Kaplan Fox Initiates Securities Probe into Fulcrum Therapeutics After 51% Stock Plunge Post-Pociredir Program Halt

Pociredir Program Termination and FDA Safety Issues

On June 1, 2026, after market hours, Fulcrum Therapeutics announced it was discontinuing its pociredir program, developed for treating sickle cell disease (SCD). The decision followed a review of recent FDA end-of-phase meeting minutes, which highlighted heightened concerns about pociredir's benefit-risk profile in SCD patients. The FDA cited an "unexpectedly high rate of secondary hematologic malignancies" observed with Tazverik (tazemetostat), another PRC2 inhibitor withdrawn globally in March 2026.

Following additional information submitted by Fulcrum Therapeutics, the FDA concluded that any drug targeting the PRC2 complex carries similar malignancy risks regardless of the specific subunit targeted. This regulatory stance eliminated any viable path forward for pociredir's clinical development, leading to the program's discontinuation.

Sharp Stock Price Drop After Disclosure

The market reacted swiftly to Fulcrum Therapeutics' announcement. The stock closed at $6.42 per share on June 1, 2026. After the after-hours disclosure, shares fell sharply the next day, closing at $3.14 on June 2, 2026. This represents a $3.28 per share loss or a 51.09% decline in a single trading session.

This dramatic one-day drop is the focus of Kaplan Fox & Kilsheimer LLP's securities investigation, which is examining whether securities laws were violated in connection with the disclosure and the circumstances surrounding the pociredir program's termination.

Scope of Kaplan Fox's Investigation and Investor Outreach

Kaplan Fox & Kilsheimer LLP, a nationally recognized securities litigation firm, has initiated an investigation into potential securities violations by Fulcrum Therapeutics. The firm is reaching out to investors who suffered losses due to the stock price decline and anyone with information that could assist the investigation. Investors who believe they were harmed or have relevant details are encouraged to contact the firm.

The investigation seeks to determine whether Fulcrum Therapeutics, its officers, directors, or others violated securities laws relating to the timing and accuracy of disclosures about the pociredir program and FDA safety concerns. It will assess if all material information was properly disclosed in a timely manner.

About Fulcrum Therapeutics

Fulcrum Therapeutics is a clinical-stage biopharmaceutical company focused on developing small molecule therapies for rare hematological disorders. Its focus on rare blood diseases places it in a specialized biopharma sector where regulatory approvals and clinical timelines carry significant uncertainty.

Before discontinuing pociredir, the sickle cell disease program was a key part of Fulcrum's development pipeline. The cessation of this program and the FDA's class-wide malignancy risk determination for PRC2 inhibitors represent a major setback to the company's clinical strategy in this area.

Regulatory Background: PRC2 Inhibitors and Safety Actions

The FDA's concerns stem from safety data on Tazverik (tazemetostat), a PRC2 inhibitor withdrawn globally in March 2026 due to secondary hematologic malignancies. This withdrawal preceded Fulcrum's pociredir discontinuation by about three months.

The FDA's determination that all pharmacological agents targeting the PRC2 complex carry equivalent malignancy risk establishes a class-wide regulatory position. This effectively blocks regulatory approval paths for pociredir and other PRC2 inhibitor candidates. The timing and communication of these regulatory risks to investors are likely key aspects of the securities probe.

Kaplan Fox's Expertise in Securities Litigation

Founded in 1956, Kaplan Fox & Kilsheimer LLP has decades of experience in securities litigation, recovering over $10 billion for clients and class members. The firm operates offices in New York, Oakland, Los Angeles, Chicago, and New Jersey, enabling it to manage complex securities cases nationwide.

Notable recoveries include a $2.425 billion settlement for Bank of America shareholders related to Section 14(a) claims — the largest ever for such claims under the Securities Exchange Act — as well as $800 million for Arkansas Teacher Retirement System and other pension funds in ATRS v. Allianz Global Investors, and a $475 million settlement in In re Merrill Lynch. The firm is recognized by Chambers and Partners, Benchmark Litigation, Super Lawyers, and Lawdragon.

How Investors Can Participate in the Investigation

Kaplan Fox is inviting Fulcrum Therapeutics investors who experienced losses from the stock price drop to participate in the investigation. Investors who purchased or held shares and suffered losses may be eligible. Additionally, anyone with pertinent information is urged to come forward.

Participation does not obligate investors to any specific action. The firm requests details about holdings, transaction timing, and losses to evaluate the case and determine potential next steps.

Implications for Clinical-Stage Biopharmaceutical Firms

The Fulcrum Therapeutics case highlights the risks in clinical-stage biopharmaceutical development, where regulatory decisions and safety findings can significantly impact company valuations and stock prices. The FDA's rapid class-wide safety determination for PRC2 inhibitors illustrates how emerging data from one compound can affect the entire therapeutic class.

For investors, this underscores the importance of closely monitoring regulatory communications, FDA meeting disclosures, and clinical program updates. The steep stock price decline suggests the market may not have fully anticipated the FDA's safety concerns or Fulcrum's program discontinuation before the formal announcement.

Chronology of Key Events

Key events began in March 2026 with the global withdrawal of Tazverik (tazemetostat), a PRC2 inhibitor. Approximately three months later, on June 1, 2026, Fulcrum Therapeutics held end-of-phase meetings with the FDA regarding pociredir. After reviewing meeting minutes, the company noted the FDA's increased concerns about the drug's benefit-risk profile in sickle cell disease.

Following submission of additional data, the FDA determined that all PRC2-targeting drugs carry similar malignancy risks, eliminating the regulatory path for pociredir. Fulcrum announced the program's discontinuation after market close on June 1, 2026. The stock price then plunged 51.09% on June 2, 2026. Kaplan Fox subsequently initiated its securities investigation based on these developments.