A Unique Look at the Current and Future Directions of Cancer Vaccines

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You’re listening to Project Oncology on ReachMD. On this episode, we’ll learn about the current status and future directions of cancer vaccines with Dr. Lillian Siu, who’s a Senior Medical Oncologist at the Princess Margaret Cancer Centre and a Professor of Medicine at the University of Toronto. Here’s Dr. Siu now.

Dr. Siu:
I think the session at ASCO was very timely because, clearly, cancer vaccines have been of interest to oncologists for decades.  We’ve been trying to figure out how to prime or stimulate the immune system to attack cancer, and by and large, until the last few years, cancer vaccines have been challenging.  Perhaps the patient populations are very heavily pretreated, tumors are resistant, and perhaps in that situation it’s difficult to use vaccines to carry out its task.  But I think in the last few years we’ve seen modern renditions of cancer vaccines through different technologies, different ways to find immunogenic antigens, etc., that in my discussion or at least in our session, we talked about the new or more renewed interest to cancer vaccines, and I think it is bringing, the whole field to a new excitement era.

I think we’re going to see—cancer vaccines developed either alone or in combination, and also, we will see new patient populations being targeted by these vaccines.  Traditionally, when we develop drugs, they tend to go into patients who have advanced cancers, who have exhaustive standard treatments, and the cancers are very heavily pretreated, very resistant to all kinds of treatment, not just to immunotherapy.  But I think with cancer vaccines it is now really setting itself up for testing in the molecular residual disease or minimal residual disease setting, so patients who have definitive treatment where we can still detect microscopic evidence of cancer, whether it be by circulating tumor DNA or tumor biomarkers, that’s the group that would be very attractive for cancer vaccines because there is minimal tumor burden, less resistant cancer cells, such that a vaccine on its own may also be sufficient enough to eradicate the microscopic elements present.

The future of combination with vaccine plus another treatment, whether it’s immune checkpoint, CAR T, T-cell engagers, or even cytotoxic agents, such as ADCs, for example, would be very attractive.  I think the combination opportunities are, multiple and variable, so I think we will see many, many more of these trials, and we really need to have novel designs in clinical trials to test these combinations most efficiently while safeguarding in terms of patient toxicities.

I think it’s a very unique area that we are renewing our interest.  There are many opportunities.  We can even go to precancer patients with high risk of developing cancer that, for example, carry hereditary risk.  If we can detect it in their blood by circulating DNA or other means, potentially cancer vaccine can eradicate cancers before they even develop or take root, so I think the future is very, very exciting in this area.

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That was Dr. Lillian Siu sharing her insights on the landscape of cancer vaccines. To access this and other episodes in our series, visit Project Oncology on ReachMD.com, where you can Be Part of the Knowledge. Thanks for listening!