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NEWS - Detailed

AmMax Bio Announces First Patient Enrolled in Phase 2 Trial of AMB-05X For Tenosynovial Giant Cell Tumor (TGCT)


Novel Intra-articular Drug Delivery to Minimize Systemic Toxicity Associated with Currently Available TGCT Therapies 

First Set of Patient Data Expected in Second Half of 2021

REDWOOD CITY, Calif. May 26, 2021 —AmMax Bio, Inc. (“AmMax”), a private clinical-stage biopharmaceutical company developing novel treatments with AMB-05X, its proprietary anti-CSF1R monoclonal antibody platform, today announced that the first patient has been enrolled in its Phase 2 clinical trial for the treatment of tenosynovial giant cell tumors (TGCT).

TGCT is an aggressive tumor of the synovium primarily located in knee, hip, and ankle joints and caused by excessive production of CSF1.  AMB-05X specifically inhibits the CSF1R pathway and is therefore capable of stunting tumor growth.  AmMax has developed two long-acting dosage forms for AMB-05X, including an intra-articular injection that will be used in this study to optimize effective local administration while reducing the risk of systemic side effects.

“Current treatment options for TGCT patients are limited, with surgical resection being the most common despite the risks of complications of high rates of recurrence, long recovery times, and issues of pain management. Therefore, developing new and effective pharmacological treatment options is highly desirable” stated the principal investigators of the study, Hans Gelderblom, M.D., Ph.D., Chair of Medical Oncology, and Michiel van de Sande, M.D., Professor of Orthopedic Oncology, at the Leiden University Medical Center in the Netherlands. “We are excited to lead this clinical trial to demonstrate the potential for AMB-05X to provide a safe and effective new therapy for the treatment of TGCT.”

“We are very pleased to begin enrolling patients in our Phase 2 TGCT program,” said Larry Hsu, Ph.D., Chief Executive Officer of AmMax Bio. “Although TGCT is a non-malignant tumor, its growth is associated with several debilitating comorbidities. Therefore, any new therapeutic aimed at treating this condition must have an acceptable balance of safety and efficacy for broad utilization.  Leveraging the extensive safety data in approximately 150 patients and healthy volunteers, we believe AMB-05X will have significant safety advantages over existing treatment options, and we will use the data from this Phase 2 clinical study to advance our TGCT program into late-stage clinical development. The initiation of this trial represents a significant step forward for AmMax in the clinical deployment of our therapeutic platform.”

About TGCT

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

About AMB-05X

A potent inhibitory CSF1R monoclonal antibody, AMB-05X represents a therapeutic platform targeting serious macrophage-driven inflammatory, fibrotic and neovascular diseases.  The CSF1 receptor, 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. Overactivation of the CSF1/IL-34 – CSF1R axis substantially contributes to the inflammatory, fibrotic and neovascular characteristics inherent in many diseases.

About AmMax Bio Inc.

AmMax was founded in March 2020 to develop therapies under an exclusive worldwide license from Amgen, Inc. that leverages the diverse and critical roles played by the colony stimulating factor 1 receptor (CSF1R) signaling pathway for macrophage-driven diseases in multiple organ systems. AmMax is enrolling patients in a Phase 2 clinical program for tenosynovial giant cell tumor (TGCT) and has achieved nonclinical proof-of-concept in both neovascular age-related macular degeneration (nAMD) and idiopathic pulmonary fibrosis (IPF).

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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