SynOx Therapeutics announces positive topline results from the Phase 3 TANGENT study

SynOx Therapeutics Announces Positive Topline Results from the Phase 3 TANGENT Study, Supporting Emactuzumab as a Differentiated, Next-generation Treatment for Patients with Tenosynovial Giant Cell Tumor (TGCT)

  • TANGENT met its primary and secondary endpoints with a high level of statistical significance vs. placebo at 6 months, including ORR by RECIST V1.1 and Tumor Volume Score (TVS), and clinically meaningful improvements in PROMIS-PF and other patient -relevant functional measures
  • Rapid onset and significant functional improvement observed
  • Short-course regimen demonstrated sustained and durable clinical benefits , highlighting the potential to avoid chronic treatment burden
  • Emactuzumab demonstrated a manageable safety profile, highly consistent with prior clinical experience
  • These data reinforce emactuzumab’s differentiated profile as a next-generation, short-course therapy with the potential to address important limitations of chronic oral treatment approaches in TGCT
  • Biologics License Application (BLA) submission planned for H2 2026; EU Marketing Authorization Application (MAA) to follow

DUBLIN, IRELAND, OXFORD, UK, and PHILADELPHIA, PA — April 13th, 2026

SynOx Therapeutics Limited (“SynOx”) today announced positive topline results from the pivotal Phase 3 TANGENT study of emactuzumab in adult patients with TGCT.

Emactuzumab is a targeted CSF-1R inhibitor that is being developed as a short-course treatment for patients with TGCT, which is designed to deliver rapid and durable disease control without the need for continuous treatment. In the TANGENT study, patients were randomized to receive either emactuzumab or placebo. Patients assigned to the treatment arm received emactuzumab at a dose of 1,000 mg administered every two weeks, for a total of five doses over an 8-week period.

Results across the primary and key secondary endpoints demonstrated clinically meaningful and statistically significant benefit consistent with emactuzumab’s differentiated profile. These included measures of tumor volume reduction and patient-reported and functional outcomes, including PROMIS-PF, physical function, pain, range of motion, and stiffness. Importantly, these benefits were achieved rapidly in the short-course treatment cycle, were durable and were observed across clinically relevant patient segments.

Emactuzumab demonstrated a manageable safety profile in TANGENT, consistent with prior clinical experience. In a patient population with a chronic, debilitating but non-lethal disease, tolerability remains an important consideration, particularly when compared with long-term treatment approaches.

“The TANGENT results represent an important step in advancing a potential next-generation treatment for patients with TGCT,” said Dr. Ray Barlow, CEO of SynOx Therapeutics. “Emactuzumab’s combination of rapid onset, response rate, meaningful functional improvement, and a defined short-course regimen positions it as a potential alternative to chronic therapy. We believe this approach directly addresses key limitations of existing treatments and represents an important advancement for patients suffering from this debilitating disease. We look forward to engaging with the FDA as we advance toward a planned BLA submission in the second half of 2026.”

Dr. Jean-Yves Blay, Principal Investigator, commented further:

“Emactuzumab is the only short course treatment option in late-stage development for patients suffering with TGCT. These Phase 3 data provide compelling evidence of tumor response, a manageable safety profile, and most importantly for patients, of significant durable functional and quality of life benefits that allow patients struggling with TGCT to move forward with their lives, without continuous therapy.”

SynOx continues to follow patients enrolled in the TANGENT study to further characterize the durability of response, and the potential role of retreatment and crossover open label emactuzumab.

SynOx intends to present full data from the TANGENT trial at an upcoming medical meeting and in a peer-reviewed publication.

Based on these data, SynOx plans to submit a BLA to the U.S. Food and Drug Administration for emactuzumab in TGCT in the second half of 2026 and a MAA in the EU thereafter.

About the TANGENT Study:

The TANGENT clinical trial (NCT05417789) is a global, multicenter, randomized, double-blind, placebo-controlled, Phase 3 trial evaluating the efficacy and safety of emactuzumab in patients with TGCT. Patients in the treatment arm received 1000mg emactuzumab every two weeks for a total of five doses over 8 weeks. The primary endpoint is Objective Response Rate (ORR) at 6 months as measured by RECIST v1.1. Secondary endpoints are designed to detect the effect of emactuzumab on physical function, range of motion, stiffness, pain and duration of response as measured by both physician and patient reported assessments including Tumor Volume Score (TVS), PROMIS-PF TGCT T-score, range of motion (ROM), and assessments of pain, stiffness and quality of life.

TANGENT enrollment criteria include patients with biopsy-confirmed localized or diffuse TGCT where surgical resection would be associated with predicted worsening functional limitations through surgical joint damage, and/or subjects with anticipated high risk of early recurrence, or any other morbidity associated with the surgery, and/or subjects for whom surgical treatment is not expected to improve clinical outcomes.
Following the 6-month double-blind period, patients can enter an 18-month follow-up phase during which patients who demonstrate signs of disease progression may receive open label emactuzumab.

About Tenosynovial Giant Cell Tumor (TGCT)

TGCT is a rare, non-malignant, but locally aggressive and destructive tumor affecting the synovium, tendon sheaths, and bursa membranes primarily located in knee, hip, and ankle joints but can also occur in other locations such as the cervical spine. It is a chronically debilitating disease, which causes loss of function of the affected joints, as well as pain, stiffness, and limited range of motion, which can significantly impact quality of life.

TGCT is estimated to affect approximately 200,000 patients in the U.S. and 179,000 patients in the EU4 +UK, with an estimated incidence of approximately 50 per million (1). As patients are typically diagnosed between the ages of 35 and 50, TGCT is a long-term disease.

Existing treatment options for TGCT include surgery and oral systemic therapies, but both options are of limited benefit. Surgery is often the first-line approach, although it comes with a risk of surgical complications, severe morbidity, and can require a lengthy recovery. Surgical recurrence rates are also high, including 17% for those with localized disease (2) and 72% for those with diffuse disease (3). Additionally, many patients have tumors that are not amenable to surgery. Treatment with approved oral TKI therapies require long-term chronic administration (daily or biweekly).

About Emactuzumab:

Emactuzumab is a next-generation monoclonal antibody. As a high-affinity CSF1-R inhibitor, emactuzumab is designed to block receptor activation, deplete tumor-promoting macrophages and reduce inflammation in the tumor microenvironment.

Emactuzumab is designed to address the limitations of current treatment options as a short-course, targeted therapy intended to deliver rapid tumor reduction, meaningful functional improvement, durable benefit, and manageable tolerability following limited treatment exposure.

Emactuzumab has received Fast Track Designation (FTD) from the U.S. Food and Drug Administration (FDA) and Orphan Medicinal Product designation from the European Medicines Agency for the treatment of TGCT.

About SynOx Therapeutics
SynOx Therapeutics Limited is a Dublin, Oxford and Philadelphia-based, late-stage biopharmaceutical company developing emactuzumab, a next-generation, best-in-class monoclonal antibody against CSF-1R, for the treatment of Tenosynovial Giant Cell Tumour (TGCT) and other CSF-1-related and macrophage-driven disorders. SynOx is led by an experienced team of industry professionals with a successful track record of developing and bringing products to commercialization. The company is backed by a strong syndicate of premier life science investors including Forbion, Gilde Healthcare, HealthCap, Bioqube Ventures, and Medicxi.

For further information please contact:
SynOx Therapeutics
Ray Barlow, CEO
Tel: +44 (0) 208 058 5619
Email: [email protected]

Investor Relations Contact
Precision AQ
Danielle Dudgeon
Email: [email protected]

References
(1) Stacchiotti S, et. al. Best clinical management of Tenosynovial Giant Cell Tumour (TGCT): A consensus paper from the community of experts. Cancer Treat Rev. 2023;112:102491. doi:10.1016/j.ctrv.2022.102491.
(2) Mastboom M, Palmerini E, Verspoor F et al. Surgical outcomes of patients with diffuse-type tenosynovial giant-cell tumours: an international, retrospective, cohort study The Lancet Oncology, 2019; 20, 877-886.
(3) Verspoor FG, Zee AA, Hannink G, van der Geest IC, Veth RP, Schreuder HW. Long-term follow-up results of primary and recurrent pigmented villonodular synovitis. Rheumatology (Oxford). 2014 Nov;53(11):2063-70. doi: 10.1093/rheumatology/keu230.

SynOx Therapeutics Strengthens Board of Directors with Leading Experts in Commercialisation and Corporate Development Amid Continued Corporate Progress

Charles “Chip” Romp and Tom Heyman join SynOx’s Board, bringing deep launch, lifecycle, and corporate development expertise as the company advances its next-generation therapy emactuzumab toward key regulatory and commercial milestones

DUBLIN, IRELAND, OXFORD, UK, and PHILADELPHIA, PA — October 21, 2025

SynOx Therapeutics Limited (“SynOx”), a late-stage clinical biopharmaceutical company developing emactuzumab for Tenosynovial Giant Cell Tumours (TGCT), today announced the appointments of Charles “Chip” R. Romp and Tom J. Heyman to its Board of Directors. These appointments further align SynOx’s business with its forward strategy as the company nears topline data for emactuzumab and continues its focus on regulatory and commercial activities. In August 2025, SynOx completed enrollment in the Phase 3 TANGENT clinical trial; topline data are expected in the first quarter of 2026.

Ray Barlow, Chief Executive Officer of SynOx Therapeutics, said:

“We are delighted to welcome Chip and Tom to SynOx. Chip brings an exceptional depth of commercial leadership to the Board, with a proven track record of building launch organisations, establishing new oncology standards of care, and driving lifecycle expansion across multiple blockbuster brands at Seagen and Genentech. Tom is one of the most accomplished corporate development leaders in our industry, with nearly four decades experience guiding transformational partnerships, licensing deals, and global strategic growth initiatives at Johnson & Johnson.”

“Together, their complementary expertise significantly strengthens SynOx’s readiness for commercialisation, partnering, and other strategic pathways as we continue to advance emactuzumab’s late-stage clinical program and prepare for the milestones ahead. I would also like to take this opportunity to sincerely thank Jon Edwards, who has stepped off the Board, for his invaluable contributions and guidance during an important period of SynOx’s growth.”

New Board Appointees

  • Charles “Chip” R. Romp is a seasoned oncology commercial executive with more than 25 years of experience leading U.S. and global launches and lifecycle strategies. He currently serves as President & CEO of Secura Bio and previously was EVP, U.S. Commercial at Seagen, where he was a member of the Executive Committee and helped lead the launch and commercial growth of Adcetris®, Padcev®, Tukysa®, and Tivdak®. Earlier, he spent 12 years at Genentech in senior oncology and immunology roles, including as National Sales Director for Avastin® and Rituxan®. He also serves on the Board of Minds and Assembly.
  • Tom Heyman is joining the SynOx Board as Bioqube Ventures’ representative. He spent 37 years at Johnson & Johnson, including as President of JJDC (Johnson & Johnson Development Corporation) and Global Head of Business Development at Janssen, where he led and oversaw major licensing, M&A, and strategic collaborations. He currently serves on the boards of Exelixis (NASDAQ: EXEL), Legend Biotech (NASDAQ: LEGN), Akero Therapeutics (NASDAQ: AKRO), and IMEC.

SynOx Progress and Near-Term Milestones
In August 2025, SynOx completed enrollment in TANGENT, its global, randomized, double-blind, placebo-controlled registrational Phase 3 trial of emactuzumab in TGCT patients who are not amenable to or would not benefit from surgery. Top-line data are expected in the first quarter of 2026.

Emactuzumab previously received Fast Track Designation from the U.S. Food and Drug Administration for TGCT, reflecting the seriousness of the disease and the unmet medical need.

Based on clinical work to date, SynOx believes that emactuzumab represents a next-generation therapeutic option with the potential to address key patient needs by offering an effective, short-course treatment with rapid onset and a durable response — enabling individuals with TGCT to better manage their disease and move forward with their lives.

About TGCT and Emactuzumab
TGCT is a rare, locally aggressive tumour of the synovium, tendon sheaths, and bursa membranes that can cause substantial pain, stiffness, reduced mobility, and diminished quality of life; more than 50% of diffuse TGCT cases recur within three years after surgery.

Emactuzumab is a humanised monoclonal antibody targeting CSF-1R, designed to inhibit and deplete macrophages in tumour tissue; in clinical studies it has shown rapid tumour reduction, functional improvement, and a manageable safety profile in TGCT.

Additional details on TANGENT are available at ClinicalTrials.gov (NCT05417789).

About SynOx Therapeutics
SynOx Therapeutics Limited is a Dublin, Oxford and Philadelphia-based, late-stage biopharmaceutical company developing emactuzumab, a next-generation, best-in-class monoclonal antibody against CSF-1R, for the treatment of Tenosynovial Giant Cell Tumour (TGCT) and other CSF-1-related and macrophage-driven disorders. SynOx is led by an experienced team of industry professionals with a successful track record of developing and bringing products to commercialization. The company is backed by a strong syndicate of premier life science investors including Forbion, Gilde Healthcare, HealthCap, Bioqube Ventures, and Medicxi.

Contacts:
SynOx Therapeutics
Ray Barlow
Chief Executive Officer
Tel: +44 (0) 208 058 5619
Email: [email protected]

 

 

SynOx Therapeutics Completes Enrollment in Registrational Phase 3 TANGENT Clinical Trial Significantly Ahead of Timeline

Top-Line Results from Study Evaluating Emactuzumab for Tenosynovial Giant Cell Tumours (TGCT) Expected in First Quarter of 2026

DUBLIN, IRELAND, OXFORD, UK, and PHILADELPHIA, PA – August 5, 2025

SynOx Therapeutics Limited (“SynOx”), a late-stage clinical biopharmaceutical company developing emactuzumab for Tenosynovial Giant Cell Tumours (TGCT), today announced completion of patient enrolment in the TANGENT study. TANGENT is the company’s  global, multi-centre, randomized, double-blind, placebo-controlled registrational Phase 3 trial of emactuzumab in patients with TGCT who are not amenable to or who would not benefit from surgery. SynOx expects to report top-line data from the study in the first quarter of 2026.

Emactuzumab is a potentially best-in-class CSF-1 receptor (CSF-1R) inhibiting monoclonal antibody (mAb).  Clinical evaluation to date has demonstrated the compound to be a promising, next-generation mAb therapy with the potential to offer a short treatment cycle, rapid onset and long duration of response that differentiates it from chronically administered oral agents. This potentially best-in-class profile helped drive strong interest in the TANGENT trial among patients and clinical investigators across sites in the United States, Canada, Europe and Asia, leading to rapid study enrollment.

“Completion of enrollment in our registrational TANGENT trial marks an important milestone for SynOx and for the TGCT community,” said Elyse Seltzer, M.D., Chief Medical Officer of SynOx Therapeutics. “We are deeply grateful to the patients, families, investigators, and clinical sites whose dedication has made this study possible and allowed SynOx to fully enroll the trial significantly ahead of our projected timeline. We remain committed, data permitting, to delivering a much-needed new treatment option for this debilitating condition.”

“This is a transformational time for SynOx as we advance emactuzumab through its pivotal Phase 3 program,” said Ray Barlow, Chief Executive Officer of SynOx.  “We’re excited about the next steps and look forward to delivering top-line data that we hope demonstrate how emactuzumab can transform care for patients with this grievous disease.”

 

About the TANGENT Study

TANGENT (ClinicalTrials.gov Identifier: NCT05417789) is a randomized, double-blind, placebo-controlled Phase 3 trial evaluating the efficacy and safety of emactuzumab in patients with TGCT who are not amenable to or would not benefit from surgery. Patients who consent and meet eligibility criteria are randomized in a 2:1 fashion to receive either emactuzumab (1000 mg every two weeks for five doses) or matched placebo.

The primary endpoint is objective response rate (ORR) as assessed by RECIST criteria at six months post-randomization. Key secondary endpoints include patient-reported outcomes (PROMIS-PF), functional assessments of range of motion, pain, stiffness, durability of response, and safety. Patients are followed for two years from randomization, with those demonstrating disease progression after the six-month assessment eligible to receive open-label emactuzumab during follow-up.

 

For the full press release see here:  SynOx Completion of TANGENT Study PR

SynOx Therapeutics Receives Fast Track Designation from U.S. Food and Drug Administration for Emactuzumab for Tenosynovial Giant Cell Tumours (TGCT)

DUBLIN, IRELAND and OXFORD, UK, April 14, 2025 – SynOx Therapeutics Limited (“SynOx”), a late-stage clinical biopharmaceutical company developing of emactuzumab for Tenosynovial Giant Cell Tumours (TGCT), today announced that the United States Food and Drug Administration (FDA) has granted Fast Track Designation (FTD) to emactuzumab for the treatment of TGCT patients that are not amenable to or who would not benefit from surgery. Emactuzumab, a potentially best-in-class CSF-1 receptor (CSF-1R) inhibiting monoclonal antibody, is currently being evaluated in the TANGENT study, a global, multi-centre, randomized, double-blind, placebo-controlled registrational Phase 3 trial.

TGCT is a rare, non-malignant but aggressively growing tumour of the synovium, tendon sheaths and bursa membranes 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, as well as pain, stiffness and limited range of motion. Receipt of FTD for TGCT was supported by data from Phase 1/2 clinical studies demonstrating rapid, robust tumour reduction and durable response combined with a manageable safety profile. Emactuzumab has also previously received Orphan Medicinal Project designation from the European Medicines Agency.

“The granting of FTD for emactuzumab in TGCT highlights the devastating toll that this disease has on patients, as well as the critical need that remains for new treatment options,” said Elyse Seltzer, M.D., Chief Medical Officer of SynOx Therapeutics. “Based on our clinical work to date, we believe that emactuzumab has significant potential to address key patient needs by offering an effective, short-course treatment with rapid onset and a durable response that allows individuals suffering from TGCT to better manage their disease and move forward with their lives. We look forward to completing the ongoing TANGENT study and progressing emactuzumab toward potential commercialization.”

 

About Fast Track Designation

The FDA grants Fast Track designation to facilitate the development and expedite the review of medicines to treat serious conditions and fill an unmet medical need.  Fast Track status allows for enhanced communication and collaboration between the FDA and drug developers, potentially speeding up the delivery of life-saving treatments to patients.

 

For the full press release see here:  SynOx U.S Fast Track Designation PR