June/July 2020 – Cancer vaccine as an added strategy

As discussed in previous blogs, apart from the surgery I did in Germany, chemotherapy has been the principal weapon I have been relying on to fight my cancer. However, I have been keen to also consider other forms of therapies as long as I could be satisfied that no negative interaction with chemo might be created by taking any new drugs.

The metabolic approach proposed by the Care Oncology Clinic that I described in my February 2020 blog clearly falls in this category, since the drugs they recommend are very old, their side-effects are well understood and – as far as I understand – there is no known negative impact on the effectiveness of my chemo medications.

Since March, I have been doing further research to see whether there is anything else I could add to my armour and I bumped into the topic of so-called cancer treatment vaccines.

Cancer vaccines are a form of immunotherapy and are designed to “re-educate” the patient’s immune system to identify cancer cells as enemies and to try and kill them. As nicely set out in the following passage from the cancer.gov website (see https://www.cancer.gov/about-cancer/treatment/types/immunotherapy/cancer-treatment-vaccines):

“Cancer treatment vaccines are a type of immunotherapy that treats cancer by strengthening the body’s natural defenses against the cancer. Unlike cancer prevention vaccines, cancer treatment vaccines are designed to be used in people who already have cancer—they work against cancer cells, not against something that causes cancer.

The idea behind treatment vaccines is that cancer cells contain substances, called tumor-associated antigens, that are not present in normal cells or, if present, are at lower levels. Treatment vaccines can help the immune system learn to recognize and react to these antigens and destroy cancer cells that contain them.”

As far as I understand, the most straightforward cancer vaccines are so-called generic vaccines, which are made from specific tumour-associated antigens that are present in the cancer cells (and not in the healthy cells) of many patients.

As long as a patient expresses the antigen in question (which can be established by relying on a simple biopsy of the patient’s tumour), then the generic vaccine could generate the desired immune reaction. Intuitively, the higher the percentage of cancer cells containing the antigen, the higher the probability that the vaccine will be effective.

A much more complex type of vaccine is based on the patient’s specific tumour cells and related antigens. These so-called “personalised cancer vaccines” involve extremely data-intensive work and result in a vaccine that unlike the generic one is completely custom-made and, as such, should elicit a stronger response.

As explained in the royalmarsden.nhs.uk website, which recently summarised the results of an early trial for personalised cancer vaccines (see https://www.royalmarsden.nhs.uk/promising-signs-early-trial-personalised-cancer-vaccines):

“To produce the vaccine, samples of the tumour and blood are taken and run through an algorithm. This finds a part of the tumour that the body would recognise as ‘foreign’ and uses the information to create a vaccine that is unique for that patient. When given back to the patient, alongside the immunotherapy, it is hoped the body elicits an immune response, identifying and killing those cancer cells.”

After reading a bit more about this, I decided to discuss the issue with my oncologist during my March consultation with him. While alerting me to the experimental nature of cancer vaccines (and, therefore, the lack of any hard data in support of their effectiveness), he told me that he was fine with me trying them and even gave me the contact details of a Professor in Frankfurt, whom he rated highly.

I immediately got in touch with the Professor and she described two possible options:

1) a generic vaccine, called NY-ESO-1. As noted in a recent article by Afsheen Raza et al. (see https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-020-02306-y) “The promise of NY-ESO-1 as a candidate for specific immune recognition of cancer comes from its restricted expression in normal adult tissue but frequent occurrence in multiple tumors including melanoma and carcinomas of lung, esophageal, liver, gastric, prostrate, ovarian, and bladder.” The Professor explained that NY-ESO-1 is an antigen that appears to be capable of generating powerful immune responses and, to verify whether this could be useful for me, she told me that we would only need to check whether the cancer material removed in Heidelberg in 2019 expressed this antigen or not;

2) a fully personalised vaccine, which would be developed by analysing all the relevant mutations in my tumour. Being much more targeted than the generic vaccine, one would expect the personalised vaccine to be more effective than the generic one. But it would also be much more expensive and it would take around two months for the creation of any such vaccine to be completed.

The Professor’s recommended course of action was to start with the generic vaccine. She offered to get in touch with Heidelberg to get a couple of tumour blocks and to assess whether my cancer cells contain the required NY-ESO-1 antigen. If so, I would be able to get going with it relatively quickly. And I would need to travel to Frankfurt every two weeks to get the vaccine injected in my arm.

I agreed with the strategy and, after just a few weeks, I was told that I was a good candidate for the generic vaccine, since I apparently do express the NY-ESO-1 antigen!

So I happily agreed to travel from London to Frankfurt every two weeks, still in full Covid crisis, probably making me one of the most frequent air travellers in Europe of 2020! One may think that I must also be one of the craziest people in Europe to even consider doing something like this, given the risks associated with the virus and my not so great health conditions.

Well, I may be a bit crazy but in my defence, it is not so easy to reach such a conclusion (at least not just on this basis) since account needs to be taken of the potential benefits of the vaccine approach, which will hopefully extend my life expectancy and, in an ideal world, get rid of the cancer altogether.

Of course, in the absence of any hard data, it is simply impossible to carefully evaluate the beneficial impact of the vaccine on my cancer versus the risk of catching the Covid virus (assuming that I have not had it already – see previous blogs). But my instinct, which I have always chosen to follow from the beginning of the whole cancer saga, told me that I should give priority to the vaccine here. And so I went along with it.