Good thing this is webcast.
All right. Let's go ahead and get started here. So really happy to have Ron Martell, CEO of Jasper Therapeutics, up next. Really busy week for you guys, actually. So maybe you can just start off with an overview, maybe kind of recap the update that you gave this week, and then we'll go from there.
Sure, well, first of all, Gavin, on behalf of all of my colleagues at Jasper, really thank you and the Evercore team for the opportunity to be here today, so yes, Jasper Therapeutics, we're a clinical stage biotech company. Our lead program is monoclonal antibody, Briquilimab that we refer to as BRIC, in clinical development, in chronic spontaneous Urticaria, inducible Urticaria, and some exciting data that we announced yesterday in asthma, and we held a meeting yesterday to discuss an update on the Beacon study in chronic spontaneous Urticaria, as well as announce the asthma data.
Awesome. All right, so let's dive right into it. Let's start off on the CSU with the double-blind investigation. Maybe you can just, especially for those who weren't following along yesterday, I've been in meetings all day, so maybe you could recap it for me too. What were the key findings from the double-blind investigation?
Certainly, well, rewinding the clock a little bit to understand why we initiated this internal investigation was in July, we reported out data on what we refer to as cohorts eight and cohorts nine, and cohort eight is 240 milligrams Q8 week, and cohort nine is 240 milligrams, followed by 180 milligrams Q8 week. When we looked at those data back in July, we saw something very unexpected. We saw 10 of the 13 patients who did not have a clinical response, something highly unusual. Up to that point, at the 240 milligram dose level, we had seen five of five complete responses, and so to say that these were anomalous is a bit of an understatement, so we initiated an investigation, a broad-scope internal investigation, started off by looking at the drug product.
The reason we looked at the drug product was these two cohorts of patients. That was the first time we had ever used this specific lot of drug. We immediately asked the sites to no longer use that product. We sent them new product to redose the patients. We set about looking at everything, beginning all the way back at the raw materials and the drug manufacturing process, all the way through the end patient data. What we announced yesterday is the conclusion of that investigation is very clear evidence that there's nothing wrong with the drug product. Unfortunately, what happened was nine of these 10 patients don't have mast cell mediated CSU. As part of the investigation, we convened a panel of three independent key opinion leaders involved with clinical development in Urticaria.
We provided them with all of the findings, including individual dossiers on each patient. And they're the ones that came to the conclusion that these patients, unfortunately, don't have Urticaria.
All right. That makes sense. And I guess with that said, for the ongoing study and really all future studies, are you taking any different steps to ensure that doesn't keep happening?
Yeah. So one of the important things to note in Dr. Martin Metz, who was one of the KOLs on the panel and was on the call yesterday, he noted that in the world of Urticaria, probably 20%-25% of the patients are, let's use the term, misdiagnosed. Diagnosing CSU is a clinical diagnosis or a diagnosis by exclusion. So there is no biomarker, no biopsy that you can do. And even the trained experts get it wrong one in four, one in five times. And if you look at other clinical trials, and Dr. Metz pointed this out yesterday as well, if you look at other clinical trials in Urticaria focused on the mast cell, you probably see that type of a number in those clinical trials as well. So what can we do? What have we done?
For those new patients that were enrolling, we put a number of additional measures in, one of which is we put a third reviewer, clinical reviewer, in screening to evaluate these patients, to look at their medical histories. We require that patients have at least six months of history of a diagnosis with CSU. Other diseases like Urticarial vasculitis wax and wane a bit more. And with CSU, while yes, it's episodic, the episodes generally last two, three, five years. So if you've had it longer than six months, that probably is an indication. Also, if the patient is being referred into a medical center that specializes in CSU, we're requiring that the full medical history come along with the patient. So a number of those types of things that we've put into place.
Last but not least is certainly really identifying centers of excellence for diagnosing these patients.
All right. That makes sense. All right. So let's look ahead to Beacon then. Maybe just level set on expectations, both from an efficacy perspective and a safety perspective. What's a good outcome in your mind?
Yeah. So the data we'll have in our next upcoming data milestone, we've guided to be the first half of Q1. And there'll be a significant amount of data coming. We'll have data on the new patients in cohorts eight and nine. And so we'll stop there for a minute and talk about expectations around those patients. I think that previously with 240 milligrams, again, now an n of six at a single dose, we saw six of six have complete responses. While we're really excited about those data, I don't know that we should expect to continue to have a 100% complete response rate. So I think if we have an efficacy response rate that's similar to Celldex, which is around 50%, that would be an absolute win. I think anything above that then shows that we're better than Celldex.
I think what we're really focusing on is the safety data. And that was one of the important things we noted yesterday is while those 10 patients didn't have an efficacy response, we know that they all received active drug. And so all of those patients received at least one dose of 240, followed by 180, or six of those patients received 240 Q8 week and received at least three doses of 240. And the safety profile there looked really good. And that was one of the questions when we had the data earlier this year, looking at 240, saying, "Okay, you had great efficacy, but what happens to the kit-related adverse events if you repeat dose?" And we were really pleased by that. And so I think that, again, the bar is safety, what Celldex has seen.
But if we can deliver on what we think is the safety profile, given our half-life, then that's an absolute home run.
Yeah. And you're testing different dosing regimens. And I guess as you continue getting and analyzing additional data, what's your current a priori assumption for what the optimal dose is going to be and the dose regimen is going to be?
Yeah. I would say based on all the data we have now, and certainly with the data we'll present in early next year, and there's another data set coming that I'll talk about that will be our largest cohort to date, but based on all of the efficacy data we've seen now, I would say that going into the phase II-B study next year, one arm could easily be 240 Q8, and the other arm could easily be 240, followed by a maintenance dose of 180.
Also every eight.
Every eight. Yes. Yes. Correct.
That makes sense. All right. What about on the OLE side as we're looking ahead? What is the status of patients enrolling there? Is there going to be an update there alongside the full Beacon data? What should we expect?
There will be. So as part of the data, when we bring the data forward on the new patients in cohorts eight and nine, in addition to that, we'll have longer-term follow-up safety that I just described. But from the OLE, all of the patients from Beacon have been given the opportunity to roll over into the OLE. And we're really pleased that all but two of the patients chose to roll over. So they must have seen some benefit to want to continue to roll over into the open label extension. But having said that, let me be clear on the design. So Beacon is designed for 24 weeks. Then the patients have to wash out of the Briquilimab, and their UAS7 has to go to above 12. So their disease has to come back, and then they have an opportunity to come into the OLE.
In fact, the two patients that chose not to come into the OLE, that's because they went on to a different clinical trial, and they weren't eligible to. Specifically to your question, the data we'll have early next year on the OLE, we'll have somewhere between 35 and 40 patients on the 180 milligram Q8 week data. It'll be our largest cohort to date.
Great. And I guess beyond this update then, looking ahead at the phase II-B, what's your current thought on how that study will be designed and the capital requirements for that?
Yeah. So that study will be a three-arm clinical trial where we'll take two of the doses, and maybe the doses that we discussed earlier, we'll take those two doses in and a placebo arm. That study will probably be somewhere in the 100-120 patient range. If we look at what Celldex did, they had 40-50 patients in each arm, highly statistically significant based upon the powerful efficacy that we see with these antibodies. The cost of that study is probably somewhere in the $40-$50 million range.
Yeah. All right. Let's shift gears here. Let's go over to the asthma side of things for allergen challenge. Maybe you can just quickly recap the study design there. It's probably important to refresh. And then also kind of a top-line summary of the data from yesterday.
Our study in asthma that we refer to as the allergen challenge study is a classic allergic asthma study. The study was originally pioneered by Omalizumab years ago. And now if you look at almost every drug on through Tezspire, they conducted the same type of study. And in fact, at the same Canadian group at McMaster and McGill in Canada, they really specialize in these types of studies. It's a pretty straightforward study. Two weeks before administration of drug, patient comes in, receives an allergen challenge, whatever they're allergic to, cat, dander, pollen, mites, whatever it is, whatever their allergy is, measure their FEV1, do the blood draws, look at their sputum for Eosinophils. They come back in two weeks. They received 180 milligrams of Briquilimab. They go away for six weeks. Six weeks, they come back.
You give them that challenge again, measure their FEV1, take their sputum, et cetera. Same thing at 12 weeks. The end points of the study are six weeks and 12 weeks. Specifically at those time frames, it's the EAR or early asthmatic response and LAR. The EAR is from 0 to 120 minutes. The LAR is from the two-hour point to eight-hour time point. Really some interesting findings here. This study was really designed with a single dose, proof of concept. It's been known for a long time that mast cells are the conductor in the orchestra during the release phase of asthma. The mast cell is the cell that gets the party started. They release histamine, prostaglandin D2, and create that asthmatic response. It's also been known that mast cells are involved in the recruitment phase or the LAR.
They recruit everything like Eosinophils. And we all know about Eosinophils. But what wasn't known until we just did our study, and I think that this is something that is really interesting in the field aside from Briquilimab, is that it's been known that the mast cells are involved in recruitment. But if you took out the mast cell, would there be another immune cell that would step up in the recruitment phase? And it doesn't appear that way. When we look at the Eosinophils here at the late asthmatic response at both six weeks, and really interesting at 12 weeks, we see a major reduction in Eosinophils in the sputum in the patients that were treated with Briquilimab.
Interesting, and I guess one of the questions for this study then is, as we look ahead, how do we take this data and kind of translate it to a later stage asthma study, like something as you're looking at FEV1 also on exacerbation side? Can we look at the prior data from the field and start to make some of those translations?
I think you can, although recognizing that this is a small sample size. Unfortunately, we halted the study early because when we looked at the data on the Beacon study back in July, what we also knew was that this study in asthma was being conducted with that same lot that was in question at the time. So of an abundance of caution, we halted enrollment. What we now know based on the Beacon data and also now looking at the allergen asthma data, that drug absolutely worked. There was no problem. Unfortunately, we halted enrollment. So we have to be aware of the sample size here. But yes, one of the first things that we did when we saw this data is we went back and we pulled out the Tezspire phase I data and looked at what their FEV1s looked like, looked at what their Eosinophils looked like.
These endpoints correlate to aren't completely predictive of, but yeah, the next study would be an exacerbation study.
Yeah. So is that your planned next step in development for asthma, or would you test any different doses, different schedules kind of in the same allergen challenge design?
We're having discussions, and again, we've seen these data all of one week ago today, having discussions with experts in the field in clinical development of asthma drugs, and I think we could probably do both and probably look at multi-dose in the next study as well as dose intervals. As you know, in Beacon, we originally were looking at could we get to 12-week dosing in CSU? That wasn't possible. Based upon the 12-week endpoint here, maybe it's possible here. We'd like to explore a loading dose here followed by a maintenance dose. I think this is an indication that absolutely is begging for a maintenance dose and still look at exacerbations at like 24 weeks, but we'll have better guidance on that in Q1.
Yeah. Okay. That makes sense. Maybe we'll talk about this in Q1 too, but thinking about patient selection in asthma, are there any biomarkers or patient groups that you're looking at, whether that's type 2 high versus low, other comorbid disease? How are you thinking about that?
Yeah, so I definitely think for the next clinical trial, we'd probably move away from the allergic asthma, and I think it's one of the pieces we really need to convene the experts in the space because based upon what we saw with the Eosinophils, that puts into play both T2 high and T2 low, and so, but is that something you want to do in your very first study, and so let's talk about that in Q1.
Yeah. That makes sense. Awesome. All right. Maybe we can wrap up here just with cash runway and just lay out all the catalysts for the next year.
Sure. So as everybody knows, thanks to Herb and the team, we did a capital raise here about a month ago, put another $30 million on the books. That gives us cash runway into the middle of next year into Q3. So it gives us cash to be able to initiate or get to the initiation of the phase II-B, but not conduct that study. And the catalysts really are the data set that are coming early next year.
Awesome. Well, we'll talk again soon. Thanks so much for joining us.
Thank you, Kim.