In this episode, 2024 David Karnofsky Memorial Award winner Lillian L. Siu reviews her career developing novel therapies in the phase I setting, the evolution of her field, and her mentor’s dreaded “evil red pencil.”

Siu was among the first scientists to read out the signals of safety, pharmacology, and preliminary efficacy of therapeutic agents that ushered in a new era of cancer therapy. She has been involved in the early development of over 50 drugs and has focused on ways to improve efficiency and scientific relevance of clinical trials.

Over the course of her career as a phase I clinical trialist, Siu watched as the field moved away from using “maximum tolerated dose,” the growing need for early-phase efficacy data, and the emergence of intermediate biomarkers.

After a nearly 30-year-long career, Siu’s advice for young oncologists is simple: Don’t give up.

“Learn from every mistake or every challenge and rise above it and be tenacious,” Siu said. “Be persistent, because there’s never an end that is a bad ending. It is always a good ending if you put enough effort in it. Maybe not entirely the way you want it, but at least if you put in the effort, something will return to you that is worth your effort. I truly believe in that, and certainly I see that in my career.

“I don’t only have positive results, I have very often negative results, but it’s fun. Learning from your mistakes is half of the fun, and cherish that kind of moment to learn from it.”

Siu spoke with Jacquelyn Cobb, reporter with The Cancer Letter. A transcript of the conversation appears on The Cancer History Project.