Research Spotlight - Antibody-Drug Conjugates (ADCs): One Step Closer to Curing Cancer

Researchers have recently created a new type of cancer drug called ADCs. What are they? How do they work? Dive into this research spotlight to learn all about this exciting new topic!

Cancer is a deadly disease that affects millions of people in the US alone. It’s caused by malfunctioning cells that grow and divide uncontrollably, creating masses called tumors that can spread throughout the body. Cancer can happen in virtually any part of your body and in many different forms, making it hard to diagnose and treat. That’s one reason why there are no cures for cancer right now, but doctors and scientists have worked for decades to find drugs and treatments that can treat its symptoms. 

(Credit: UICC)

One of these drugs is called Enhertu. It was developed in 2022, and it’s used to treat breast cancer. Enhertu belongs to a new class of a growing group of cancer drugs called antibody-drug conjugates (ADCs). So, what are ADCs? Let’s first break down the name. 

Antibodies are proteins created by the immune system that target and bind to antigens, which are molecules on invading pathogens. Pathogens can include bacteria, viruses, and any other foreign molecule that causes harm to the body. Antibodies’ ability to seek out specific molecules is what makes them perfect for ADCs. 

Next, drugs. There’s a variety of drugs available to fight cancer, and many are a part of chemotherapy treatments. The main goal of chemotherapy is to prevent the metastasis, or spreading, of cancer cells and tumors and kill them off. They can do this by blocking cell division, interfering with DNA or protein synthesis, or artificially triggering apoptosis (cell death).

When two molecules are linked, we call them conjugates. So, to sum it all up, ADCs are created when a specially designed antibody that targets cancer tumors is linked to a toxic cancer-fighting drug through a linker molecule. 

(Credit: Mapping Ignorance)

Okay, but how does it all work? First, ADCs are injected into the bloodstream. The antibody is important because it seeks out the cancer cell or tumor it’s specific for and takes the drug along with it directly to where it is needed. Once the antibody finds its target antigen on the cancer cell, it gets engulfed by the cell, and the toxic drug is released inside. This targeted drug release is exactly what makes ADCs so great; it prevents toxic cell-destroying drugs from spreading randomly throughout the body and harming healthy cells. This allows patients to avoid nausea, fatigue, hair loss, and other side effects of regular chemotherapy.

That’s not the only benefit of ADCs, though. It’s also easier to make ADCs more specific to certain types of cancers since you can “mix and match” different targeted antibodies with different drugs. Instead of one-size-fits-all medicines, we can now create unique ADC combinations for each patient! Also, drugs that were previously considered to be too toxic can now be used since we have much more control over where they act. 

However, if there’s one thing doctors and scientists have learned, it’s that no cancer treatment is perfect. Even though ADCs allow doctors to treat patients more effectively than ever before, they can still cause harmful side effects. No antigen is unique to cancer cells, meaning every once in a while, ADCs will target and kill healthy cells. There’s also the possibility of the toxic drug diffusing (spreading) to nearby healthy cells. Scientists are currently tinkering with different antibody targets and linker molecules to get the best results. Which antibody seeks out cancer cells the best? What kinds of linker molecules are able to hold on to the drug long enough to reach their target but easy to detach from the drug when needed? These are all questions they are looking into.

All in all, ADCs are clearly an exciting area of research. They have the possibility to treat previously untreatable cancers. This exciting news has led more and more companies to pour large amounts of money into ADC research, making it a fast-growing field. Scientists say that in the future, they want to link medicines other than chemicals, such as radioactive molecules that can carry out radiation therapy or molecules that activate the immune system to attack the tumor. 

We hope this article helped you understand this new topic a little bit better. If you’re interested, check out the links below for some further reading about ADCs. Stay tuned for future research spotlights exploring new discoveries in different science fields– you can also leave a comment to suggest new topics we should highlight!

Links & References

• https://www.scientificamerican.com/article/a-new-type-of-cancer-drug-shrinks-hard-to-treat-tumors/

• https://www.astrazeneca.com/our-therapy-areas/oncology/antibody-drug-conjugates.html

• https://www.ncbi.nlm.nih.gov/books/NBK564367/