• FL-501 fully restored body composition and reversed key indicators of cachexia in preclinical models
• Findings confirm GDF-15's role in cachexia and support advancing FL-501 into the clinic

CAMBRIDGE, Mass., April 25, 2025 /PRNewswire/ -- Leap Therapeutics, Inc. (Nasdaq:LPTX), a biotechnology company focused on developing targeted and immuno-oncology therapeutics, today announced it will present preclinical data of FL-501 in a poster presentation at the American Association for Cancer Research (AACR) Annual Meeting taking place April 25-30 in Chicago, Illinois.

FL-501 is a potential best-in-class monoclonal antibody targeting growth differentiation factor 15 (GDF-15), a cytokine that is implicated in multiple diseases and therapeutic areas, including cancer cachexia.

"Cancer cachexia is a devasting and potentially life-threatening condition characterized by significant weight loss, muscle wasting, fatigue, and severely reduced quality of life. It is a major contributor to cancer-related mortality, and unfortunately there are no effective treatment options available to patients," said Jason Baum, PhD, Chief Scientific Officer of Leap. "These data not only demonstrate that FL-501 is a novel and potential best-in-class anti-GDF-15 antibody, but also capable of fully restoring body composition in preclinical models that is comparable or better than other, clinical-stage antibodies. We look forward to progressing the development of FL-501 and bringing the asset into the clinic in 2026."

Key Findings:

• In humanized FcRn mouse studies, FL-501 demonstrated a 2-3-fold longer half-life and 50% reduced clearance compared to its wild-type precursor and ponsegromab
• In mouse cachexia models using GDF-15-overexpressing colorectal cancer cells, FL-501 fully restored body composition, comparably or better than clinical-stage antibodies visugromab and ponsegromab
• In a non-small cell lung cancer patient-derived xenograft model, FL-501 effectively countered cisplatin-induced weight loss, restoring body weight, composition, and condition scores
• These findings confirm GDF-15's role in cachexia and support FL-501's advancement in development

Poster Details:

Title: FL-501 is a potential best in class GDF-15 inhibitor with extended half-life and potent anti-cachexia activity in preclinical models
Presenter: Roma Kaul, PhD, Leap Therapeutics
Session Category: Experimental and Molecular Therapeutics
Session Title: New and Emerging Cancer Drug Targets
Date and Time: Tuesday, April 29, 2025, 9:00 a.m. – 12:00 p.m. CT
Poster Board Number: 15
Published Abstract Number: 4258

About FL-501

FL-501 is a potential best-in-class monoclonal antibody in preclinical development that targets growth differentiation factor-15 (GDF-15), a cytokine that is produced at elevated levels in response to various stresses, including chronic inflammation, obesity, cardiovascular diseases, cancers, and chemotherapy treatment. High GDF-15 expression is associated with cancer cachexia including loss of appetite, nausea and weight loss. FL-501 was engineered for higher affinity to GDF-15 and longer plasma half-life compared to competing therapies. In addition to cachexia, FL-501 may be able to reverse immunosuppression in cancers where elevated GDF-15 is correlated with poor survival, as well as play a role in treating other GDF-15-related diseases. FL-501 is being developed through a collaboration agreement with Adimab.

About Leap

Leap Therapeutics (Nasdaq: LPTX) is focused on developing targeted and immuno-oncology therapeutics. Leap's most advanced clinical candidate, sirexatamab (DKN-01), is a humanized monoclonal antibody targeting the Dickkopf-1 (DKK1) protein. Sirexatamab is being studied in patients with colorectal cancer. Leap's pipeline also includes FL-501, a humanized monoclonal antibody targeting the growth differentiation factor 15 (GDF-15) protein, in preclinical development. For more information about Leap Therapeutics, visit http://www.leaptx.com or view our public filings with the SEC that are available via EDGAR at http://www.sec.gov or via https://investors.leaptx.com/.

FORWARD-LOOKING STATEMENTS

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CONTACT: 
Douglas E. Onsi
President & Chief Executive Officer
Leap Therapeutics, Inc.
617-714-0360
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Matthew DeYoung
Investor Relations
Argot Partners
212-600-1902
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