TTFields in Locally Advanced Pancreatic Adenocarcinoma

Host Dr. Shannon Westin and guest Dr. Hani Babiker discuss the JCO article "Tumor Treating Fields With Gemcitabine and Nab-Paclitaxel for Locally Advanced Pancreatic Adenocarcinoma: Randomized, Open-Label, Pivotal Phase III PANOVA-3 Study."

TRANSCRIPT

TTFields in Locally Advanced Pancreatic Adenocarcinoma

Dr. Shannon Westin: Hello everyone, and welcome to another episode of JCO After Hours, the podcast where we get in depth with manuscripts that have been published in the Journal of Clinical Oncology. I am your host, gynecologic oncologist Shannon Westin, social media editor at the JCO, and just excited to be here to learn today about pancreatic cancer.

None of our participants have conflicts of interest related to this podcast, and it is my honor to introduce Dr. Hani Babiker. He is an associate professor of medicine, consultant in oncology at the Mayo Clinic in Jacksonville, Florida.

Welcome, Dr. Babiker.

Dr. Hani Babiker: Hi, Dr. Westin. Thank you for the great opportunity to discuss our trial, and thank you for having me here. I really appreciate it, and I am excited.

Dr. Shannon Westin: All right, so are we. So we are going to be talking about “Tumor Treating Fields with Gemcitabine and Nab-Paclitaxel for Locally Advanced Pancreatic Adenocarcinoma: A Randomized, Open-Label, Pivotal Phase III PANOVA-3 Study.” This was simultaneously published and presented in the JCO and at the annual meeting of ASCO on 5/31/2025.

So, let's level set. Can you speak to us just a little bit about pancreatic cancer? What is the survival, and what is the typical treatment for locally advanced disease? This gynecologic oncologist has not kept up in this field.

Dr. Hani Babiker: Absolutely, Dr. Westin, and thank you for that question. Pancreatic adenocarcinoma is a lethal cancer. When I first started my career, the 5-year survival, per the Surveillance, Epidemiology, and End Results, was at 4.5%. I always, whenever I was giving talks, say that I really hope that I will see it in the double digit. Now, the 5-year survival for all pancreatic adenocarcinoma is 13.3%. And the 5-year survival, and although it is a double digit, I still hope that I will see it in a higher double digit in the future. It is even worse in patients with metastatic cancer, about 3% 5-year survival for metastatic pancreatic cancer. It is a dismal diagnosis. I really hope in the future we will find a better therapeutic approach to this lethal cancer.

Dr. Shannon Westin: Yes, I just lost a very dear friend and colleague to this disease, so I completely agree with you.

Well, now that we are settled kind of with the basics here, I would love to talk a little bit about kind of the primary piece of this intervention, the Tumor Treating Fields. So, how does this work? And what diseases has it gotten indications in as yet?

Dr. Hani Babiker: Absolutely. So, Tumor Treating Fields is alternating frequency electrical fields that have been studied preclinically and shown that it abrogates cancer cell proliferation. Earlier on, we knew that it inhibits polymerization of tubulin, and hence, it affects cancer cells from proliferating. Later, we are learning that there are multiple mechanisms of action. It affects permeability, allowing for better drug delivery. It also inhibits cancer cell proliferation through affecting autophagy mechanisms that pancreatic cancer cells will use for proliferating and becoming more aggressive. There is also some early data preclinically in colorectal cancer cell lines and lung cancer cell lines and in vivo models showing that it potentially could activate the microenvironment to make it more pro-immunogenic. We recently published papers showing that it could also affect the nanomechanical properties of the tumor microenvironment within pancreatic cancer, hinting towards affecting, potentially, the stroma.

So, there are multiple mechanisms to Tumor Treating Electric Fields. It is a new, novel therapeutic approach. Sometimes when I speak with my trainees, I say, "Well, we have surgery, we have radiation and chemotherapy, and this is something new." Tumor Treating Fields initially was studied in refractory GBM and got an indication there. Subsequently, frontline treatment of GBM in a randomized clinical trial, and then malignant pleural mesothelioma and non-small cell lung cancer. We have studied it in pancreatic cancer.

Dr. Shannon Westin: I don't think I have ever heard it described so perfectly. That was brilliant. So thank you, and I hope everyone listening knows that you just got a masterclass on this mechanism. You know, they dabbled in it a little bit in ovarian cancer and it didn't quite make the grade, so I was a little definitely disappointed. But very excited about the data we're going to talk about today.

So let's get into the PANOVA-3 study. Can you highlight the overall design and also the key eligibility criteria that would be helpful for our listeners?

Dr. Hani Babiker: Absolutely. So, it started off with preclinical work in pancreatic cancer showing Tumor Treating Fields with chemo abrogate cancer cell perforation. It led to a trial, the PANOVA-2 trial, that was run in Europe that showed efficacy for OS and PFS in patients with locally advanced pancreatic cancer, which included metastatic and locally advanced pancreatic cancer, more so in locally advanced that led to the PANOVA-3 trial, which was an international, global study. This was in more than 190 centers, 20 countries in Latin America, North America, Europe, and Asia. It was a randomized trial. Patients were randomized 1 to 1 to either chemotherapy with gemcitabine plus nab-paclitaxel per drug label. The other arm was with Tumor Treating Fields at 150 kHz for a recommendation for patients to wear it 18 hours per day.

The primary end point of the trial was OS, overall survival. The secondary end point included other efficacy landmarks such as local PFS, pain control, quality of life, and safety. And there was a post hoc that looked at distant PFS.

Dr. Shannon Westin: That's a pretty common secondary end point in pancreatic studies of looking at the pain-free interval. I thought that was really brilliant because, you know, I think in gyn cancers, we see resolution of symptoms as being a really big deal, but it's not necessarily something that we always look at. So I thought that was really nice that you included that.

Okay, talk to us a little bit about the population. So, the population that actually got treated in PANOVA-3 is pretty generalizable to what people are treating in the clinic.

Dr. Hani Babiker: So, in pancreatic cancer, unfortunately, most of our patients present, approximately 80%, with metastatic disease. Local is divided to resectable, borderline, and locally advanced. We studied this trial, a randomized trial, in locally advanced and unresectable, which is really an unmet need. Most of our patients with locally advanced and unresectable are grouped up with other trials in the metastatic setting without a focus on locally advanced and unresectable, save for a few trials. This year, a trial that we were looking for for a long time, the LAPLACE trial, unfortunately, that we were very excited about, this is a molecule that targeted connective tissue growth factor, that showed earlier efficacy in a randomized trial, did not meet up the median OS end point. And hence, PANOVA-3 is the first trial in locally advanced and unresectable that did meet its primary end point.

So, it's a very unmet need in locally advanced and unresectable. A lot of the times, our patients in clinic are treated with frontline chemotherapy that was studied in metastatic disease and locally advanced and unresectable, which include either FOLFIRINOX, NALIRIFOX, or gemcitabine/abraxane. I do have in my clinic multiple patients that would stay on the regimen for such a long time, and then we would have to devise a mechanism of maintenance, although this is not studied really in details, either with capecitabine or dropping the oxaliplatin to continue FOLFIRI. And then we also approach chemoradiotherapy. So the trial was in a disease in pancreatic cancer that really is an unmet need.

So the inclusion criteria included a patient with locally advanced and unresectable. These were done at multiple centers. Most of them academic centers were discussed at the tumor board, and if it's unresectable, they will be meeting specific metrics of appropriate liver function tests, kidney function tests, and blood counts. We excluded patients that obviously had, given that these are electric fields, patients that have, for example, stimulators or pacemakers, knowing that this could potentially affect some of these devices. But for the most part, it was locally advanced and unresectable patients with a very good performance status and good counts.

Dr. Shannon Westin: That's great. I think everyone's excited to hear about the primary outcome of overall survival. What did you find, and how does it compare to some of the recent trials?

Dr. Hani Babiker: We're very excited that it did meet its primary end point of median overall survival. It was very exciting knowing that a lot of us were disappointed a little bit of some of the trials that were presented at ASCO GI, such as the LAPLACE trial that I alluded to. Just before the presentation, the PRODIGE 29 trial that is in locally advanced and unresectable that randomized patients with locally advanced disease to either FOLFIRINOX or single-agent gemcitabine, allowing for a crossover, although it did meet its primary end point of PFS, there was no overall survival benefit. So that kind of got us a little bit disappointed, but having the PANOVA-3 trial being positive in median OS got us all excited.

In addition, the 12-year overall survival rate was increased in both the intention-to-treat and modified intention-to-treat. The modified intention-to-treat were patients that have had at least one cycle of therapy with TTFields daily and/or one cycle with chemotherapy, which was gemcitabine plus nab-paclitaxel. There was a trend to improvement in PFS and local PFS, although that did not have statistical significance, but the 12-year PFS rate in both the intention-to-treat and modified intention-to-treat was significant. For me, as one of the investigators, that told me that there might be a specific biomarker that would tell me that patients could respond greater than others, more exceptional than others, given that 12-month PFS rate was improved. On a post hoc analysis, the distant PFS was improved with the intervention of Tumor Treating Fields with gemcitabine plus nab-paclitaxel. In addition, there was an improvement in global health status and quality of life in addition to pain-free survival, which is a strong hurdle in our patients with pancreatic adenocarcinoma that most present with significant abdominal pain.

Dr. Shannon Westin: One of the other questions that I think has come up is around central review. So did you all use central review in this study?

Dr. Hani Babiker: Most of the centers were academic centers. These were discussed in tumor boards, which included radiation oncologists and surgeons. I wanted to point out that it's very important to note that the primary end point was overall survival. So the primary end point was not PFS. Hence, the central review would help us, for example, with elaborating and making sure patients were actually locally advanced disease, but in a setting where the primary end point is overall survival, that was the key point of the clinical trial. This trial was discussed at academic centers, and all included tumor boards to decide if patients were locally advanced or not. In the trial, there was a good proportion of patients, or percentage, that had a CA 19-9 more than 1000. That could indicate that potentially there are a fraction of patients that actually had metastatic disease, micrometastatic disease. So that could hint towards why the median OS was slightly lower then in both arms when compared to, for example, the trial that was presented at ASCO GI, the LAPLACE trial. However, having said that, we were very excited about the trial. It was the first positive trial in locally advanced and unresectable to meet median OS survival.

Dr. Shannon Westin: It's so awesome. So congratulations. Okay, so let's talk a little bit about your very detailed secondary end points because you had a lot of really prudent choices there. So anything that was interesting or informative in those end points?

Dr. Hani Babiker: One major hurdle back we have for most of our patients with pancreatic adenocarcinoma, like I mentioned earlier, is pain. We try to approach it, obviously, with narcotics. If it doesn't work, we try to do celiac axis block interventionally, and that sometimes is successful and sometimes is not. So actually, to see the pain-free survival end point to be met was very exciting for us. And as for me, as a scientist that studies TTFields in clinic and lab as also to develop a mechanism and understanding really how that works. That was very important for us that in addition to chemotherapy, it improved pain-free survival or deterioration of pain. And most importantly, our patients with pancreatic cancer, this disease is very aggressive. It affects quality of life of patients. Patients feel fatigued, tired. It's a procoagulant tumor that causes clots and strokes, etcetera, marantic endocarditis. And one big problem we deal with when we're seeing patients in clinic is obviously that quality of life. Although data have shown with treatment, with frontline regimens, that quality of life improves with treatment and chemotherapy, it's actually great to see that that improvement happens early in addition to Tumor Treating Fields.

The other interesting point was that it was not only pain and quality of life, but also digestive symptoms that are improved with this intervention, knowing that a lot of our patients do have pancreatic cancer, pancreatic exocrine insufficiency that affect also with digestion, and a lot of our patients have abdominal pain after eating and diarrhea. So it was interesting to see that also improved with the intervention.

Dr. Shannon Westin: You have touched a little bit on some of the adverse events, kind of with the TT mechanisms, but I'd love to hear a little bit more detail around adverse events in general in this study, as well as specific AEs related to the Tumor Treating Fields.

Dr. Hani Babiker: Absolutely. So when we compared both arms, there was a similar toxicity related to the regimen, mostly with chemotherapy, but in specifically to Tumor Treating Fields, there was a rash, and that included dermatitis and rash. Most of the side effects were grade 1 and grade 2. Grade 3 toxicities related to skin was less than 10%, approximately 7% to 8%, and hence did not affect many patients. But it was something to note, and it's something that in the future, when we develop a mechanism of treating patients to note early. We in our clinic have learned to treat patients in the clinical trial early with topical steroids to each patient, of shifting the arrays to mitigate some toxicity and rash. We do advise our patients in hot areas, we keep them aware that sweating, for example, can lead to higher conductivity of electrical fields with a predisposition for rash. So if there's an opportunity to stay in a little bit of a cold area, make sure that the arrays are shifted, use topical steroids early. If it's a significant rash, to hold treatment for at least 48 hours and speak to the investigators. And through these mechanisms, we have learned that we were able to mitigate the rash quite a bit.

Dr. Shannon Westin: That's awesome. Thank you so much. Yeah, I'm, it's summer right now, and I think- I'm in Texas, you're in Florida, like we know.

Okay, so I guess, again, you have been kind of touching on this, but I would love to know, like if in the quality-of-life assessments or if just in your discussions with patients, like how easy is this to use? How easy is the Tumor Treating Fields device to use, and what do patients really think?

Dr. Hani Babiker: Absolutely. We have learned that whenever we speak with patients, it's always good to discuss with them briefly the science of it. A lot of patients would want to know if it's interventional, is that something that goes, is delivered percutaneously or not, and we explain that these are delivered through arrays that are through the skin. We always touch base with them about a lot of question I get about mechanism of action and then about compliance. So I think one important thing to note is that compliance with the use of the device is a lot of the question we'll get quite a bit. Patients know there's going to take an effort from them, and some of my patients enjoyed it because they felt like they also are fighting the disease by wearing the device. I have learned very quickly that having a team, surrounded by a team that knew how to mitigate some of the side effects and knew how to explain how to use the device helped quite a bit. And this included some of our nurses and our nurse practitioners and our clinical research coordinators who've done a wonderful job of showing these arrays actually to patients before they start on the trial, look at it, know how it works.

The other point to know is that the sponsor provided Device Support Specialist, we call them DSS, they have been instrumental in helping us, helping the patients know how to use the device, how to use the generator, how to change the batteries, and that helped us conduct the trials and enroll very well. I would envision in the future with education and relying on the Device Support Specialist and having a team that knows how to use the device and mitigate some of the side effects will go a long way for patients to learn about this treatment. Many of the times our patients said while they are on the clinical trial felt like they are also being part of this team in applying the device and fighting the cancer.

Dr. Shannon Westin: That's awesome.

Well, I guess the bottom line. Is it ready for prime time? Is this something you are going to use for your patients in the clinic?

Dr. Hani Babiker: Absolutely. In a disease that has poor prognosis, and we are trying our best to find new treatments to fight this cancer and treatment modalities, presenting patients with all the treatment options that are out there would be recommended. It's what I would do it for in my clinic. And you know, it's funny that I am mentioning that right now. I had a patient who was seen internationally asking about the trial and the device and had locally advanced and unresectable before they start frontline treatment. I do think that there is going to be an educational piece. Obviously, this is not a pill, it's not an intravenous chemotherapy that we're very well and accustomed to. And some of us in academic centers know it very well. I usually joke that whenever I am talking about it in pancreatic cancer, if there is a radiation oncologist in the room, they will be like, "Yeah, we know all about it. We have been treating patients with GBM over there." So a lot of the times, when we first went to trial, if I had any questions, I would call them and ask them. So from their perspective, they, because they use it as a standard of care in treatment of GBM, they develop significant expertise in it. I think in the GI world, specifically and with oncologists that treat pancreatic cancer and specifically oncologists in the community, learning about the device and how to use it, how to recommend it, how to mitigate side effects, will be hopefully for prime time in the future.

Dr. Shannon Westin: That's great. Sounds like some real educational opportunities there.

Well, this has been awesome. Thank you so much, Dr. Babiker. I mean, I learned a ton, and I wish that we could find a way to use this in gynecologic cancers, but really, really just want to commend you on the design of the trial and the success in this really devastating disease.

So again, this was "Tumor Treating Fields with Gemcitabine and Nab-Paclitaxel for Locally Advanced Pancreatic Adenocarcinoma: A Randomized, Open-Label, Pivotal Phase III PANOVA-3 Study."

And as always, I am your host, Shannon Westin. Please go check out our other offerings wherever you get your podcasts and have an awesome day.

The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions.

Guests on this podcast express their own opinions, experience, and conclusions. Guest statements on the podcast do not express the opinions of ASCO. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.

 

Dr. Babiker Disclosures

Consulting or Advisory Role: Endocyte, Celgene, Idera, Myovant Sciences, Novocure, Ipsen, Caris MPI, Incyte, Guardant Health

Speakers' Bureau: Guardant Health

Research Funding:  Spirita Oncology, Novocure, AstraZeneca, JSI, Incyte, Qurient, HiFiBiO Therapeutics, Revolution Health Care, Elevation Oncology, Dragonfly Therapeutics, Zelbio, BMS, Mirati Therapeutics, Strategia