Pentixapharm Announces Encouraging Preclinical Data for First-in-Class Glycan-Dependent Anti-CD24 mAb Radiopharmaceutical GT-008

• Novel radiopharmaceutical GT-008 demonstrates potential for selective tumor targeting with reduced side effects in preclinical studies

• Single-dose administration of 177Lutetium-labeled GT-008 induced remission of established tumors and was well tolerated

• Initial preclinical proof-of-concept data demonstrate selective tumor targeting, favorable biodistribution, and early signals of anti-tumor activity in breast cancer model 

• Program expansion underway to explore additional tumor types, dosing regimens, and radionuclide formats

Berlin, Germany, June 19, 2025 – Pentixapharm, a clinical-stage biopharmaceutical company focused on radiopharmaceuticals, announces encouraging first results from a preclinical proof-of-concept study with its lead radioimmunotherapeutic candidate, GT-008.

GT-008 is a first-in-class, glycan-dependent monoclonal antibody engineered to selectively target a tumor-associated O-glycoform of the tumor marker CD24 with high prevalence on tumors but limited expression on healthy cells.

Conjugated and radiolabeled with Lutetium-177 [177Lu] to evaluate its suitability for targeted radionuclide therapy, GT-008 showed complete responses after single dose treatment in a breast cancer xenograft mouse model.  Biodistribution data demonstrated specific and stable tumor accumulation leading to pronounced anti-tumor effects in a preliminary tolerability and activity study. Early in vitro data had already demonstrated specific and high affinity binding to breast cancer cell lines in the nM range leading to efficient internalization.

The new study results highlight the enormous potential of radioimmunotherapy with glycosylation-dependent mAbs against novel GlycoTargets for the treatment of solid tumors.

Derived from former Glycotope´s GlycoTarget mAb discovery platform and further engineered to achieve high tumor to organ ratios and low unspecific uptake, the GT-008 program marks Pentixapharm’s expansion beyond its CXCR4-focused theranostic platform into glycan-dependent antibody-based radiopharmaceuticals.

Further preclinical investigations are actively progressing to broaden the dataset, including larger preclinical in vivo study cohorts, different tumor indications (e.g., ovarian, endometrial, and other solid tumors), alternative radioisotopes and dosing schedules.

"The compelling early data with GT-008 validates our strategic acquisition of Glycotope's target discovery platform in 2024, positioning us at the forefront of next-generation radiopharmaceuticals with a highly differentiated approach," said Dirk Pleimes, Chief Executive Officer of Pentixapharm. "By leveraging glycosylation-dependent antibodies, we're developing potentially safer and more selective targeted therapies, addressing a key challenge in the rapidly growing radiopharmaceutical market."

About GT-008

GT-008 is a first-in-class, glycan-dependent monoclonal antibody targeting CD24, a GPI-linked cell surface glycoprotein implicated in tumor progression. By recognizing a tumor-associated O-glycoform of CD24 - limited on healthy cells - the antibody shows high affinity and specificity for cancer cells, while binding to CD24-expressing healthy cells is reduced. This lowers the potential for on-target/off-tumor activity, overcoming key limitations of conventional CD24-targeting antibodies and other binding modalities. GT-008 is Pentixapharm’s first radiopharmaceutical candidate addressing CD24 and may enable additional therapeutic formats beyond radiotherapy.

About Pentixapharm

Pentixapharm is a clinical-stage biotech company discovering and developing novel targeted radiopharmaceuticals headquartered in Berlin, Germany. It is committed to developing ligand-based, first-in-class radiopharmaceuticals with strong differentiation and commercialization potential across high-need diagnostic and therapeutic areas. Its pipeline comprises CXCR4-targeted compounds in clinical development and a portfolio of early-stage radionuclide-antibody conjugates, aimed at treating hematologic malignancies, solid tumors, and diagnosing diseases of the cardiovascular, endocrine, and immune systems.

For more information, please contact:

Pentixapharm Holding AG
Investor Relations
ir@pentixapharm.com
Tel. +49 30 94892600
www.pentixapharm.com