John still clearly remembers how it all started. "I was working as an internist at Leiden UMC when I received a call from Hergen Spits, who had been my co-supervisor. He told me that there was going to be a unique placement at the Netherlands Cancer Institute: a physician who could bridge the gap between lab and clinic. Right up my alley, he thought. And he was right. I applied immediately."
That unique position involved two years as a postdoc followed by two years of training as an oncologist, after which he would be a permanent member of staff. "This combination of research and training really appealed to me. Initially, I would also forego all clinical duties so I could fully focus on my role."
That's how John ended up at the Netherlands Cancer Institute in 1997, at the Immunology Department. "I remember someone telling me to consider a spot at the office of someone named Ton Schumacher, a young researcher who had just been hired and who was trying to cure mice using immunotherapy. A distinctive, quiet man. He did not say much, but when he did, it would be meaningful."
Back then, no one could have imagined that this would be the beginning of a collaboration leading to many great breakthroughs. "We have been collaborating for twenty-five years. I still have two offices, one of which is at Ton's department. Sjoerd Rodenhuis provided me with a period of time to focus entirely on research while other physicians looked after my patients."
Gradually, the immunology department started to grow. John: "The department was founded in the 80s, but the general sentiments towards it were that it was mostly tolerated. Expectations were low. Things changed around 2006, when American researcher Steven Rosenberg presented the results of a treatment using TIL, tumor-infiltrating lymphocytes. No one seemed to trust him. Many colleagues even believed that he had omitted the negative outcomes."
John wasn't as suspicious of him as the others. "I visited Rosenberg's lab in Bethesda, Maryland, in 2008. I wanted to see it with my own eyes. That same year, I told Ton Berns, the director at the time, that this new therapy seemed so promising that we needed a place to start working on it ourselves. One of Rosenberg's postdocs who happened to be Dutch joined us to help us to set it up."
Special rooms were set up in the pharmacy at the Slotervaart hospital, where we could grow the body's own T cells to attack tumor cells later, once back in the patient's body. "In 2010 or 2011, we treated the first patients with this TIL therapy. About half of them showed a response to the treatment. Two patients even went into complete remission. That was fantastic news."
One of these two patients from the first study was a man with a young daughter, who didn't have any more treatment options available to him. "He had already tried all known treatments, but nothing worked. He had large tumors on his legs. The treatment exhausted him completely. But less than three weeks after the treatment, he called me to say: something is happening on my leg. And he was right, the metastases were looking visibly smaller. After about twelve weeks, everything was gone."
John parted ways with him as a patient last summer. "Ten years have passed, and he is still clean. I don't have to think of him as a patient anymore. He was very grateful, because he had been given the opportunity to see his daughter grow up. She is now a teenager. Quite hard, he thought. He never expected to be around to experience that."
In 2008, John was appointed professor of immunotherapy in oncology at LUMC. In 2009, he became medical cluster head. "That's what I did until July 2018. Then I became theme leader of Immunology. In this role, I try to strengthen the connection between clinic and research. My own work proves how much these connections can achieve."
We couldn't have gotten where we are today without a vision and collaboration. "It has been a privilege to be on the front line of the latest developments together with my amazing colleagues. Not to mention the other developments I contributed to, including DNA vaccines through tattoos, cell therapy, or checkpoint inhibitors for melanoma and other cancer types."
Looking back, he is happy to reflect on the way his field has grown over the past twenty-five years. "Initially a department that was tolerated, or considered promising at best, we have grown into one of the leading and most successful treatment options. Just recently, we could open two new patient rooms. Immunotherapy is a force to be reckoned with."