Good morning. Welcome to Voyager Therapeutics' Q1 2023 conference call. All participants are in listen only mode. There will be a question and answer session at the end of this call. Please be advised that this call is being recorded at the company's request. A replay of today's call will be available on the investor section of the company's website approximately two hours after completion of this call. I would now like to turn the call over to Pete Pfreundschuh, Chief Financial Officer. Please go ahead.
Thank you. Good morning. Joining me on the call today are Dr. Al Sandrock, CEO, and Dr. Todd Carter, our Chief Scientific Officer. We issued our Q1 2023 financial results press release this morning. The press release and 10-Q are available on our website. We plan to provide a brief summary of key highlights from the quarter and reserve the majority of time for Q&A. In a moment, I will turn the call over to Al. Before I do this, I want to remind everyone that during this call, Voyager representatives may make forward-looking statements, as noted in slide two of today's deck. These forward-looking statements include future expectations, plans and prospects. All forward-looking statements are inherently uncertain and are subject to risks and uncertainties that may cause actual results to differ materially from those indicated by these forward-looking statements.
You are encouraged to review and understand the various material risks and uncertainties facing the company as described in the company's most recent annual report on Form 10-K filed with the SEC. As of the filing of today's quarterly report on Form 10-Q, there have been no material changes to the risk factors described in our annual report. All SEC filings are available on the company's website. It is my pleasure to turn the call over to Al.
Thank you, Pete. Good morning, everyone. Please turn to slide three. I'd like to take a moment to recognize the incredible innovation happening right now in neurotherapeutics and in gene therapy. We believe we are witnessing a renaissance in neurotherapeutics. Just this year, the second disease-modifying therapy for Alzheimer's disease received accelerated approval. The first drug was approved for Friedreich's ataxia. We've seen breakthroughs in treating negative symptoms of schizophrenia, something for which there are no approved therapies. Just two weeks ago, the FDA granted accelerated approval to an antisense oligonucleotide for SOD1, amyotrophic lateral sclerosis. Importantly, the FDA based the approval on the finding that treatment-driven reductions in neurofilament are reasonably likely to predict clinical benefit in SOD1 ALS patients, establishing a precedent for a biomarker-based path to accelerated approval. I hope this will drive further new treatments for patients suffering from this devastating disease.
At the same time, the gene therapy field is coming of age. We have recently seen the FDA approval of the first gene therapy for hemophilia B. Gene therapies offering important potential advances in treating Duchenne muscular dystrophy and hemophilia A are approaching PDUFA dates. Through that, we may see the accelerated approval path utilized for a gene therapy. Importantly, long-term data on Zolgensma, one of the first gene therapies approved, recently demonstrated durability of effect after 7.5 years, which physicians have called transformational. Voyager sits at the intersection of neurotherapeutics and gene therapy. We believe we are uniquely positioned to leverage the advancements in both fields. To date, the delivery of gene therapies into the central nervous system has proven challenging. Approaches to inject these therapies into the brain pachymeninx or various CSF spaces have not been very successful.
Voyager's TRACER capsid discovery platform is the foundation of our approach to solving this delivery challenge. Voyager scientists have engineered multiple capsid libraries, each with more than 20 million novel variants of AAV9 and AAV5 capsids to select those novel capsids that display greatly increased transduction in the central nervous system following intravenous delivery. We have leveraged these capsids to advance our own and our partners' CNS gene therapy programs, several of which are now advancing towards clinical trials. This is how Voyager is enabling the future of neurogenetic medicines. From where I sit, it's an incredibly exciting place to be. Moving to slide four, I will briefly review our investment rationale. Our first pillar of value is our TRACER capsid discovery platform, which I just discussed.
In the preclinical studies, our novel capsids delivered intravenously have demonstrated more than 100-fold higher transgene expression in the brain compared to conventional AAV9 capsids. We have shown high levels of CNS gene expression at low doses, we have demonstrated the ability to target specific cells such as neurons or glia, while de-targeting the liver and dorsal root ganglion cells. We look forward to sharing more data on our capsids at ASGCT later this month. Our second pillar of value is our CNS pipeline. We are advancing four programs through late research and towards IND. Two of these programs are wholly owned. Our humanized anti-tau antibody for Alzheimer's disease and SOD1 gene therapy program for ALS. The other two are GBA1 gene therapy program for Parkinson's disease and our frataxin gene therapy program for Friedreich's ataxia, are being co-developed with Neurocrine. Our third pillar of value is partnerships.
We completed capsid option and license agreements with Pfizer and Novartis. We've executed strategic collaborations around our pipeline programs with Neurocrine. We are exploring more such transactions. Turning to slide five , we continue to make progress advancing our CNS pipeline. I'll note a few recent highlights. During Q1 , we selected a lead humanized anti-tau antibody candidate, VY-TAU01, for the treatment of Alzheimer's disease. In March, we presented new data at the AD/PD meeting, highlighting the differentiating characteristics of this lead candidate. Last month, we received pre-IND written feedback from the FDA for VY-TAU01. Voyager continues to expect to initiate GLP toxicity studies this year to enable an IND filing in H1 of 2024. Another change this quarter was to the timeline for our SOD1 ALS gene therapy program.
Voyager previously said we expected to identify a lead development candidate for this program in H1 of this year. That has moved out to H2 of this year as we continue to evaluate data from this program to identify the optimal development candidate. We intend to provide updated guidance on the IND timeline once we select a development candidate. Given where we are today, we expect the IND to occur in mid-2025. Our frataxin gene therapy program for Friedreich's ataxia and our GBA1 gene therapy program for Parkinson's disease and other GBA1-mediated diseases both continue to advance in collaboration with Neurocrine. I'm pleased with the progress we are making here. Additionally, during Q1, we launched two new early-stage gene therapy programs combining vectorized siRNAs with our novel intravenous TRACER capsids.
One combines two siRNAs to enable specific knockdown of mutant HTT and MSH3 for the treatment of Huntington's disease. The other uses siRNA to reduce tau expression in the brain for the treatment of Alzheimer's disease. I'd like to now turn the call over to Pete Pfreundschuh to discuss our financial results for the quarter.
Thanks, Al. I will cover some key financial points on this call and refer you to our press release and 10-Q issued today for further details. Please turn to slide six. We announced Q1 2023 collaboration revenue of $150.5 million, composed of $69.5 million from the 2023 Neurocrine collaboration agreement for the GBA1 program. $79 million from the Novartis option exercises, and $2 million from the 2019 Neurocrine collaboration agreement activities. Our R&D expense was $18.6 million, an increase of $4.2 million as compared to Q1 2022, driven by increased headcount, increased program-related R&D spend, and milestone fees, and offset by decreased facility costs. Our G&A expenses were $9 million for Q1 of 2023, as compared to $7.7 million for the same period in 2022.
The increase in G&A expenses was primarily a result of increased compensation costs driven by headcount increases. As a result of strong revenues in Q1 2023, the company had net income of $124 million, resulting largely from our collaboration revenues, as well as increase of $1.8 million in other income, due primarily to increased interest revenue from cash marketable securities. Regarding the balance sheet, Voyager reported $273.3 million in cash equivalents in marketable securities at the close of March 31, 2023. We also had a receivable at the close of Q1 2023 from Novartis's $25 million option payment received in April.
Together, this resulted in pro forma cash equivalents, and marketable securities totaling $298.3 million for the close of the quarter. Of note, deferred revenue increased by $18.7 million, related primarily to the upfront payment from Neurocrine allocated to the three new discovery programs of $74.4 million, offset by the recognition of $54 million into revenue from the Novartis options exercise. The company has a sound balance sheet enabled by our non-diluted collaboration revenues. We expect that our balance sheet plus expected reimbursements will be sufficient to meet our planned operating expenses and capital expenditures into 2025. I will now turn the call back over to Al.
Thank you, Pete. Turning to slide seven. As you can see, Voyager has had a productive start to 2023. We began the year by securing a $175 million upfront payment in strategic collaboration with Neurocrine Biosciences, followed by Novartis' opt-in decision on capsids to two neurologic disease targets, triggering another $25 million payment. These transactions strengthened our balance sheet and enabled us to further advance our platform and pipeline. As discussed, we selected a development candidate for our anti-tau antibody program for Alzheimer's disease. We aim to select a development candidate for the ALS SOD1 program later this year. We launched two new early-stage gene therapy programs for Huntington's disease and Alzheimer's disease. In addition, I'm thrilled to welcome George Scangos to our board of directors, as we announced in a press release this morning.
George is one of the most accomplished executives in the entire biotech industry, having served as CEO of Vir Biotechnology, Biogen, and Exelixis. His vast experience building biotech companies that deliver highly innovative therapies to patients while creating value for shareholders will be invaluable to us as we strive to develop Voyager into a leader in neurogenetic medicine. Looking forward, we continue our work to break through the barriers constraining the fields of gene therapy and neurology. We will continue to share the exciting data we are generating at scientific conferences, including at ASGCT later this month. Importantly, our pipeline advancement is leading towards what we view as multiple opportunities for value creation. We look towards 2024 and 2025, we anticipate the potential for multiple IND filings across our wholly-owned and collaborative and/or licensed programs.
This translates into multiple opportunities to earn milestone payments, even more importantly, as clinical trials begin, several shots on goal to establish human proof of concept for our novel capsids. Furthermore, there is potential to see early biomarker-based evidence of disease impact in some of these very difficult CNS indications. Of course, we continue to engage in active discussions with potential partners around our platform and pipeline. In summary, it's been a great start to 2023, as always, it is all due to the incredible Voyager team. I look forward to continuing our momentum throughout the year. With that, we're happy to take any questions you may have. Operator?
Thank you. If you would like to ask a question, please press star one one on your telephone, and as we'll wait for your name to be announced before you actually ask your question. One moment while we prepare our Q&A roster. The first question that I have today will be coming from Jay Olson of Oppenheimer. Your line is open.
Hey, congrats on all the progress, thank you for taking our questions. We're interested in the work you're doing on tau. You're advancing an anti-tau antibody and initiating a tau knockdown gene therapy program and could potentially have a vectorized anti-tau antibody. Can you just talk about how you'll optimize the development strategy and prioritize all of your different tau targeting modalities? Eventually, do you think that anti-tau therapies can be monotherapies, or do you think they are best to be combined with anti-A beta therapies? Finally, can you just talk about how you'll balance the trade-off of advancing your tau therapies independently versus seeking a partner? Thank you.
Thanks, Jay. Those are great questions. First of all, what we like about tau is that we believe it's a very important and well-validated target for Alzheimer's disease. Because of that, we're taking multiple approaches against this target. As you pointed out, we have an antibody against the C-terminal domain of tau. The development strategy there is to move forward with the passive antibody first and see whether or not we get proof of concept. In other words, to see whether or not we can block the spread of tau by looking at tau PET scans. We think this is very feasible, and we can do it with not that many patients over a one-year period.
If we obtain proof of concept, then we have a couple of choices there. One is we can continue to proceed with the antibody to tau all the way through to approval, or we add, and/or we can then initiate a vectorized anti-tau antibody program. That would be the sort of the crossroads that we will see there. In addition, we have this vectorized tau knockdown, which we think is an additional shot on it against a very important target. This will be different in the sense that it doesn't rely on antibodies binding to extracellular tau. This approach is to decrease the expression of all forms of tau, intracellular and extracellular.
We saw some preliminary evidence of that approach at the AD/PD meeting with the Biogen Ionis antisense against the tau, where they were able to see effects on tau PET imaging. We think it's a very important target. We think having multiple approaches is helpful against this target. We think we can obtain proof of concept pretty rapidly in the clinic, taking advantage of tau PET imaging. The final question relates to whether or not we're going to partner. You know, we're always talking to partners and we're always open to anything. We could go to proof of concept by ourselves. We have the capability to do that, and I believe we have the resources to do that. However, you know, we're open to anything.
But ultimately, I can't imagine that we would go all the way to commercialization for a disease as large as Alzheimer's disease. We will need to partner that program. The question is when. We have some choices there. Finally, your question about combination, or monotherapy. I believe Look, I think we just started the era of disease-modifying therapies for Alzheimer's disease with the approval, accelerated approval of two anti-A beta antibodies. As we all know, the efficacy is modest in the 25%-30% range on the CDR- Sum of Boxes. We'd love to get better treatment effects, and one approach might be to combine, with an, a tau-reducing, approach, whether it's an antibody or a knockdown. I think that we're gonna, you know, we are likely to test combination treatments.
Because I think once tau spreading starts to occur, you may need to address tau independently separate from the anti, amyloid antibodies or in combination with them. I hope that answers all your questions, Jay.
That was perfect. Thank Thank you so much for taking all those questions.
Mm-hmm.
Thank you. One moment while we prepare for the next question. Our next question will be coming from Jack Allen. Again, please wait for your name to be called before you ask the question. Your line is open. Jack Allen, your line is open.
Oh, sorry about that. I was on mute. Thank you so much for taking the questions, and congratulations on all the progress. I wanted to stick with the tau theme here as well, and I wanted to ask Al, I'm sure you're aware of the Eli Lilly results from their recent study where they measured tau and stratified patients by tau. I was wondering if you had any early thoughts on a specific population within the Alzheimer's disease group that you'd look to enroll, and any comment you have around the differential effects it seems like Eli Lilly saw in their higher versus intermediate tau cohorts?
Hi, Jack. That's a really interesting question. I look forward to seeing the data at a scientific conference. From what I gather, the people who had the higher tau burden when they started the treatment had less of a treatment effect. I think that underscores what I was just saying, that we may need to combine with a tau approach, a tau-targeted therapy. In terms of the population, you know, even by, even when we enroll patients with mild cognitive impairment, which is the early symptom, the earliest symptomatic disease, the disease is pretty far advanced in terms of molecular pathophysiology, right?
I mean, not only has amyloid been accumulating for up to 20 years and have reached essentially a maximum burden in the brain, we've seen tau has already started to progress in many of these patients. I think that the, even when you do the combination, you're gonna need to go to an early stage of patient, at least MCI and maybe even earlier.
Got it. Great. Thank you so much for that insight. Then I was also wondering if you had any comments on the competitive landscape as it relates to tau and any other programs you're closely monitoring to see early proof of concept in this space?
Well, I think that, you know, there are a number of mid-domain targeted antibodies that are now approaching lead outs from efficacy trials, to my understanding. That'll be very interesting. You know, in our hands, we had multiple mid-domain antibodies that we could have humanized ourselves. In our hands, they weren't as consistently effective in the spreading assay in the animal studies, where we take human pathological tau, inject them into the animals, and look at the spread of pathological tau. We're very hopeful that our C-terminal antibody is, remains differentiated, but I think it'd be wonderful to see efficacy with the mid-domain antibodies. These Alzheimer's disease patients need something additional, I believe, in addition to the anti-amyloid therapies.
Todd?
I just wanted to add that, from our studies, at least in our preclinical models, it's pretty clear that the epitope matters, quite a bit. There are mid-domain antibodies that of our own that work, and there are mid-domain antibodies that don't work. Our C-terminal antibody, as Al mentioned, gave us the most robust and the strongest effect. I think that as we see these antibodies come through the clinic, it will be very informative for the whole field to learn, hopefully, what works and then maybe what doesn't.
Great. Thank you so much for the color, and congratulations again on the progress.
Thanks, Chad.
Thank you. One moment while we prepare for the next question. Our next question will be coming from Phil Nadeau of TD Cowen. Phil Nadeau of TD Cowen, your line is open.
Morning. Thanks for taking our questions and let us add our congratulations on the progress. A couple from us, keeping on the tau theme. In terms of the tau antibody that you've chosen as the development candidate, how does that antibody compare to the one that produced the data at AAIC 2022? Is it simply a humanized version of that prior antibody, or are there any other changes?
Go ahead, Todd.
Sure. We have shown data on a number of antibodies. The data you're talking about from AAIC included data from multiple panels of antibodies with different epitopes. The antibody we're taking forward is a humanized version of the lead antibody from that presentation.
It's a humanized version of the antibody that produced the 71%-74% declines in-
Yes.
-in tau? Yeah. Okay. That's helpful. Second, on the GLP tox, it sounds like you're gonna complete the GLP tox and be able to file an IND within a year. That strikes us as faster than average. How can you get that done so quickly? Is that based on feedback from the FDA or just prior experience?
It's both, actually. you know, there have been other humanized antibodies against pathologic proteins. The tricky part here is that the target for the antibody is not expressed in wild type animals, which is typically what's used in tox species as the tox species, right? So in order to look at on-target toxicity, you have to look in animal models where that's the only place that you have the pathological tau as being expressed. Those models, you know, the animals don't do well. They die prematurely because of the disease, and so you have to work within the limitations of that. So we do have experience with humanized antibodies against pathological proteins in the brain. We've drawn on that experience. Also we have FDA feedback.
Our preclinical toxicology plan is based on both.
Great. Then one last housekeeping question for Pete. Pete, the $25 million milestone that was received in April, is that all gonna be booked in Q2, or is there gonna be an amortized component?
We, from a rev rec perspective, recorded that obviously in Q1, but cash is in Q2.
Perfect.
Hopefully that helps. You can see that in the numbers.
Got it. Thank you.
Thank you. One moment while we prepare for the next question. Our next question will be coming from Yanan Zhu of Wells Fargo. Your line is open.
Hi. Thanks for taking our questions. Perhaps a tau question and a SOD1 ALS question. For tau, how would you think about the criteria for success, once you get the tau antibody, PET imaging data, given the findings of the tau antisense, as you mentioned before? I'm guessing mainly, if tau reduction on PET is less potent, then if there's still a reason that the antibody approach can be a reasonable modality to be further pursued. On SOD1, the question is, could you give more color on the delay for the nomination of the candidate? Is it more about payload or vector optimization or some other reasons? Thank you.
Thanks. Those are great questions. I'll take the first one, and Todd will take the second one. On the tau, you know, well, first of all, the antisense oligonucleotide is injected intrathecally. Our antibody is an intravenous drug that we're gonna inject every 4 weeks. That's a pretty big difference right there in the mode of administration. We will obviously compare to others that are showing data on tau. We do have a minimum product profile that takes into account our competition. We will move it forward if we have First of all, we have to have a statistically significant reduction in the spread of tau. We'll compare to competitors and see if there's space for an additional treatment.
Just keeping in mind that the different modes of administration, the higher ease of use of an intravenous antibody, and the fact that, you know, I think there's room for more than one treatment. When I was a physician, I always liked having multiple options for my patients. Todd?
On SOD1, as you know and pointed out, the development candidate and therapy is a combination of a capsid and a payload. The transgenes. We're continuing to work and evaluate the transgenes and our capsids. Our capsids continue to perform very well. I invite anybody on the call to check out the ASGCT presentations next week. We have a symposium presentation, an oral presentation, and some posters on our novel capsids. We're seeing quite reproducible results and continued performance in crossing the blood-brain barrier. What we're trying to do is identify the optimal payload with the optimal capsid to meet our candidate criteria. We hope to do that at, in the back half of this year.
Got it. Thanks for taking the questions.
Thank you. One moment while we prepare for the next question. Our next question will be coming from Laura Chico of Wedbush. Your line is open.
Good morning. Thanks very much for taking the question. I guess, Al, staying on this tau theme, I wanted to ask if with the upcoming reimbursement decision for the anti-amyloid antibodies, is there any learnings there that can inform or perhaps change your development strategy for tau? Then one for Pete, can you just remind us, it's obviously been a big year in terms of milestones, coming in, the potential for any remaining milestone payments in 2023. Thanks, guys.
Thanks, Laura. Yeah, on the reimbursement, question, that's a really important question, and we have a lot to learn, I think, as the year goes on this year. I think, look, we have to be mindful of the total number of patients that are going to require treatment, and we don't wanna do anything that'll be, you know, unhelpful to society. We wanna help patients, and we wanna make sure patients have access to the drug. I think there's a lot for all of us to learn, in the coming years. But yeah, I think you're pointing to the, to the, to the concept that if there's a combination treatment, that's two drugs that have to be reimbursed. We'll have to take that into account.
Laura, with regards to your second question, we don't provide a lot of forward-looking guidance with regards to future milestones. I know we've shared publicly the milestones relative to all of our partnerships and relationships that we have in aggregate and kind of with some breakdown, a lot of that's been redacted. I can say it this way, with regards to our existing relationships, there are some potential milestones that we could be getting in more of a near term. I would say it that way. Again, we don't guide specifically with regards to those. You know, I think that's most probably where we would, we would leave it for now. Hopefully that helps.
Okay. Yeah. Thank you very much, guys.
Thank you. One moment while we prepare for the next question. Our next question will be coming from Joon Lee of Truist Securities. Joon Lee, your line is open.
Hey. Thanks for taking our questions. You know, for the Huntington's program, it's interesting that you're taking both an allele-specific and non-allele specific approaches with SNP and MSH targeting. Can you elaborate a little bit on your strategy here? Do you plan to include multiple siRNAs in a single construct to address multiple SNPs? Would you also combine SNP as well as MSH in a single construct? Thank you.
Yeah, thanks. I'll start and I'll ask Todd to finish the answer. I would say that in some ways, both are kind of an allele specific, both targets, because MSH3 targets the expansion which only occurs off the mutant. Obviously the allele specific mutant huntingtin targets is an allele specific approach. In some ways, I look on it as both are kind of preserving both targets. By targeting both of these, we're preserving the expression of wild type huntingtin, which I think is the goal, because, you know, I think there's a lot of concern that we need to preserve wild type huntingtin expression.
Yeah, I mean, I'll let Todd answer, but our aim is to combine both siRNA, vectorized siRNAs into the same vector. Go ahead, Todd.
That's right, Al. We do plan, Joon, on incorporating both siRNAs. The payload for the siRNAs is relatively small, so it's not a problem to fit multiple in a single vector. We can do a bicistronic approach. That said, I mean, we could explore and evaluate these independently as well, so that's always an option we could choose to move forward with. We plan on going after MSH3 PAM in a PAM manner, which would affect the mutant alleles specifically. The approach to the allele specific huntingtin is a SNP-based approach to knock that down in an allele specific manner.
Joon, you're right that, you know, a SNP-based approach, we're not gonna be able to treat every single Huntington patient. We'll start with the most common alleles, and then ultimately we may need to do a second, allele specific, you know, mutant HTT program and so forth.
Right.
Go ahead.
Thank you. I have a follow-up on the tau program. You know, you have, as someone people alluded to, you have multiple programs, multiple shots on goal. You have the approach to targeting extracellular species as well as the intracellular species with the siRNA. Is there one species, in your view, that is probably more important to address or? I know you'd probably say both, but which one has more, like evidence as a more dangerous or pathogenic form?
Well, I wish I knew the answer to that question. I think that's part of the complexity here, is that there are multiple forms, if you will, of tau in the extracellular space. You know, it's pretty certain that targeting just the N-terminal containing, extracellular species of tau probably doesn't work because the multiple approaches have been tried for those. I think that I don't have an answer. Maybe Todd, do you know what the pathologic species is?
No, I don't. Yet.
No, I mean, you know, more along the lines of, you know, intracellular versus extracellular because your siRNA approach will target, I believe, the intracellular species preferentially.
Yeah. Well, it actually will target both. I mean, it'll target the synthesis of all forms of tau. If we decrease, we will definitely increase intracellular, which the antibody probably won't be able to do very much at all. It will also, eventually it will also target extracellular tau too, because that's the source of extracellular tau is intracellular tau.
Would you say that the siRNA approach then would have a little bit higher probability of success, or that's still TBD?
You know, every approach is gonna have its own benefit-risk profile and mode of administration issues and things. I think, you know, I think it's still too early to know, to be certain which approach is gonna be optimal for patients. I think it's such an important target, we wanted to go after it with multiple approaches.
Thank you.
Mm-hmm.
Thank you. One moment while we prepare for the next question. Our next question will be coming from Sumant Kulkarni Excuse me, Kulkarni of Canaccord. Your line is open.
Morning. Thanks for taking my question. Nice to see all the progress of the company. It's clearly an exciting time to be targeting the specific conditions that you are. I have a question on your SOD1 ALS gene therapy program. Now that tofersen is available, how do you expect the landscape to change with respect to clinical trial recruitment? Is there any merit in running a specific preclinical model in combination with tofersen?
Okay, I think I heard the first question, but I'll start and then I'm not sure I heard the second one. I think the first question relates to the feasibility of recruiting patients in the setting of tofersen being approved. I think there's first of all, it's wonderful that patients with a terrible disease have treatment options. Congratulations to Biogen and Ionis for getting that across the finish line. For us, you know, we could either take patients who are already on tofersen and give them the gene therapy and see if the requirements for tofersen is decreased, perhaps, to zero, but it could just be decreased. We can track neurofilament as a marker to know whether or not the treatment is adequate, for example.
Another approach would be to go to untreated patients. There may be parts of the world where it's hard to access tofersen. And then a third approach would be to go very early, even before symptoms, to get rid of the toxic gain-of-function autosomal dominant mutation. Those are the three approaches we're considering now. Time will tell whether which one of these is the best option. I think it's, I think that the, as I alluded to in my comments, the fact that neurofilament is considered by regulators, at least FDA, as a validated surrogate outcome measure only helps in terms of making the development more feasible, I believe.
Yeah.
You may have to repeat the second question because I'm not sure I heard it.
Sure. The second part of that was, is there any merit in running a specific preclinical model for your gene therapy in combination with tofersen to optimize the product?
The question was whether we're doing preclinical studies. There are a couple of SOD1 transgenic mouse models, G93A, G37R, et cetera. We could add, do the combination study in vivo, but I'm not certain that that would be necessary before we did the study in patients. I think that we have a very good blood-based biomarker that we can use to monitor patients in terms of the amount of injury to motor neurons. Some of these animal models, they're not very predictive of what happens in the clinic, so I worry about relying too much on these animal models.
Got it. Thank you.
Thank you. Again, if you would like to ask a question, please press star one one on your telephone. The next question is coming from Jack Allen of Baird. Your line is open.
Great. Thank you so much for taking the follow-up. I just wanted to reach out and see if you have any comments around the availability of non-human primates. I know earlier this year, there was a ban of importation of these critical research assets, and I wanted to gauge your, I guess, awareness of this and any comments you have as it relates to your preclinical programs that you have ongoing.
Hi, Jack. Todd. That's a great question. I think the entire field is watching very carefully. We certainly are watching the non-human primate availability quite closely. To date, we have not been adversely affected by non-human primate availability. We've set up agreements with multiple vendors to make sure we have options in case an issue should arise. All I can say is that we're doing our best to mitigate any risk and watching very closely.
Great. Thank you so much.
Thank you. This concludes today's Q&A session. There are no more questions in the queue. I would like to turn the call back over to Dr. Al Sandrock for closing remarks.
Thank you everyone for joining us today and for the great questions. Feel free to follow up with us directly if you have any further questions. Thanks again.
Thank you everyone for joining today's conference call. This concludes today's event. You may all disconnect, and everyone have a great rest of your day.