Editas Medicine, Inc. (NASDAQ:EDIT) Q1 2023 Earnings Call Transcript

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Yanan Zhu: Maybe to continue the discussion a little bit from the prior question. Gilmore, you mentioned that the total hemoglobin for the first patient is quite robust in the normal range. The percent of fetal hemoglobin appears to be very much in line with competitor gene editing product. So, I was wondering, is the — greater total hemoglobin reported for that patient, is that due to the total number of red blood cells? Could that potentially be a reason, or could it be related to the baseline level of hemoglobin in that patient? And along that line, to continue a little further and to — perhaps looking into what we could expect from patient number two at EHA. I was just wondering, could you remind us the baseline hemoglobin for patient number two and what is the normal range for the female patient, which obviously is the second patient? Thank you.

Baisong Mei: So thanks for the question, Yanan. So, I will start with answer to your first part of the question regarding the fetal hemoglobin versus the number of red blood cells and all these. So, what we see is actually robust erythropoiesis for these patients we observed. So, their hemoglobin level is contributed by both the hemoglobin per cell as well as the number of red blood cells. And you can see that — we actually do see the increase also on both ends of that. And then also I want to mention that even though we also have like around 45% of fetal hemoglobin, and because of the total hemoglobin level is high and the total amount of fetal hemoglobin is also high. So, that’s kind of in that. And then regarding the second patient, and we will present the data very soon.

So, I will not comment on the specifics of the patient data, but I can mention that, of course, the male and female normal hemoglobin level are different. Usually, for male is around 13.5% to up to 18-gram per deciliter, for female is around 12 to 14, depending on the reference lab. So there’s some difference in there, too.

Gilmore O’Neill: Okay. I think one other thing, Yanan, you asked a question about what was the baseline hemoglobin of the patient one. And I think what we can say is that the hemoglobin or the total hemoglobin increase that we saw occur very rapidly just within the first few months of dosing comprised a 3.5 gram per deciliter increase.

Baisong Mei: Yes. Maybe just add a little bit nuance on that baseline for sickle cell patient, especially for gene-editing trial. And because the patient — when they prepare for pheresis and conditioning, they usually have blood transfusion. So, the baseline actually we have is not the lowest level we recorded. We just set at the time of the visit 2 as a baseline. So actually it’s compounded, it could be many different reasons for the baseline on that, too. That’s just a nuance. It’s actually — it’s lower than — it’s around a little bit over 10 grams per deciliter when we actually — on our record for this patient. This is just an example about the baseline, maybe not confusing.

Yanan Zhu: Very nice. Thank you for all the explanation. Maybe a quick follow-up. Do you expect this to be also a differentiator for TDT and perhaps maybe at a greater level of significance because anemia is a major manifestation of that disease? Thank you.

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