Thanks very much. Good morning, shareholders, analysts, and colleagues. Good evening to those dialing in from other time zones. The purpose of this call is to address the disclosure released to the market this morning regarding our FDA Biologics License Application for Telix Pharmaceuticals 250 CDx, provisionally designated as Zyrtex. Unfortunately, per our disclosure, we have today received a Complete Response Letter, or CRL, from the U.S. Food and Drug Administration in relation to our drug approval application. This is clearly not expected or positive news, and we want to give the opportunity for Q&A and engagement on the topic while noting that there isn't a huge amount of additional information to share at this early stage. In short, we have received a CRL on the basis of three highly related issues. The first is a series of chemistry, manufacturing, and controls, or CMC, topics.
These are, for the most part, fairly straightforward issues that reflect the overall complexity of the manufacturing package for Zyrtex. The second, somewhat related issue, pertains to inadequacies in demonstrating comparability between the drug product used in our highly successful Phase III Zircon trial and the scale-up manufacturing process that Telix Pharmaceuticals intends to use for commercial use. Third, the manufacturing and supply chain for the product is very complex and relies on a significant number of third parties for delivery. This is, in fact, part of the reason why Telix Pharmaceuticals has been so focused on building and internalizing much of this capability in-house to streamline and better control the process around our commercial manufacturing activity. Two of our third-party suppliers received Form 483 observations during recent site inspections, and the FDA has asked that responses to those 483s be resolved prior to resubmission.
This is a fairly standard process when there are identified CMO and supplier deficiencies. The feedback from the FDA and the CRL is detailed and useful and reflects a high degree of engagement around the product, reflective of its breakthrough status and the priority review we were granted. A number of the CMC and comparability issues outlined by the FDA and the CRL were actually part of post-late cycle review submissions and responses to information requests from the agency, but were apparently not reviewed in time for the PDUFA goal date. This is one of the challenges of a priority review process because it's a really tight timeline, but we are confident that we can address these issues and remediate the application fairly quickly. Per our disclosure, we will immediately start work on a Type A meeting request to address all the issues raised in the CRL.
I don't have a determinate timeline to give you at this stage, but it shouldn't be more than a few weeks to prepare the briefing document, given all the really superb work the team has done on this package. From that point, it's up to 30 days to confirm the meeting, and we will, of course, report back once we've mapped out a clear remediation timeline based on the agency's feedback on the CRL and, of course, the third-party remediation as well. Finally, before I open it up to questions, I'd like to add two important pieces of color around where we are at. Firstly, this is a really novel product. Nobody's ever submitted a drug approval dossier for a biologic-based PET agent to the FDA before, and this novelty also lies in the use of zirconium-89, really defining this as a first-in-class product.
We're at the vanguard of developing a new class of products, and we are consequentially being held to a very high standard. While there are always some things in hindsight that we might have done a little better, a big part of where we are at reflects both this product novelty and overall maturity of the supply chain. As I've said, we believe we'll get it over the line and make it commercially successful, but it needs to be acknowledged that we are also breaking new ground here, and speed bumps can and sometimes do occur. We remain fully committed to bringing this amazing first-in-class product to patients, driven by the urgency of addressing a significant unmet medical need in renal cancer.
The second thing I want to note for completeness is that this commercialization delay for Zyrtex, as was the case for Pixclara, does not impact our financial guidance for financial year 2025, as we do not include revenue from unapproved products in our guidance. Okay, I’ll leave it at that and open up to questions from the floor.
Thank you. If you wish to ask a question via the phones, please press star one on your telephone and wait for your name to be announced. If you wish to cancel your request, please press star then two. For webcast participants, you can type your question into the ask a question box and click submit. We will take questions from analysts. Please limit questions to one per person and rejoin the question queue for any follow-up questions. The first question today comes from Tara Bancroft from TD Cowen. Please go ahead.
Thanks very much for taking the question. This is Nick Hunt for Tara. What are the key differences between the products studied, so the Telix Pharmaceuticals 250 CDx studied in the Phase III Zircon trial and then the scaled-up manufacturing process, and how quickly could you generate data to confirm the comparability between the two? What would that look like? Would that be another trial? Would that just be a single data process? Thanks.
Yeah, we'd actually mapped out that comparability activity with the FDA in advance and, in fact, had agreed on a roadmap with the FDA. I think it's going to be a mixture of analytical and clinical comparability. We do have a whole bunch of extra data that wasn't included in the original BLA submission, so I don't feel like we're going to have any really significant time delays to collect new data. I feel this is a dossier reconstruction or resubmission exercise rather than a new data gathering exercise. Just to answer the first part of your question, from the company's perspective, the changes weren't particularly dramatic. They mostly focused around a more commercial scale production of the antibody as well as a larger specific activity radiochemistry, as you would expect for multi-dose production.
I think fundamentally, as you know, these kinds of comparability nuances are a pretty specialized area from the FDA's perspective. Hopefully, that gives you some useful color.
Yep, definitely. Thank you.
Thanks.
Thank you. The next question comes from David Stanton from Jefferies. Please go ahead.
Morning, Tony. Thanks very much for taking my question. I guess I know it's going to be very hard, but a reasonable timeframe for resubmission, might that be sort of end of calendar year 2025? I guess from there, you'll still need a six-month review process. At the earliest, it might be a one-year delay to getting this product on the market. Is that a reasonable way to think about it?
I think it's a reasonable thesis, but we're not giving guidance on timelines until we finalize the timeline and the scope of work on the basis of the FDA's feedback. We'll have that in a few weeks' time. I really feel like, based on our understanding of the Complete Response Letter, that this is not a protracted process to get to understanding of what additional info the FDA wants to see in the submission. I think you're probably aware that CMC-related CRLs are fairly commonplace at the moment, particularly with biologics. I think that it'll be a fairly concise conversation with the FDA. To draw on the earlier question, I think we're not looking at creating vast amounts of new data. I see this more as a dossier construction and clarification issue. I don't think it needs to be protracted.
We also have a breakthrough therapy designation, which means there's a fair amount of impetus on the FDA to consider our review comments or review submission fairly swiftly. I want to acknowledge there's been a high degree of engagement from the agency. It hasn't always been speedy or necessarily clear, but it's certainly been a high degree of engagement, and I don't see that as being rate limiting for the resubmission of the application. Mainly just a little bit of comfort. The topics that we're talking about don't relate to the clinical component of the submission. I think that also makes the fact that it's all focused around a bunch of CMC and manufacturing issues potentially make the dossier review a little more streamlined if the FDA feels inclined to grant us that privilege.
Thank you.
Thank you. The next question comes from David Dye from UBS. Please go ahead.
Great, thanks for taking my questions. Just on the two manufacturing and supply chain partners that you're dealing with where they received the notice of deficiencies, could you maybe impart some color around who are the partners and what are some of the remediation procedures and processes that are required for the resubmission process?
Yeah, we wouldn't typically disclose those third parties unless we were compelled to do so at this point in the process. There may be a future point in the process where it makes sense for us to do that. I don't have personally color to give you on those deficiencies or what the classification of those deficiencies may be. My perception is that, you know, Form 483s with sort of the typical observations that we're dealing with are fairly commonplace, and it's pretty typical for the FDA to ask for them to be remediated as part of a resubmission. I don't think I'm highlighting to you an intractable problem, but it is an additional part of the CRL that we think is useful color to give to shareholders and investors and analysts, and that's why we've noted that particular part of the deficiencies noted in the CRL.
Thank you. The next question comes from Robert Burns from HC Wainwright. Please go ahead.
Hi, guys. Thank you for taking my question. Following up on the prior question, can you sort of elucidate whether, you know, given the fact that there are two third-party manufacturing and supply chain partners, does one need to be resolved before the other one is able to complete that deficiency? Any clarity on the sequence, or are these two parts independent?
No, they're completely independent. One is a raw material supplier, or I say an API supplier, I guess technically, and the other one is one of the processing steps in the manufacture of one of our drug substances. To be honest with you, we were a little surprised that the 483s got kind of roped into the conversation because, in some respects, these sort of observations are part and parcel of those kinds of manufacturing activities. The deficiencies don't relate to, for example, the critical components of the product, like our antibody manufacturing or our final radio labeled drug product manufacturing. They're really related to things that mostly involve intermediates or APIs. I think, again, I don't want to be misleading, and I don't want to set unrealistic expectations, but I don't think that our disclosure around third-party manufacturers is really the rate-limiting step.
I do think it's something that will take a little bit of time to get done, but I don't think it's something that's an insurmountable part of the CRL remediation.
Okay. Last question from me. The additional data that the FDA is requesting for comparability, does that need to be clinical, and do you have it at this time point, or do you need to run a comparability analysis, like Phase I study, to do that?
We have quite a bit of additional comparability data. It's analytical comparability, it's in vivo non-clinical, and it's clinical comparability data that is not currently factored into the FDA's analysis of our BLA. We did some extra work in parallel to the BLA because we had anticipated that when we submitted the dossier in other jurisdictions, other ex-U.S. jurisdictions, we might get asked some difficult questions, and it was based really on our sort of nuanced understanding of how different regulators see biologics. We did extra work, and we have extra work to give the FDA that they have not reviewed in a fulsome fashion. There is a possibility that they may ask us for additional data.
We will not know the answer to that until we have the Type A meeting with the FDA, but we have a lot of extra stuff we can put down on the table that I think is meaningful and relevant to the conversation. Again, looping us back down to timelines, I don't see a protracted resubmission timeline because we have to go and run another substantive clinical trial or something like that. I don't see that as the reality of the situation at this point in time, based on the information that we have, with the caveat that we have not had that Type A follow-up meeting on the CRL yet. Hopefully, that gives you a bit of extra color.
I'll have my hand in the queue.
I don't mind. It was a pretty succinct question, so why don't you fire away while you're there?
Okay. Obviously, the FDA has requested additional data. Are they requesting clinical data specifically?
No, not specifically, but on the comparability data, it's going to be a fairly wide-ranging question. It may be that it requires additional clinical comparability data. We do have additional clinical comparability data that we can give them. It wasn't in the scope of the initial comparability work that we had agreed with the FDA, but we did it anyway because we wanted to be ready for other regulators. We'll just have to see whether what we've got is adequate to meet the FDA's needs.
Okay. Thank you for that clarity. That's all for me.
Yeah, no problem. Thanks for your question. I'll take the next one.
Thank you. The next question comes from Dennis Hume from Taylor Collison. Please go ahead.
Hi, Chris. Can you just clarify the timeline that you expect once you've resubmitted the application? Is your expectation that the review would be six months from the date that you resubmit the application?
We don't know because we haven't agreed with the FDA what sort of priority or expedited review status we might be eligible for. Given that we have a breakthrough therapy designation and given that we were granted a priority review, their willingness to review the dossier on a more streamlined basis may also depend on whether they are willing to look at just the changes that are relevant to the CRL or whether they will take a more holistic approach. We'll get some guidelines around that potentially from the Type A meeting, and I really want to stress the next stage in the process is really to have that Type A meeting to understand where we've got sticking points that are going to have longer remediation times, and then we'll be in a position, I think, to really update the market on what the timelines look like.
Okay. Thank you. That's all from me.
All right. Thanks, Dennis.
Thank you. The next question comes from Andrew Payne from CLSA. Please go ahead.
Yeah, thanks for taking my question. Obviously, this is the second serial you've had this year, both of which have come as a surprise, obviously, given the products you're putting forward. Just wanted to know if there's any additional challenges you're seeing at the FDA at the moment. Do you think there's additional pressures given the climate there, or things getting more scrutinized more thoroughly?
Look, I think it's an insightful question, and I can appreciate you asking it. I also appreciate the implication in your question that there may be more background to our track record than just Telix Pharmaceuticals. The Pixclara and the Zyrtex CRL should not be conflated with each other. They're very, very different submission processes. Pixclara, as you may recall, is really a moving of the clinical goalpost for the submission. I'm not going to go into that particularly today. I think we've addressed that sufficiently in the public domain, and we'll be giving an update shortly on Pixclara per our public disclosures. I think on the Zyrtex side of things, it really does come down to the fact that it's a super novel product.
I mean, it's the first ever biologic PET product, and so you've got different parts of the FDA that don't typically kind of co-review a product or reviewing a product, and I think that's been interesting. It's been an interesting and, frankly, educational experience given that we are one of the few companies developing radio labeled biologics. I am trying to be a little philosophical about the situation in the sense that, whilst I'd prefer not to learn at shareholders' expense, we are definitely doing a new class of products that will take some learning curve from a regulatory perspective. We're seeing that not, frankly, just with the FDA. We're seeing that with all regulators globally, and not just for a drug product dossier or a drug approval submission, but also for clinical trials.
I mean, getting clinical trials off the ground in this space, and we have many of them running, has been a very steep learning curve. I think that's kind of my preferred take on answering your question. I think it's fairly generally known that the world's changed a lot since the start of the year. I think the FDA is certainly an organization that has been impacted by those changes, but I also do want to acknowledge that the folks that we've been dealing with in the agency have been very science-driven, have been, for the most part, procedurally responsive. It's on that basis that I'm pretty optimistic that there's a clear platform for us to remediate what are reasonably put forth issues with our submission package.
That's great. Thanks very much.
Thank you. The next question comes from David Bailey from Morgan Stanley. Please go ahead.
Good morning. Just in relation to the two third-party manufacturers or partners there, is there scope to change to different suppliers? Will you stick with them? Will you look in-house? What's the solution in relation to sorting that third-party manufacturing prior to resubmission?
That's a really good question. For one of the suppliers, we actually already have an alternative supplier that is not, at least notionally, related to the Form 483 that was raised. We haven't explored yet whether the FDA's concern is a more general concern or whether it's something super specific, and frankly, I don't have that level of detail in front of me at this point in time, but we have qualified, in that one case, alternative suppliers. Generally speaking, the suppliers that we've chosen are suppliers that we've built a pretty deep relationship with, and I think our preference, again, based on what we see as the solvable level of severity of these Form 483s. I think it's just easier for us at this point in time to kind of stick with the folks that we know and the folks that we've been working with.
In the fullness of time, if you take a look at Illuccix, for example, when we launched, when we got Illuccix approval, also admittedly with a small delay, but when we got Illuccix approved, we had pretty much sole suppliers for most parts of the supply chain. Now, today, with Illuccix and GalliX, we have duplicate suppliers for most parts of the, or redundant suppliers for most parts of the supply chain. I think that's something that will kind of necessarily evolve post-BLA. I think the goal right now is to just manage the existing complexity that we have in the BLA, get through the FDA's major concerns, and then focus on supply chain resilience kind of post-approval.
Got it. Just a quick follow-up, just in relation to the CMC, just confirming that it just relates to the scaling up of the manufacturing process only, nothing else outside of that?
Yeah, I mean all of the three issues are all related to the manner and the implementation of the drug product for the commercial package. There's been no issues raised around the clinical trial material that we use in the Phase III Zircon trial. This isn't like a fundamental product kind of integrity issue. This is really around what is the delta between the material we use in a clinical trial versus the material that we use for commercial scale-up. You can understandably imagine that there have to be, by definition, some differences in those products. They use different grades of radioisotope. They use different amounts of radioactivity because you've got to produce larger batches of material, and that does result in some product characterization differences.
Our view as a company is we submitted the dossier reasonably believing that we had characterized those differences and defended them, and that they don't reflect a change in product quality attributes or a change in fundamental clinical attributes. The FDA wants to see a deeper determination of that assertion, and that's really the focus of the submission. I think it's really, as you've sort of implied, it's really about that commercial scale-up material.
Understood. Thank you very much.
Yeah, good question. Appreciate it.
The next question comes from Andy Hussey from William Blair. Please go ahead.
Great, thanks. Thanks for taking our question. Thanks for the additional information, Chris. For us, it seems like there are two processes, right? One for the Phase III Zircon study and one for the scale-up manufacturing. I'm curious if you can comment on the supply left for the old process, the process that you use to produce the Phase III. Do you have enough to potentially do a clinical-based comparability study, or do you need to go back and go back to the old process and produce more drug product to satisfy the FDA's request? Thank you.
That's a typically solid question from you, Andy. I think there are two things I can say. We do have inventory for the old, not the old, but the clinical material, so I don't see that as a problem. That's an active chemistry, manufacturing, and controls process. When we manufacture doses in some jurisdictions, we use that process still today just because it's a very convenient scale of manufacturing for, like, clinical trial use. Yes, the short answer is we do have inventory. I also want to reiterate a statement that I made earlier. We do have a clinical comparability study, not part of the original BLA submission. We did this study, frankly, because we wanted to be prepared for dossier submission in other jurisdictions.
We have a centralized European submission planned, and we're negotiating a date for submission for that as part of our, as you would expect, our global rollout of Zyrtex. Drug development, as you know, doesn't stop the day you file your BLA. There's a continuous data gathering process, and we felt that there was merit in running additional studies, which we have done. The FDA will have to opine on whether that additional clinical study that we have is something that's adequate. We think it is. If not, if we need to throw a few more patients into it or we need to do a slightly expanded study, we can do that very quickly. We have an open comparability study protocol today running.
We have an expanded access program that's running today, although the FDA will certainly opine in our Type A meeting whether or not that's something they want to keep going, want us to keep going on. They were very comfortable with us continuing the expanded access program with Pixclara. We'll have to see what they say about Zyrtex. I don't see any difficulty in getting additional patient data on top of the current patient comparability data that we already have. This is a really great question, but that's not going to be a rate-limiting issue for us.
That's helpful. Thank you, Chris.
Thank you.
Thank you. The next question comes from John Hester from Bell Potter. Please go ahead.
Thank you. I was going to ask a question about the EAP, but you've just answered that, so thank you for that. Any downstream effect on the rest of the business, Chris, in terms of your R&D program? I mean, this was hopefully going to generate a fair bit of cash in the next one to two years. Do you see any reason why you would need to pull back any other programs as a result of this outcome today?
I don't want to be misleading, but I don't think we're talking about really material time delays. Obviously, we'd all like to be, I think all of our shareholders would love us to be seeing, to be making more revenue streams. We have had a super intense year this year, I think it's fair to say, and that comes from, obviously, we're doing a product launch right now. Our HCPCS code for Illuccix comes into effect 1st of October, so we're really gearing up for that. We've just announced our BYPASS Phase III trial that's launching. That's going to double the size of the market opportunity for PSMA. We've got nearly 20 European approvals or 19 European approvals, so we've got market launches going on there. There's a fair bit of activity that can reinforce those revenue streams already.
I think it's not a catastrophic speed bump from an R&D investment perspective. We're always looking at the sustainability of our R&D strategy. We ideally like to self-fund it as much as we can. Again, I don't think this is a material issue for the company. Dave Stanton in his question kind of threw out the number of a year. I don't see this as being a year delay. I see it as considerably less than that. Again, we won't really know until we finalize the issues that the FDA has raised. It's onward and upward. We're financed to take on Prospect Global and the major clinical activities that are currently activated, and I'm pretty comfortable with that.
Good one. Thank you.
Yeah, thanks for your question. I'll take one more question, and I think we're going to have to wrap it up because I actually need to catch an airplane, so I apologize for that. Fire away.
Thank you. The last question comes from David Stanton from Jefferies. Please go ahead.
Morning, and I'll be very fast. I mean, bottom line is, Chris, does this affect R&D spend for F2026? You've probably answered it in the previous answer. We just want to check.
Yeah, I mean, we're trying to, I think what we've said very consistently along the way is that our R&D spend will grow with our revenue stream. We haven't forecasted yet what the impact of Zyrtex is. Obviously, there's some fairly good models out there, including yours, about where the product will go. There's always a launch ramp-up time. We see the unmet need for Zyrtex is really there. We'd ideally like to keep the momentum up for launch by maintaining the expanded access program. We'll have to have a conversation with the FDA about that. I think really this needs to be taken as a speed bump rather than a catastrophic event from an R&D investment perspective.
Understood. Thank you.
Yeah, thanks for your question. Unfortunately, we'll have to wrap it up there, but I appreciated the questions and the candor of the questions. Just as a final parting comment, I started the company to take this product to market, and I'm personally disappointed in this delay. That said, it really doesn't reflect the quality of the technology or the approvability of the product, and the team's really committed to getting it done. I also think that it is important to understand this isn't going to be the last product like this that we commercialize, and the lessons learned are valuable. These CRLs, whilst they're frustrating, certainly help us to become a better company, and we're learning a lot of things that are super relevant to the development of the whole portfolio.
I know that's not much of a consolation, but the patience is appreciated, and thank you for your time today. I'll wrap it up there.