BIIB BIOGEN INC Capital Structure Changes 8-K Filing 2025 - Debt-Equity Swaps Biogen Inc. entered into an agreement to issue $1.75 billion in senior notes, including $400 million due in 2031, $650 million due in 2035, and $700 million due in 2055, on May 6, 2025, to help retire existing debt and for general corporate purposes. The sale was completed on May 12, 2025.Get access to all SEC 8-K filings of the BIOGEN INC