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al from Canada · 01-14-2006, 08:19 PM

Just to clarify.....95% of the studies on AVASTIN have been done on HER2 (-) patients. AVASTIN targets VEGF which may be over-expressed, or not at all, as is HER2, in a variety of cancers. All these cancers are different. For example, lung cancer can be HER2 positive but herceptin has no effect in lung cancers. Why??? They don't know but....

What we do Know as a result of study information revealed at SABCS by Dr. Slamon himself; that 70% of HER2 cancers also are also over-expressed VEGF; and that a study from a relatively small sampling of HER2 patients has demonstarted that AVASTIN has clear anti-tumour activity IN HER2 POSITIVE BC patients...enough so that when questioned at a discussion forum. he stated that adding avastin to herceptin in HER2 patients was their best shot at maximizing treatment, and by adding xeloda, even better.

What else you have to know is that these conclusions on avastin not working in BC are a result of critical errors in study design. Yes, avastin + xeloda didn't work but they were done in the general BC population. Assume that only 30% of that population was HER2 + and only 70% of that 30% was VEGF + then of course you will get lousy results. You also can't discount Kathy Millar's work on AVASTIN + TAXOL (E-2100) which showed a dramatic response.

One of the best expamples of this was with IRESSA, which is a HER1 antangonist. The sampling in which iressa was tested was far too large therefore it was never approved for BC. Many oncologists have seen the flaw in this study design and are starting to prescribe iressa off-label for things like brain mets in HER2 disease. Other more recent studies unvealed at SABCS show a high level of activity beween herceptin and iressa. Dr. Slamon himself talked about the importance of study design in order to properly target these designer drugs and get approvals. He stated that if herceptin. which was designed for HER2 BC, were tested in the general population, that is all BC patients, the drug that is so revered by all of us, would never have gotten FDA approvals.

We all have to make our own decisions given the available information BUT, just make sure you read the information accurately.

This is my last word on this topic,
Al

01-14-2006, 08:19 PM	#5
al from Canada Senior Member Join Date: Jul 2005 Location: Ontario, Canada Posts: 722	HER2 - VEGF correlation Just to clarify.....95% of the studies on AVASTIN have been done on HER2 (-) patients. AVASTIN targets VEGF which may be over-expressed, or not at all, as is HER2, in a variety of cancers. All these cancers are different. For example, lung cancer can be HER2 positive but herceptin has no effect in lung cancers. Why??? They don't know but.... What we do Know as a result of study information revealed at SABCS by Dr. Slamon himself; that 70% of HER2 cancers also are also over-expressed VEGF; and that a study from a relatively small sampling of HER2 patients has demonstarted that AVASTIN has clear anti-tumour activity IN HER2 POSITIVE BC patients...enough so that when questioned at a discussion forum. he stated that adding avastin to herceptin in HER2 patients was their best shot at maximizing treatment, and by adding xeloda, even better. What else you have to know is that these conclusions on avastin not working in BC are a result of critical errors in study design. Yes, avastin + xeloda didn't work but they were done in the general BC population. Assume that only 30% of that population was HER2 + and only 70% of that 30% was VEGF + then of course you will get lousy results. You also can't discount Kathy Millar's work on AVASTIN + TAXOL (E-2100) which showed a dramatic response. One of the best expamples of this was with IRESSA, which is a HER1 antangonist. The sampling in which iressa was tested was far too large therefore it was never approved for BC. Many oncologists have seen the flaw in this study design and are starting to prescribe iressa off-label for things like brain mets in HER2 disease. Other more recent studies unvealed at SABCS show a high level of activity beween herceptin and iressa. Dr. Slamon himself talked about the importance of study design in order to properly target these designer drugs and get approvals. He stated that if herceptin. which was designed for HER2 BC, were tested in the general population, that is all BC patients, the drug that is so revered by all of us, would never have gotten FDA approvals. We all have to make our own decisions given the available information BUT, just make sure you read the information accurately. This is my last word on this topic, Al __________________ Primary care-giver to and advocate for Linda, who passed away April 27, 2006.