Designing Clinical Trials for Patients With Rare Cancers: Connecting the Zebras

Dr. Hope Rugo and Dr. Vivek Subbiah discuss innovative trial designs to enable robust studies for smaller patient populations, as well as the promise of precision medicine, novel therapeutic approaches, and global partnerships to advance rare cancer research and improve patient outcomes.
TRANSCRIPT
Dr. Hope Rugo: Hello and welcome to By the Book, a podcast series from ASCO that features engaging conversations between editors and authors of the ASCO Educational Book (ascopubs.org/toc/edbk/current). I am your host, Dr. Hope Rugo. I am the director of the Women's Cancers Program and division chief of breast medical oncology at the City of Hope Cancer Center [in Los Angeles].
The field of rare cancer research is rapidly transforming thanks to progress in clinical trials and treatment strategies, as well as improvements in precision medicine and next-generation sequencing that enable biomarker identification. According to the National Cancer Institute, rare cancers occur in fewer than 150 cases per million each year, but collectively, they represent a significant portion of all cancer diagnoses. And we struggle with the appropriate treatment for these rare cancers in clinical practice.
Today, I am delighted to be joined by Dr. Vivek Subbiah, a medical oncologist and the chief of early-phase drug development at the Sarah Cannon Research Institute in Nashville, Tennessee. Dr. Subbiah is the lead author of a paper in the ASCO Educational Book titled "Designing Clinical Trials for Patients with Rare Cancers: Connecting the Zebras," a great title for this topic. He will be telling us about innovative trial designs to enable robust studies for small patient populations, the promise of precision medicine, and novel therapeutic approaches to improve outcomes, and how we can leverage AI now to enroll more patients with rare cancers in clinical trials.
Our full disclosures are available in the transcript of this episode.
Dr. Subbiah, it is great to have you on the podcast today. Thanks so much for being here.
Dr. Vivek Subbiah: Thank you so much, Dr. Rugo, and it is an honor and pleasure being here. And thank you for doing this podcast for rare cancers.
Dr. Hope Rugo: Absolutely. We are excited to talk to you. And congratulations on this fantastic paper. It is such a great resource for our community to better understand what is new in the field of rare cancer research. Of course, rare cancers are complex and multifaceted diseases. And this is a huge challenge for clinical oncologists. You know, our clinics, of course, cannot be designed as we are being very uni-cancer focused to just be for one cancer that is very rare. So, oncologists have to be a jack of all trades in this area.
Your paper notes that there are approximately 200 distinct types of rare and ultra-rare cancers. And, by definition, all pediatric cancers are rare cancers. Of course, clinical trials are essential for developing new treatment strategies and improving patient outcomes, and in your paper, you highlight some unique challenges in conducting trials in this rare cancer space. Can you tell us about the challenges and how really innovative trial designs, I think a key issue, are being tailored to the specific needs of patients with rare cancer and, importantly, for these trials?
Dr. Vivek Subbiah: Rare cancers present a perfect storm of challenges. First, the patient populations are very small, which makes it really hard to recruit enough participants for traditional type trials. Second, these patients are often geographically dispersed across multiple cities, across multiple states, across multiple countries, across multiple zip codes. So, logistics become complicated.
Third, there is often limited awareness among clinicians, which delays referrals and diagnosis. Add to that regulatory hurdles, funding constraints, and you can see why rare cancer trials are so tough to execute. To overcome these barriers, we are seeing some really creative novel trial designs. And there are four different types of trial designs that are helping with enrolling patients with rare cancers.
The first one is the basket trial. So let us talk about what basket studies are. Basket studies group patients based on shared genetic biomarkers or shared genetic mutations rather than tumor type. So instead of running separate 20 to 30 to 40 trials, you can study one therapy across multiple cancers.
The second type of trial is the umbrella trial. The umbrella trials flip that concept of basket studies. They focus on one cancer type but test multiple targeted therapies within it.
The third category of innovative trials are the platform studies. Platform trials are another exciting innovation. They allow new treatment arms to be added or removed as the data matures and as the data evolves, making trials more adaptive and efficient.
The final category are decentralized tools in traditional trials, which are helping patients participate closer to where they are so that they can sleep in their own bed, which is, I think, a game changer for accessibility.
These designs maximize efficiency and feasibility for rare cancer research and rare cancer clinical trials.
Dr. Hope Rugo: I love the idea of the platform trials that are decentralized. And I know that there is a trial being worked on with ARPA-H (Advanced Research Projects Agency for Health) funding in triple-negative breast cancer as well as in lung cancer, I think, and others with this idea of a platform trial. But it is challenged, I think, by precision medicine and next-generation sequencing where some patients do not have targetable markers, or there isn't a drug to target the marker. I think those are almost the same thing.
We have really seen that these precision medicine ideas and NGS have moved the needle in helping to identify genetic alterations. This helps us to be more personalized. It actually helps with platform studies to customize trial enrollment. And we hope that this will result in better outcomes. It also allows us, I think, to study drugs even in the early stage setting more effectively. How can these advances be best applied to the future of rare cancers, as well as the challenges of not finding a marker or not having a drug?
Dr. Vivek Subbiah: Thank you so much for that question. I think precision medicine and next-gen sequencing, or NGS, are truly the backbone of modern precision oncology. They have transformed how we think about cancer treatment. Instead of treating based on where the tumor originated or where the tumor started, we now look at the genetic blueprint of cancer. The NGS or next-gen sequencing allows us to sequence millions of DNA fragments quickly.
Twenty, 30 years ago, they said we cannot sequence a human genome. Then it took almost a decade to sequence the first human genome. Right now, we have academic centers and commercial sequencing companies that are really democratizing NGS across all sites, not just in academic centers, across all the community sites, so that NGS is now accessible. This means that we can identify these actionable alterations like picking needles in haystacks, like NTRK fusions, RET fusions, or BRAF V600E alterations, high tumor mutational burden. This might occur across not one tumor type, across several different tumor types.
So for rare cancers, this is critical because some of these mutations often define the best treatment option. Here is why this matters. Personalized therapy, right? Instead of a one-size-fits-all approach, we can tailor treatment to the patient's unique molecular profile. For trial enrollment, this can definitely help because patients can join biomarker-driven trials even if their cancer type is rare or ultra-rare.
NGS technology has also helped us in designing rational studies. Many times monotherapy does not work in these cancers. So we are thinking about rational combination strategies. So NGS technology is helping us. Looking ahead, I see NGS becoming routine in clinical …