Mirum Pharmaceuticals, Inc. (MIRM) shares plummeted 14.18% in after-hours trading on Wednesday, following the release of the company's second-quarter 2026 financial results.

The biopharmaceutical company reported a quarterly loss of $1.06 per share, significantly missing the analyst consensus estimate of a loss of $0.68 per share by 55.88%. This represents a sharp deterioration from the loss of $0.12 per share in the same quarter last year. Net loss widened to $67.23 million, compared to a net loss of $5.86 million a year earlier, as operating expenses surged to $218.78 million from $132.77 million. While total net product sales rose 37.91% to $176.24 million, beating the consensus estimate of $166.12 million, the substantial increase in operating costs and the deeper-than-expected loss overshadowed the revenue growth and triggered a sharp sell-off in extended trading.