What drove BIIB's earnings growth in 2024?

Biogen's earnings growth in 2024 was driven by a combination of factors including new product launches, strategic growth initiatives, and cost management.

1. **New Product Launches**: The launch of new drugs such as Leqembi and Zurzuvae contributed to the growth in earnings. Leqembi, launched for Alzheimer's disease, saw significant sequential growth in sales, while Zurzuvae showed promise in its initial launch in the U.S..
2. **Strategic Growth Efforts**: Biogen's strategic focus on neuroscience and rare diseases, coupled with collaborations like the one with Eisai for Leqembi, has been beneficial. The company's "Fit for Growth" initiative is expected to generate significant savings, contributing to the anticipated EPS growth in 2024.
3. **Cost Management**: Biogen has seen a decline in adjusted research and development (R&D) expenses, which dropped 21% year-over-year to $4.... This cost management likely contributed to the improved net income margins.
4. **Market Uptake of Existing Products**: The accelerated uptake of Leqembi and the successful launches of Skyclarys and Zurzuvae also supported the growth in earnings.

In summary, Biogen's earnings growth in 2024 was driven by a combination of new product launches, strategic growth initiatives, and effective cost management.