Site Catalyst FDA Advisors Vote Unanimously That Avastin Approval Should Be Withdrawn, And You Could Hear The Pain
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FDA Advisors Vote Unanimously That Avastin Approval Should Be Withdrawn, And You Could Hear The Pain

by Dr. Len June 29, 2011

The votes are in, and the Food and Drug Administration's Advisory Committee said unanimously that the approval of Avastin (bevacizumab) for the treatment of metastatic breast cancer should be withdrawn.

 

The decision did not go down quietly, with women loudly voicing their disagreement, and one saying that this shouldn't be happening in the United States of America. I could not sit there and hear the cries without feeling their pain and anguish.

 

But the FDA advisors were very clear in their assessment: despite treating thousands of women, there was no group of women who appeared to benefit from the drug.  The side effects are real and the potential harms significant, and to have the drug remain on the market could mean that many  women would continue to be exposed to the drug and possibly die as a result, without hope of true benefit.

 

As one might anticipate, that did not sit well with the survivors in the audience and their supporters.  In a response which anticipated the protest, one of the advisory committee members implored women to look carefully at the evidence and realize that the data from the trials did not support their belief that Avastin saved their lives. Yesterday, another advisor said doctors who led their patients believe that Avastin saved their lives did a disservice to those women since the evidence did not support that conclusion.

 

That's a tough sell for a survivor.  And it may be a tough sell for some experts as well, such as the breast cancer guideline panel at the National Comprehensive Cancer Network who made it clear at a recent meeting in March that they were unanimously of the opinion that Avastin benefits women with metastatic breast cancer.

 

How can such knowledgeable scientists come to such different conclusions? 

 

This isn't the first time such an event has occurred in the annals of cancer detection and treatment.  Issues such as screening mammography, PSA testing and CT colonography for the early detection of colon polyps and cancer come to mind.

 

The real question is how to deal with this conundrum, and how best to protect the interests of the public and the concerns of those women who were present at the hearing and those they represented.

 

This is not the final decision regarding Avastin.  The docket will remain open for several more weeks in July to receive comments from anyone who is interested in sending them to the FDA.  Then the FDA Commissioner will make the final decision.  When that will happen is uncertain, but the hearing officer made clear the FDA is aware that many are awaiting that announcement.

 

In the meantime, it is important to remember that FDA approval for the use of Avastin in the treatment of metastatic breast cancer has not yet been withdrawn.  Women currently on Avastin should have discussions with their oncologists, but likely will not stop the drug.  Insurers would be wise to continue to provide coverage for women currently on Avastin for breast cancer and understand that approval is still in place. And people with other cancers should realize that today's recommendation does nothing to change the approval for their treatment if they are receiving Avastin.

 

The FDA's decision is not going to be an easy one.  It is our hope they will make that decision with full consideration of the science and the interests of the public, and the women who have been and will continue to be diagnosed with metastatic breast cancer. For them, this decision is more than academic--it is their lives, and it is understandable why they are upset.

 

Hopefully, wisdom will prevail.

Comments

6/29/2011 5:04:41 PM #

Gregory D. Pawelski

For the FDA advisors to suggest there was no (sub) group of women who appeared to benefit from the drug seems appalling, because some subsets of women do appear to benefit from the drug. The difficulty is finding who those subsets are.

The side effects of Avastin are no different than the risks of other toxic chemotherapy agents for advanced cancer. As far as Avastin and its side effects are concerned, cancer patients may be taking doses of treatments that are possibly well in excess of what they need.

Writing in the Journal of Clinical Oncology, Dr. Ian Haines cites an emerging body of evidence showing that many cancer drugs may be just as effective and produce fewer side effects if taken over shorter periods and in lower doses.

He gave as one example, Avastin, the dose being used is 15 milligrams per kilogram of body weight, despite other research showing it may work with 3 milligrams per kilogram of body weight.

Genetech is proposing still another confirmatory trial. Fine. But without drug appoval yet. Their researchers have been looking for tests to help predict how patients will respond to Avastin.

I have suggested before, perhaps they should use something like the cell-based functional profiling platform (AngioRx Assay) to identify a potential targeted population of cancer patients that it thinks will benefit from Avastin, and then conduct a randomized clinical trial among this group.

The endpoints (point of termination) of genetic assays that look whether an individual has a particular mutation or amplification within the cell or a relatively small number of processes (pathways), and therefore tests for "theoretical" candidates for a particular targeted drug.

The endpoints of the functional profiling technique are expression of cell death, both tumor cell death and tumor associated endothelial (capillary) cell death, and examines not only for the presence of the molecular profile, but also for their fundtionality, for their interaction with other genes, proteins and processes occuring within the cell, and for their "actual" response (prospectively) to anti-cancer drugs.

They should have done this in the first place!

Gregory D. Pawelski

7/12/2011 4:04:30 PM #

Lung Cancer

It is hard to believe that when something has been proven to work for some, that is is taken away.  I am always surprised at the bureaucracy that makes decisions for products that made it to the market place with merit in the first place.  

Lung Cancer

7/19/2011 11:23:24 AM #

Gregory D. Pawelski

Many chemotherapy drugs, in addition to killing tumor cells, also fight angiogenesis. However, the anti-angiogenic effects of dose-dense therapy may be masked and marginalized by the way it is usually administered. The main targets of high-dose chemotherapy are presumed to be proliferating tumor cells. The main targets of low-dose chemotherapy are the endothelial cells of the growing vasculature of a tumor. In other words, chemotherapeutics are used as anti-angiogenic agents.

The process of angiogenesis is controlled by two distinct types of proteins, referred to as "angiogenic growth factors" and "angiogenesis inhibitors." Medical researchers have identified 19 angiogenic growth factors in the human body and 31 angiogenesis inhibitors. In a healthy body, a perfect balance of factors that promote and prevent angiogenesis is maintained. After cells become cancerous, the regulation of this balance is disturbed, stimulating the production of new blood vessels.

Targeted therapies, such as Avastin, were originally designed with the goal of replacing chemotherapy, to reduce the serious morbidities associated with standard high-dose chemotherapy. Although targeted therapies may be somewhat less toxic, most of them have been found to have very modest efficacy, at least when used as single agents in treating patients with advanced disease. They have therefore mainly been used in combination with standard chemotherapy or radiation protocols.

It is becoming more apparent to administer drugs to patients with certain types of cancer on a weekly schedule. The advantage of low-dose chemotherapy is the possibility of combining it with anti-angiogenic drugs as well as other types of targeted therapies, such as those that target specific signal-transduction molecules or with antitumor vaccines.

Blood vessel cells are less likely than tumor cells to become resistant to chemotherapy, so if cancer cells become drug resistant, these medicines should still be able to shrink tumors by destroying their blood supply. When administering both anti-tumor and anti-angiogenesis drugs, the endothelial cells (involved iin angiogenesis) are the first in the tumor to undergo cell death (apoptosis).

Adding Avastin, which only goes after VEGF-sensitive cancer cells, you need to go after other pro-angiogenic factors which can substitute for VEGF: FGF, PDGF, ephrin A1, angioprotein 1, IL-8, etc. And with Taxol promoting an increase of IL-8, how effective is it with Avastin? With the low-dose protocol having an anti-angiogenic effect, you really wouldn't need to add a drug like Avastin into the mix.

Gregory D. Pawelski

7/25/2011 8:02:49 AM #

Dan Spinato

It is hard to believe that when something has been proven to work for some, that is is taken away.  I am always surprised at the bureaucracy that makes decisions for products that made it to the market place with merit in the first place.  

Dan Spinato

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About Dr. Len

Dr. Len

J. Leonard Lichtenfeld, MD, MACP - Dr. Lichtenfeld is Deputy Chief Medical Officer for the national office of the American Cancer Society.

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