Funny that this comes out the day after GlaxoSmithKline's melanoma vaccine failed in phase III.[0]
Some science background on how these work. The idea is that some cancer types express specific proteins that can theoretically be targeted by your immune system, similar to how your immune system can target proteins from the Influenza virus. The goal of these vaccines is to make your immune system recognize this protein (called an antigen) and mount an immune response to kill all the cancer cells expressing the antigen (usually unique to tumour cells).
The problem is in inducing the immune response, usually these antigens don't mount strong immune responses so the attack is too slow relative to the rate that cancer cells divide and spread. Sometimes you also end up stimulating the wrong immune response, as the human immune response is quite complicated. In fact, tumors naturally stimulate inflammation and angiogenesis (immune responses) to spread! To make matters worse, some tumours even suppress the capability of immune cells to fight in the local area, rendering this vaccine useless.
The normal operating procedure for these vaccines is to remove some immune cells from the patient, cause them to become sensitive to a specific antigen, mix them with an immune system stimulant and inject them back into the patient. The ultimate goal of all of these methods is to improve the immunogenicity (ability of the vaccine to elicit an immune response) of vaccines, these guys are not making a new vaccine. Rather, this is just a new delivery method.
A very promising drug called Stimuvax by Merck which used liposomes (and had 100% regression in mice vs 50% in this study) to increase immunogenicity failed as well[1] so this should be taken with great caution, researches were overly optimistic on previous vaccines such as Stimuvax. Although the idea for the Harvard/Dana-Farber study is incredibly novel.
one dangerous thing is that most conventional cancer drugs cause immunosuppression (usually bone marrow suppression) so if you're taking these cancer vaccines you're going to be forgoing conventional treatments for the duration that you're on the vaccine. But if they have a higher success rate it would obviously be worth it; even if it has the same success rate since the vaccines would likely have less side effects.
This does not appear to be correct, while one might logically conclude that a drug causing suppression would negate the effects of adoptive immunotherapy this doesn't appear to be the case.
Recent research (see below) suggests that apoptosis from chemotherapy may actually strengthen the immune response. The same group also conducted pre-clinical trials and observed that immunotherapy directly after chemotherapy was significantly more effective than either group alone or immunotherapy before chemotherapy.
If you do a literature search for adoptive immunotherapy in immunosuppressed patients you will find more studies. The only contraindication appears to be in patients with completely eliminated immune systems, which rarely happens because of chemo.
cites two most relevant papers, one of which is specifically about the strategy to replace the chemotherapeutically depleted T cells with in vitro expanded ones, post chemotherapy. It's certainly possible, though, not enough studies have been conducted, and will probably depend on which chemotherapeutic compound is administering (small molecules tend to have differential spectra of activities). Doxycycline, in mice in at least one study was shown to have no particular effect on immunotherapeutic effect. Gemcitabine, which does do some immunosuppression but doesn't activate BER - so it only affects a subset of immune cells, does potentiate immunotherapies.
Some science background on how these work. The idea is that some cancer types express specific proteins that can theoretically be targeted by your immune system, similar to how your immune system can target proteins from the Influenza virus. The goal of these vaccines is to make your immune system recognize this protein (called an antigen) and mount an immune response to kill all the cancer cells expressing the antigen (usually unique to tumour cells).
The problem is in inducing the immune response, usually these antigens don't mount strong immune responses so the attack is too slow relative to the rate that cancer cells divide and spread. Sometimes you also end up stimulating the wrong immune response, as the human immune response is quite complicated. In fact, tumors naturally stimulate inflammation and angiogenesis (immune responses) to spread! To make matters worse, some tumours even suppress the capability of immune cells to fight in the local area, rendering this vaccine useless.
The normal operating procedure for these vaccines is to remove some immune cells from the patient, cause them to become sensitive to a specific antigen, mix them with an immune system stimulant and inject them back into the patient. The ultimate goal of all of these methods is to improve the immunogenicity (ability of the vaccine to elicit an immune response) of vaccines, these guys are not making a new vaccine. Rather, this is just a new delivery method.
A very promising drug called Stimuvax by Merck which used liposomes (and had 100% regression in mice vs 50% in this study) to increase immunogenicity failed as well[1] so this should be taken with great caution, researches were overly optimistic on previous vaccines such as Stimuvax. Although the idea for the Harvard/Dana-Farber study is incredibly novel.
[0]http://www.gsk.com/media/press-releases/2013/the-investigati... [1]https://en.wikipedia.org/wiki/Stimuvax