FULC Stock Slumps Nearly 50% After Hours As FDA Kills Only Clinical Program Over Cancer Risk

• On May 28, Fulcrum received meeting minutes in which the agency expressed heightened concerns about the benefit-risk profile of pociredir.
• The regulator’s observations left no viable regulatory path forward for pociredir. 
• In conjunction with the program termination, Fulcrum said it has initiated a comprehensive strategic review to explore alternatives.

Shares of Fulcrum Therapeutics Inc. (FULC) fell sharply in after-hours trading on Monday after the clinical-stage biotech company announced it is fully discontinuing development of its lead candidate, pociredir, for sickle cell disease (SCD), and launching a strategic review to explore a sale or other transactions to maximize shareholder value.

With the discontinuation of pociredir, the company has lost its only clinical-stage asset, leaving Fulcrum essentially with no near-term pipeline. Earlier programs, such as losmapimod for facioscapulohumeral muscular dystrophy, had already been discontinued after a failed 2024 trial. Pociredir had held Fast Track and Orphan Drug designations from the FDA for SCD, a genetic blood disorder.

FULC shares traded 49% lower after hours at the time of writing.

What Drove The Decision?

The decision stems from recent feedback from the U.S Food and Drug Administration. On May 28, Fulcrum received meeting minutes in which the agency expressed heightened concerns about the benefit-risk profile of pociredir, an EED inhibitor that targets the PRC2 complex. Those concerns were triggered by the global withdrawal of Tazverik (tazemetostat), another PRC2 inhibitor, in March 2026 after it showed an unexpectedly high rate of secondary hematologic malignancies.

The FDA concluded that any pharmacological intervention targeting the PRC2 complex carries equivalent malignancy risk. This stance, combined with previously disclosed preclinical malignancy observations for pociredir, left no viable regulatory path forward.

“Following a thorough review of regulatory feedback, the totality of available data, and the implications for a viable regulatory path, we have made the very difficult decision to discontinue development of pociredir,” said Alex C. Sapir, Fulcrum’s president and chief executive officer. Sapir noted that no new safety signals have emerged in human trials of pociredir to date, but the FDA’s position on class-wide risk outweighed the drug’s observed clinical benefits.

In conjunction with the program termination, Fulcrum said it has initiated a comprehensive strategic review to explore alternatives aimed at maximizing stockholder value. These may include a merger, acquisition, business combination, or other transactions involving the company or its assets. The company is also taking steps to significantly reduce operating expenses and preserve capital. It has not set a timeline for concluding the review and does not plan further updates unless a transaction is approved or other disclosure becomes appropriate.

How Did FULC Retail Traders React?

On Stocktwits, retail sentiment around FULC rose from ‘bearish’ to ‘bullish’ territory over the past 24 hours, while message volume rose from ‘low’ to ‘normal’ levels.

A Stocktwits user opined that the stock will likely test all-time lows on Tuesday.

FULC stock fell 8% over the past 12 months. 

Read More: RIVN Stock Surges For 8th Straight Day: Rivian’s Rival To Tesla Model Y Nears June 9 Delivery Kickoff

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