An experimental treatment made rectal cancer tumors disappear for a small trial group
SACHA PFEIFFER, HOST:
A tiny group of people with rectal cancer just experienced something of a miracle - their cancer simply vanished after an experimental treatment. In a very small trial, these patients took a drug called dostarlimab for six months, and in the end, every one of them saw their tumors disappear. Now, this trial was small - just 18 people - and there's still more to be learned about how the treatment worked. But some scientists say these kinds of results have never been seen in the history of cancer research.
So to talk more about this is Dr. Hanna Sanoff of the University of North Carolina's Lineberger Comprehensive Cancer Center. She's not involved with the study. That was done by doctors with New York's Memorial Sloan Kettering Cancer Center. But Dr. Sanoff has written about the results. Welcome to the program.
HANNA SANOFF: Thank you.
PFEIFFER: Now, we are typically very cautious about focusing on studies that are so tiny, but there has been so much cautious enthusiasm about this that we wanted to talk about it. Could you tell us your reaction when you heard about the results?
SANOFF: Absolutely. I mean, I am incredibly optimistic. Like you said in the introduction, we have never seen anything work in 100% of people in cancer medicine.
PFEIFFER: We should note, I believe, that with rectal cancer, some cases can involve chemo, radiation, surgery, maybe a combination of all of those. How does this drug work?
SANOFF: This drug is one of a class of drugs called immune checkpoint inhibitors. And these are immunotherapy medicines that work not by directly attacking the cancer itself but actually getting a person's immune system to essentially do the work. And these are drugs that have been around in melanoma and other cancers for quite a while but really have not been part of the routine care of colorectal cancers until fairly recently.
PFEIFFER: And typically, drugs have side effects. What kinds of side effects were there with this one?
SANOFF: Very, very few in this study - in fact, surprisingly few. Most people had no severe adverse effects at all.
PFEIFFER: You've said before that this clinical trial is practice-changing for the field. In what way do you view it as practice-changing?
SANOFF: Well, our hope would be that for this subgroup of people - which is, I think we should point out, only about 5% to 10% of people who have rectal cancer - if they can go on and just get six months of immunotherapy and not have any of the rest of this - I don't even know the word to use. Paradigm shift is often used, but this really absolutely is paradigm-shifting.
PFEIFFER: I do want to emphasize that we often cheer for people when we hear that they have kicked cancer. But the aftermath of what they can deal with physically and side effects can still be life-changing, which is why the idea of being able to skip surgery is so revolutionary.
SANOFF: Yes. In rectal cancer, this is part of the conversation we have with someone when they're diagnosed - is, you know, we are very hopeful for being able to cure you, but unfortunately, we know our treatments are going to leave you with consequences that may, in fact, be life-changing. I mean, I have had patients who, after their rectal cancer, have barely left the house for years - and in a couple of cases, even decades - because of the consequences of incontinence and the shame that's associated with this.
PFEIFFER: Have you ever had patients that said they've regretted getting the treatment?
SANOFF: You bet.
PFEIFFER: So if this drug ends up being as good as it preliminarily seems to be, what's the next step?
SANOFF: What I'd really like us to do is get a bigger trial where this drug is used in a much more diverse setting to understand what the real, true response rate's going to be. It's not going to end up being 100%. I hope I bite my tongue on that in the future, but I can't imagine it will be 100%. And so when we see what the true response rate is, that's when I think we can really do this all the time.
PFEIFFER: That's Dr. Hanna Sanoff of the University of North Carolina's Lineberger Comprehensive Cancer Center. Thank you very much.
SANOFF: Thank you. Transcript provided by NPR, Copyright NPR.