Biogen Inc Q1 2023 Earnings Call Transcript

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

Question: Colin Nigel Bristow - UBS Investment Bank, Research Division - Analyst : And also welcome, Chuck. We're excited to be working with you again. On subcut LEQEMBI, what does FDA specifically said is required for approval? And then can you just speak to how important the [subcut] formulation is to the commercial story? What proportion of patients would it allow you access to the infusion or not? And then just a sort of a subpart on the commercial part. The VHA excluding APOE4 [homozygotes]. Can you just speak to the risk that you see either as a labeling or commercial risk on full approval and as access broadens? Priya Singhal - Biogen Inc. - Executive VP, Head of Development and Interim Head of Research, Global Safety & Regulatory Sciences Okay. Thanks, Colin. I can start -- Yes, I can start with the subcutaneous formulation. So the plan is on track, and Eisai has said that they would be filing by Q1 2024. Just to back up, the evaluation is being conducted in the Phase III open-label extension by a subcutaneous sub-study. And Eisai has also stated that they have discussed the requirements for proceeding with this filing and generating the data and then subsequent filing with FDA and other regulators. And they believe that the strategy currently does allow for an evaluation of PK, PD and safety, which would be required. I'll move to the next aspect. I think that you asked was about the APOE4 homozygotes. So Eisai presented some of these data at ADPD and also made comments on this topic. And they believe that really the data set was rather small. The number of APOE4 homozygotes was quite small. They don't believe that the overall conclusions are different in terms of CLARITY AD and confidence in the data. The other aspect here to keep in mind is that actually many of the secondary endpoints favored LEQEMBI. So there could be a component of placebo not declining as much in this comparator group, and that was one of the points that they made as well. Now with regards to the commercial view on subcutaneous, I'm going to turn it to either Chris or Mike.