Resistance is Not Futile
One medicine by itself will likely not be able to cure all cancers. It’s certainly not for lack of trying. I, like all others in this fight, would like nothing more than to be proven wrong.
- There is tremendous hope to transform cancer into a manageable disease with combinations of targeted medicines. Combining medicines isn’t a new idea, but it’s one that’s been evolving over the years: first, with combinations of chemotherapies, and now with the potential to combine immunotherapies (a relatively new class of medicines).
For more on the potential of immunotherapies, read Ira Mellman's take.
How to Fight An Adaptable Enemy
To outsmart “resistance” to medicines and prevent relapse – and change cancer from a deadly disease to a manageable, chronic condition – we must develop treatments that directly overcome one of the main strengths of cancer cells: their ability to adapt in order to survive.
Cancer is cunning, and rational combinations of treatments that defeat critical cancer survival mechanisms are one of the most promising ways to help people with cancer live long and productive lives. It will take multiple medicines, diagnostic tests, companies, and the involvement of countless physicians, patients and regulators to reach this goal.
Targeting Cancer Cell Communications
Many new “targeted” medicines work by interrupting a single communication channel that tell cancer cells how to grow and spread.
This tends to work for some time, but cancer cells eventually find a way to reroute their communications. This can restart tumor growth and lead to relapse, even after a time of tumor shrinkage or stability. This is one reason why many cancers remain incurable.
Predicting How Cancer Will Adapt
We’ve spent many years researching the molecular “switchboard” that underpins cancer growth. The result is that more and more often we know - and in some cases can predict - how cancer cells will adapt and find ways around a medicine.
Fitting Attack to Adaptation
In some cases the best course of action may be to wait until resistance to the first medicine begins before layering on the next wave of attack.
In other cases, it makes sense to come in with a one-two punch from the very beginning, and it may be that medicines that are modestly effective on their own can be very effective when part of a combination with other medicines that use different approaches.
Either way, what’s important is that these combination strategies are developed based on a deep understanding of the biology of cancer, and are tested to understand not only if they work, but if they are also safe when used together.
The Molecular Toolkit
Almost every one of our cancer medicines – those that are available today and those that are currently being investigated – are designed to interfere with one of the underlying molecular causes of cancer.
We want to give doctors a molecular toolkit of medicines that target different pathways, alongside diagnostic tests that accurately predict who is most likely to respond to them.
At Genentech, we’re enrolling or have completed about 30 trials investigating combinations of medicines (from our company and others) that may be even more effective at fighting cancer. Cancer is smart. Together, we are getting smarter.