What caused Merck's operating expenses spike in Q4 2023?

Merck's operating expenses did not experience a spike in Q4 2023. On the contrary, the company's Q3 2023 earnings report revealed a decrease in operating expenses, which was attributed to lower administrative costs and no significant business development expenses.

1. **Decrease in Administrative Costs**: Merck reported a 4% decrease in operating expenses, amounting to $5.8 billion. This reduction was primarily driven by lower administrative costs.
2. **No Significant Business Development Expenses**: There were no notable business development expenses recorded in the quarter, which was a contrast to the $690 million in charges incurred during the same period in the previous year.

Overall, Merck's operating expenses declined in Q3 2023, rather than increased.