Good morning and welcome to PDS Biotech's update on its 2025 ASCO presentations. All participants are currently in listen-only mode. Following the formal presentation, we will open the call up for a question-and-answer session. I'd now like to turn the call over to Mike Moyer with LifeSci Advisors. Please go ahead, sir. Thank you, Operator. Good morning, everyone, and welcome to PDS Biotech's update on its ASCO 2025 abstracts related to Versamune HPV. I am joined on the call today by the following members of the company's management team: Dr. Frank Bedu-Addo, Chief Executive Officer, and Dr. Kirk Shepard, Chief Medical Officer. Dr. Bedu-Addo will begin with an overview of the recently announced updates scheduled to be presented at ASCO, putting the updates in context of the evolving head and neck cancer disease state, and Dr. Shepard will then join the call to help address questions from covering analysts. As a reminder, during the call, we will be making forward-looking statements which are subject to various risks and uncertainties that could cause our actual results to differ materially from these statements. Any such statements should be considered in conjunction with cautionary statements in our press releases and risk factors discussed in our filings with the SEC, including our quarterly reports on Form 10-Q and annual report on Form 10-K, and cautionary statements made during this call. We assume no obligation to update any of these forward-looking statements or information. Now, I'd like to turn the call over to Dr. Bedu-Addo. Frank? Dr. Bedu-Addo, your line may be muted. Thank you, Mike, and good morning, everyone. It's our pleasure to speak with you again and to provide an overview of the exciting data accepted for presentation this year at the ASCO Annual Conference. Next slide, please. Besides our VERSATILE-003 trial, there are two EGFR-by-specific drugs simultaneously enrolling in phase three development in first-line recurrent metastatic head and neck cancer. Inherently, with three competing studies, there is some confusion surrounding P16 positive disease and HPV16 positive disease. We are the only company with an HPV16 positive polymerase chain reaction test, or PCR test, requirement for inclusion in our studies. This is a very important differentiation between the patient types and for clinical trial sites participating in the ongoing three recurrent metastatic first-line head and neck cancer phase three programs. I will therefore start the presentation by reviewing the important differences between a P16 positive head and neck cancer and an HPV16 positive head and neck cancer, as well as the reported similarities and differences in incidence and prognosis. I'll then discuss the updated VERSATILE-002 results and finally the ongoing VERSATILE-003 registrational trial, both being presented next week at ASCO. Next slide, please. As I mentioned, I'll start by introducing the P16 classification. Why is this important? Today, when a patient is diagnosed with head and neck cancer, very frequently, they will get a standard immunohistochemistry test called a P16 test. This test will determine if the patient is either P16 positive, meaning the patient's tumor tests positive for any type of HPV infection, or on the other hand, the patient's tumor is HPV negative, in which case they will be P16 negative. The patient at this stage will be characterized as either P16 positive or P16 negative. It is important to note that there are 12 types of HPV that are associated with cancer, so a P16 positive patient may be infected with any of these 12 HPV types. A PCR test is required to confirm the exact type of HPV infection that the patient may have. However, this test is not routinely performed today. HPV type 16, also called HPV16, is well documented to be the most carcinogenic type of HPV, and these patients are reported to have significantly worse prognosis than P16 positive patients in general. Since Versamune HPV is specific to HPV16 positive head and neck cancer, all patients in the VERSATILE-002 and VERSATILE-003 trials have the inclusion criteria requirement during screening to confirm that they were specifically HPV16 positive. Next slide, please. As the head and neck cancer indication is undergoing a rapid transition in incidence rate from predominantly HPV negative to predominantly HPV16 positive, we hired a reputable market research firm in November 2024 to perform an independent query of 52 head and neck cancer oncologists to better understand the current incidence rate of HPV16 positive head and neck cancer in the United States. According to the survey, about 59% of all head and neck cancers today are HPV16 positive in the United States. This percentage aligns with PDS Biotech's expert oncologist steering committee's feedback on incidences in the United States and Europe, which ranged between 60%-70%. In the survey, there was about a 50/50 split among those who felt that HPV16 patients were more likely to progress to recurrent or metastatic disease versus HPV negative patients. Next slide, please. Several experts continue to analyze and project the growth in HPV16 positive head and neck cancer incidence. Some publications suggest that by 2030, the incidence of HPV positive head and neck cancer will be growing at a rate of about 30% annually. On the slide published in the medical journal Lancet in 2022, the authors study the current preventive HPV vaccine adoption rates, as well as the HPV infection trends and the HPV negative head and neck cancer. They project the incidence rates for HPV negative cancer as well as for each of the 12 types of HPV. What they show is that the dramatic projected increases in head and neck cancer over the next couple of decades are driven almost exclusively by HPV16, as depicted by the prominent green wave on the top portion of the graph. In the United States today, it is estimated that our specific target population of recurrent metastatic HPV16 positive head and neck cancer constitutes between 40-60% of the patients and is rapidly growing. Next slide, please. Now, this slide summarizes a study of early-stage head and neck cancer patients performed at the London Health Sciences Center, Western University in Ontario, Canada. Now, this study was performed with 280 patients and excluded any patients who had terminal disease or distant metastasis. The study compared clinical outcomes for HPV16 positive patients, HPV negative patients, and P16 positive head and neck cancer patients infected with other types of HPV besides HPV16. The study showed that P16 positive patients, excluding the HPV16 positive patients, had the best prognosis, and HPV16 positive patients and HPV negative patients had very similar but worse prognosis. The takeaway here is that in early-stage disease, P16 positive patients generally have better survival prognosis. However, HPV16 positive patients specifically have worse prognosis, similar to HPV negative patients in early-stage disease. Now, this similarity in survival between early-stage HPV16 positive and HPV negative is in agreement with the results of our independent survey in which there was an almost 50/50 split among the oncologists regarding whether HPV16 positive head and neck cancer or HPV negative head and neck cancer patients were more likely to progress to recurrent metastatic disease. Next slide, please. Now, on this slide, we transition to advanced recurrent metastatic disease, the current focus of the VERSATILE-002 and VERSATILE-003 studies. There has been a lot of conversation regarding the effect of P16 positivity versus P16 negative on response rates and survival. On the left, I show the results of a meta-analysis of seven clinical trials in first-line recurrent and/or metastatic head and neck cancer, P16 positive and P16 negative patients who received an immune checkpoint inhibitor or an immune checkpoint inhibitor plus the EGFR inhibitor, cetuximab. In the study, P16 negative patients had significant objective response rate or ORR and survival benefit on the immune checkpoint inhibitor plus cetuximab. P16 positive patients had no objective response benefit and weak and not statistically significant survival benefit. On the right side of the chart, I show a study of advanced oral cancer patients which went a step further to specifically identify HPV16 positive patients. This study reports that the HPV16 positive patients had the worst survival prognosis compared to HPV negative patients. The key takeaway here is that the clinical evidence suggests that in the recurrent metastatic disease stage, the survival of HPV positive patients is no better than HPV negative head and neck cancer patients, and HPV16 positive patients may potentially have the worst survival prognosis. These studies suggest that the rapid increase in incidence of HPV16 positive head and neck cancer and the poor prognosis of these patients constitutes a significant and growing medical problem. Our phase three program, VERSATILE-003, is the only ongoing registrational trial specifically targeting HPV16 positive head and neck cancer. As we will see next in the updated VERSATILE-002 data slides, the phase two data in this population specifically is highly encouraging, and we believe that PDS Biotech is very well positioned with the ongoing phase three trial to significantly improve the treatment options for this growing group of high-risk patients. Next slide, please. Now, transitioning to the VERSATILE-002 data. Here, we show the Kaplan-Meier plot for overall survival and the table below showing both progression-free survival, or PFS, and median overall survival, or MOS. For the first time, we report stratification by CPS status. Starting with the overall survival, we report an encouraging MOS of 29.3 months for patients with low CPS of 1-19. As you may know, several products have not yielded much improvement over the 10.8 months median overall survival reported for pembrolizumab in this population. For patients with high CPS greater than or equal to 20, for which the published MOS is 14.9 months, we report an encouraging median OS of 39.3 months. For patients with CPS greater than or equal to 1, the population for which we will be seeking label claim approval, the published result for the KEYNOTE-048 study is 12.3 months. The longest survival published in this population to date is 17.9 months in the LEEP-10 trial. In the VERSATILE-002 trial, we report a median overall survival of 30 months. Importantly, this result has been durable and has remained steady over the last 12 months. The lower limit of the 95% confidence interval has now increased from 19.7 months in the data cut of April 2024 to 23.9 months. It is also noteworthy that the majority of patients in this trial were in the low CPS 1-19 group. We are therefore highly encouraged with these results as we enroll for the phase three study. The PFS results have also continued to hold steady over the last year due to the durability of the anti-tumor immune responses reported with Versamune HPV. Next slide, please. Besides the MOS and PFS, we continue to be pleased with all other measured clinical responses. The objective response rate for CPS greater than or equal to 1 remains unchanged at 36% from our last report. We see a 28% ORR in the low CPS group and a 48% ORR in the high CPS group. The disease control rate, DCR, of 75% and median duration of response of 22 months in the low CPS group is encouraging. Do note that the upper limits of the 95% confidence interval for disease control rate are not yet estimable. Next slide, please. Now, that brings us to our ongoing phase three trial. We continue to bring on more high-profile sites, such as the three Mayo Clinic sites. This trial is very similar to the VERSATILE-002 trial we just discussed, but now includes a control arm of pembrolizumab. Also, based on direction from the FDA, median overall survival is the primary endpoint for the trial. The trial also utilizes a companion diagnostic to identify and confirm the enrollment of HPV16 positive patients. We expect that this diagnostic will also be approved together with Versamune HPV. With that, I will go over to the operator for the question and answer session. Operator. Thank you. At this time, we'll be conducting a question and answer session. If you'd like to ask a question, please press star one on your telephone keypad. A confirmation tone will indicate your line is in the question queue. You may press star two if you'd like to remove your question from the queue. For participants using speaker equipment, it may be necessary to pick up your handset before pressing the star keys. Our first question comes from the line of Mayank Mamtani with B. Riley Securities. Please proceed with your question. Yes. Good morning, team. Thanks for taking our questions. Yeah, an important delineation here. You point to the P16 positive, excluding HPV16, and then your target cohort population of HPV16 positive. Are you able to comment on what sort of literature is out there indicating the overall survival that you see with kind of real-world population? I know we have some data with other trials on where maybe survival tracks for the specific HPV16 positive because a lot of the other trials that we see there include a very broad P16 positive bucket. They're not specifically looking into HPV16 positive. Maybe, Frank, if you could comment on what we know on survival and response rate in that population, not the new adjuvant, but in the front-line recurrent metastatic. I have a follow-up on your new data at ASCO. Hey, Mayank, good question. You are absolutely correct. A lot of work has been done looking at HPV negative and HPV positive patients. However, as it is becoming more and more evident that these dramatic growth rates in HPV positive head and neck cancer or in head and neck cancer in general, these significantly increasing growth rates, the identification that these are specifically due to HPV16 has led researchers to go in to try to understand why HPV16 specifically is becoming so prevalent, even though it was regarded in general that P16 positive patients potentially had better prognosis. Right? Based upon this finding, a lot of research in the space is going on today. One key thing that has been found, first of all, it has been identified why HPV16 is the most carcinogenic type of HPV. It has been identified that HPV, and this is published, HPV16 specifically shuts down what's known as the STING pathway. The STING pathway is what's responsible, it's one of the pathways responsible for activating or upregulating the type I interferon signaling pathway, which is absolutely critical to generate an effective T-cell response. HPV16 essentially turns the tumors cold by shutting down the body's ability to induce an immune response against it. That is one of the key reasons why HPV16 is so difficult to treat and very different from P16 in general. Based upon that, a couple of the presentations I presented today, I can send over to you. Based upon those publications, for example, in the recurrent metastatic stage, we see one key study that was performed where it was the HPV16 positive patients were specifically identified versus the rest of the P16 and also HPV negative. In that study in oral cancer, what they showed was that if you were HPV16 positive specifically, you had dramatically worse survival prognosis than either HPV negative, who also had better survival prognosis than the other types of P16 positive patients. The virus, the HPV16 type 16 virus specifically, by doing a really good job of shutting down that type I interferon pathway, makes this probably one of the most difficult types of head and neck cancer to treat. That is why it is becoming a really significant problem with the rapid growth in this specific type of cancer. That is why we believe right from the start that the best way to treat and control an HPV16 positive cancer would be to actually target the underlying cause. With these HPV16 cancers, the E6 and E7 proteins actually get integrated into the tumor DNA. Right? By generating T-cells that specifically target those E6 and E7 proteins and eliminate them, our data today shows that this to date has provided the most robust survival and treatment approach for the specific type of cancer patient. That is one key reason also why the FDA wanted us to include a companion diagnostic, because it is becoming more and more evident that these specific patient types have to be accurately identified and appropriately treated. Yep. That is great. Very comprehensive. Thank you, Frank. On the significance of the lower bound improvement in your V002 survival analysis, does that in any way inform your phase three likelihood of success, its powering assumptions? Because it is a five-month delta, it looks like, on the lower bound. If you could remind us what you are assuming for Keytruda monotherapy control arm in your phase three, and just the implication of what that separation could look like in your phase three. Yes. In our phase three, actually, we have quite a conservative design. Bear in mind that we are looking at HPV16 positive patients who are potentially the most difficult to treat. However, we have designed this trial utilizing the data that is predominantly in HPV negative patients, which is potentially easier to treat. In addition to doing that, we have assumed that our control arm will do better than Keytruda has ever done to date. Right? We have assumed that our control arm will do 18 months median overall survival. No trial with Keytruda has ever shown that to date. Even though we are looking at HPV16 positive patients, we have still assumed better than we've ever seen to date in a predominantly HPV negative patient population. What we have also done in our treatment arm is that even though we are seeing a 30-month median overall survival, we have assumed that in the phase three for our statistical analysis, we've utilized a 28-month median overall survival. Right? We have overestimated, we believe, on the control arm and underestimated on the treatment arm. Right? By doing that, we have about a 10-month delta between the control and the treatment arm. I think from our statisticians' estimates, they believe that we have designed quite a conservative trial with very significant potential to meet those endpoints pretty early. Understood. Lastly, would love to hear any overlap between the sites that you've selected for VERSATILE-003 and a number of peer phase three trials that are underway, including from Merus, and how you might be handling this competitive pressure for patients, although it looks like your population is very different and this companion diagnostic approach should be helpful. Thanks again for taking our questions. Appreciate it. Sure, Mike. I'll answer this question, and I'll hand over to Kirk because he's really dealing—they're dealing with the clinical sites and the KOLs. I will just reiterate what was said on our last KOL event by Dr. Kevin Harrington at the Royal Marsden in the U.K. One of the things he said very clearly is that as an oncologist in head and neck cancer, if a patient is HPV16 positive, this is the trial I'm putting that patient on because there's no other trial that has demonstrated conclusively the ability to treat this specific patient population that could potentially be the most difficult to treat. Right? That was the statement made by one of the key experts in this field. I'll hand over to Kirk to see if he has anything else to add to that. Yeah. Frank, can you hear me okay? Yes. We can hear you. Yes. Yeah. I mean, echoed from Dr. Harrington who said that too, that if he puts people on study, it would be our study for HPV16 positive. We're hearing it as we open up our sites, where some sites—not all sites, but some sites—also have the Merus or another study for HPV16 negative. They have all said that we will be putting our patients who are HPV positive on our study, the VERSATILE-003, which to us is reassuring that they believe the science, believe the data so far that they will be treating their patients with VERSATILE-003 for HPV16 positive. Thanks a lot, Kirk. Thank you. Mayank, I think it's very important to note that with HPV16 positive patients, no other ongoing phase three trial to date has demonstrated the potential to successfully treat this specific high-risk patient population, except the VERSATILE-002 trial. Thank you. Our next question comes from the line of Joe Pantginis with H.C. Wainwright. Please proceed with your question. Hey, guys. Good morning. Thanks for taking the questions and a very nice update. First, let me start on the back end with VERSATILE-003. How do you think today's update and recent updates as well can further drive interest and enrollment from sites you say may not necessarily have even considered, or in general, how this might help to drive enrollment? Kirk, do you want to take that first? Sure. Yeah. That's a good question. We are very encouraged by the fact that this data is supporting a lot of recruitment of sites to be a part of our study. We were fortunate that with the VERSATILE-002 sites, almost all of those wanted to be a part of this study. That started with a very good core, particularly here in the United States. We found with the data that we have presented with the specificity of the HPV16 positive populations that this has helped our recruitment of sites. Not that's helpful. Moving back a little bit to today's update, you provided, like you said, new information, and I wanted to get a little more perspective. Seems like Versamune HPV is showing nice activity across CPS scores. I mean, were you expecting this? How much of a surprise was it? What's the overall importance of the data seen across these CPS scores? I think we were hopeful that this is what we would see, right? Because again, with a checkpoint inhibitor, patients who have low CPS scores, we have much less PD-L1 expression, therefore less impact of the checkpoint inhibitor. However, what we also know is that checkpoint inhibitors do not actually induce, recruit, and create new T-cells. They activate more or less the pre-existing T-cells. Right? And if Versamune HPV was actually doing what it has been designed to do, which is to generate, recruit, train, and activate these HPV16 specific T-cells, we were very hopeful that even in the patients who have low CPS score, that we would see a significant therapeutic benefit or significant survival benefit. This was in line with the mechanism by which Versamune HPV works. We were encouraged but not surprised to see the result. If you recall, even in the second arm where we looked at checkpoint-resistant patients, there were a number of patients there who had CPS even less than one and were seeing really good survival benefit in those patients even when they were second-line checkpoint inhibitor resistant. Right? These studies, both arms of the study, both in the checkpoint naive and checkpoint-resistant arm, have really strongly validated the role of Versamune HPV in really extending patients' lives. We see that extension in survival even in cases where patients have failed and progressed on checkpoint inhibitors and even when they have CPS less than one. Got it. I appreciate that. I guess the broader question, and this really is the continuing theme and the core theme of today's call and your prior updates as well for 002, you've really peppered a lot of different comments and information about this. I'm going to go—excuse me—I'm going to go to the crux of the problem here or the perceived problem. Why do you feel there's so much, say, confusion in differentiating the populations of HPV negative versus HPV positive and HPV16 positive and P16 positive? I mean, you did a good job at the beginning with these slides, but ultimately, why do you feel there's sort of ongoing confusion? Joe, it does not help that P16 and HPV16 both have the number 16. The same number, yes. First of all, that does not help. I think from our discussions, that has been quite a bit of the confusion, right? When people say HPV16, it is a subset of P16, but it is not very easy to grasp that concept, right? I think that is why we felt it would be very important as we go through this process and now in phase three to really help the markets understand the fact that P16 is all types; any type of HPV will fall under the P16 category. There are over 100 types of HPV, right? Twelve are more highly associated with cancer, but there are over 100 types of HPV which will all be P16 positive. Right? However, I think what the industry and the oncologists are now beginning to understand is, wait a minute, HPV16 appears to be the big problem in head and neck cancer. HPV16 is the type of head and neck cancer that's actually growing and potentially the most difficult type to treat. Right? We are now beginning to realize that there is a growing medical problem. Part of that is also helping to drive the education, right? The epidemiologists are doing their work. The scientists are doing their work understanding what's going on with the different types of HPV. I think that's all helping to hopefully drive this understanding. I do agree with you that even today, there is quite a lot of confusion regarding P16 positivity and HPV16. Right? I think that's why we're continuing to help educate the markets about this difference and how we differ from the other two ongoing phase three clinical trials. A lot of their work has also more or less supported the fact that HPV-positive patients, especially if you're HPV16, is more difficult to treat, right? If you look at Bicara's presentation at ASCO in 2023, they had much better responses in HPV-negative patients than HPV-positive and therefore decided to focus on HPV-negative. Right? If you also look at Merus' presentation at ASCO in Asia, they reported the same thing, right? 40-something% ORR in HPV-negative, only 13% ORR in HPV-positive. I think, and with some of the publications I presented today, it's becoming more and more apparent that especially in the later-stage diseases where you may have an enriched HPV16 population, these cancers are actually very difficult to treat and these patients have very poor survival. We are hopeful that we can work and give the patients who potentially have the worst survival the best potential for an improved survival. Great. Frank, thanks for the reminder. Very well stated. Here's to focusing on the right 16 of the 16s. Right. Sure. Exactly. Thank you. There are no further questions at this time. Dr. Bedu-Addo, I will turn the floor back to you for final comments. Thank you very much. In closing, we are very pleased to have recently initiated the VERSATILE-003 registrational trial that we've discussed today. This study, as we've discussed, is the first phase three clinical trial specifically in the growing population of HPV16 positive head and neck cancer. We are excited based on the strong VERSATILE-002 results about the potential for Versamune HPV in head and neck cancer. We look forward to providing updated results from our ongoing phase two VERSATILE-002 study at ASCO next week. Again, our engagement with investors and clinical investigators has validated our approach and the long-term opportunity that we believe the HPV16 targeted immunotherapy represents in the HPV16 positive head and neck cancer indication. We look forward to keeping you updated on our progress. Thank you very much again. Thank you. This concludes today's conference call. You may disconnect your lines at this time. Thank you for your participation.