NovaBridge Biosciences (NBP) Earnings Call Transcript & Summary

Hello, and welcome to the I-Mab Company Update Conference Call. [Operator Instructions] Please note, today's event is being recorded. I would now like to turn the conference over to your host today, Leah Liu. Please go ahead, ma'am.

Hi, everyone. This is Leah. I'm the IR Director for I-Mab. Welcome to the call, and thank you for joining us. On the call today, we have our Founder and Chairman, Dr. Jingwu Zang; our CEO, Dr. Joan Shen; our CFO, Mr. Jielun Zhu; and our U.S. Site Head and the Project Lead for our lemzoparlimab project in the U.S., Claire Xu. So I guess without further ado, I'll hand over the mic to Dr. Zang to give you a description on our recently released -- well, just released data at SITC on our U.S. project for lemzoparlimab. So Dr. Zang?

Thank you, Leah. First of all, I'd like to thank you all for joining us today for this call. We are very pleased to present and to summarize the clinical data of Phase I clinical trial for lemzoparlimab. And I thought it would be helpful, I can start by summarizing the key data from this clinical trial. And then we leave sufficient time for some of you to ask questions. We'll be very happy as a team to address your questions. Now let me start by giving you a high-level summary of all the data -- of the data that we're disclosing today. Now this is a typical Phase I clinical trial. It's a dose-escalation study. We started at lowest dose at 1 milligram per kilo, all the way to 30 milligram per kilo. So 5 dose levels. It's a single-agent dose escalation in patients with solid tumor, okay? So altogether, we enrolled 20 DLT eligible patients for this clinical trial. Now let me highlight the conclusions from this study. First of all, all the data related to safety of the molecule lemzoparlimab indicates that among all the dose levels, 20 DLT eligible patients, we have not seen DLT. There was no dose-limiting toxicity observed in any dose level involved in this study. We have not seen severe anemia, which is very common to CD47 antibodies of the same class. We have not seen anemia. So for the safety data, it's quite clear, the drug is very well tolerated in patients with cancers. This is number one. Number two is that at a high dose -- at high dose levels, at 10-milligram per kilo or above, we have seen linear PK profile. There's no significant sink effect, which is also a common -- sink effect is also a common phenomenon for CD47 antibody of the same class. And these 2 differentiating points are related to the minimum bonding of our CD47 antibody to red blood cells. Therefore, we're seeing a pretty clear safety profile and also pretty favorable PK profile. The other thing I want to mention here is that the entire study did not require priming dose strategy, dosing strategy. We did not have to use priming dose or anything in that nature. So all the study -- the entire study was conducted with a single agent, single injection in a more traditional fashion. All right. So safety, PK profile, no need for priming dosing strategy, those are the 3 clinical advantages we have concluded from this Phase I clinical study. Now in terms of efficacy, we have been looking in this study, we had tried even at a relatively low dose with a limited number of patients, we tried to detect efficacy signal. What I can summarize for you here today in our poster, all the detailed data discussed in our poster, indicating that at high dose level, at a 30 milligram per kilo level, 1 out of 3, 1 patient out of 3 was confirmed to have a PR. So 1 out of 3 at 30 milligrams per kilo is confirmed PR. And this is what we have observed so far. And remember, this patient had prior treatments with PD-1, PD-L1 therapies, so this patient failed PD-1, PD-L1 therapies and got on our study and developed the PR -- had a PR. All right. So I thought I'm going to stop here since Dr. Shen is also on the line; our project leader, Dr. Xu, Claire Xu, is also on the line. I'm very pleased to welcome questions from the investors -- from the audience and then we will try our best to address.

[Operator Instructions] And the first question comes from Louise Chen with Cantor.

Congratulations on your data. So I had a few. First question I had was what type of solid tumors do you think TJC4 works the best in? That 30 mg per kg partial response, what type of tumor type was that, if you can say? And then what do you think your monotherapy, your positive monotherapy data means for your combo trials? I would note that one of your competitors has shown some good combo data. So curious if you think you could even do better given your drug benefit. And then how will you decide if you're going to start patients on monotherapy or combination therapy? Are you going to look at biomarkers, tumor types? How will you distinguish or stratify your patient population?

Those are all very good questions. Let me start with the first question. This patient who developed -- who has a PR is a melanoma patient, okay, with liver metastasis. And clearly, after the treatment -- now the patient is in the 7th cycle of the treatment. And after treatment, the patient clearly showed PR, and we're very pleased with the result. That's number one. Number two, well, this is clearly a single agent effect. Going forward, we are in the middle of a extended study in combination with a PD-1 solid tumor and with Rituxan for lymphoma. So we are at a stage at this current stage to evaluate the effect of combination therapy with lemzoparlimab and PD-1 or Rituxan for solid tumor and lymphoma. Now we still have to wait to see the data. And it's very likely by combining with PD-1 or perhaps another therapy, lemzoparlimab may have a better efficacious effect on solid tumor. Now to address your third question, it's still not clear at this point what type of solid tumor is susceptible to CD47 antibody treatments. It's -- there's no conclusive data at this point. Now we are tackling this issue from 3 [ directions ]. One is, we have done translational medicine studies by looking at biomarkers, specifically CD47 expression among different solid tumors. So it's quite clear now, based on the data, some solid tumors express very highly [indiscernible], and others express less, at lower level, a relatively lower level of CD47. So it's not equal. And this is very important information because based on this information, we will be able to decide what are the solid tumor or tumors we want to focus on for a better chance of success. And this is something we already factor into our clinical development plan and clinical protocol. So this is the first source, first direction. The second direction is that based on our current study, because our current study, the U.S. study, is in patients with solid tumors, different solid tumors, now we are collecting data from the current study and, more specifically, from the ongoing study in combination with PD-1 for solid tumor to see once we put all this data together, this may give us some indication as to what tumor types we should focus on. And then the third is that we're actively evaluating published data from other companies, Arch Oncology, ALX, Trillium [indiscernible]. Putting all this together, we hope that we are in good position to have an educated guess in terms of what tumor types we want to select out with for a better chance of success.

And the next question comes from Kelly Shi with Jefferies.

Congrats on the progress. So my first question is, you have a confirmed PR. And would you give us more color on tumor regression across the cohorts? Maybe if you see a dose response in this escalation phase.

I may turn that question to Claire. Claire, could you elaborate on this question?

Kelly, thanks for the question. So I would say a majority of the patients of the dose -- single dose escalation have been in progress, and we have about -- we have 3 patients still on study. I would say, right now, I think it's too early to comment on the dose response of -- on the -- of the single-agent [ cohort ] with only observed this 1 PR in the monotherapy. So I will say we will continue to evaluate, especially, I mean, right now, we are on the combo dose escalation, we're escalating -- we're evaluating both 20 and 30. I think as the combo dose escalation will be more likely to answer your question.

I will have -- sorry, go ahead.

Yes. What I want to add here is that in this study, we also look at the receptor occupancy at the different dose levels. Now we know at 20 milligrams per kilo and 30 milligram per kilo, these 2 high doses, we could see 100% receptor occupancy. And this is very important information for us to determine what are the efficacious doses we are looking at, effective doses we are looking at. Going forward, we will have a better sense as to how to determine the efficacious dose.

It's very helpful. I also have a follow-up to clarify the time line for the next data update from your China trial in liquid tumors. Would that be the early next year?

Yes. Maybe I'll just say a few words. Perhaps Dr. Shen can address your question exactly. At this point, we're running in parallel 2 clinical trials, 1 in U.S. that's on solid tumor and lymphoma in combination. In China, we are focusing on patients with [indiscernible] and the liquid tumor. At this point, we're in the middle -- well, we're already at a high dose level of a single-agent dose escalation in patients with AML. And we are doing everything to speed up the clinical trial and to complete this study after we finish the 30 milligram per kilo dose. So next year, we'll be able to, working together with AbbVie, to decide on the clinical development plan globally by AbbVie, in China by us to get into a Phase II clinical study in AML, MDS in China. Joan, could you elaborate a little bit more on the question.

Yes. Right. To answer your question, we, in China, have finished the 20-milligram per kilo cohort escalation with single agent. And then we plan to proceed to the 30 milligram per kilo, and we are expecting to finish that in the first quarter of next year, actually earlier than about February.

And the next question comes from Joe Catanzaro with Piper Sandler.

I was hoping if you could maybe provide a little bit more detail again on the patient with the PR. Appreciate that it's a melanoma patient, prior PD-1. Just curious, I guess, the interval between the patient's prior PD-1 treatment and coming on study. And then you had mentioned looking at CD47 expression levels as a potential biomarker. Just wondering if you have any sense or able to look at CD47 baseline expression on this patient achieving the PR. And then as a follow-up, I appreciate that you're not seeing a sink effect in -- based on the PK profile. Have you been able to get any sense of target saturation within the tumor or any other intratumoral PD effects that give you confidence around the doses you're moving forward with, with the combinations?

Right. Thank you for the question. Claire, could you address this question -- or the 2 questions.

Yes, sure. So regarding your first question about this melanoma patient. So this patient did receive both EP and Nivo combo, and the interval is about 1.5 months before receiving our dosing, our protocol did mandate 28 days washout period. So for your second question about this targeted composition. So as Dr. Zang mentioned earlier, so right now, at the peripheral measurement, you can see above the 20 milligram per kilo showed maximum saturation. So we are actually continuing evaluate the tumor penetration of lemzoparlimab at the combo dose activation. Because today, I mean, what we released is single-agent dose escalation, we didn't mandate the biopsies from those patients. So we really think -- but the way really, I think, great ways that we really need to look at the target efficacious drug composition at a tumor level. So we've had some very encouraging data from the combo dose activated 20 milligram per kilo in the pembro combo arm. So we'll continue to evaluate that, and I think you will see our data very soon.

Okay, got it. Congrats on the progress here.

Sure.

[Operator Instructions] As there are no more questions at the present time, I would like to return the floor to management for any closing comments.

Yes. Jielun, could you make a comment here.

Yes, sure. Thank you very much for everyone's time and attention to our Phase I data from our U.S. dose escalation study. So we're very excited to share this data with you, and we look forward to your continued attention to this highly differentiated CD47 therapy. We believe in the potential of this therapy to make a lot of difference to patients worldwide. Thank you very much. We can wrap up the call here now.

Okay. Thank you. The conference has now concluded. Thank you for attending today's presentation. You may now disconnect your lines.

Thank you, everybody.

Thank you.