FivepHusion, an advanced clinical-stage biotechnology company, is pleased to announce that Dr Marion Mateos, Co-Principal Investigator of the phase 1/2 Deflexifol® at Relapse Trial (DART) proudly supported by the Kids with Cancer Foundation, recently presented a poster of the phase 1 (Part A) trial results at the Society of Neuro-Oncology (SNO) 2025 Annual Meeting in Honolulu, Hawaii, USA, which was held from the 19th – 23rd November.
The poster can be found on the FivepHusion website here.
Key outcomes of the phase 1 trial are:
- Nine participants (aged 4-14 years) with ependymoma (n=6), diffuse midline glioma (DMG) (n-2) and embryonal tumour with multilayered rosettes (n=1) were enrolled
- Deflexifol® is well tolerated in children, with a side effect profile consistent with adults
- Deflexifol® pharmacokinetic properties are similar to those reported previously in adults, and for 5-FU in children
- The Deflexifol® paediatric maximum tolerated dose (MTD) was defined as 525mg/m2 bolus (of delivered 5-FU) followed by a 3000mg/m2 infusion. These results reflect:
- ~25% greater than typical 5-FU clinical dosing in adults
- ~9x the previously reported 5-FU MTD in children
- The Recommended Phase 2 Dose for future paediatric studies was declared as the MTD
- The DART phase 2 expansion cohort (DART Part B) evaluating the activity of Deflexifol® in children with ependymoma will commence soon
The phase 1/2 DART study is an Australian investigator-initiated trial, led by Principal Investigators Professor David Ziegler and Dr Marion Mateos and sponsored by the Australian and New Zealand Children’s Haematology / Oncology Group (ANZCHOG) in collaboration with FivepHusion. The trial is designed to investigate Deflexifol® monotherapy as a treatment for paediatric ependymoma and other childhood brain cancers. All major paediatric oncology centres in Australia are participating in the trial, and major trial funding has been provided by the Kids with Cancer Foundation, through Sydney Children’s Hospitals Foundation, and the Robert Connor Dawes Foundation.
Dr Christian Toouli, CEO and Managing Director of FivepHusion commented, “Presentation of the DART Phase 1 results at SNO 2025 was an excellent opportunity to raise international awareness of Deflexifol® and its potential use in the treatment of paediatric ependymoma and other brain cancers. Congratulations and thanks to Dr Mateos for presenting the DART study results at such a prestigious international congress.”
Deflexifol® is an advanced clinical-stage, next-generation co-formulation of 5-FU and leucovorin (LV), a drug that significantly enhances 5-FU activity. Deflexifol® has been previously evaluated in two successfully completed clinical trials in adults with a variety of solid tumours; the DART study is the first clinical evaluation of Deflexifol® in paediatric patients. FivepHusion is harnessing the proven cytotoxic activity of 5-FU together with the unique, optimised attributes of the Deflexifol® co-formulation to pursue Deflexifol® development in a range of strategic solid tumour indications presenting with significant unmet medical needs, including paediatric ependymoma.
Ependymomas are rare central nervous system tumours (annual incidence of ~4 patients per million) that are more common in young children 0-4 years of age. The current standard treatment for ependymoma is surgery and radiotherapy, though relapse occurs in one third of all paediatric patients and is associated with a poor prognosis. Currently, there are no therapeutic drugs approved for the treatment of ependymoma, presenting a significant unmet medical need for the development of safe and efficacious new treatments for this disease.
Previously, 5-FU has been reported as a promising drug candidate for the treatment of paediatric ependymoma by independent research groups1,2, and in a clinical trial conducted at the St Jude Children’s Research Hospital (Memphis, Tennessee, USA)3. Recently, independent studies have gained further insights into understanding the susceptibility of paediatric ependymoma to 5-FU4. Research by FivepHusion collaborators indicates that Deflexifol®, as an optimised co-formulation of 5-FU and LV, may be efficacious against paediatric ependymoma and other brain cancers. Due to its improved safety, tolerability, and potentially superior anti-tumour efficacy, Deflexifol® offers the exciting opportunity of addressing the limitations of current 5-FU formulations to enable development as potentially the first approved drug for ependymoma and possibly other brain tumours.
About FivepHusion
FivepHusion (www.fivepHusion.com) is an advanced clinical-stage, globally focused biotechnology company optimising cancer therapy to improve patient treatment outcomes and quality of life.
The FivepHusion lead asset is Deflexifol®, a proprietary, novel, and optimised co-formulation of the chemotherapeutic agent 5-FU and its biomodulator LV, a drug that significantly enhances 5-FU anti-cancer activity. These drugs are commonly used globally to treat solid tumours including colorectal, pancreatic, gastric, head & neck, and some breast cancers. However, due to their chemical incompatibility, current formulations of 5-FU and LV suffer from limitations in their safety, tolerability, effectiveness and pharmacological compatibility. These disadvantages contribute to limited efficacy, unpleasant side effects and toxicities, and a reduced quality of life experienced by cancer patients.
FivepHusion is developing Deflexifol® via the FDA 505(b)(2) and EMA Article 10b regulatory pathways as a next-generation replacement of standard of care formulations of 5-FU and LV for the first-line treatment of metastatic colorectal cancer (a ~US$13B market5) and other tumours with a projected global incidence of >6 million patients. Anticipated peak revenues for Deflexifol® are ~US$1.8B. Deflexifol® is also being developed as a new therapy for cancers with high unmet medical need, including paediatric ependymoma. The paediatric brain cancers market is reported to be US$1.7B6.
In addition to Deflexifol®, FivepHusion has secured commercial rights to ResectAssist™, an innovative drug delivery platform technology enabling targeted delivery of anti-cancer drugs directly into solid tumours, maximising the drug efficacy while minimising side effects. The lead candidate, ResectAssist™-FOLFIRINOX, is in development to treat locally advanced pancreatic cancer.
Deflexifol® is a trademark of FivepHusion. ResectAssist™ is a trademark of the University of Wollongong.
Forward-Looking Statements
This announcement (and any attachments) may contain certain forward-looking statements that are based on any number of assumptions and estimates which may prove incorrect and relate to circumstances and events that may not take place. Forward-looking statements involve known and unknown risks, uncertainties, and other factors (such as significant business, economic and competitive uncertainties and contingencies, and regulatory and clinical development risks and uncertainties) which may cause the actual future plans, results or the performance of FivepHusion and its development pipeline opportunities Deflexifol® and ResectAssist™ to differ materially from the plans, results or performance expressed or implied by such forward-looking statements. Past performance is not a reliable indicator of future performance. There can be no assurance that any forward-looking statements will be realised. FivepHusion does not make any representation or give any warranty as to the likelihood of achievement or reasonableness of any forward-looking statements.
1 Atkinson et al. 2011, Cancer Cell 20(3):384.
2 Donson et al. 2018, Mol Cancer Ther. 17(9):1984
3 Wright et al. 2015, Neuro Oncol. 17(12):1620.
4 Griesinger et al. 2024, Clin Cancer Res. 30(8):1544.
5 DelveInsight 2025, Colorectal Cancer Market Insight, Epidemiology And Market Forecast – 2034.
6 Market Research Future 2025, Brain Tumor Treatment Market.