Hi, everyone. My name is Emily Schotman. I'm an associate here at Leerink Partners. I'm happy to introduce Yuval Cohen, the CEO of Corbus Pharmaceuticals, who will be presenting some information about the company today. Thanks so much for being with us.
Thank you for having me. It is our first time here. It has been incredibly productive and very pleasant. I am going to assume everybody that is here or listening knows a lot about what we are doing. I am going to move at a fast clip and really just talk about the latest updates. Focusing on 701, our Nectin-4 ADC, a reminder we had our first ever Western data come out at ASCO GU. That is primarily U.S. sites with a handful of U.K. sites. The first and foremost thing we wanted to establish was, can we show and contextualize our Western data compared to the data generated by CSPC in China? What we saw was that, in general, the treatment emergent adverse event was very similar.
In fact, we have a lower treatment emergent adverse events, as a rule of thumb, than was seen in China. That's not so unusual. I think what we're seeing, not just at Corbus, but maybe with other programs as well, is Chinese clinicians tend to report grade 1 and 2 more often than Western clinicians. That certainly fits into that pattern. The adverse events that are of interest to us are those that are problematic for Padcev, so skin rash, as well as peripheral neuropathy. What we did is we provided both the narrow definitions that we can compare with China, since they use narrow definitions, as well as the broad definitions. Broad definitions are typically used in later studies. We thought it would be a very good practice and very transparent to showcase them already.
Our narrow definitions are nearly identical to what was seen in China. These are our broader definitions. Again, on the whole, these are rare. They're often the same person. They tend to not result, with the exception of one, in any discontinuation. We had a sum total of one discontinuation due to an adverse event in this data set. We're very pleased with that. Discontinuations, reductions, interruptions, both China and our data set are markedly different than Padcev. Some differences, again, that have to do not with our drug, because it's the same drug, but rather with clinical practice. What we're seeing for us, and again, as we look at other data sets as well, Chinese clinicians tend to be much more keen on keeping patients at the preset doses, whereas in Western clinical practice, we prioritize patient quality of life.
It is more common to reduce while keeping the patient on. Overall, pretty similar, and certainly, as I said, different than Padcev. The one big difference between our studies, although that was pretty obvious to begin with, was the effect of having an aggressive, proactive, ocular prophylaxis program, something that was not present in the Chinese dose escalation, but is present now in the dose expansion that is underway. Unsurprisingly, when you enact that type of prophylaxis, you have an effect on reducing ocular toxicity. As you can see, they were cut by about half thanks to that strategy. Overall, we can combine our safety database with that of CSPC in China. We can also juxtapose it to the other Nectin-4 MMAE-armed constructs out there. We are very gratified that we do seem to be markedly differentiated. That is very encouraging to see.
Our PK, unsurprisingly, is very similar to the PK seen in China. On the efficacy front, this slide is probably the last time we'll present data this way. This is a waterfall of every single type of tumor that was in the study. It's very colorful. It includes a whole number of tumors that are not responsive. That's pretty much why it's the last time you'll see it. Nevertheless, since we were going to be asked about it, we combined all of them and looked at the overall response rates. They're very similar to China. Although, remember, these really are quite different tumor types. Oh, it's also worth remembering all of our unconfirmed responses at the time of this data cut were still in the study. That's encouraging. Our swim lanes are very similar.
Our median duration in the swim lane for this study was about 88 days. Our study only started in April. This data cut was done in December. Now, probably for the slightly more interesting or exciting part, we look at the three tumor types that are of interest to us. They are of interest to us for different reasons. We juxtapose, as we have done in these previous slides, China versus our data set. This is China from ASCO of last year, of course. The first one is bladder cancer. Now, bladder cancer is not of interest to us as a standalone company to pursue as a label. It is, nevertheless, informative for two other reasons. Bladder is the only tumor type where we can juxtapose directly to Padcev. Padcev is not available in any other tumor types.
It's within bladder that we can flesh out the narrative in a data-driven manner around the difference between us and Padcev. The other reason that bladder is of importance to us is for a strategic. Corbus, as a standalone company, is not interested in trying to go against or head-to-head with Padcev plus Keytruda in bladder. That is incredibly ambitious and better left for other companies. For a strategic, that is a doable endeavor as long as they're interested. It will be a very expensive study, but certainly worthwhile pursuing, we think. We need to generate data in order to have that conversation eventually with a strategic. Now let's talk about what we saw in bladder. On the left-hand side was a CSPC. CSPC's patients were all from China. They're all Padcev naive. Our patients are a combination of U.S. and U.K. sites.
Three of our four evaluable patients at the time of this data cut were Padcev pretreated, which is the norm for the US now. For Padcev pretreated patients, there really isn't much of a point. We're obviously not seeing much of a response. It would be interesting to speculate whether that's because they no longer have Nectin-4 or they're resistant to MMAE. That's more of an intellectual question. It's not really a question we're pursuing. Again, this is not a niche indication that we are interested in, which is Padcev retreatment. The one patient we had that was Padcev naive had a very robust and quick response. That was reassuring. We will continue to have more and more bladder patients. We will emphasize Padcev naive ones, of course, because, again, that's where we can juxtapose with Padcev.
An indication which is of interest to us, of very high interest to us, even as a standalone company, is cervical cancer. A reminder, it's about 14,000 women every year in the U.S. and a similar number in the EU. It's a rare tumor type in the West. It is a relatively common tumor type in China. On the left-hand side was the Chinese data from cervical patients at ASCO last year. On the right-hand side are the first two patients that were valuable to us in our data set. Phase I clinics or hospitals or centers in the U.S. tend to not see a lot of cervical patients. Those are seen more in centers along the southern part of the United States.
Most of the cases of cervical cancer in the West, in general, are adult women who have immigrated into the West and are past the age of vaccination for HPV. Nevertheless, we have two patients. Both of them had tumor shrinkage, quite dramatic tumor shrinkage. We have our first unconfirmed at the time complete response. We have a second patient with tumor shrinkage. Unfortunately, her tumor developed in another tumor developed in a new location. She is classified as PD. She continues to be on the study, of course, and being treated. Early days, but encouraging and certainly fits with what was seen in China. We will have meaningfully more patients coming both out of China and out of the West as part of Project Optimus.
The sort of unexpected tumor surprise that we had was in a novel tumor type that was not previously explored in China. That is head and neck. We are not the first ones to show this. Padcev showed data in head and neck back at ASCO 2023. The data was encouraging, but not particularly robust. Our data, early days, small numbers, nevertheless, is intriguing and promising, to say the least. We have actually seven patients. One is not on the waterfall. Of the seven patients, we have an ORR of 4 and a DCR of 6. Early days, but certainly encouraging. Two more things to remember when you look at this waterfall. These patients were not selected for Nectin-4. We do not enrich for Nectin-4. The other thing is it is HPV agnostic. We have a mixture of HPV positive and HPV negative patients here.
Yet they respond. That is very encouraging. Again, the second latter part of this year, the second part of this year, we will have meaningfully more patients as part of Project Optimus. We look forward to seeing how the data stacks up with a larger group of patients. This is a one case study. It is unusual for us to put in case studies. This was a very unusual case study. This happens to be a head and neck patient that was doing very poorly, an ECOG of 2, oxygen supplementation, difficulty in mobility. Six weeks later, had a very, very dramatic reduction in their tumor burden and have changed from ECOG 2 to ECOG 0, which is highly unusual and we thought quite noteworthy. This is a waterfall that, think of it as a thought exercise.
What we did with this waterfall is we combined China's data set with our data sets. Of course, these are two different data sets. Nevertheless, the hypothesis that we are engaging here is that they do bridge nicely together. They are combinable, at least as a thought exercise. We also only show the three tumor types that responded. That is really reassuring. The three bladder cancer patients who did not respond here, one of them is a patient from China that had absolutely no Nectin-4 whatsoever. That is probably not that surprising. Two of them were Padcev pretreated Nectin-4 from the United States. Again, in retrospect, not surprising. Overall, we found this to be quite encouraging. We have completed dose escalation. We have, since early December, engaged now in dose optimization or Project Optimus.
We've publicly declared three cohorts or three tumor types: head and neck, bladder, and cervical. Again, bladder is not a label that we are pursuing as a standalone company. Nevertheless, it's a very informative data set. Head and neck and cervical are of high priority for us as a standalone company. Those are monotherapy cohorts. We will soon be initiating the same tumor types, but combination with a checkpoint inhibitor. They have to be done in tandem. You have to get a sort of a critical mass of monotherapy before you can launch into the combination. We should have an informative data set for this in the second half of the year. We are targeting a large medical conference to showcase that data in the second part of 2025. We look forward to showing that.
Once we have that data, we'll be able to assess it and sit down with the regulatory authorities and discuss the path forward in cervical and the path forward in head and neck. A reminder that there are a family, a largish family of tumors that are known to be Nectin-4 enriched. That's what we are targeting. Like I said, we're not targeting bladder. We're targeting outside of bladder. Many of these are open swim lanes for us. In other words, our peers are not in those swim lanes. Most importantly, Padcev is not in any of those swim lanes. Another thing that's worth remembering based on preclinical data is our Nectin-4 MMAE ADC has a higher effect on low Nectin-4 tumor types, at least preclinically.
Given that we're seeing the type of responses we're seeing in the absence of enrichment, we're comfortable that that is translating into the clinic. That, of course, provides a very worthwhile clinical and potentially marketing advantage. Just a brief reminder of what these three tumor types look like in terms of patient numbers and severity, as well as frontline therapy. You can see the attraction of cervical as a rare tumor type where there is a potential for a faster-than-usual path to a label. You can also see the attraction of head and neck. It's about the similar size to bladder, far less busy. No other Nectin-4 modalities are currently being explored in head and neck in a very high proportion, sadly, of patients who are metastatic.
With that, I'm going to skip all the way and just respond or summarize what's happening with our obesity asset and answer the very common questions that we're asking, which is, what does the timeline look like for our CB1 inverse agonist CRB-913? We are about to dose our first human in a SAD study under an open IND here in the U.S. The SAD will then lead to a MAD study. The MAD, at the moment, is seven days. We don't plan to have it longer than that unless the PK in humans turns out to be longer than the PK in preclinical models. The MAD is in clinic, of course. The SAD is on entirely healthy volunteers. They're not even overweight. The MAD is a combination of normal weight and overweight individuals. We should be done with that sometime in the late summer, early fall.
The SAD/MAD will then permit us to move forward to a much more informative data set, which is a Phase 1b dose range finding study. That will be, at the moment, a 90-day study, multiple doses. In 90 days, we should be able to see weight loss quite easily with a CB1 inverse agonist. Every single one of them showed weight loss at 90 days. That should be a fairly low bar to achieve. More importantly, 90 days should give us a degree of comfort around neuropsychiatric adverse events. Neuropsychiatric adverse events tend to aggregate at the beginning of studies. That is pretty classic for the class. Within 90 days, we should be able to see if there are any imbalances or hopefully no imbalances between the groups that are being dosed with 913 and the placebo.
The last thing I'll say is just to mention on our cash balance and runway. Our earnings came out yesterday. Our cash balance as of the end of 2024 was $149 million. Our cash burn is unchanged. We project cash till the third quarter of 2027. That includes funding all the programs we just discussed. With that, I just want to thank everybody here and happy to take any questions in case anybody has them. Thank you.