the most commonly used chemotherapy drugs for cancers like colorectal and non-small cell lung cancer. It is currently being tested mesothelioma treatment.

In early clinical trials, Avastin showed potential for extending the life expectancy of mesothelioma patients. However, there are some serious side effects beyond the typical nausea and fatigue chemotherapy patients often experience. Some studies even suggest Avastin may increase death rates, especially with certain drug combinations. More research is necessary to determine if Avastin is a safe and effective treatment for mesothelioma.

What is Bevacizumab?

Avastin, bevacizumab, is a chemotherapeutic agent approved by the FDA in 2004. Administered intravenously, the drug circulates in the bloodstream, and acts on tumors by inhibiting growth of blood vessels.  Avastin is only approved for use in certain types of cancer, although doctors can use discretion in prescribing it for other patients.

Approved uses include metastatic colorectal cancer, non-squamous non-small cell lung cancer, glioblastoma, metastatic renal cell carcinoma, cervical cancer, and some cases of epithelial peritoneal, fallopian tube, and ovarian cancers. Intravenous doses are given over a period of 60 to 0 minutes every two to three weeks.

How it Works

Most chemotherapy drugs work by being circulated through the blood, attacking any rapidly growing and dividing cells. This mostly targets fast-growing tumor cells, but simultaneously affects healthy cells. The result is he characteristic side effects of chemotherapy, like hair loss. While Avastin is called a chemotherapy drug, it works differently than most other chemotherapy drugs.

Avastin inhibits a process in tumors called angiogenesis. Angiogenesis is the growth of blood vessels supplying tumors with blood carrying oxygen and nutrients. By cutting off this process, it slows tumor growth. Eventually, the cancer cells begin to die, being starved of oxygen and nutrients. While this is an effective way to destroy the cancer, it is not specific to the tumor. The inhibition of angiogenesis can affect healthy systems, causing high blood pressure, coronary artery disease, and other complications.

Side Effects

As with other chemotherapy drugs, Avastin has possible side effects. However, side effects differ because this drug works in a different way. Also, there is increased potential for serious and severe side effects. The most common side effects of Avastin are nosebleeds, headaches, nasal congestion, high blood pressure, excessive protein in the urine, changes in ability to taste, back pain, dry skin, peeling skin, and rectal hemorrhage.

Avastin comes with several warnings and precautions because it can cause serious adverse effects in some patients. Some side effects are listed in a black box warning, the FDA’s most serious warning label. These serious side effects include gastrointestinal perforation, occurring in over three percent of patients treated with Avastin. Other serious side effects include bleeding and difficulty healing which can be potentially fatal.

Avastin for Mesothelioma – Ongoing Trials

Several years after Avastin was approved by the FDA, researchers began serious investigations into how this drug might help patients with mesothelioma. Some studies have found little improvement in patients when including Avastin in combination with cisplatin and gemcitabine. Others show the introduction of Avastin can help patients. This research includes a case study in which a man with peritoneal mesothelioma did not respond well to other treatment regimens, but saw marked improvement with Avastin.

Clinical trials using Avastin in mesothelioma patients have been conducted with mixed results. These include studies combining Avastin with pemetrexed and cisplatin, combining it with Tarceva, and comparing combinations of chemotherapy drugs including Avastin to the same combinations without Avastin. All of these have been conducted with participating mesothelioma patients.

The Risk of Death

There have been many clinical trials using Avastin, either alone or in combination. From a meta-analysis of several of these, researchers discovered a disturbing trend. There is a serious risk of death when Avastin is combined with more standard chemotherapy drugs. The results of the meta-study were published in 2011 and showed the risk of death was serious.

The analysis included more than 10,000 patients in clinical trials. While fatalities were uncommon, they did prove a trend. 2.5 percent of patients who received Avastin died compared to 1.7 percent of patients not receiving Avastin. The increase is significant when comparing deaths among patients who received Avastin in combination with other chemotherapy drugs to those who did not. The death rate tripled for those who received Avastin. The most common cause of death was hemorrhaging, followed by infections and gastrointestinal perforations.

Researchers ultimately concluded that, for most patients, the risks of these potentially fatal side effects are outweighed by the benefits of combining Avastin with chemotherapy. They did point out, however, knowing the risks is important for patients and doctors.

Avastin is a targeted drug used like chemotherapy drugs and is often combined to help cancer patients. Many of these patients have undergone other treatments with limited success. These patients and are seeking an alternative despite the risks of serious adverse side effects. For mesothelioma patients, research is ongoing. However, Avastin may prove a novel treatment for this otherwise difficult cancer.