SynOx Therapeutics raises $44 Million to Advance Therapy for Rare Debilitating Tumors

Rare Daily Staff

SynOx Therapeutics closed a $44 million (€37 million) series A financing to support development of emactuzumab to improve the lives of patients with TGCT, rare benign tumors that grow around joints and tendons.

HealthCap and Medicxi led the financing with participation by Forbion and Gimv.

TGCT (tenosynovial giant cell tumor), also referred to as pigmented villonodular synovitis (PVNS), is a rare tumor that affects the synovium, the thin layer of tissue that covers the surfaces of the joint spaces and tendon sheaths, the layer of membrane that covers tendons. The tumor is rarely malignant but causes the synovium and tendon sheaths to thicken and overgrow, causing damage to surrounding tissue.

The current standard of care for TGCT is surgical resection. However, in patients with a recurrent, difficult-to-treat, or diffuse form of TGCT, the tumor may wrap around bone, tendons, ligaments and other parts of the joint. In these cases, the tumor may be difficult to remove and/or may not be amenable to improvement with surgery. Multiple surgeries for more severe cases can lead to significant joint damage, debilitating functional impairments and reduced quality of life, and amputation may be considered.

SynOx is a spin out of Celleron Therapeutics, which itself is a spinout from Oxford University in the U.K., secured exclusive worldwide rights for the clinical development, manufacturing and commercialization of emactuzumab under a 2018 license agreement with Roche. The financing will enable SynOx to continue the development of emactuzumab, for the treatment of diffuse TGCT and other indications.

Emactuzumab is a clinical-stage humanized IgG1 CSF-1R targeted antibody designed to target and deplete macrophages in the tumor tissue. It has shown a favorable safety profile in patients and encouraging efficacy for TGCT, a rare disease characterized by the proliferation of macrophages in the synovial tissue in the joint and tendon sheath.

“We are very excited to be developing emactuzumab as a breakthrough treatment for the extreme and debilitating effects of TGCT,” said Nick La Thangue, CEO of SynOx.  “SynOx will be focused on generating all necessary data to register this new therapy in a time- and cost-efficient way.”

A paper on emactuzumab, published in the European Journal of Cancer, Volume 141, December 2020 edition, details the long-term clinical activity, safety and patient-reported quality of life for emactuzumab-treated patients with diffuse-type TGCT.

Photo: Nick La Thangue, CEO of SynOx