SynOx, Dublin biopharma firm, raises $92m

Dublin and Oxford-based SynOx, a late clinical-stage biopharmaceutical company developing a novel treatment for CSF-1 related and macrophage-driven disorders, announced that it has raised additional funding in a final close of its Series B financing.

The Series B extension was led by new investor Gilde Healthcare and brings the total capital raised by SynOx in the round to $92 million, including earlier investments from Forbion, HealthCap and Bioqube Ventures.

“Proceeds from the financing are supporting a registrational Phase 3 clinical trial of emactuzumab, a potentially best-in-class CSF-1 receptor (CSF-1R) inhibiting monoclonal antibody for the treatment of Tenosynovial Giant Cell Tumour (TGCT),” said SynOx.

“In conjunction with the closing of the Series B extension, SynOx today announced that the first patients have been dosed in its Phase 3 registrational study of emactuzumab.

“The study, named TANGENT, is a global, multi-centre, randomized, double-blind, placebo-controlled Phase 3 trial designed to evaluate the efficacy and safety of emactuzumab in patients with TGCT.

“The study’s primary outcome measure is overall response rate (ORR). Investigators will also assess several secondary outcomes including functional and quality of life measurements, impact on tumour volume, and duration of response. Investigators expect to enrol approximately 130 patients in the trial. Additional study details can be found on ClinicalTrials.gov (Identifier: NCT05417789).

“TGCT is a rare, non-malignant but aggressively growing tumour of the synovium, primarily located in knee, hip, and ankle joints and caused by excessive production of CSF-1.

“It is a chronically debilitating disease for patients causing loss of function of the affected joints, pain, stiffness and limited range of motion. Emactuzumab specifically inhibits CSF-1R and earlier clinical work in TGCT1 showed it to be a highly effective, next-generation therapy with a short treatment cycle, rapid onset of action and long duration of response.”

SynOx CEO Ray Barlow said: “We are pleased to add Gilde Healthcare to our impressive investor syndicate and are appreciative for their support of our team and our vision for the potential of emactuzumab to address the unmet needs, and improve the quality of life, of TGCT patients around the world.

“The dosing of patients in the TANGENT trial marks an important milestone for SynOx and is a testament to the dedication and hard work of our team. We look forward to efficiently conducting this study and continuing to pursue our goal of advancing emactuzumab toward market for TGCT patients in desperate need of new treatment options.”

As part of the Series B extension, Arthur Franken, general partner at Gilde Healthcare, will join the SynOx Board of Directors. Franken brings more than two decades of venture and growth capital investment expertise, including several public listings and trade sales.

“We are pleased to join SynOx as an investor and help support the late-stage development of emactuzumab, which we believe has a best-in-class profile as a CSF-1R targeted antibody,” said Franken.

“Importantly, we also believe that the SynOx team is well positioned to successfully complete clinical development of emactuzumab and deliver this important treatment option to TGCT patients.”