Dr. Sumanta (Monty) Pal and Dr. Petros Grivas discuss innovative new intravesical therapies and other recent advances in the treatment of non-muscle invasive bladder cancer.

TRANSCRIPT

Dr. Sumanta (Monty) Pal: Hello and welcome. I'm Dr. Monty Pal here at the ASCO Daily News Podcast. I'm a medical oncologist and professor and vice chair of academic affairs at the City of Hope Comprehensive Cancer Center in Los Angeles. And I'm really delighted to be your new host here.

Today's episode is going to really sort of focus on an area near and dear to my heart, something I actually see in the clinics, and that's bladder cancer. We're specifically going to be discussing non-muscle invasive bladder cancer, which actually comprises about 75% of new cases.

Now, in recent years, there's been a huge shift towards personalized bladder-preserving strategies, including innovative therapies and new agents that really are reducing reliance on more primitive techniques like radical cystectomy and radiation therapy. And I'm really excited about this new trend. And really at the forefront of this is one of my dear friends and colleagues, Dr. Petros Grivas. He's a professor in the Department of Medicine and Division of Hematology Oncology at the University of Washington. It's going to take a while to get through all these titles. He's taken on a bunch of new roles. He is medical director of the International Program, medical director of the Local and Regional Outreach Program, and also professor in the Clinical Research Division at the Fred Hutch Cancer Center. Petros, welcome to the program.

Dr. Petros Grivas: Thank you so much, Monty. It's exciting for me to be here.

Dr. Sumanta (Monty) Pal: Just FYI for our audience, our disclosures are available in the transcript of this episode. 

We're going to get right into it, Petros. Non-muscle invasive bladder cancer, this is a really, really challenging space. We see a lot of recurrence and progression of the disease over time, about 50% to 70% of patients do have some recurrence after initial treatment, and about 30% are ultimately going to progress on to muscle-invasive or metastatic disease.

Now, I will say that when you and I were in training, non-muscle invasive bladder cancer was something that was almost relegated to the domain of the urologist, right? They would use treatments such as BCG (Bacillus Calmette-Guérin) in a serial fashion. It was rare, I think, for you and I to really enter into this clinical space, but that's all changing, isn't it? I mean, can you maybe tell us about some of the new therapies, two or three that you're really excited about in this space?

Dr. Petros Grivas: Monty, you're correct. Traditionally and conventionally, our dear friends and colleagues in urology have been managing patients with non-muscle invasive bladder cancer. The previous term was superficial bladder cancer. Now, it has changed, to your point, to non-muscle invasive bladder cancer. And this has to do with the staging of this entity. These tumors in superficial layers of bladder cancer, not invading the muscularis propria, the muscle layer, which makes the bladder contract for urine to be expelled.

As you said, these patients have been treated traditionally with intravesical BCG, one of the oldest forms of immunotherapy that was developed back in the 1970s, and this is a big milestone of immunotherapy development. However, over the years, in the last 50 years, there were not many options for patients in whom the cancers had progression or recurrence, came back after this intravesical BCG. Many of those patients were undergoing, and many of them still may be undergoing, what we call radical cystectomy, meaning removal of the bladder and the lymph nodes around the bladder. The development of newer agents over the last several years has given the patients the option of having other intravesical therapies, intravesical meaning the delivery of drugs, medications inside the bladder, aiming to preserve the bladder, keep the bladder in place.

And there are many examples of those agents. Just to give you some examples, intravesical chemotherapy, chemotherapy drugs that you and me may be giving intravenously, some of them can be given inside the bladder, intravesical installation. One example of that is a combination of gemcitabine and docetaxel. These drugs are given in sequence one after the other inside the bladder, and they have seen significant efficacy, good results, again, helping patients keeping the bladder when they can for patients with what we call BCG unresponsive non-muscle invasive bladder cancer. And again, there's criteria that the International Bladder Cancer Group and the FDA developed, how to define when BCG fails, when we have BCG unresponsive non-muscle invasive bladder cancer.

Dr. Sumanta (Monty) Pal: And we're actually going to get into some of the FDA requirements and development pathways and so forth. What I'm really interested in hearing, and I'm sure our audience is too, are maybe some of the new intravesical treatments that are coming around. I do think it's exciting that the gemcitabine and docetaxel go into the bladder indeed, but what are some of the top new therapies? Pick two or three that you're excited about that people should be looking out for in this intravesical space.

Dr. Petros Grivas: For sure, for sure. In terms of the new up-and-coming therapies, there are a couple that come to mind. One of them is called TAR-200, T-A-R 200. This agent is actually a very interesting system. It's an intravesical delivery of a chemotherapy called gemcitabine, the one that I just mentioned a few minutes ago, that is actually being delivered through what we call a pretzel, which is like a rounded [pretzel-shaped] structure working like an osmotic pump, and that is being delivered inside the bladder intravesically by urologists. And this drug is releasing, through the osmotic release mechanism, this chemotherapeutic drug, gemcitabine, inside the bladder. And this can be replaced once every 3 weeks in the beginning. And the data so far from early-phase trials are really, really promising, showing that this agent may be potentially regulatory approved down the road. So TAR-200 is something to keep in mind.

And similarly, in the same context, there is a different drug that also uses the same mechanism, and this osmotic release, this pretzel, it's just encoded with a different agent. The different agent is an FGFR inhibitor, a target therapy called erdafitinib, a drug that you and me may give in patients with metastatic urothelial carcinoma if they have an FGFR3 mutation or fusion. And that drug is called TAR-210.

Dr. Sumanta (Monty) Pal: And can I ask you, in that setting, do you have to have an FGFR3 mutation to receive it? Or what is the context there?

Dr. Petros Grivas: So for TAR-210, TAR-2-1-0, usually there is a checking to see if there is an FGFR3 mutation or fusion. And the big question, Monty, is do we have adequate tissue, right? From a limited tissue on what we call the TURBT, right, that urologists do. And now there is a lot of development in technology, for example, urine circulating tumor DNA to try to detect these mutations in the urine to see whether the patient may be eligible for this TAR-210. Both of those agents are not FDA approved, but there are significant promising clinical trials.

Dr. Sumanta (Monty) Pal: So now let's go to a rapid-fire round. Give us two more agents that you're excited about in this intravesical space. What do you think?

Dr. Petros Grivas: There is another one called cretostimogene. It's a long name.

Dr. Sumanta (Monty) Pal: They really make these names v