Clapper, Patti, Schweizer and Mason

A recently completed joint clinical study between the Massachusetts General Hospital and the University of Chicago investigated the effectiveness of Avastin (Bevacizumab) and Tarceva (Erlotinib) used as a combination treatment for malignant mesothelioma.  The trial was designed to determine whether or not these two drugs could add to traditional chemotherapy in treating this type of asbestos cancer and to what extent the addition would benefit mesothelioma patients. 

Janne Pasi, MD. PhD. of the Dana-Farber Cancer Institute oversaw the trials which collected randomized mesothelioma patients 18 years old or older who had previously been treated with some form of chemotherapy that did not include either Avastin or Tarceva.

During the three-year mesothelioma clinical trial, patients were administered monitored dosages of both drugs in addition to periodic testing with the overall goal of measuring the progression-free time enjoyed by patients and their overall life expectancy.  Additionally, researchers were concerned with the safety of the drug cocktail because it had never been used for these purposes before.  To that end, they closely monitored physical reactions and side effects reported by or observed in the study participants. 

Participants were tested using CT scans, MRI scans, and x-ray imaging every six weeks in order to (as accurately as possible) asses the state of their mesothelioma.  Other data was collected as well, including baseline bloodwork before treatment began and periodic bloodwork throughout the trial phase. 

Previously Bevacizumab has been used successfully in treating colorectal cancer, certain brain tumors, lung cancer, and renal cell cancer.  Bevacizumab is an antiangiogenic drug.  It works by slowing or stopping the growth of blood vessels in tumors.  This effectively starves cancerous cells of the nutrients they need to grow and survive.  It can, in some cases, effectively halt tumor growth and even cause cell death. 

It was, at one time, administered as a treatment for breast cancer.  However, the side effects associated with were deemed too detrimental and it is no longer generally used for that purpose.

Those side effects include creating holes, called ulcers, in the stomach or intestinal wall.  This can lead to serious complications, not the least of which is internal bleeding.  It can also affect the speed with which the body heals and slow closure of open wounds, etc.  Scientists were worried that these symptoms might arise in mesothelioma patients as well and make treatment with this drug more detrimental than beneficial.

Erlotinib, on the other hand, is generally used in combination with other chemotherapy drugs in patients who have failed to respond to treatment with other therapies.  It is a kinase inhibitor, which means that it stops the cell life cycle of cancerous cells by disrupting the protein signal system which tells them to grow and multiply. 

While the clinical trial has concluded, only preliminary results have been released.  It may take months before the full scope of the data has been analyzed and even longer for those conclusions to lead to decisive action.  However, because this was a Phase II clinical trial, the next likely step would be a Phase III trial sometime in the near future.

Source:  Bevacizumab (Avastin) and Erlotinib (Tarceva) in Previously Treated Mesothelioma