Citizens Says FDA’s 'Unexpected' Phase 3 Request Clouds Mirum’s Near-Term Outlook – MIRM Stock Crashes 15%

The firm said the U.S. Food and Drug Administration’s request for an additional Phase 3 trial of Volixibat to treat a liver disease is expected to delay the program.

• Citizens lowered its price target to $137 from $146 while maintaining an ‘Outperform’ rating, according to The Fly.
• The FDA recommended conducting a Phase 3 study before a potential new drug application.
• Mirum raised its full-year net product sales guidance to $680 million to $700 million, from its previous outlook of $660 million to $680 million.

Shares of Mirum Pharmaceuticals (MIRM) plummeted 15% in early trading on Thursday after the biotech firm disclosed a regulatory setback for its lead pipeline candidate, overshadowing better-than-expected second-quarter revenue and prompting Citizens to lower its price target.

MIRM shares cracked the crucial 200-day moving average (200-DMA) for the first time since May 2025.

FDA Request Could Create Near-Term Uncertainty

Citizens lowered its price target to $137 from $146 while maintaining an ‘Outperform’ rating, citing an unexpected regulatory hurdle for its liver disease candidate Volixibat despite a strong second-quarter performance, according to The Fly.

On Wednesday, CEO Chris Peetz said that following a pre-new drug application (NDA) meeting, the U.S. Food and Drug Administration (FDA) recommended conducting a Phase 3 study before a potential NDA submission, which Mirum now expects could occur in the first half of 2027.

The firm said the FDA’s request for an additional Phase 3 trial of Volixibat in primary sclerosing cholangitis (PSC) is expected to delay the program and create near-term uncertainty.

Volixibat has already received the FDA’s Breakthrough Therapy and Orphan Drug designations.

MIRM Raises FY2026 Sales Outlook

Mirum reported a better-than-expected topline while also raising its full-year 2026 sales guidance. Revenue came in at $176.2 million, topping analysts’ estimates of $167.3 million, according to Fiscal.ai data. The company reported a wider-than-expected loss of $1.06 per share, compared with Wall Street’s forecast for a $0.76 per-share loss.

Mirum ended the quarter with $561.3 million in cash, cash equivalents and investments and raised its full-year net product sales guidance to $680 million to $700 million, from its previous outlook of $660 million to $680 million.

MIRM Bulls See ‘Great Entry Point’

Retail sentiment surrounding MIRM on Stocktwits turned ‘bullish’ from ‘bearish’ over the past 24 hours, amid ‘high’ message volumes.

One user called the stock’s slump an ‘overreaction’ and said the current levels represent a ‘great entry point.’

View this Stocktwits post

The stock has gained around 13% so far this year.

For updates and corrections, email newsroom[at]stocktwits[dot]com.<