Read the Full Video Transcript

Alicia Morgans: Hi. I'm so excited to be here today with Dr. John Taylor, who is joining me from the University of Kansas here at GU ASCO 2025, where you presented the LEGEND trial, really exciting. Please tell me a little bit about this study. Tell me about this gene and-- in the non-muscle-invasive BCG-refractory setting.

John A. Taylor, III: Sure. So this is a pivotal trial for the EG-70 drug. We got to say it at least once. It's detalimogene voraplasmid-- I think is the technical name. But this is an immune-stimulating drug. It is a non-viral vector, which makes it unique in the field, to some degree.

It is a non-vector carrier. And it carries genes that stimulate the RIG-I pathway. I believe that's the retinoic acid gene-activating pathway. And that's the first line of defense in our cells against bacterial and viral invasion. And that stimulates the innate immune system. It also causes local stimulation of interleukin 12, which enhances T cell activation and activity. So it also hits the adaptive immune system.

So the trial we presented today is the phase II trial. They've already completed the pivotal phase I trial, which did safety and tolerability, as well as the direct to phase II dose. So the phase II trial has several cohorts. We're presenting mostly on cohort 1. Cohort 1 is the BCG-refractory non-muscle-invasive high-grade disease with CIS.

We have data on 21 patients from that cohort so far. So the anticipated enrollment is about 100. And they'll receive the drug intravesically. They can have up to four cycles initially. And if they have a complete response, they can go out to eight cycles, which would be a total of two years.

Alicia Morgans: So really interesting. So tell me a little bit about this drug. The non-muscle-invasive BCG-refractory setting seems to have gotten pretty crowded in the last few years, which is a great thing for patients, especially given BCG and refractory diseases or unresponsive diseases is not a good thing to have. So can you share a little bit about what makes this drug unique and why it's important to continue to develop it?

John A. Taylor, III: So I think that the space, fortunately, is getting crowded. Most of the novel agents that are out there are doing what EG-70 is doing. They're harnessing the immune system in some way-- so some ode to BCG, our historical immunotherapeutic. But they're doing it in a different manner, in a more directed manner.

All of these drugs, with the exception of some of the PD-1/PD-L1 inhibitors that are approved or being tested in this space, are administered intravesically. A lot of the difficulty with intravesical administration is patient discomfort with treatments, mostly local irritation, but more importantly, the preparation of the agent. And BCG requires preparation under a hood. A lot of these other agents require cold storage and preparation. Some of them do require a terminal decontamination at end of treatment.

The novel aspect, the unique thing about the EG-70 is it's stored at room temperature in a lyophilized powder. It can be mixed in the procedure room or the treatment room or the office without a hood, without any special precautions, with just sterile water.

The administration is similar to many others. Dwell time is roughly similar. But one of the data points that we presented was the lack of significant treatment-related AEs. So if you look at efficacy, it's right along the line of other drugs that are out there, which is good. It doesn't necessarily need to be dramatically better. It needs to be a tool in the toolbox. And that's the neat thing about the space now-- is we have so many tools that we can potentially reach for.

The treatment-related AEs were no more than grade 1 or grade 2. And in hindsight, they were mostly related to administrative route, catheterization. So they predominantly irritated voiding symptoms-- urgency, frequency, a little dysuria-- but no significant systemic or other AEs associated with the treatment.

Alicia Morgans: Wow. That's so important. And as you said, certainly from a patient perspective, it's important to have low levels of AEs. Also, from a clinician perspective, it's difficult sometimes to respond when things are really difficult for patients to tolerate. But also really interesting that this can be mixed with sterile water, even in that clinical space, without requiring the hood and without requiring those procedures to inactivate it at the end-- does this make a difference in your practice just in terms of the flow of things and the way that busy urologic practices tend to function?

John A. Taylor, III: Yeah, I think so. And again, I practice in an academic setting. So we're used to this type of flow with other agents and other drugs. I think for an office-based practice, it makes it a lot easier. The ability to just have the drug stored in your office, to mix it in your office-- you don't need special hoods or other entities to use this agent. I think that really makes this novel with the ease of use.

And back to the AEs, the other thing that-- it's important for patients because, remember, for most of these patients, they've had multiple rounds of treatments. Their bladders can be pretty beat up. And they can have significant problems holding agent or having other issues when they come into these types of trials.

And the fact that they tolerated this agent so well is really important.

Alicia Morgans: Absolutely, especially since some of these patients may, in addition to having their bladders beat up-- they're older patients in a lot of cases and can have other medical conditions that make it just difficult to do some of the things that we ask them to do. So as you think about this and think about the response rates that you mentioned earlier, can you put that in context for us? And how long did this study report on followup in terms of the sustained disease control?

John A. Taylor, III: So the disease that we reported is what most of the trials are looking at, which is an any-time response rate, which was around 71%. And again, I just have to go back. These are BCG, refractory BCG, recurrent patients who have really no other option other-- potentially cystectomy. Now maybe we do have other options.

So the overall response rate or any-time response rate was 71%, which is right in the ballpark what we're seeing with other agents as well. The three-month complete response rate was 67%. And the six-month response rate was 47%.

The year data is not out. Kaplan-Meier estimates put it around 51%. So we're seeing roughly around a 50% 12-month complete response rate, which is great, A, for the patient population. And B, it's right in line with the other entities that we're seeing less the treatment-related AEs.

Alicia Morgans: Great. So if you had to put this data and put this agent in context and give a message to the listeners, what would that message be?

John A. Taylor, III: Stay tuned would be my answer. I think as a urologist in this space, it's extremely exciting. If you look back 15 years ago, we had BCG and mycobacterium cell wall complex. And that was it. Fifteen years later, we've got trials in phase-- completed phase I, in phase II, all showing similar efficacy, which is good in this disease space. And we're going to have lots of tools.

The future is going to be, how do we sequence these? How do we combine them? What do we do with them? How do we benefit our patients to help them overcome this disease? So I think the future is very exciting, including EG-70 and the other agents that are coming out.

Alicia Morgans: Wonderful. Well, I love that message, stay tuned. And we certainly will. I congratulate you on your presentation at GU ASCO 2025. And I thank you for your time and expertise today.

John A. Taylor, III: Thank you. It's my pleasure.