Fulcrum Therapeutics Announces Clinical Hold on FTX-6058 in Sickle Cell Disease

CAMBRIDGE, Mass., Feb. 24, 2023 (GLOBE NEWSWIRE) — Fulcrum Therapeutics, Inc.® (Nasdaq: FULC), a clinical-stage biopharmaceutical company focused on improving the lives of patients with genetically defined rare diseases, today announced that on February 23, 2023, the U.S. Food and Drug Administration (FDA) verbally informed the company that it has issued a full clinical hold regarding the Investigational New Drug (IND) application for FTX-6058 for the potential treatment of sickle-cell disease. The Agency indicated that it would provide a formal Clinical Hold Letter to the company within 30 days.

The clinical hold was initiated by the Agency due to previously reported preclinical data. Fulcrum will suspend dosing in the Phase 1b trial of FTX-6058 and intends to work diligently with the Agency to resolve the hold as soon as possible.

“Patient safety remains paramount to me. I am encouraged by the Agency’s willingness to work with us to clarify the therapeutic potential of FTX-6058. Fulcrum intends to address questions related to modulation of the PRC2 complex and the preclinical data,” said Robert J. Gould, Ph.D., Fulcrum’s interim president and chief executive officer. “We continue to have confidence in the benefit-risk profile of FTX-6058 and remain committed to our goal of providing a differentiated therapeutic option for people living with sickle cell disease.”

About FTX-6058
FTX-6058 is an investigational oral small-molecule inhibitor of Embryonic Ectoderm Development (EED) that was discovered using FulcrumSeek™, Fulcrum’s proprietary discovery engine. Inhibition of EED leads to potent downregulation of key fetal globin repressors, including BCL11A, thereby causing an increase in fetal hemoglobin (HbF). FTX-6058 is being developed for the treatment of sickle cell disease (SCD) and other hemoglobinopathies. FTX-6058 is currently being evaluated in a Phase 1b multi-center open-label trial in people with SCD (NCT05169580). Initial data demonstrated proof-of-concept and achieved absolute levels of HbF increases associated with potential overall patient benefit. To date, FTX-6058 has been generally well-tolerated in people with SCD with up to three months of exposure, with no drug-related serious adverse events reported. FTX-6058 has been granted U.S. Food and Drug Administration (FDA) Fast Track designation and Orphan Drug Designation for the treatment of SCD.

About Sickle Cell Disease
Sickle cell disease is a genetic disorder of the red blood cells caused by a mutation in the HBB gene. This gene encodes a protein that is a key component of hemoglobin, a protein complex whose function is to transport oxygen in the body. The result of the mutation is less efficient oxygen transport and the formation of red blood cells that have a sickle shape. These sickle shaped cells are much less flexible than healthy cells and can block blood vessels or rupture cells. People with sickle cell disease typically suffer from serious clinical consequences, which may include anemia, pain, infections, stroke, heart disease, pulmonary hypertension, kidney failure, liver disease, and reduced life expectancy.

Forward-Looking Statements
This press release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995 that involve substantial risks and uncertainties. All statements, other than statements of historical facts, contained in this press release are forward-looking statements, including express or implied statements regarding the clinical hold on FTX-6058, the clinical hold letter from FDA, responding to FDA to resolve the clinical hold; and the potential therapeutic benefit of FTX-6058, among others. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “will,” “would” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward-looking statements are based on management’s current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in, or implied by, such forward-looking statements. These risks and uncertainties include, but are not limited to, risks associated with Fulcrum’s ability to address FDA’s questions and resolve the clinical hold; continue to advance FTX-6058 and its other product candidate in clinical trials; initiate, resume and enroll clinical trials on the timeline expected or at all; obtain and maintain necessary approvals from the FDA and other regulatory authorities; replicate in clinical trials positive results found in preclinical studies and/or earlier-stage clinical trials of losmapimod, FTX-6058 and any other product candidates; obtain, maintain or protect intellectual property rights related to its product candidates; manage expenses; realize the anticipated benefits of the strategic realignment; manage executive and employee turnover; and raise the substantial additional capital needed to achieve its business objectives, among others. For a discussion of other risks and uncertainties, and other important factors, any of which could cause Fulcrum’s actual results to differ from those contained in the forward-looking statements, see the “Risk Factors” section, as well as discussions of potential risks, uncertainties, and other important factors, in Fulcrum’s most recent filings with the Securities and Exchange Commission. In addition, the forward-looking statements included in this press release represent Fulcrum’s views as of the date hereof and should not be relied upon as representing Fulcrum’s views as of any date subsequent to the date hereof. Fulcrum anticipates that subsequent events and developments will cause Fulcrum’s views to change. However, while Fulcrum may elect to update these forward-looking statements at some point in the future, Fulcrum specifically disclaims any obligation to do so.

Contact:

Investors:
Chris Calabrese
LifeSci Advisors, LLC
ccalabrese@lifesciadvisors.com
917-680-5608

Media:
Dee Smith
Executive Director, Corporate Communications
Fulcrum Therapeutics, Inc.
dsmith@fulcrumtx.com
202-746-1324