Viking Therapeutics, Inc. (VKTX) Earnings Call Transcript & Summary

Welcome to the Viking Therapeutics VK2735 Maintenance Study Top Line Data Conference Call. [Operator Instructions] As a reminder, this conference call is being recorded today, September 22, 2026. I would now like to turn the conference over to Viking's Manager of Investor Relations, Stephanie Diaz. Please go ahead, Stephanie.

Hello, and thank you all for participating in today's call. Joining me today is Brian Lian, Viking's President and CEO; Hubert Chen, Viking's Chief Medical Officer; Greg Zante, Viking's CFO; and Dr. Louis Aronne, former President of the Obesity Society and a renowned investigator and KOL in the field of weight loss therapeutics. Before we begin, I'd like to caution that comments made during this conference call today, September 22, 2026, will contain forward-looking statements under the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995, including statements about Viking's expectations regarding its development activities, time lines and milestones. Forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially and adversely, and reported results should not be considered as an indication of future performance. These forward-looking statements speak only as of today's date, and the company undertakes no obligation to revise or update any statement made today. I encourage you to review all of the company's filings with the Securities and Exchange Commission concerning these and other matters. I'll now turn the call over to Brian Lian for his initial comments.

Thanks, Stephanie, and good morning to everyone joining us on the call today. Earlier this morning, we issued a press release describing the top line results from Viking's novel maintenance dosing study of VK2735. As a reminder, VK2735 is a dual agonist of the GLP-1 and GIP receptors in development for the potential treatment of obesity. Co-activation of these receptors has been shown to decrease glucose, reduce appetite, lower body weight and improve insulin sensitivity in patients with obesity, type 2 diabetes or both. Due to these 2 mechanisms having complementary activities, this approach has shown generally improved therapeutic benefits compared with GLP-1 monoagonism. As we look across the development program for VK2735, as this slide shows, we have a lot of activity going on. Viking is currently conducting 2 Phase III clinical studies with subcutaneous formulation of VK2735 called VANQUISH-1 and VANQUISH-2. VANQUISH-1 is evaluating VK2735 for the treatment of adults with obesity and VANQUISH-2 is evaluating the treatment of adults with obesity and type 2 diabetes. Both trials are fully enrolled, and we expect the results from the program to be available in 2027. We are also excited to be developing an oral tablet formulation of VK2735. We're planning to begin in the near future, 2 additional Phase III trials with this formulation. These 2 studies will mirror the subcutaneous VANQUISH studies and target patients with obesity and patients with obesity and type 2 diabetes. Today's focus will be on the right-hand side of this slide, and that's our recently completed innovative dose-ranging study designed to evaluate multiple more convenient, less frequent dosing regimens for the long-term maintenance of weight loss. Prior clinical and nonclinical studies with VK2735 demonstrated the compound's differentiated exposure and pharmacokinetic profile, including a slower time to peak exposure, which may mitigate gastrointestinal side effects. Additionally, VK2735 has an extended half-life that suggests the potential for more convenient and less frequent regimens for weight management. In particular, our prior Phase II VENTURE study demonstrated prolonged plasma exposures at levels we believe suggested correspondingly prolonged therapeutic benefits. The totality of these prior results led us to explore the novel maintenance dosing study that we are reporting this morning. We believe providing patients with flexible dosing options will help ensure that each individual can tailor their treatment for maximal effect and convenience. Less frequent dosing regimens could represent attractive options for those patients who have achieved their weight loss goals and are seeking to maintain that weight loss moving forward. Importantly, by using the same therapeutic agent for both the initial weight loss and for the longer-term maintenance phase of weight management, we believe patients may experience reduced side effects compared with options that require switching between different therapeutic agents. By reducing side effects, we believe adherence to treatment may be improved, allowing patients to ultimately realize the long-term benefits of weight loss such as improved cardiovascular health, enhanced physical function and increased quality of life. During the fourth quarter of 2025, Viking initiated a novel dose range finding study to explore various maintenance dosing regimens. In this study, all subjects initially received weekly doses of VK2735, followed by a transition to a range of maintenance regimens, including weekly, monthly and every other week dosing or placebo. The objectives of the study were to evaluate the safety, tolerability and pharmacokinetic profile of VK2735 under these various regimens. Exploratory endpoints are assessing the change in body weight from baseline as well as the change in body weight during the maintenance portion of the study. The results from this study will help inform the selection of doses in the upcoming VANQUISH extension studies expected to begin late 2026 or early 2027. Before we discuss the results, I'd like to remind everyone that we have only recently received these data. We believe we have enough information to report on certain of the study's objectives, but we have not yet received all of the data nor have we had time to rigorously evaluate every line item in the data received. As these are top line results, there may be differences in certain elements of the data that arise upon receipt of the final results later this year. We also plan to present the results at future medical meetings, so we may wish to preserve certain details until those presentations. With that background, we're pleased to share with you on this call an overview of the initial results as well as key takeaways from the study. This slide summarizes the maintenance study design. This is an elegant study that could actually be viewed as 4 studies in 1, a 21-week induction study, a 12-week monthly maintenance dosing study, a 12-week every other week maintenance dosing study and a 33-week study utilizing a 17.5 milligram weekly dose. 180 subjects were randomized across 11 treatment groups and subjects were randomized to have a BMI of at least 30 but no other comorbidities. Induction doses ranged from 15 milligrams per week up to 22.5 milligrams per week or placebo administered once weekly by subcutaneous injection for 21 weeks. Final doses were achieved via titration that generally followed 2-week dosing blocks for successively higher doses. Following the 21-week induction period, subjects were transitioned to a range of maintenance regimens, including monthly and every other week dosing or placebo for an additional 12 weeks. This slide shows the weight loss achieved through the initial 21 weeks of weekly dosing. Here, we see a nice steep progression at all dose levels with no signs of plateau at 21 weeks for any dose. Week 21 weight loss ranged from approximately 16% to approximately 19% compared with approximately 0% for placebo. All doses clearly separated from placebo starting at week 4 with p-values at each dosing level less than 0.0001 compared with placebo. This slide shows the proportion of subjects across combined VK2735 treatment groups achieving specific weight loss thresholds. Among treated subjects, 98% achieved 5% weight loss, 90% achieved 10%, 65% achieved 15% weight loss and 32% achieved 20% weight loss. This compares well with the placebo cohort, of which only 13% achieved 5% weight loss and none achieved 10%, 15% or 20% weight loss at week 21. These are very robust data and based on the trajectory shown on the prior slide, almost certainly expected to improve with continued dosing. Turning now to the maintenance portion of the study. This slide is looking at the maintenance effect when subjects were transitioned to every other week dosing from weekly dosing, and it shows the proportion of the initial weight loss that was retained following the transition from weekly to every other week dosing. Among VK2735 treated subjects, the mean weight loss retained at week 33 ranged from 83% to 97% compared with 61% among subjects transitioned from 17.5 milligrams weekly to placebo with p-values less than 0.01 for each cohort versus placebo. Here, we can see the placebo cohort demonstrating a rapid decline of weight loss benefit over the 12-week treatment window compared to each of the every other week dosing regimens. Given the fact that dosing was effectively reduced by up to 85% in these treatment groups, the data are particularly impressive and support the concept of less frequent dosing as a potentially viable regimen for longer-term weight management. Turning to the monthly maintenance portion of the study. Here, we see the proportion of the initial weight loss that was retained following the transition from weekly to monthly dosing. Among VK2735 treated subjects, the mean weight loss retained at week 33 ranged from 82% to 90% compared with 61% for placebo with p-values less than 0.01 for each cohort versus placebo. As with every other week dosing, the fact that dosing was effectively reduced by up to 85% in these cohorts demonstrates a compelling maintenance signal and supports the concept of less frequent monthly dosing as a potentially viable regimen for longer-term weight management. When we look at the cohort of subjects who were maintained on a 17.5 milligram weekly dose for the entire 33-week treatment window, this slide shows the continued weight loss trajectory for the cohort throughout the study period, reaching 21.7% weight loss from baseline and 22% placebo adjusted. No plateau was observed, suggesting further weight loss might be expected with continued dosing. We believe these results are very encouraging. Looking across the current treatment landscape, the currently approved GLP-1/GIP agonist has demonstrated approximately 14% placebo-adjusted weight loss at week 33. In addition, the most advanced triple agonist in development with glucagon activity demonstrated approximately 17% placebo-adjusted weight loss at the 33-week time point. These are, of course, published data using different titration methods and not head-to-head study data. But nonetheless, we understand it will be a top-of-mind question despite the significant caveats and risks in cross-trial comparisons. Turning to tolerability. This slide shows the discontinuations and GI adverse events reported for the 21-week induction period of the study. Overall, there were very few discontinuations due to adverse events. And looking at the common GI adverse events of nausea, vomiting, diarrhea and constipation, we see a profile very consistent with what was observed in our prior Phase II VENTURE study with maybe slightly lower rates of nausea and slightly higher rates of vomiting, but overall, very consistent with what was observed previously. This is really quite interesting as these subjects titrate faster every 2 weeks compared with the 3-week schedule used in the Phase II study. Overall, no surprises here and a consistent profile despite accelerated titration. Turning to tolerability under an every other week dosing regimen. Here, we see a very clean profile. Treatment-emergent adverse events were similar to placebo and GI-related adverse events were generally low and no different from placebo. This is very encouraging and indicates no incremental change in adverse events versus placebo when dosing under an every other week schedule. Even more impressive are the adverse events under the monthly dosing schedule. Here again, we see a clean overall profile with minimal GI-related adverse events. As this table shows, overall rates of nausea, vomiting, diarrhea and constipation were not meaningfully different from placebo, suggesting excellent tolerability under a monthly dosing regimen. In addition to the impressive weight maintenance effects discussed a minute ago, this is an equally exciting result from this study. When we started the study, we were cautiously optimistic that the tolerability profile that might be observed when subjects extend their dosing intervals to 4 weeks would be close to that observed under the standard weekly schedule for use for titration. These data suggest that despite a gap of 4 weeks between doses, these individuals did not resensitize to GI adverse events such as nausea or vomiting. This supports our view that VK2735's differentiated PK profile with an extended half-life and excellent long-term exposures may provide for greater flexibility in dosing compared with existing options. In summary, we are extremely pleased with the outcome of this study as we believe it demonstrates a credible maintenance effect, which was a key objective going in. We have observed a high rate of weight loss maintenance up to 97% following transition to every other week dosing from weekly induction. The trial also demonstrated up to 90% weight loss maintenance following transition to monthly dosing, suggesting the potential viability of both regimens in the setting of maintenance dosing. We also saw a highly competitive weight loss of 22% among subjects titrated to 17.5 milligrams weekly for 33 weeks and no evidence of a plateau at that point, which suggests there may be more to go. Finally, under both maintenance regimens, we observed tolerability that was not meaningfully different from placebo. This again suggests the viability of less frequent dosing without incremental worsening of common adverse events. More work is needed, but we're certainly happy with the results. I'll close by reiterating that we believe long-term weight management will not follow a standard one-size-fits-all approach. Individuals pursuing sustainable weight loss will seek a range of treatment options that allow them to personalize their weight loss journey at every stage. We believe offering flexibility and optionality to patients will lead to improved adherence to treatments, allowing patients a greater opportunity to realize the long-term benefits of weight loss such as improved cardiovascular health, enhanced physical function and increased quality of life. Dr. Louis Aronne, who has unmatched experience in developing and prescribing GLP-1 and dual GLP-1/GIP agonist is also joining us on this call and can share his perspectives in the Q&A session on what these promising findings mean for patients. This concludes our prepared comments for today. Thanks for joining us, and we'll now open the call for questions. Operator?

We will now begin the Q&A session. [Operator Instructions]. Please note that we have large number of participants in the queue, the company will do its best to answer as many questions as possible. Thank you. At this time, we will pause momentarily to assemble our roster.

[Betsy], this is Brian Lian on here. While we're compiling the queue, maybe I'll take the first question and just ask Dr. Aronne if he can share any thoughts on the data and what it might mean for patients. Dr. Aronne?

Thank you very much, Brian, for letting me see the data and inviting me to participate. What I can say is that based on my 35 years of experience doing this, I think it's pretty clear that VK2735 is highly effective. It's among the best that we've seen for available drugs at 22% weight loss over 33 weeks. One of the things that we're learning is that efficacy, maximum efficacy is maybe not the most important thing these days now that we've gotten such good efficacy, but that treatment persistence is actually key. And having simpler and less frequent treatment regimens would make sense as a better way to use these. We're actually seeing that clinically. Our patients, once they hit a plateau are starting to use the drugs that are currently available less frequently. One of the interesting things is that here, lower doses seem to be effective and quite tolerable for maintenance. So the full dose, if someone saying 17.5 weekly, you don't need to use 70 milligrams monthly in order to maintain significantly lower doses appear to be maintaining the maximal weight loss or something close to that. Another interesting aspect to this trial is how well tolerated the drug is. It appears to me to be at least as well tolerated as the currently available options despite the rapid titration scheme. That's usually when we see most of the side effects and the fact that it's tolerable even though it was about twice as fast as we would normally titrate, I think, speaks to its tolerability. It looks like 17.5 milligrams is the best balance. It produced the greatest weight loss, and that may be because it had fewer side effects than the higher doses, but we're seeing this in other trials where one dose seems to shine through. And I think that in the long run, this is very promising for less frequent treatment regimen. I think that every other week is clearly realistic and once a month in other subjects or other patients is how this will be used. So I think an important point you made is that flexibility in treatment is what's key. And when people look at the fact that not everybody continues on the current medications, it's because we need more medications with slightly different mechanisms of action and slightly different ways of taking them. So thanks very much for asking me to comment on this.

Thanks very much, Dr. Aronne. We'll open the call up now for questions, operator.

The first question today comes from Steve Seedhouse with Cantor Fitzgerald.

Congrats on a really nice data set. I have just a 2-part question on dose selection and then one follow-up, if I could. So on the doses, first of all, have you decided on the maintenance dose that you would incorporate into the Phase III open-label extension? And is it possible that you could incorporate something like patient choice, flexibility to choose their dose as you've been articulating on the call here. And then also, the press release mentioned the opportunity to evaluate additional higher doses. And I'm curious if that's referring to like higher than 22.5 mg or higher than 17.5 in the Phase III or what that's referring to? And if you would test that in the oral maintenance study?

Yes. Thanks, Steve. For the second question, yes, it does mean that based on the very clean tolerability that we've seen here, it opens the possibility to explore higher doses. Just -- we just see no real impact on tolerability at all in the maintenance phase. What doses that we plan to take on in the maintenance, we haven't decided yet. We're still in the process of going through all the data. But I think we have a reasonably good idea of what that range would be, but we're not prepared to announce those doses today. But I think it gives us plenty of options based on the data.

Okay. And then the other question I had was just Obviously, there's sort of 2 factors in the induction phase here weighing on adverse events, there's the aggressive titration, but then there's that 1.25 milligram mini step at the start. And obviously, you've incorporated that in a sense in Phase III as well. And I'm curious if you have the data on AEs by week and if you can basically see if that 1.25 milligram step was helpful and mitigated some of the early adverse events relative to Phase II.

Yes. Thanks, Steve. It seems to help a little bit. We don't have all the per cohort data for those histograms that we like to present. But it does suggest that -- first of all, I'll say, across the entire induction phase, if you look at the combined treatment groups, the rates of GI adverse events were always extremely low, probably in the 5% range across the induction period. But how important that 1.25 is, I think it's helpful. We'll have a better idea once we get the breakouts, but I do think that does help.

The next question comes from Biren Amin with Piper Sandler.

On the data. Maybe on the maintenance phase of the study, Brian, could you maybe just talk about the placebo arm? I think 61% of the patients kept weight loss. Was that as expected when you designed the study? Or was that higher than expected based on your original assumptions?

Yes. Well, the data show that the placebo cohort, the mean of the placebo cohort was a 61% retention. So in other words, they rebounded by 39%, if that makes sense. And that is within range from published studies over 12 weeks, when you withdraw therapy, you typically see anywhere from, call it, 15% to 40% rebound in a 12-week period. And so that 39% rebound is within range from what's been published previously.

And then maybe just one question on the 17.5 milligram weekly dose for both induction period as well as at week 33. Clearly, you're seeing progressive weight loss across both time periods. Can you just maybe talk about the nausea and vomiting rates that you saw with those doses and just read-throughs into VANQUISH-1 based on these data, given that's the high dose that you're testing in VANQUISH-1 and VANQUISH-2?

Yes. Very well tolerated in that maintenance period for the 17.5. It seems like -- and this is not unique to Viking. It just seems like the GI adverse event profile of GLP-1 activation tends to be an early GI tolerability signal that fades over time. So no real difference there. I think it's very well tolerated. And as Dr. Aronne said, despite the acceleration in titration in that 21-week induction period, tolerability was really consistent with what we've seen in the Phase II study.

The next question comes from William Wood with B. Riley.

On the very nice data. Just thinking about for the induction period, 20 mg came out the best with 22.5 mg actually coming in slightly worse than 22.5, at least on the weight loss. So I was curious if you could speak to any differences in the patient population that may have been enrolled or discontinuations? Or how do you think sort of -- is this more sort of towards a small sample size? And then following the weekly to monthly transition, you actually achieved a higher percent maintenance with the 17.5 mg dose than the 22 mg. So just curious as you think why that may be occurring? Any thoughts on that on those 2 would be very appreciated.

Yes. Thanks, William. I think the -- when you look at the cohorts, really all of them, I don't know, better or worse is the right characterization. They all are very good. And as far as the 22.5, I think it's a very small cohort. So probably the most likely explanation there is that the N was small. You do see a modest dose response when you go up from 17.5 mg to 20 mg -- 15 mg, 17.5 mg to 20 mg and then a slight downtick in the 22.5 mg. But really, that doesn't concern us. It's a very small cohort size there.

Got it. And then maybe if I can squeeze in one more. Just given the lack of tolerability spiking it on a per month basis and now incorporating those lower doses, could you provide how you sort of think about tolerability improving even further in the VANQUISH-1 trial coming out?

Yes. Thanks, William. Well, we think the data support our thesis that we had after the VENTURE study, the Phase II study that it seems like the PK profile where we have sort of a slower onset of action, a later Tmax, it probably serves to mitigate some of the common GI adverse events that are observed. And then you couple that with a lower starting dose of 1.25, and we would hope that, that would mitigate some of the GI adverse events that are really common to these therapies.

The next question comes from Annabel Samimy with Stifel.

Congratulations on the data. So I mean, I have to say you have a wide luxury of options here. So I just want to go back to the question regarding what your expectations are for the open label, how you might use this data to select an actual dose range because it seems like there's a pretty clear -- there's a consistency of response anywhere between 85 and 90 regardless of the dose. So is there a possibility to offer a physician's choice for the open-label section of VANQUISH? And what would the regulatory requirements be for that phase of the trial?

Yes. Thanks, Annabel. I think what we'd like to do, we haven't made decisions on doses just yet, but what we'd like to do is incorporate probably examples of both the every other week and the monthly regimen in the extension. We do have some questions in front of the FDA right now about dose selection and dose frequency. So when we receive our responses from the FDA, we can make a better informed decision. But right now, I think we have nice options, as you say, to select doses either monthly or every other week, every week.

The next question comes from Mike Ulz with Morgan Stanley.

It's Abhinav on the line for Mike. Congratulations on the data. I guess just thinking about the oral maintenance study coming up, I guess what we see is the read-through from the subcu to the oral. Should we expect similar tolerability and then -- and weight maintenance? And then I guess a question for Dr. Aronne is with the data on hand today, I guess, how would you integrate VK2735 into your practice should it be made available? And I guess also on that, could you talk about the importance of having an oral option?

I'll take the first question with the oral. The oral doses that we selected are 17.5, 27.5 and 35. The exposures there with -- since the oral has lower exposures, we expect the exposure to come down a little bit versus the subcu, but it's offset a little bit by the daily dose regimen. So how that actually plays out, we won't know until we see the data. But I think there's offsetting factors there that make us pretty excited about the potential for the oral maintenance option. And I'll turn it over to Dr. Aronne for the second question.

Yes. I think that having the option of every other week and once monthly dosing is going to turn out to be very useful in the long run. And we need that in order to maintain persistence. If you look at the biggest threat to weight loss maintenance with the current drugs, it's that people stop taking them after a period of time. And if they could take them less frequently, I firmly believe that they would do a better job of it. So to me, the fact that you could take 10 milligrams every other week and maintain the weight loss, that's pretty remarkable. So I can see where this fits right away.

The next question comes from Gregory Renza with Truist.

It's [Anish] on for Greg. Congrats on the data this morning. Just first, in the context of retention, how do you think about the 4-week on maintenance exposure? And is there a dose below which the every other week construct stops holding? And second is a quick one. How durable do you see weight loss off drug? And how does that shape the commercial case for staying on a maintenance dose at all?

Yes. Thanks, Anish. So it looks like even down to that 5 mg every other week, you see a pretty effective maintenance despite coming way down in dose from that 17.5 mg per week. You do see a little bit of a dose response there. So the exposures are showing up there. But I would say an 80% weight loss maintenance is still very, very encouraging. And I think some people would gravitate to that. Where it goes from there, obviously, if you go to 2.5 every other week, that's probably going to give you a less effective maintenance dose. But that -- the floor looks like it's sub-5 milligrams, which is surprisingly good for that. And what was your second question?

The second question was just on the durability of weight loss off drug. I know we're not here yet, but just a good chance to kind of give us a sense of how you're thinking about that in the commercial case for staying on a maintenance dose.

Yes. Well, we know -- and I think Dr. Aronne probably has far more insight on this than I do. But we know that as you see in the placebo cohort that withdrawing therapy leads to a pretty rapid regain. And I don't know, Dr. Aronne, if you have any other comments on that.

Sure. There's tremendous variability from person to person in how long they can maintain if they don't take medication. We see some people who must continue taking it weekly or even more frequently than weekly with the current medications. And others can seemingly take a dose every 10 days, 2 weeks or even once a month, even with the current meds. So I think that having flexibility being able to accommodate patients' needs is really the key to long-term persistence.

The next question comes from Ryan Deschner with Raymond James.

Congratulations on the impressive data readout. The weight loss maintenance appeared to kick up, I guess, in the maintenance in the final weeks in that week 29 to week 33. How are you thinking about what's driving this? And how do you think this might mature over subsequent time points as we'll see it in the extension for some of these cohorts? And I have a follow-up.