Watching the Future
Sitting Down With… Peter Marks, Director of the Center for Biologics Evaluation and Research (CBER) at the FDA, USA
James Strachan | | Interview
How did you start your career?
I went into college thinking I was probably going to become a PhD biochemist. At the time, cell and molecular biology were becoming more popular and they caught my interest. After I got a part-time job at a hospital taking blood, I started to think about going to medical school and working in medical research. Ultimately, I chose to become a physician-scientist but, over the years I’ve occupied several different roles in academia and industry.
How did you get involved with the FDA?
My first industry role was with Genzyme and involved interacting with the Center for Biologics. The Center had both an applied scientific research component and a regulatory component working with a nifty set of products. It was so interesting to me that, in 2011, I applied for a job there. At the time, gene and cell therapies were becoming very exciting – and, as a hematologist-oncologist, blood products were, of course, of interest to me. The opportunity to have an impact on the development and availability of important medical products was attractive. And it meant I could make use of different skills in one job. What I do now is a combination of science, medicine, administration, and even a little teaching from time to time.
What skills are important for a regulator?
Looking at people who have been mentors in this space, like Janet Woodcock, it’s clear that you need to understand science and medicine really well to do a good job as a regulator. This includes the science at a fundamental level, as well as the manufacturing of products and the technologies involved. Without that knowledge, you can’t make necessary decisions about cutting-edge products. You also have to know how to manage people. The Center for Biologics has around 1,300 full-time equivalents. They are mostly knowledge workers… and managing knowledge workers can be challenging. You need to know when to zoom in to get into the weeds of the data and when to zoom out and let others deal with the data while you make the high-level decisions. That, to me, is an important balance to have.
What is the biggest challenge you face?
The biggest challenge is uncertainty. There is always some uncertainty with cutting-edge science. For example, on one hand, a gene therapy may help to cure a disease or treat it long-term. On the other hand, there may be side effects associated with it. Not knowing exactly what will happen ahead of time is what makes the job challenging. Sometimes, it takes a long time to know whether a decision was a good idea or a bad one. The challenge is to negotiate the uncertainty in as skilful a manner as possible.
What work are you doing in terms of harmonizing gene therapies?
This is one of my favorite topics and an area we are actively working on. We’re developing a white paper on global harmonization of cell and gene therapy regulatory approaches. If we have different regulatory frameworks in different countries, then patients in different countries likely will be deprived of these therapies simply because of the cost of market entry. If studies are performed in one location and are then required in a different location, that will present a barrier. We’re going to need a lot of work to move toward harmonization and we’ll need to start small. Right now, if someone in the US develops a therapy for mucopolysaccharidosis type I and someone in the EU develops a therapy for mucopolysaccharidosis type III, the regulatory requirements may be different and the therapies may never cross the Atlantic. This means patients would have to travel to get access. Harmonization could help therapies enter other countries.
How far are we from being able to manufacture gene therapies at scale?
We’re not that far away, but there are challenges. With mAbs, people came together to help develop technologies that could produce and purify large protein quantities. With gene therapies, there is still a lot of proprietary work that can limit information-sharing. One of my goals is to help the field share information and grow. I think we can make better cell lines and purification methods and develop continuous methodologies for producing these gene therapies. But that will require a type of collaboration and cooperation that we haven’t yet fully achieved.
What advances in gene therapy do you think could be transformative?
In vivo genome editing has tremendous potential because it can help overcome some of the problems we have with current gene therapy vectors, including longevity of expression. You need expression of an editing construct for a period of time – ideally in the dividing cells – but after your correction occurs, you’re done. Too much persistence is undesirable because it can lead to off-target effects. Genome editing could treat many diseases, but there is a whole regulatory paradigm that we have yet to fully create for genome editing. It’s very exciting – and it’s advances like this that keep me coming to work every day.
What advice do you have for developers of therapies?
Engage with the FDA – or whatever regulatory authority you are applying to – frequently. Do not be afraid to ask the hard questions. And do not be afraid to question the regulator’s responses if they don’t make sense. Such dialogue between developer and regulator is really important. I recommend closing the loop: you ask a question, the regulator responds, and then you respond back with, “From your response, we think we need to do X.” Often, regulator comments can be open to interpretation but, if you close the loop and give feedback to the regulator on what you have heard, it becomes unambiguous. For example: “We hear you. We need to have a potency assay before we proceed to phase III. Is that what you mean?” The regulator can then confirm, and you’ll know you’re on the right track.