Panitumumab/ Vectibix Information

I have more information about this chemo that I'm on and I think it's interesting and helpful so I'd like to pass on what I've learned.

When I first tried it in February I had a severe toxic reaction and couldn't continue after only one treatment. We then tried the oral chemo which I've forgotten the name of, sorry, and it not only didn't help, I developed one more tumour while on it for a total of four in my left lung now. So we decided to try the Panitumumab again as my tumour had been tested and it is effective. I don't know if this is typical but in the city near us the tumours are kept in the basement of one of the hospitals for things like this.

So, on to the chemo. With panitumumab it's typical to get a rash on the face, scalp, and upper torso. The severity of the rash is indicative of how well the chemo is working. It looks bad and is difficult to hide even with make up as it's lumpy but it's not a terrible thing to have. And the worse the rash is the better it's working. There can be some additonal side effects such as nausea, fatigue, other skin issues, and some odd hair growth such as long eyelashes. This depends on the patient, like all chemos. For me, I've had all of them execpt the eyelashes so far but my over plucked eyebrows are starting to come back after all these years. 

I now know that the reason the rash is indictaive of how well the chemo is working is because it works by seeking out a protein that the tumours contain and then 'telling' the body to attack that area. The skin also contains smaller amounts of this protein so it is attacked as well to a much lesser degree. 

Which brings us to the fact that this is an immunotherapy drug. Panitumumab is a newer chemo, not a traditonal chemo, and is immunotherapy, which is the future of chemo drugs. Instead of being pumped full of poison in the hope that some will kill enough of the cancer cells, it targets the tumours and tells the body to attack it. It ramps up the immune system to get the job done. Which is why it's also not a chemo that makes the patient vulnerable to other illness like the traditional ones do. No worrying about not touching door handles and things like that.

Because it is an immunotherapy drug, it does not seem to be subject to the cancer becoming impervious to it. This can happen with traditional chemos. The cancer, like a virus, can change itself and become immune to the chemo that's previouslybeen effective against it. At the cancer centre I go to they've never seen it happen with immunotherapy drugs and the scientists think it won't because it's the body fighting the cancer, not the chemo itself.

Another thing I found interesting is that it's dosage based. I started out at 75% dose and after a few treatments was wondering why I wasn't being bumped up to 100% and was worried that it was because of my previous overreaction and that it wouldn't be as effective at 75%. I found out that it's based on body mass so I'll never be at 100%. I might even have to go down to 70% because I've lost weight the last two times I've been there. As long as I have a good rash on my face it shows it's working.

The down side, unfortunately, is that not every colon cancer will be affected by it. The cancer has to have the protein for it to work and only 50% of patients have the protein in their colon cancer. So it is not for everyone. But they are coming up with new immunotherapy drugs all the time and they believe there will be a new one for people who don't have the protein in a year or so. Our cancer centre receives an average of over a hundred new drugs to try every year for cancer patients. Not all of them work but many are working and are becoming the new go to drug for various cancers. 

I've read often about how immunotherapy drugs are the future of cancer treatments until there's something better. It makes sense since, from what I understand, the problem with cancer is that the body doesn't fight it, it doesn't recognise it as being something to fight. These drugs make it do so.

I've posted this in the hope it will help someone else on here. If I've missed something or am lacking some information, please do add to this. I am glad to know more about what is being pumped into me every two weeks. And I like the idea that my own body is doing the work. And I only had one poke for the IV yesterday! Last time it was four because I have small veins. 

Jan