Tazverik’s withdrawal from the global market in March 2026 has now claimed a second casualty — and the collateral damage reveals something uncomfortable about how the FDA is drawing class-level conclusions from mechanism-adjacent data. Fulcrum Therapeutics is discontinuing pociredir, its EED inhibitor for sickle cell disease, after the FDA concluded on May 28 that inhibiting any subunit of the PRC2 complex carries equivalent secondary malignancy risk, regardless of which subunit is targeted. Fulcrum pushed back, arguing that EED and EZH2 perform distinct biological roles. The FDA acknowledged the argument and rejected it anyway.
That regulatory stance is the real story here, and it has consequences that extend well beyond Fulcrum’s $333.3 million cash balance. The FDA has effectively issued a class-wide malignancy warning for PRC2 modulators based on tazemetostat’s post-approval safety profile — not on any signal from pociredir itself. Fulcrum reported no treatment-related serious adverse events across the 12 mg and 20 mg dose cohorts in PIONEER, with dose-dependent fetal hemoglobin induction that was, by any clinical measure, working. Shutting down a mechanistically distinct molecule because a related complex member failed is a notable expansion of class-risk reasoning, and every company with a chromatin-modifying asset in development now has a new precedent to navigate.
For Fulcrum specifically, the strategic review announcement is a controlled liquidation signal. A company with no pipeline and $333 million in cash is not exploring “strategic alternatives” — it is preparing to be acquired, most likely for its treasury. The SCD space has seen brutal attrition over the past two years, and the buyers most interested in Fulcrum will be those who want the cash and the hematology infrastructure, not the science. The EED inhibitor rationale, the proprietary discovery platform, the Fast Track and Orphan Drug designations — these are largely stranded assets at this point.
The single consequence worth tracking is how the FDA formalizes its PRC2 class-risk position. If this reasoning migrates into written guidance or informs an advisory committee discussion, it will set the threshold for any future chromatin-biology program attempting a sickle cell or hemoglobinopathy indication — a threshold that, as of today, appears to have no clear evidentiary path to clear.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
