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NEWS - Detailed

AmMax Bio’s AMB-05X Receives EMA PRIME Designation for the Treatment of Tenosynovial Giant Cell Tumor (TGCT)


AMB-05X is the First and Only Investigational Drug Candidate to Receive PRIME Designation for the Treatment of TGCT 

PRIME Designation Validates Unique Therapeutic Potential of AMB-05X as Demonstrated in Prior Phase 2 Study of TGCT

Initial Results from Phase 2b Trial Remains on Track for Second Half of 2023

REDWOOD CITY, Calif. January 19, 2023 —AmMax Bio, Inc. (“AmMax”), a private clinical-stage biopharmaceutical company developing innovative therapeutics in oncology, including a next-generation antibody-drug conjugate (ADC) and a mAb targeting colony-stimulating factor 1 receptor (CSF1R), today announced that the European Medicine Agency (EMA) has granted AMB-05X Priority Medicines (PRIME) designation for the treatment of tenosynovial giant cell tumor (TGCT).

“The positive proof-of-concept data from our prior 12-week Phase 2 study of AMB-05X in TGCT provided the basis for our PRIME application,” said Larry Hsu, Ph.D., Chief Executive Officer of AmMax Bio. “We appreciate EMA’s decision to award AMB-05X its PRIME designation, which validates the high potential therapeutic value of the program and the significant unmet medical need for patients impacted by TGCT.”

In November 2022, AmMax presented positive Phase 2 data for the novel local administration of AMB-05X in patients with TGCT at the Connective Tissue Oncology Society (CTOS) meeting. The significant efficacy data across multiple clinical endpoints and a favorable safety profile support the potential of AMB-05X as a best-in-class therapy for the treatment of TGCT, regardless of surgical resectability.

PRIME designation was launched by the EMA to enhance support for the development of medicines that target an unmet medical need. PRIME fosters the efficient development of medicines by enhancing interaction and early dialogue with developers of promising medicines, to optimize development plans and speed up evaluation so these medicines can reach patients earlier. Through PRIME, the EMA offers early and proactive support to medicine developers to optimize the generation of robust data on a medicine's benefits and risks and enable accelerated assessment of medicines applications. This will help patients to benefit as early as possible from therapies that may significantly improve their quality of life. (1)

In September 2022, AMB-05X was also granted Fast Track designation by the U.S. Food and Drug Administration (FDA).


About TGCT

Tenosynovial Giant Cell Tumor (TGCT), with a worldwide incidence of over 300,000, is a serious and debilitating locally aggressive tumor in which patients can experience severe pain, disability, and diminished quality of life. Surgical resection, the primary standard of care for TGCT, carries significant risk to patients, including complications from infections and prolonged postoperative care, and frequent relapse.  A safe and efficacious pharmacological therapy that can be used alongside surgery remains a significant unmet need.  AmMax is uniquely positioned to address this need for patients with TGCT by leveraging the target selectivity and enhanced safety profile of AMB-05X via local intra-articular administration, while creating a sizable commercial opportunity from improved patient care.

About AMB-05X

A potent monoclonal antibody against CSF1R granted Fast Track designation by the FDA and PRIME designation by EMA for TGCT, AMB-05X represents a therapeutic platform targeting serious macrophage-driven inflammatory, fibrotic and neovascular diseases.  CSF1R, via its binding to two regulatory cytokines, CSF1 and IL-34, is critically involved in the regulation of macrophages and related cells in multiple biological processes across many organ systems, making it an attractive target with broad therapeutic applications.

About AmMax Bio Inc.

AmMax is a private biotechnology company focused on leveraging our core expertise in translational science and drug development to build a clinical portfolio of first-in-class and best-in-class oncology products in areas of significant unmet medical need.

The Company’s core portfolio is a novel antibody-drug conjugate (ADC) with a proprietary next generation topoisomerase 1 inhibitor-based linker-payload (the TMALIN platform) that is expected to enter the clinic in 2023. Additionally, the Company’s CSF1R platform includes AMB-05X, a potentially best-in-class locally administered treatment for TGCT.  AmMax is currently leveraging positive clinical data and an improved safety profile to advance AMB-05X in an actively enrolling Phase 2 study.

For more information, please visit the company’s website at


AmMax Bio, Inc.

Andrew Sauter, CFO


Tel: 650-787-3777

To view the original version on Globe Newswire, please visit 

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