Demystifying Clinical Trials: A Comprehensive Guide to The Science of Hope


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In this episode, Dr. Diane Reidy-Lagunes and Dr. Alex Drilon, Chief of MSK’s Early Drug Development Service, answer the most common questions about participating in clinical trials. Through hearing the experience of patients, they discuss the practical aspects as well as the fears and misconceptions associated with clinical trials. They explain their rigorous development, different phases, and potential to save patients’ lives now and in the future.

MSK is proud to support the key initiatives of the National Cancer Plan by helping to develop effective treatments and end cancer as we know it. Click here to learn more about the National Cancer Plan.

Episode Highlights

What is a clinical trial? Are clinical trials safe?

A clinical trial provides access to treatments not yet approved for specific cancer types. In recent years, scientific advancements, coupled with the design of targeted therapies, have contributed to an impressive evolution in clinical trials. Previously, historical response rates were as low as 1 out of 10 patients in early-phase trials, whereas now, some studies show responses in up to 8 out of 10 patients, reflecting a remarkable improvement in efficacy.

What are the different phases of clinical trials?

Clinical trials progress through distinct phases. Phase 1 determines optimal dosages, phase 2 assesses effectiveness in a smaller group, and phase 3, conducted on a larger scale, often compares the new treatment against an approved one. Modern approaches include “seamless trials,” which combine phases for accelerated drug development.

Are there downsides to joining an early-phase study?

Early-phase trials, particularly phase 1, may involve increased assessments, frequent visits, and extended hospital stays to closely monitor patients. Despite these challenges, patients who respond well to the treatment often find the inconveniences balanced by significant, previously impossible, improvements in their quality of life.

What happens if I get the placebo in a clinical trial and my cancer grows? Can I switch from the placebo to the real drug?

Yes, if a patient’s disease progresses during a clinical trial, they have the option to be unblinded to see if they are on the placebo. They can then cross over to receiving the trial’s active drug or drop out of the trial altogether to receive standard treatment. In placebo-controlled studies, patients should consider the possibility of receiving a placebo and discuss this risk with their doctors. In situations where the disease might progress rapidly without active treatment, doctors weigh the benefits of trial participation against using already approved therapies. 

Can I drop out of a clinical trial?

Yes, clinical trial participation is voluntary and patients can withdraw at any point. Signing the informed consent is not binding, and patients may opt out for reasons such as adverse effects, disease progression, or practical challenges associated with frequent visits.

How do I find a clinical trial for my cancer?

Have a discussion with your doctor, explore advocacy groups for your specific cancer, and leverage online resources to find trials currently enrolling. Memorial Sloan Kettering’s system matches patients to trials based on genetic information, streamlining the process and educating patients of all potential options.

Cancer Straight Talk from MSK is a podcast that brings together patients and experts, to have straightforward evidence-based conversations. Memorial Sloan Kettering’s Dr. Diane Reidy-Lagunes hosts, with a mission to educate and empower patients and their family members.

If you have questions, feedback, or topic ideas for upcoming episodes, please email us at: [email protected]

Show transcript

Dr. Diane Reidy-Lagunes:

Clinical trials. There's a sense of mystery that surrounds them. What's it really like to be on one?


It was a research trial and I was a candidate for it. I was scared 'cause I didn't know if it would work, but I was optimistic.

I was a little apprehensive. What I ended up doing was I asked my doctor questions. I researched it on my end and my one big thing was always to trust the process.

In doing this treatment since March, I feel like a normal person. I don't feel like I have cancer.  I do have to go in every week to have my infusion, and I just follow the rules.

There was a Facebook group for the participants that I was invited to that has been a great support system for me.

One thing that I say a lot is: what a time to be alive and have this medical technology available to us.

I did hesitate because I'm not knowledgeable on science. I'm not a doctor. But I had faith in my doctor, so I knew that I was in the best hands possible.

Dr. Diane Reidy-Lagunes:

Today on the pod, we're giving you the inside scoop about the realities of being on a clinical trial: the fears, the misconceptions and the truth, uncovered. Let's talk about it.

Hello. I'm Dr. Diane Reidy-Lagunes from Memorial Sloan Kettering Cancer Center, and welcome to Cancer Straight Talk. We're bringing together national experts and patients fighting these diseases to have evidence-based conversations. Our mission is to educate and empower you and your family members to make the right decisions and live happier, healthier lives. For more information on the topics discussed here, or to send us your questions, please visit us at

We are so pleased to be joined by Dr. Alex Drilon, my medical oncology colleague and friend who's a thoracic oncologist here at MSK and is also Chief of our Early Drug Development Service. His goal is to bring new drugs to patients with all types of cancers, especially in cases where all standard treatment options have been exhausted. Alex, thank you so much for sharing your expertise and welcome to the show.

Dr. Alex Drilon:

Thanks Diane. It's my pleasure to be here.

Dr. Diane Reidy-Lagunes:

We're so thrilled to have you here to talk about a really important concept, which is clinical trials. Let's start with the basics. What is a clinical trial?

Dr. Alex Drilon:

The way I like to describe a clinical trial is that it's a program that gives somebody access to a treatment that's not yet approved for their cancer type. In many cases, that's a new treatment. Someone might have designed a totally new drug, and it might be nicely matched to the cancer type that you have. But in other situations, there may be a drug that's approved for a different type of cancer that's not yet approved for your type of cancer, but because of the interesting results that have been generated, they're now extending this to look at your type of cancer. And often you can be treated with one drug, but sometimes it's a combination of two drugs or three drugs. There's a range of clinical trials, but at the root of it, it's really getting access to a potential new treatment for you.

Dr. Diane Reidy-Lagunes:

When we look back at the history of clinical trials, so much has changed. In the past, many clinical trials were like that final Hail Mary pass, but now we see so much more success with the trials that we're conducting today. Can you briefly provide us with an understanding of what has changed?

Dr. Alex Drilon:

Absolutely. I think we're fortunate that the science has really advanced over the years, and we have all these brilliant chemists who are designing new drugs for new biomarkers or targets in somebody's cancer.

Historically, 1 out of 10 patients may have responded to a clinical trial and sometimes it could even have been less than that. Now we're seeing some trials, even in the earliest phases of their testing, where we can see responses in up to 6, 7, or 8 out of 10 patients. So a really remarkable difference.

And if you think about some of the treatments that are already approved, where if you get to maybe the second round of treatments or the third round where the likelihood of response is lower, it's very possible that this new clinical trial with a new drug may even have a higher likelihood of achieving control of your cancer.

Dr. Diane Reidy-Lagunes:

That really is remarkable. You talked about some of the earlier versus later phase types of clinical trials that we conduct here. Can you help us walk through what those different phases are?

Dr. Alex Drilon:

In the historical sense, a phase 1 trial is where we have a new therapy, and the primary goal is to figure out the best dose of that treatment. In a phase 2 trial, traditionally what happens is that you start to look to see how well a drug works in a smaller number of patients, so that when you get a phase 3 trial, you can test to see how well a drug works in a much larger group of patients and sometimes compare that new treatment against a treatment that's already approved, which is what we call randomization.

Now I use the terms historical/traditional because one of the strategies that we have today is to try to shorten the time to these new drugs and exciting treatments getting approved. We live in this climate where we have what we call “seamless trials,” where it might not be a standalone phase 1 to find the dose and phase 2 to find the activity, but you can have a phase 1 / 2 trial where it's two-in-one and you can find out if a drug is working after you find out the best dose of a drug.

I bring up the perception issue because, historically, it was thought that if you joined a phase 1 trial that you were joining a trial where they were not really looking to see if a drug worked and they were only looking to see what the best dose was. But because we have all these exciting new treatments, some of which work very well, and while it may be sort of a secondary thing we look at on a phase 1 trial, I've seen patients who have responded very well even during the phase where we're looking for a dose and even at doses lower than the dose we eventually pick.

Dr. Diane Reidy-Lagunes:

So to recap, phase 1 is dose finding, which also includes safety, right? If you go too high, then obviously patients can have side effects. If it's too low, maybe we could do a little bit better. And then once we find the dose, you go to phase 2. And like you said, traditionally that would often take years, if not longer. But now it's easier and much faster to be able to go to that phase 1, 2, and combine the two.

Dr. Alex Drilon:

Absolutely. That's right.

Dr. Diane Reidy-Lagunes:

Any downsides to being on an earlier phase study then? Because like you said, a lot of the very cool science starts off in the earlier phase, but these are novel new drugs that really haven't been tested yet.

Dr. Alex Drilon:

This is good to talk about because you brought up that beyond looking for the dose on a phase 1 trial, you also want to make sure that the new treatment is safe for patients. And because of that and the fact that we're still very unfamiliar with the new treatment, there are many more assessments or visits or tests then one might have on a phase 2 trial or a phase 3 trial.

So there are some phase 1 trials where you might have to come every week in the interest of your safety. We want to watch you very closely. There are others which are a little bit more intensive, where you might have to come three days the first week. Some of the newer immune therapies, for example, you may need to even be in the hospital for the first treatment just to make sure that we're really watching over you closely.

And when I say you have to be here a few days, some of those days can be very long. One thing that we do on a phase 1 trial is we want to make sure that we're not undershooting or overshooting the amount of drug that we're giving, so we often measure the levels of these new drugs in the blood. To do that, we have to do many blood draws across a full day and sometimes the next day, and we check other things like the heart. So whereas in regular treatments you might get just one ECG or EKG, you probably will get many EKGs on a phase 1 trial just to make sure that the rhythm and conduction of the heart looks good.

But despite the fact that there are many more assessments and that it's much more of a time commitment, it has been worth it for our patients that have access to these new treatments that really turn things around for them. They might have had horrible symptoms from their cancer and were not in a good place. I've seen some of these newer treatments get people back to going out with their friends, spending time with their family, going back to work and doing the things that they want to do.

Dr. Diane Reidy-Lagunes:

Absolutely. Let’s hear from Grace who was on an immunotherapy research trial.


My name is Grace. I'm 28 years old. I was 18 when I was first diagnosed with adrenal cancer, and then I was 20 years old when I first went on an immunotherapy research trial and 22 when I finished. Now ever since, I've been thriving and cancer free. When I first entered the trial, I was only one of I think 20 people, and I knew at that point that it did not work for a few people. I also knew that it worked for some people, even after just one treatment.

Dr. Diane Reidy-Lagunes:

Grace is an example of somebody that really reaped enormous benefits from one of our trials at MSK, and like you said, some of our earlier phase studies have had remarkable responses. What does that mean for our patients though? When you go in to some of these early phase studies and you see that we are getting such great success, is there something in the secret sauce here or is there something that we should know about as it relates to these phase 1 studies, in the way that you as Chief select them?

Dr. Alex Drilon:

I think what we've tried to do is be very thoughtful with the types of trials that we bring in. The number of trials that we do at Memorial Sloan Kettering, or that any center does, is really a fraction of what's out there in the world. What we try to do is leverage what our experts know, especially those that have done a lot of research – like our scientists in the laboratory, for example – and look at the field and say, “Well, maybe we have 4 or 5 different options. Which is the best one to bring in that may have, if we were to guess, the highest likelihood of turning around somebody's cancer?” It's all about trying to pick the best possible drug.

But the other thing that we do is we look at which patients are referred to the phase 1 clinic. Sometimes we see that we're getting a lot of referrals for say, colon cancer, and we don't have as many trials for that population. So we will then go out and look for a good trial for those patients just so we fill in those spaces and reach more patients.

Dr. Diane Reidy-Lagunes:

Can you talk to us a little bit about how you find those patients, and how patients can enroll in these phase 1 studies?

Dr. Alex Drilon:

I think we are a unique center with a unique strategy for this. The first few things I'm going to say are ways that patients can get on a trial at any center, any hospital around the world, where the doctor hears about it and the doctor brings it up with a patient, or the patient, their friends or their family might hear about something and then they bring it up in the clinic.

Here, we have a system where you can have sequencing of your cancer to look at its genes, which can be targets for these new therapies. So when we’re looking at those genes, we might also be looking at targets for immune therapies: things like the number of mutations in the cancer, for example, or certain features of the cancer. We have a computer system that allows us to match some of these targets to a particular trial that's open and taking patients at the center, and there's an email that's sent out to the doctor taking care of the patient that says, “Hey, this is available. It might be a good fit.”

What we’ve found is that that interaction, that reaching out directly to the doctor, helps maximize awareness of what we have. I feel like that extra layer, among other things that we're trying to do in the phase 1 unit, has really brought in more patients that overall seem better matched to the trials that we have.

Dr. Diane Reidy-Lagunes:

That's great. So we've been talking a lot about the earlier phase studies. Some of the later phase studies have a placebo arm potentially in the study. Let's hear from Alicia who was diagnosed with brain cancer at age 27. She was on a placebo arm of a double-blind study before actually getting the real drug.


My name's Alicia. I'm a nurse anesthetist. I'm 32 years old and I was diagnosed with a grade 2 astrocytoma in 2018. It's a brain tumor, it's low grade and it's in my right frontal lobe. I had surgery to remove the brain tumor in 2019. I had MRI scans every 3 months for about a year when my tumor started growing again, and that's when I found out about the clinical trial that I could join. It was a double-blind study with a placebo arm, so I could either get the placebo or the real drug. So I started the trial. By December of 2021, my tumor had grown 20% from the baseline, so I was unblinded and I was on the placebo for that entire year and a half. I had the option to transfer over to the real drug and I took that, and I've had no growth since.

Dr. Diane Reidy-Lagunes:

Alicia's story is a pretty powerful one for us to learn from. Alex, a lot of people have a strong fear of being on a placebo like she was for so long, and what if the tumor grew to a point where we got into trouble? But she was able to cross over to get the therapy, which has been successful in her situation. Can you talk about the difference between single-blinded and double-blinded studies, and any advice to patients who may be potentially eligible for these types of studies but are really worried about it?

Dr. Alex Drilon:

I think that the concept behind this is that if someone that's treating a patient or the patient knows what they're getting – you know, is it the sugar pill or is it the real treatment – then that may influence the outcomes of the study. So what happens is, you introduce what you mentioned, which is blinding.

In a single blind study, the patient doesn't know if they're getting placebo or the actual therapy. And in a double-blind study, which is much more rigorous, neither of the patient nor the doctors or advanced practice providers treating the patient, neither of those groups know if they're on the placebo or the actual treatment. And I think that can be very nerve-wracking because obviously if you get assigned to the placebo arm, you're functionally not getting any treatment.

One piece of advice is to discuss the trial with your doctor before you agree to it. Certainly there are situations where a doctor will look at both the trial option and other options that are approved for your cancer and say, “You know, given that there's a possibility that you'll be assigned to the placebo, is that safe? Because if it’s not a good idea, I'd rather give you something that's already approved.” However, there certainly are patients where the cancer might have shown some growth but isn't growing at an incredible rate where it's reasonable to say, “Well, you could be assigned to the placebo arm or to the actual therapy.”

Now recognizing that that still might not be the best possible situation, we've introduced this idea of the cross-over, where if you are on the placebo arm, the study eventually gives you access to the treatment itself so you can cross over and get the true treatment, which is much, much better than getting the placebo and never getting the actual therapy.

Dr. Diane Reidy-Lagunes:

I think that’s absolutely right. Again, just to reiterate, have a conversation with your doctor on the pace of your disease and if it's a safe decision to enroll in such a trial, knowing that there is a possibility for you to be on placebo and could your cancer sort of get away from us, if you will. Many cancers that I take care of, as you know, are much slower growing and so we have the opportunity to run the test of time and then also have the potential for that crossover, which is tremendous, like for Alicia where it's been working for so long. So I think that conversation is pivotal.

We talked a little bit about, at MSK, there’s one way that we know if a clinical trial is available and if you may potentially be a good candidate for that. But I'm sure like you, I have many patients that do a lot of research on the internet and try to sort of look for all these different trials, and it can get really overwhelming. So any thoughts for patients that say, “I would travel anywhere”? Because, like you said, there's a huge time commitment, there's a cost, and it's really unclear if these trials are going to help or not. So any advice that you give your patients on whether they should be traveling for these studies or not?

Dr. Alex Drilon:

It really gets to that question, “Is it worth it for me?” And the first step is obviously to talk to your doctor because while your doctor might not have every trial at his or her hospital, your doctor might know what else is out there. And if there's something that's really exciting and interesting, even if it involves you going to a different state or sometimes even a different country, especially if it's a situation where it's a new drug that works in 8 out of 10 patients, those are tremendous odds that something could help you. I think that’s reasonable.

Another example is when we developed targeted therapies for a target called NTRK, the clinical trials actually paid for some patients to fly in from other countries. So we had patients come to the institution from China, from Brazil, they would fly over every month and get this therapy. But it was worth it because it worked in the majority of patients, and patients got their quality of life back and were able to go back to work. It's really a conversation about the odds.

In terms of figuring out what else is out there, beyond talking to your doctor, it would be good to look into whether or not there is an advocacy group for your particular cancer. I've seen this a lot where there's a lung cancer advocacy group that looks at these different trials for you. There are some groups that are very specific. There's a group that targets NTRK trials called the N Trackers, and there's a Facebook page where people share their experiences on different trials and share resources with each other, so that's another good way of finding out what's out there.

Dr. Diane Reidy-Lagunes:

That’s a great idea. Can patients drop out of clinical trials?

Dr. Alex Drilon:

Yes, and it's important to emphasize that when you say yes to a clinical trial and sign the informed consent, it is not binding. You can decide at any point in time, even a second after you sign, that you don't want to do it. So it's important that your doctor has that conversation with you.

Patients can drop out of trials for several reasons. There are some that may be very sensitive to therapy, that can have bad side effects even when we try to lower the dose, and they decide that it's not worth it and they come off. There are patients where we've tried to do our best with matching them to the trial, but despite trying it, the scans don't look good and the cancer is still growing. Those patients should definitely come off a trial to do something else. Like I said, this is really your choice. And if you decide that the burden of coming in for several visits a month is way too much, you can opt out. We've seen a few patients do that, where they thought that they were okay with the commitment, but it was just too much for them and their family.

Dr. Diane Reidy-Lagunes:

Absolutely. Sometimes though, patients feel like they don't necessarily know the outcome. Is there communication to learn about what happened, in terms of the outcome of that medication and if it was approved? Is there any feedback for patients that are enrolled in these studies?

Dr. Alex Drilon:

We get this question a lot. We mentioned before that there are extra blood draws, extra tests that are done, and some of those are done to help understand how well a drug might work, and often those results aren't immediately disclosed or released to patients. I think that we as a community can be a little bit better with this since someone is committing to the trial and it's a lot of time and effort for them, their family and friends.

Eventually, if a trial works out well, we present the data at a conference or it's published in a paper so that the information gets into the public domain. But one of the challenges is, before a disclosure like that or a conference like that, the data is embargoed, meaning that we can't really release it because we have to make sure the analysis is done right and that we had enough patients to make a decision. So it is one of the challenges that we deal with on clinical trials.

Dr. Diane Reidy-Lagunes:

Yeah, we need to circle back more often, I totally agree. Any final thoughts for our patients or their loved ones who may be listening and interested in pursuing clinical trials?

Dr. Alex Drilon:

This goes back to what we talked about in the beginning: clinical trials today are very different from the clinical trials of 20, 30 years ago. Being in the phase 1 clinic, we see a lot of new treatments come through that have shown a lot of promise. So it's something that I would definitely consider because it gives you an option that you would otherwise not have had. The rewards can be great if you have a very good fit for your cancer.

Dr. Diane Reidy-Lagunes:

Well, keep on going. Thank you so much for joining us today and for all you do.

Dr. Alex Drilon:

You’re welcome. It was great being here.

Dr. Diane Reidy-Lagunes:

Thank you for listening to Cancer Straight Talk from Memorial Sloan Kettering Cancer Center. For more information or just send us your questions, please visit us at Help others find this helpful resource by rating and reviewing it on Apple Podcasts or wherever you listen. Any products mentioned on the show are not official endorsements by Memorial Sloan Kettering. These episodes are for you but are not intended to be a medical substitute. Please remember to consult your doctor with any questions you have regarding medical conditions. I'm Dr. Diane Reidy-Lagunes. Onward and upward.