Why did ANNX's operating profit drop sharply in Q4 2024?

The operating profit of Annexon Inc (ANNX) declined significantly in Q4 2024 due to several factors: 1. **Increase in General and Administrative Expenses**: The net loss for the quarter increased to $34.8 million, up from $32.5 million in the same quarter of the previous year. This rise was primarily attributed to higher general and administrative expenses, which rose to $9.3 million from $6.9 million. 2. **Higher Research and Development Costs**: Research and development expenses also increased to $30.1 million from $27.9 million, mainly due to higher consulting and professional services costs. In summary, the operating profit drop was likely a result of increased expenses, specifically in general and administrative costs, and research and development costs. These increases outpaced the revenue growth, leading to a sharper drop in operating profit.