Why did SEPN's operating profit plummet in Q4 2024?

The operating income of Septerna, Inc. (SEPN) took a significant hit, dropping to -$20.81 million in Q4 2024, compared to the previous quarter's operating income of -$10 million. This decline of **-20.81 million** in Q4 2024 can be attributed to several key factors:

1. **Clinical Trial Discontinuation**: Septerna decided to halt its Phase 1 clinical trial for SEP-786 due to adverse events, specifically elevated bilirubin levels in trial participants. This decision led to a substantial decline in its operating income. The discontinuation of SEP-786 was a strategic move to focus on next-generation programs, but it came at the cost of short-term revenue potential.
2. **Strategic Shift**: The company is shifting its focus from SEP-786 to a next-generation oral PTH1R agonist and other programs. This strategic pivot likely resulted in a loss of revenue from the discontinued program, as well as increased expenses associated with initiating new projects.

In summary, the decline in SEPN's operating income in Q4 2024 is primarily due to the discontinuation of its Phase 1 clinical trial for SEP-786 and the strategic shift in focus to next-generation programs, which collectively contributed to a significant negative impact on the company's financial performance during that quarter.