Cellectar Biosciences, Inc.

Ladies and gentlemen, thank you for standing by and welcome. At this time, all participants are in listen-only mode. Following the presentation, there will be a question and answer session. Please be advised that today's conference may be recorded. I would now like to hand the conference call over to Anne-Marie Fields, Managing Director at PrecisionAQ. Please go ahead.

Thank you. Thank you, Operator. Good morning, and welcome to Select Our Biosciences first quarter 2025. Financial Results and Business Update Conference Call. Joining us today from Selectar are Jim Caruso, President and CEO, who will provide an overview of the company's progress before turning the call over to Chad Collian, CFO, for a financial review of the quarter and the year. Following this, Jared Longar, Chief Operating Officer, will give an update on the company's progress and plans for its promising clinical development pipeline of radiopharmaceuticals. Selectar issued a press release earlier this morning detailing the content of today's calls. Copy can be found on the investor page of SelectR's corporate website. I want to remind callers that the information discussed on the call today is covered under the safe harbor provisions of the Private Securities Litigation Reform Act. I caution listeners that management will be making forward-looking statements. Actual results could differ materially from those stated or implied by our forward-looking statements due to risks and uncertainties associated with the business. These forward-looking statements are qualified in their entirety by the cautionary statements contained in today's press release and in the company's SEC filings. The content of this conference call contains time-sensitive information that is accurate only as of the date of this live broadcast, May 13, 2025. The company undertakes no obligation to revise or update any forward-looking statements to reflect events or circumstances after the date of this conference call and webcast. As a reminder, this conference call and webcast are being recorded and archived. We will begin the call with prepared remarks and then open the line for your questions. I will now turn the call over to Jim Caruso. Jim?

Thank you, Hillary, and thank you all for joining us this morning as we review the progress SelectR has made throughout the first quarter of 2025. We entered 2025 with a continued focus on our PDC platform, our radio conjugate pipeline, and finalizing the requirements from the FDA and EMA, or European Medicines Agency, regarding ibuprofen I-131 for the treatment of Waldenstrom's macroglobulemia, or WM. We rapidly scheduled and completed a productive meeting with the U.S. Food and Drug Administration regarding the accelerated approval regulatory path for ibuprofen I-131 and WM. The results from the Phase II Clover-WAM clinical trial of Iopophicin I-131 as a treatment for relapsed refractory WM demonstrated the drug's unique efficacy and safety product profile, which we believe represents a significant opportunity as a promising therapeutic candidate in a relapsed refractory market where no approved drugs currently exist. In parallel, we are seeking guidance from the EMA on conditional approval for ipofasine I-131 as a treatment for WM based on the Cloverfam Phase II study. We believe the compelling results from this study support the conditional marketing authorization strategy and will make available this critically needed new medicine to WM patients in Europe more rapidly. In addition to our iapofasine program in WM, we continue to progress our solid tumor-focused radioisotope programs, which include our alpha emitter for pancreatic cancer and the OG emitter for evaluation in triple negative breast cancer, both of which highlight the novel utility of our delivery platform. Jared will speak further to these programs later in the call. As we explore strategic alternatives for the company, we have engaged Oppenheimer as an exclusive financial advisor to assist us. These alternatives may include, but are not limited to, mergers, acquisitions, partnerships, joint ventures, licensing arrangements, or other non-dilutive transactions. Now, let me turn the call over to Chad for a review of our financial results. Chad?

Thank you, Jim, and good morning, everyone. I will address our financial results for the period ended March 31, 2025. We ended the quarter with cash and cash equivalents of $13.9 million, as compared to $23.3 million as of December 31, 2024. We expect that cash on hand is adequate to fund budgeted operations into the fourth quarter of 2025. As Jim stated, we have engaged Oppenheimer & Company to serve as our exclusive financial advisor, as we seek to explore strategic alternatives available to SelectR that will allow us to maximize shareholder value moving forward. Regarding our results from operations, research and development expenses for the three months ended March 31, 2025 were approximately $3.4 million compared to approximately $7.1 million for the three months ended March 31, 2024. The overall decrease in research and development is largely driven by the reduction of patient follow-up activities for our Clover-YM Phase II clinical study in WM and a reduction in personnel costs. General and administrative expenses for the three months ended March 31, 2025, were $3.0 million, compared to $4.9 million for the same period in 2024. The decrease in G&A was primarily driven by a reduction in pre-commercialization and personnel costs. Net loss for the three months ended March 31, 2025, was $6.6 million, or $0.14 per share, compared to $26.6 million, or $0.91 per share, during the three months ended March 31, 2024. Now I will turn the call to Jared for an operational update, including plans for our promising pipeline of radio pharmaceuticals.

Thank you, Chad, and good morning, everyone. I will now review the regulatory and clinical status of ibuprofen and two of our exciting earlier stage radioconjugates. The first is our alpha-emitting actinium-based compound, CLR121-225, and the second is CLR121-125, our lead OJ-emitting radiotherapy. The path to achieve conditional approval of ibuprofen I-131 is based on major response rate, or MRR, and to obtain full approval based on progression-free survival, or PFS. In a randomized controlled phase three study evaluating the activity of ibuprofen I-131 versus an investigator's choice comparator arm, which will provide the study investigators a choice between one of two NCCN-approved treatment options. The primary endpoint for accelerated conditional approval is superiority based upon the MRR, progression-free survival from the same patients will be used to receive full approval. This trial is expected to enroll approximately 100 patients per arm. Since there is no data available for efficacy of any comparator in this patient population, SelectR is working with the FDA to utilize claims data demonstrating the current utilization patterns by physicians to select the two NCCN guideline-listed drugs for the comparator arm. As for our earlier stage pipeline, CLR121-225 is our lead alpha-emitting radio conjugate product candidate. To date, it has shown excellent biodistribution and uptake into solid tumors with demonstrated activity across multiple solid tumor animal models, including challenging to treat pancreatic and refractory colorectal cancers. CLR121-225 has been observed to be well-tolerated in these experiments. The Phase 1 trial for CLR121-225 is designed to comprehensively evaluate the compound's biodistribution, safety, and tolerability in patients with pancreatic adenocarcinoma. The study will commence with a dosimetry phase aimed at determining the absorbed dose in both normal and tumor tissues. This initial assessment will provide valuable insights into the compound's biodistribution and potential therapeutic window, laying the foundation for subsequent phases of the trial and future development. Following dosimetry, the study will progress to a dose escalation phase, systematically evaluating increasing doses of CLR121-225 to establish the maximum tolerated dose. This approach offers an opportunity to demonstrate proof of concept for our innovative combination of phospholipid ether, or POE technology, with alpha emitters, potentially showcasing this radioconjugate's unique ability to safely treat large, bulky, solid tumors. Our OJ emitting radioconjugate product candidate, CLR121-125, represents the peak of precision in targeted radiotherapy with its emissions traveling only a few nanometers. With our delivery mechanism providing the necessary targeting to the tumor, entry into the cell, and transport to the nucleus as validated through preclinical studies, we have seen CLR121, 125 demonstrate significant tumor uptake and activity with enhanced tolerability across multiple challenging animal models, including triple negative breast cancer and metastatic breast cancer. We are preparing CLR121, 125 for a phase 1B study in triple negative breast cancer. This trial will evaluate three distinct doses and dosing regimens, and the primary objective of identifying the optimal recommended phase 2 dose. The study will include an imaging component to further elucidate the biodistribution of CLR121-125, providing crucial insights into its targeting and potential efficacy. It is important to note that the initiation and timing of these trials is dependent on the company obtaining the necessary funding. With that, let me turn the call back to Jim for closing remarks. Jim?

Thank you, Chad and Jarrett. Before opening the call to questions, I would like to thank our dedicated and talented Select Our team who continue to work with tremendous determination to move these important programs and our company forward. We remain committed to the WM community and sincerely appreciate the abundance of support and continued encouragement to advance IOPOCY and I-131 to market. Operator, we are ready to open the call for questions.

Thank you. Ladies and gentlemen, we will now begin the question and answer session. Should you have a question, please press the star followed by the number one on your touchtone phone. You will hear a prompt that your hand has been raised. Should you wish to decline from the polling process, please press the star followed by the number two. If you are using a speakerphone, please lift the handset before pressing any keys. One moment, please, for your first question. Your first question comes from Aiden Heisenhoff from Leidenburg. Please go ahead.

Good morning, everyone. Thank you for taking the questions, and I appreciate the updates this morning regarding application for condition approval in Europe. So, I want to ask a question regarding a hypothetical match of 131, apophosin 131 against rituximab in early lines. So, since you're going to run the phase three trial anyways and going to take more than perhaps two years to reach this out, would it make sense to run against rituximab in early lines of therapy just to get the bigger market and what do you think about the hypothetical efficacy against rituximab in early lines? Thank you.

Thank you, Aidan. Appreciate your participation today and certainly the question. As you would imagine, we've evaluated, you know, a number of different study designs and opportunities for ayoproposine, not only in the relapsed refractory setting, which would be our initial to market play, but obviously in earlier lines of therapy, there could be a real benefit for patients that either do not tolerate BTKIs, BTKIs, you know, are not effective, and in your particular case, you know, rituximab or rituximab combinations as well. I will say that, you know, for the U.S. FDA, the team has done a really nice job based on our November discussion to very rapidly secure an additional meeting with the FDA that occurred in March. And as part of that, you know, we have, we believe, very clear line of sight on what a pivotal study would look like, certainly in the U.S. based on the FDA's guidance. And one of those comparator arms in the relapsed refractory setting, you know, will most likely be the Tuximab. Based on data there, in these later lines of therapy, rituximab, certainly in third-liner graders, is in this kind of 10% to 20% range based on the data that we have observed using data and claims in the U.S. In earlier lines of therapy, there are clinical studies available, and I'll have Jared speak to our thinking around that.

Yeah, as Jim said, Aiden, we did look at going to an early line. The challenge with going to an early line is the size of the study becomes much larger. As you might imagine, looking at differentials in major response rate or progression-free survival in earlier lines with going against rituximab, where there is a relatively higher rate of responses as opposed to the 20%, approximate 20% that Jim just quoted for major response rate in later lines, it jumps up to 60, 70, or 80%, depending on exactly what line you're looking at. That then alters your patient population's sizing, so the number of patients required to execute that study, goes up pretty quickly and pretty significantly, making the cost of the study considerably more than what we're looking at right now. So we've hesitated on that.

Yeah, makes sense, makes sense. Regarding the phase three trial design, the investigator choice out of the all possible sort of instances and recommended choices, what is the weakest essentially hypothetical comparator arm you would choose or sort of compel physicians to choose in order to improve the chances of 131 in this phase three trial? are there any eligibility criteria where 131 would be the best suitable option versus other potential options that the NCCN recommends?

Yeah, that's a great question. And before I hand this off to Jared, as you think about this, there's little to no data available relative to most of those treatments that are identified in NCCN guidelines. They're there because they're treating other hematologic malignancies, and oftentimes in WM, in second line, you can already be in a salvage therapy mode in some form of a combination, chemotherapeutic soup, et cetera, keeping in mind this is a much older patient population. that may already have been treated with multiple lines of therapy prior from a adverse event perspective. It could be a challenge for these patients. And so there's clearly, to your point, a dearth of information relative to the performance of these drugs, certainly in second line and beyond, and clearly in a relapsed refractory setting. So there's high unmet medical need there. based on the data claims and utilizing information from third-party community-based integrated oncology delivery networks, you typically see in third-line or greater this kind of 10% to 20% response rate based on the data that we're able to garner. Yeah.

And, Aidan, if I might follow up a little bit. You know, the interesting piece, and I'll put it back into the hypothetical, the interesting piece of your question is the hypothetical piece is can you identify essentially the weakest drug to go against to ensure success? And I'll come to why we don't really care in a moment. I think it'll make a lot more sense. But at the end of the day, you know, no matter what drug you pick or pair of drugs you pick, whatever you pick as the investigator choice, You know, you obviously have the FDA to approve those choices, and the FDA wants to stick to what is the most common treatment paradigm that is ongoing right now. Obviously, physicians aren't likely to be prescribing drugs that they know are failing rapidly. That said, one of the things that I think leads to this is, you know, when you get into the second line and the third line, like Jim said, and you're in this sort of already coming into a salvage therapy, frequently what you actually see is physicians are just satisfied with patients' not having a major response, but achieving stable disease or suppression of the sequela associated with the disease, so peripheral neuropathy, maybe reduction in their fatigue, what have you. And that's what they're really trying to do. They're not actually trying to alter the disease course. They're just trying to ameliorate symptoms and signs of the disease, essentially. What's interesting is, what does that mean? That means, as Jim said, most of these other drugs, at least from what we're seeing, have very low major response rates and very short progression-free survival. So as we said, rituximab, or even some of the rituximab combinations, range in and around this 10% to 30% maximum major response rate in sub-six months of progression-free survival. And so we feel very confident that with our near 60% major response rate, which I think was 58.2%, in the overall patient population, that we will easily be able to demonstrate with major response rate the potential of hypophysine here. And then when you look at the PFS, again, if you're looking at sub-six months and you look at what our ongoing PFS was in the study the last time we reported, which was north of 11 months, you know, again, we think we have a very strong, compelling position as it relates to any comparative that we will select. And we do think, you know, with the discussions with the agency, the selection here is really about a fixed course therapy that compares with our fixed course therapy. And so that means, you know, you're basically rituximab and rituximab combinations only as your alternative. I think on the other piece, when you think about eligibility, you asked the question about, you know, is there a way to enhance the eligibility to ensure, again, better patient population for ibuprofen? And we think we've done that. Fundamentally, you know, this post-BTKI patient population that we're pursuing, keeping in mind that now with ibrutinib approved in the first line, you're seeing a lot more utilization of BTKI in combination with rituximab in that first line setting. What does that mean and why is that important? What we've seen through both anecdotally and then also through the claims data that Jim referred to, what you see is that patients who've had a BTKI tend to fail almost every subsequent treatment after that. However, as you will note from our study and our press release, I think, this morning, you know, when we look at the post-BTKI population with hypopathy, you're looking at a 15.9% or essentially a 60% or 59%, sorry, 59% major response rate in that patient population. So again, we don't see a change. And we think, you know, that just select that patient population enriches a true separation and really identifies the need for hypoxia.

The only other thing, that was very comprehensive, Jared, thank you. The only other thought that I would, you know, provide to Aiden is this concept of re-challenging, where what you typically see Is rituximab or some rituximab combination being used in multiple lines of therapy? Hypothetically, if it was used in first, you may see it in third and fourth. And, you know, it's in this kind of, I think, 30% to 40% range for treatments used in, you know, in the second, third, fourth, fifth lines of therapy. And that's really a fun—and each time it's used, typically it becomes less and less effective. by line of therapy as you use it to re-challenge patients. And, you know, as a result of that, it just really talks to the high unmet medical need that exists here in this patient population.

Makes a lot of sense. One additional question I have regarding the conditional marketing application. So this is, you know, I think there's a 10-year report from EMA that says six out of 10 drugs that were submitted got approved. Conditioner first, and some of them actually got full approval after that. But how do you assess the commercial opportunity in Europe after you will hear back from EMA? I think you mentioned third quarter, 2026. So how do you assess the commercial opportunity given the pricing environment there, given the market size environment there. Just curious to hear your thoughts on this.

I think first, perhaps an update in terms of where we sit with the EU in terms of the potential for conditional approval there and how we're thinking about the regulatory pathway. And we also aid and view that market as a very rich one as well.

Yeah, so to your point, you know, six out of ten drugs that seek conditional approval in Europe receive it, which is a nice percentage. You know, 60% of the time they're going to get it. We think that our possibilities there may be enhanced because we have the prime designation. And the data set that we have is so strong. We did have a scientific advice meeting with the EMA previously during that meeting. It was commented by them about the study design. Sort of separate from the U.S., they were much more focused on a single trial design approach for the drug, and they were very impressed with the data they were looking at at that point from the Clover Wham study. They did not have all of the data, so they are looking forward to receiving that. So we expect, as you sort of said, that we will have the meeting with them to discuss that pathway and to basically ensure that we are eligible and that we should seek the approval on that study. We also think because where we sit right now is with the new phase three study design that we've come with the FDA, we'll be sharing that with EMA. as essentially the confirmatory study for full approval in Europe. And we think that that study, as it is designed, will ensure that they are more amenable to the conditional approval, because obviously it does then address several of their traditionally desired things, a comparator-controlled trial, a comparator that is widely used throughout Europe, one that you can then use from a pricing perspective as well. So all of these things will help them to be in a position to grant the conditional approval. And then I think, as you asked the question on the commercial side, yes, pricing is different in Europe, and yes, it is significantly lower than here in the U.S. However, one of the new regulations, new approaches there is you have to do a comparative control trial so that you can get appropriate pricing and justify it. in a rare disease like this, you get some benefit, keeping in mind that, you know, this disease is predominantly a disease of older Northern European descendants. It is, you know, it is more common or equally as common in Europe, even though the population size is a bit lower, it is relatively common. And I would say that the other key component there is, you know, we do believe that rituximab will be one of the comparator arms, as that is much more highly utilized in Europe than it is here in the U.S. I think, as Jim quoted a little bit ago, Vertuximab generally in the U.S., irrespective of the line of therapy, is being given at 30-ish to 40-ish percent of the time. And Europe has almost doubled that. So now you're taking out one of the leading utilized drugs across Europe, and if you're demonstrating that you can beat it with a superiority study, you should be instantly placed in front of it as utilization across Europe. While the price might be different, you actually will likely see an increase in total volume offsetting that price differential.

And, Jared, for clarity relative to the conditional approval timeline, we will know from our friends at the EMA in the third quarter of this year as to whether or not a regulatory pathway with conditional approval would be acceptable. Correct.

And then it would, essentially from there, it's approximately, you know, the filing would go in and then it's 12 months from the filing, generally for EMA.

Right. All right. Okay. Thank you. Thanks so much for taking the questions and I appreciate the discussion.

Of course. Thank you, Aidan.

Thank you. As a reminder, if you wish to ask a question, please press the star followed by the number one. There are no further questions at this time. I will now turn the call over to the selector team for closing remarks. Please go ahead.

Well, operator, thank you for facilitating the call, and also thank you to everyone participating today. This does conclude our call, and you may disconnect. Thank you.

Ladies and gentlemen, this concludes today's conference call. Thank you for your participation. You may now disconnect.