Pharma BD Deal Intelligence
Sobi acquired US rights to AstraZeneca's RSV antibody Synagis (palivizumab) plus a US profit share on the next-gen MEDI8897 (nirsevimab) in November 2018 for $1.5B upfront ($1.0B cash + $500M Sobi shares to AstraZeneca), plus up to $470M in Synagis sales milestones from 2026, $175M for MEDI8897 BLA submission, ~$110M in MEDI8897 profit/development milestones, and $20M/yr 2019-2021 (total deal value up to ~$2.3B). AstraZeneca's largest divestiture in 5 years. Post-close, the structure evolved as anticipated: in April 2023, ahead of the Beyfortus (nirsevimab) FDA approval, Sobi restructured the arrangement — converting its US nirsevimab profit share into a tiered royalty (25% at launch, rising 2025-2028 to 30-35% of US net sales), paying Sanofi $66M for prior R&D and terminating the AstraZeneca participation agreement for $15M. Beyfortus's July 2023 broad-label approval and Merck's clesrovimab (Enflonsia, 2025) then displaced palivizumab, and Sobi withdrew Synagis from the US market effective December 31, 2025 (FY2025 Synagis revenue had collapsed to ~SEK 89M while the Beyfortus royalty contributed ~SEK 849M), validating AstraZeneca's exit timing while leaving Sobi the durable nirsevimab royalty tail.
Assessment window: 5yr post-close.