Analyst Note
| Karen Andersen, CFA |Biogen saw a 25% decline in revenue in the second quarter as multiple sclerosis revenue fell 24% with the launch of generic versions of Tecfidera in the United States. However, the key focus of the earnings call was recently approved Alzheimer's disease drug Aduhelm and the controversy surrounding its approval. Given the significant uncertainties around reimbursement and competition, we continue to assume a small share of patients receive Aduhelm even in the out years of our model, which still results in $7 billion in global Aduhelm sales by 2030. We think Biogen's core MS business and expansion into depression, stroke, and neurogenerative diseases support a wide moat, and we're maintaining our $391 fair value estimate.