Utilizing Biomarkers to Develop First-in-Class Antibody Drug Conjugates to Treat Advanced Solid Tumors

PE: How is AbbVie using novel cancer biomarkers to develop potential first-in-class ADCs for the treatment of advanced solid tumors?

Valencia: We're constantly looking for biomarkers that can help us to do two key things. The first is to tackle cancer cells. and spare normal cells. We’re looking for specific antigens that are over-expressing tumor cells, and you see limited expression in normal cells. We want to make sure that target that’s over-expressed is critical for the survival of the cancer cell. Once you block it, you can actually drive a cancer cell death. That’s what we're looking for. In that perspective, c-Met is one of those biomarkers that is over expressing multiple tumor types such as lung, colorectal, gastric, and other GA tumors. We as an industry have tried to tackle c-Met in the past but have been unsuccessful. It would actually be successful to tackle what we call met, which is a gene inside the cell.

There’s this thing called met amplification, where the cancer cell produces multiple copies of the gene, and around 30% of patients have it. We can actually tackle that with small molecules. But once the gene becomes a protein and gets over-expressed in the cell, that over-expression is something we haven’t been able to target. For example, we know that on lung cancer, c-Met over-expression is about 25% to 50% in colorectal cancer, and it could be anywhere from 30% to 70% depending how you measure it, so it’s quite prevalent.

With ADCs, we’re trying to tackle c-Met over-expression on the surface of cancer cells. That was novel, and we can do it through ADCs. 706 has a target called SEZ6, and it’s a target that is over expressed in neuroendocrine cells or neuroendocrine neoplasms. When you think about it, multiple tumor types kind of have a subset of cells that are neuroendocrine driven. Small cell lung cancer is one of the few that has everything driven by neuroendocrine cells. The beauty of SEZ6 is over-expressing those cells and limited expression in normal cells. So, we can tackle it with an ADC and drive the results that we're seeing today.

PE: ADCs have redefined the treatment of cancer in recent years. Can you please discuss the promise of this emerging class and what the future may hold?

Valencia: At the end of the day, ADCs work like a trojan horse. You have a good antibody that cancer cells are happy to receive, but once you hook into the cancer cell receptor, you deliver the payload, which is pretty much chemotherapy. It’s actually a highly potent version of the regular chemotherapy cancer patients are given on a regular basis. So, from that perspective, our goal is to replace chemotherapy. Our grand goal with ADCs is to replace good old, decades old chemotherapy that is really toxic for some patients. That’s how we see the redefinition of cancer treatment in the future with ADCs. So, what do we see in the future? Well, if you think about it, chemotherapy is being given in combination with other agents. In the future, we see ADCs being given in combination with chemotherapy. There will be one with other agents such as immuno-oncology agents. So, if you combine the ADC and the PD1s, you can start seeing that synergy come together and kind of start really dreaming about cures for the patients. All in all, we're super excited about ADCs replacing chemotherapy.