Ardelyx Inc. (NASDAQ: ARDX) experienced a significant decline of 10.68% in post-market trading on Thursday. The sharp drop followed the release of the company's fourth-quarter and full-year 2025 financial results.

The biopharmaceutical firm reported quarterly earnings of $0.00 per share, which missed the analyst consensus estimate of $0.01 by a substantial margin. This result also represents a 95% decrease compared to earnings of $0.02 per share from the same period last year. Although quarterly sales of $125.215 million surpassed expectations, investor focus shifted to the disappointing bottom line and a concerning trend in annual profitability.

According to the financial reports, Ardelyx's net loss for the full year 2025 widened to $61.6 million, compared to a net loss of $39.1 million in 2024. This indicates ongoing challenges in achieving profitability despite revenue growth from its key products, IBSRELA and XPHOZAH. The combination of the earnings miss and the expanding annual loss appears to have driven significant selling pressure among investors.