What the explosion of immunotherapy research means for Canadian cancer patients
Slash, burn and poison. For decades, these have been largely the only treatment methods available for cancer. But surgery, radiation and chemotherapy do not offer hope to all cancer patients, and even those whose cancer does go into remission are often made sick by the treatment.
It's no surprise, then, that the emergence of a fourth pillar of cancer therapy — immunotherapy — has generated excitement among cancer scientists, patients and the larger medical community.
The explosion of research and experimentation in immunotherapy has so transformed medicine that it's been called cancer's "penicillin moment." But not all patients have responded positively to immunotherapy, and far more research is needed to understand which patients benefit and why.
Stéphanie Michaud is the President and CEO of BioCanRx, a Canadian network of scientists, cancer stakeholders, academic institutions, NGOs working to accelerate the development of immunotherapies. She spoke to The Sunday Edition's guest host David Gray about the promises and future of immunotherapy in Canada. Here's part of their conversation.
For those of us who are still trying to wrap our heads around all of this, could you explain in simple terms how immunotherapy works?
Immunotherapy is a new treatment that actually uses one's own immune system in order to fight the cancer. There are many different kinds of treatments that can be used that are either cell-based viruses that are engineered, or antibodies. The ones that are becoming routinely available in hospitals across this country are some of those antibodies. They're called checkpoint inhibitors, and these are commonly used in the treatment of advanced melanoma and non-small cell lung cancer. And depending on the kind of of immunotherapy that's used, they work in different ways in order to what we call modulate the immune system, so that it can be activated to fight the cancer.
So, if I follow you, the approach is no longer to act directly on the cancer but on the immune system?
In some ways, depending on the kind of product that you're using. Because cancer is a very smart disease and, similar to antibiotic resistance, it does acquire certain mechanisms over time to help it evade the immune system. And it actually co-opts the immune system in doing so and learns some of its tricks.
And so when this is blocked by the use of the drug, for all intents and purposes it is now seen by the immune system and then attacked.
But doesn't this fly in the face of what we've thought cancer was about until now? As I've always understood it, cancer was assumed to be too much a part of ourselves to be noticed as non-self. And now you've found a way for cancer to be noticed by the immune system?
Yes, and this is one example. It's also about targeting very specific molecules that are on the surface of cancer cells and in some cases also on the surface of normal cells. So a great example of that is actually CAR-T therapy, which is constantly in the news these days. The way that CAR-T works is that cells are taken from the patient, T cells are isolated from that and are then infected with a virus that has a DNA payload that causes a bit of genetic engineering of these T cells, and really super-charges them to be able to attack cancer.
What you're talking about is a radically different way of treating cancer from the old 'cut, burn and poison' methods that we've been using for hundreds of years. What makes this so much better than those other means?
All those other treatments have a place and for certain cancers work extremely well. And also it should be said that immunotherapy is not without its own set of toxicities. The difference is that we are embarking on this road to personalized medicine and we are targeting cancer in a very specific way. And so instead of bombarding the body with drugs that may or may not work, we are able to intelligently target the cancer in order to elicit a response.
The immune system is an incredibly powerful tool in our arsenal and to be able to utilize a system approach to dealing with a disease that is as complex as cancer is unprecedented.
Can you walk me through some of the results we know of so far? How effective have immunotherapy approaches been for cancer patients receiving the treatment?
I'll use the case of Emily Whitehead and CAR-T. This young lady was palliative and she had had leukemia as a young child. The treatments that exist today for pediatric leukemia are quite effective and cure rates are typically on the order of 80 to 90 percent. But there is that part of the population which, unfortunately, the treatment fails them — and so this is the population that is targeted by CAR-Ts.
And in her case, her parents decided to opt for her to receive this treatment. She presumably had hours to live and she got very, very sick because it caused a lot of side effects. But what we've learned since is that getting sick from this treatment usually means that the treatment is working. So in the case of Emily Whitehead, we had a child who was at end of life who is now post-treatment, alive and well, seven years on. And the drugs successfully removed kilograms of tumors.
These kinds of stories where individuals who are at stage 4, in certain cases told to get their affairs in order, are being treated with these novel therapies and we're seeing outstanding results — that is, in the realm of cancer, quite extraordinary.
I think the most famous example comes from December 2015, when former U.S. President Jimmy Carter was treated with checkpoint inhibitors. His immune cells actually cleared the cancer from his liver and brain, and it got some people using the word 'cure,' which I know is dangerous when we talk about cancer. But are we at that stage now? Can the word cure be used in oncology?
I think it is too soon to say cure. We still don't know what the long-term benefits of these therapies will be. Going back to the example of CAR-T, the results of those trials were so extraordinary that in the case of the FDA they actually provided a conditional approval of the drug after phase two because the results were so striking. After a certain time point, folks were in remission and these are folks that would have passed away from the disease.
We're at the stage now of watching what is happening to those patients to see how far the remission will extend. And then perhaps in in ten years from now, we'll be able to talk more confidently about the word cure.
So, say I'm a cancer patient in Canada. What does all this hype about immunotherapy actually mean for me now? What's actually available here?
There are medications that are available here that you would be able to access depending on the kind of cancer that you have. So, for example, checkpoint inhibitors are routinely used here in Canada. CAR-T, for example, has been approved in Canada. It's not yet available because we're still under that negotiation phase with respect to reimbursement, but it has been approved.
What's the cost of these treatments? Who can afford them?
In Canada, drugs that are received in a hospital setting are covered. Then we get into coverage with respect to different insurance plans and folks that are not covered. And of course that's a big part of the whole pharmacare debate. And these drugs are coming down the pipe and the Canadian health care system will have to grapple with how they will be able to pay for them. Case in point is, of course, CAR-T. The price tag on this therapy in the United States, for the Kymriah products, is $475,000 US. And that doesn't include the pre-treatment costs, and then the subsequent, in certain cases, hospitalization and follow-up treatment. So it can really run in excess of $1 million US per patient, or even more so.
That rollout of that therapy here in Canada, it has been approved but it's still in the phase of being negotiated with the different provinces with respect to what will be reimbursed and the cases under which it will be used.
The Canadian Agency for Drugs and Technologies in Health (CADTH), the body responsible for advising governments on whether or not they should cover new drugs, is advising provinces not to cover this treatment until the price for it comes down. What do you make of that?
That is the recommendation of CADTH and it really ultimately will be up to individual provinces to make their own decisions with respect to reimbursement. These are difficult issues to grapple with. And if you're strictly looking at impact on budget, yes it will be difficult, but it's important to think about it in terms of how we could potentially innovate with respect to reimbursement. There are a number of very sophisticated approaches that are being developed around the world with respect to dealing with these.
This Q&A has been edited and condensed for clarity. To hear the whole interview with Stéphanie Michaud, click 'listen' above.