AmMax Bio Announces AMB-05X Granted FDA Fast Track Designation for the Treatment of Tenosynovial Giant Cell Tumor (TGCT)

Proof-of-Concept Established in Phase 2 Trial of TGCT, with Positive Efficacy Results Across Multiple Clinical Endpoints and Favorable Safety Profile After 12 Weeks of Therapy with AMB-05X 

Novel, Local Delivery and Positive Data from the Phase 2 Study Support the Potential of AMB-05X as a Best-in-Class Therapy for Treatment of TGCT

REDWOOD CITY, Calif., Sept. 07, 2022 (GLOBE NEWSWIRE) -- AmMax Bio, Inc. (“AmMax”), a private clinical-stage biopharmaceutical company developing innovative therapeutics in oncology, including targeting the colony-stimulating factor 1 receptor (CSF1R), today announced that the U.S. Food and Drug Administration (FDA) has granted AMB-05X Fast Track designation for the treatment of tenosynovial giant cell tumor (TCGT).

“We are very pleased to receive Fast Track designation for AMB-05X from the FDA, which clearly reflects the significant unmet need facing thousands of patients suffering from TCGT and its numerous associated co-morbidities,” said Dr. Larry Hsu, Chief Executive Officer of AmMax Bio. “Physicians have shown tremendous enthusiasm for a locally injectable form of CSF1R inhibitor to address this localized disease in the joint.   AMB-05X is designed to be administered via an intra-articular injection at the site of the tumor to minimize the systemic exposure and the associated serious safety concerns.”

The FDA’s Fast Track designation is a process designed to facilitate the development and expedite the review of drugs to treat serious conditions and address significant unmet medical needs. The FDA defines addressing a significant unmet medical need as providing a therapy where none exists or providing a therapy which may be potentially better than available therapies. The benefits of Fast Track designation include but are not limited to early and frequent communication with the FDA throughout the entire drug development and review process. In addition, a drug with Fast Track designation is eligible for rolling submission and priority review of its Biologics License Application and/or New Drug Application. These assure that questions and issues are resolved quickly, often leading to earlier drug approval and access by patients.1


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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, 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 the clinical development of innovative oncology products. Under an exclusive worldwide license from Amgen, Inc., AmMax is leveraging positive proof-of-concept data and an improved safety profile to advance AMB-05X into the next phase of its clinical development program for tenosynovial giant cell tumor (TGCT).   AmMax actively seeks to in-license potentially best-in-class oncology products in areas of significant unmet medical need.

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

AmMax Bio, Inc.
Andrew Sauter, CFO
Tel: 650-787-3777