Dyne Therapeutics Inc Topline Clinical Results from the DELIVER Trial of Z-Rostudirsen DYNE-251 in Duchenne Muscular Dystrophy Transcript

The following is excerpted from the question-and-answer section of the transcript.

Question: Moritz Reiterer, Ph.D. - Guggenheim Securities LLC - Analyst : Congrats on the data and thanks for taking my question. I have two questions on the time function tests. First, could you elaborate on the precedents for using velocity instead of time for Time to Rise in the 10-Meter Walk/Run? And secondly, if you were to analyze your data from these endpoints based on time instead of velocity, would the results still be stat sig?

Question: Avraham Novick - Morgan Stanley - Analyst : Hey. It's Avi Novick on the line for Mike. Thank you for taking our questions and congratulations on the data. So I guess just following up on the functional endpoints, I guess, have you done any market research that, I guess, as to which clinicians would find -- which of these endpoints clinicians would find most compelling? And do you think there's a possibility of driving switch from standard of care? And in addition, I guess, which of these do you see as, I guess, driving the highest probability -- or should we view as driving the highest probability of success in an eventual Phase 3 confirmatory study?

Question: Avraham Novick - Morgan Stanley - Analyst : Got it. Thank you. And then I guess with respect to the upcoming Phase 3, I guess, which of these do you see as most important for, I guess, confirming functional benefit?

Question: Andrew Tsai - Jefferies LLC - Analyst : Congratulations on the very strong results. Thanks for taking my question. As we think about the path ahead, obviously, it's submitting for accelerated approval. So can you talk about your overall confidence in CMC manufacturing? 20 mgs per kg seems like a lot of drug to produce. So I just want to understand how derisked CMC and supply are at this juncture and how you're ensuring that won't be a risk during the FDA review?

Question: Martin Auster - Raymond James - Analyst : Congratulations on the data this morning. I was wondering if you could talk a little bit more about the global commercial opportunity just in terms of how important that is? Right now, there's a drug approved in the US. Can you address how you see this opportunity playing out globally? And then maybe touch on where you see the regulatory path and the requirements for gaining access, both in European as well as rest of world markets?

Question: Edward Tenthoff - Piper Sandler & Co - Analyst : So firstly, congratulations, another big win for -- this is the second big win for DMD patients in just under a week. So really exciting to see these results. I was so impressed by the consistency of the data. Obviously, the focus is on z-ros but now with pivotal -- positive pivotal data in hand, how quickly do you think you could advance these other FORCE drugs that treat other exons into the clinic? And what do you think the regulatory path might be? Is there any chance that those move directly into registrational cohorts? Or do you think it would mirror the way you've advanced 251? And thank you very much.

Question: Edward Tenthoff - Piper Sandler & Co - Analyst : That makes a lot of sense. And again, congrats on the data and this really important work you're doing for these boys.

Question: Catherine Novack - Jonestrading Institutional Services LLC - Analyst : I just wanted to ask a little bit about -- again, questions about the endpoints ideal for the registrational study. Do you expect to have a similar age group and mix of ambulant versus non-ambulant patients so we can get a sense of which endpoints would be more ideal, let's say, something that is more sensitive in a younger population versus those who are a bit older?

Question: Catherine Novack - Jonestrading Institutional Services LLC - Analyst : For the confirmatory trial, yes.

Question: Catherine Novack - Jonestrading Institutional Services LLC - Analyst : Got it. And then just on the commercial opportunity, do you have a sense that there's any kind of loyalty whatsoever to current exon skippers? Or is -- once a drug with superior dystrophin expression is available to patients? Is that -- is dystrophin alone something that would encourage providers to change treatment? And additionally, with the monthly versus weekly dosing, would this encourage some patients who are not on drug to potentially look at being prescribed? LSEG STREETEVENTS | www.lseg.com | Contact Us consent of LSEG. 'LSEG' and the LSEG logo are registered trademarks of LSEG and its affiliated companies. DECEMBER 08, 2025 / 1:00PM, DYN.OQ - Dyne Therapeutics Inc Topline Clinical Results from the DELIVER

Question: Gavin Clark-Gartner - Evercore Inc - Analyst : We just had one question on the two new safety events. Just wondering what was the time course of onset and then the resolution for the events post infusion?

Question: Brian Skorney - Robert W. Baird & Co Inc - Analyst : Congrats on the data. I think you had previously talked about dystrophin-positive fibers and generally, we see a correlation between expression and positive fibers. But I'm just wondering if you've analyzed the IHC from these patients yet and what it looks like, both in terms of dystrophin positive fibers, as well as any standing for restoration of the dystrophin sarcoglycan complex to show localization?

Question: Keay Nakae - Chardan Capital Markets - Analyst : What is your understanding of what the EMA is going to require in terms of functional improvement measurement of the ones that you're assessing?

Question: Keay Nakae - Chardan Capital Markets - Analyst : Yeah. I appreciate that. I guess just in thinking of the multiple goals of the confirmatory Phase 3, will it be driven more by seeking to expand into the EMA? Or more checking the box of the US requirement of the confirmatory to back up the accelerated approval and whatever measurement they want to see?

Question: Tessa Romero - JPMorgan Chase & Co - Analyst : Hi, John and team. Thanks so much for taking our questions here. First one is, do you intend to have a pre-BLA meeting ahead of your planned BLA submission in the second quarter? And if so, has this meeting been scheduled? Or when do you expect it would take place? And then the second question is, to be clear, you did not see any thrombocytopenia at the 20-milligram kilogram dose. Can you just clarify exactly what you saw?

Question: Tessa Romero - JPMorgan Chase & Co - Analyst : Okay. And how do you define persistent?

Question: William Pickering - Sanford C Bernstein & Co LLC - Analyst : Hi. Thank you very much for taking my question and congratulations on the data. I was wondering if you could describe the imputation approach you used in the REC? How much of the data was imputed? And any related sensitivity analysis you may have run? And it looks like you used imputation for all endpoints except FVC. So could you describe the rationale for that?

Question: William Pickering - Sanford C Bernstein & Co LLC - Analyst : Thanks so much and congrats again.