First three patients dosed in Stage 2 of Phase IIa clinical trial of tigilanol tiglate in Soft Tissue Sarcoma

BRISBANE, 18 September 2025

QBiotics Group Limited (QBiotics) is pleased to announce that the first three patients have been dosed in the expansion arm (Stage 2) of its Phase IIa clinical trial, QB46C-H07. The trial is designed to evaluate the preliminary efficacy and safety of small molecule, tigilanol tiglate in patients with advanced and/or metastatic Soft Tissue Sarcoma (STS).

The single centre, open label study is being conducted at the Memorial Sloan Kettering Cancer Centre in the USA with Dr Edmund Bartlett, MD as Principal Investigator.

In Stage 1 of the QB46C-H07 trial, that evaluated tigilanol tiglate in 11 (10 evaluable) patients, QBiotics reported an 80% response rate in injected tumours. The decision to expand the trial followed the presentation of positive data at the 2024 Connective Tissue Oncology Summit (CTOS) Annual Meeting. The CTOS presentation included additional observations made by Investigators, showing that patients with metastatic STS disease, who were originally non-responsive to systemic therapies began to respond to systemic therapy after treatment with tigilanol tiglate.

In addition to the original study objectives, the protocol for Stage 2 includes new primary objectives - evaluating the effect of tigilanol tiglate on Objective Response Rate (ORR) by RECIST v1.1 and overall disease control (not limited to injected tumours). It also includes a new exploratory objective: the evaluation of metabolites after a single intratumoural injection of tigilanol tiglate.

CEO and Managing Director for QBiotics, Stephen Doyle commented, “In this arm of the trial, we aim to build on the encouraging response rates observed in Stage 1 and are particularly excited by the potential for tigilanol tiglate to re-sensitise patients to systemic therapies to which they were previously unresponsive. We extend our thanks to the first three patients in Stage 2 of the trial, who have been treated, and we look forward to progressing recruitment.”

STS is a rare type of cancer that generally forms as a painless lump (tumour) in any one of the soft tissues in the body. There were approximately 128,000 new cases of STS globally in 2023, with the incidence growing at 0.54% per year.1 QBiotics has been granted Orphan Drug Designation from the US FDA for tigilanol tiglate in STS, reflecting the need for new treatments for patients with this rare disease.

About Trial QB46C-H07

QB46C-H07 (Clinical trial registration, NCT05755113) is a Phase IIa, open label, clinical trial evaluating the preliminary efficacy and safety of intratumoural tigilanol tiglate in patients with a range of advanced and/or metastatic STS. QB46C-H07 is being conducted in two stages: Stage 1 was a pilot trial in 10 patients. Stage 2 is an expansion trial in up to 40 additional patients.

In Stage 1, the first primary efficacy endpoint is Response Rate (RR) of injected tumours, compared to baseline. RR was defined as the proportion of patients who achieved complete ablation (100% reduction in volume) or partial ablation (≥ 30% reduction in volume) of treated tumours and/or tumour segments following one or more treatments (up to 5 treatments in Stage 1 and up to 3 treatments in Stage 2) with tigilanol tiglate. Patients who achieved a ≥ 30% reduction in volume, irrespective of the number of treatments they received, were considered to have a response to tigilanol tiglate. A second primary efficacy endpoint is included for Stage 2 - ORR of injected and non-injected tumours as determined by Response Evaluation Criteria in Solid Tumours (RECIST) v1.1.2

Secondary endpoints include safety and tolerability assessments, and pharmacokinetics.

Exploratory endpoints include local rate of recurrence at the injection site at 6 months post-initial injection, and assessment of tumour response in biopsy samples. Surgical specimens and blood samples are also collected to assess changes in tumour biomarkers, as well as to analyse metabolites in Stage 2.3

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References:

  1. GlobalData®, American Cancer Society, Cancer Australia, Cancer Research UK, Canadian Cancer Society.
  2. Overall Response Rate as determined by RECIST v1.1 at three (3) and six (6) months post initial treatment.
  3. Metabolite analysis in the first 24 hours, following a single intratumoural injection of tigilanol tiglate

 

FURTHER INFORMATION - STEPHEN DOYLE, CEO & MANAGING DIRECTOR

communications@qbiotics.com

or  

MEDIA ENQUIRIES - JANE LOWE, IR DEPARTMENT

jane.lowe@irdepartment.com.au or +61 411 117 774

 

NOTES FOR EDITORS

ABOUT QBIOTICS

QBiotics is an unlisted, public, Australian life sciences company that seamlessly connects scientific discovery, development and commercialisation to harness the power of nature to treat diseases of high unmet need. 

Our current clinical focus is on novel treatments for cancer and debilitating chronic wounds. We also have an early-stage antibiotics program.

QBiotics’ lead molecule, tigilanol tiglate, is a novel, small molecule with the potential to treat a broad range of solid tumours. It is currently in Phase II clinical trials in two indications: soft tissue sarcoma (STS) and head and neck cancer (HNC). Tigilanol tiglate was granted Orphan Drug Designation by the US FDA for the treatment of STS in February 2024.

A veterinary formulation of tigilanol tiglate (STELFONTA®) is approved for the treatment of canine mast cell tumours (MCTs), in major global markets, including the USA, Europe, and Australia. QBiotics has partnered with Virbac, a global animal health company, to distribute STELFONTA®.

Our wound healing drug candidate, EBC-1013, is a small molecule, which targets multiple pathways to accelerate healing, improving outcomes in chronic and acute wounds and burns. A first-in-human Phase I clinical trial in venous leg ulcers is open for recruitment. 

For more, head to: qbiotics.com or LinkedIn