QBiotics reports 78% overall response rate in injected tumours treated with tigilanol tiglate in a Phase II head and neck cancer clinical trial

  • Positive final Phase II data from QB46C-H08 evaluating tigilanol tiglate in patients with head and neck solid malignancies, who were refractory to standard of care.
  • An Objective Response Rate (ORR) in injected tumours of 78% was achieved, based on post hoc analyses of the Best Observed Response (BOR) at any time during the study, indicating that the majority of injected tumours demonstrated either complete ablation (100% reduction in volume) or partial ablation (≥30% reduction in volume).
  • None of the completely ablated tumours recurred in the time the patients were on study (up to 5 months), adding to earlier evidence that tigilanol tiglate may provide durable responses.
  • Tigilanol tiglate was well tolerated, with most adverse events consistent with its expected local mode of action.
  • Results support the continued development of tigilanol tiglate as a potential treatment for head and neck cancers and other solid tumours.

BRISBANE, 3 August 2026

QBiotics Group Limited (QBiotics) is pleased to announce positive final efficacy and safety results from its Phase II QB46C-H08 trial, with tigilanol tiglate achieving a 78% Objective Response Rate (ORR) in injected tumours in patients with head and neck solid malignancies who were refractory to standard of care. The result, based on 14 responses across 18 injected tumours, highlights the potential of tigilanol tiglate to deliver meaningful local tumour control in a patient population with limited treatment options. This study is part of a series of small, rapid Phase II clinical trials designed to efficiently evaluate the drug's therapeutic potential across multiple solid tumour indications.

Lead Principal Investigator for the trial, Professor Kevin Harrington of the Royal Marsden cancer hospital, London, commented: "Our early experience with tigilanol tiglate in diverse head and neck cancers, including a number of difficult-to-treat forms of the disease, has been highly encouraging and suggests promising clinical activity. We look forward to further evaluating its role and determining how it can complement existing treatment options for these patients.”

QBiotics Interim CEO and Managing Director, Ebru Davidson, said: "Following on from our highly positive results in Soft Tissue Sarcoma, these results provide further evidence of tigilanol tiglate's potential to achieve meaningful tumour ablation in solid tumours. An Objective Response Rate of 78% in injected tumours is particularly encouraging in this difficult-to-treat patient population."

"Head and neck cancer remains a significant area of unmet medical need, and we believe this data further supports the potential of tigilanol tiglate as a novel intratumoural treatment across multiple solid tumour types. Our thanks to all the trial patients for their participation, and also to the trial Investigators and their teams for driving this important study.”

Head and neck cancer is a large, competitive market with real unmet need. There are approximately 940,0001 new head and neck cancer cases globally per year, and 480,0001 deaths from head and neck cancer globally per year in a global market projected to be valued at US$6.3b2 by 2033.

QB46C-H08 Phase II Trial – Key Study Outcomes

  • A 78% Objective Response Rate (ORR) was achieved in injected tumours based on Best Observed Response (BOR), with 14 of 18 evaluable injected tumours resulting in either complete or partial ablation (reduction in tumour volume).
  • 6 tumours achieved complete ablation (100% reduction in tumour volume).
  • All 6 completely ablated tumours remained recurrence free in the time that the patients were on study (up to 5 months), suggesting tigilanol tiglate may provide durable local tumour responses.
  • 64% of response-evaluable patients (9 of 14) achieved complete or partial ablation of a treated tumour or tumour segment, meeting the primary efficacy endpoint.
  • 16 of 16 treated patients were included in the safety analysis. Tigilanol tiglate was well tolerated, with most adverse events consistent with its expected local mode of action, including pain, swelling and tumour necrosis.

Tigilanol tiglate demonstrates encouraging efficacy and tolerability in head and neck cancer

The QB46C-H08 trial demonstrated encouraging anti-tumour activity and a favourable safety profile in patients with head and neck solid malignancies who were refractory to standard of care. As summarised in the key study results above, tigilanol tiglate achieved high tumour response rates, with no recurrence observed in completely ablated tumours in the time that the patients were on study (up to five months). The safety profile was consistent with previous clinical experience, with adverse events largely reflecting the expected local mode of action of the treatment.

Overall the study results demonstrate that tigilanol tiglate was well tolerated and showed encouraging anti-tumour activity in patients with head and neck solid malignancies, supporting its continued clinical development in oncology.

—ends—

ABOUT TIGILANOL TIGLATE

Tigilanol tiglate is a novel small molecule drug, discovered by QBiotics and currently being developed as an intratumoural treatment for solid tumours. Tigilanol tiglate has a multifactorial mode of action that induces pyroptosis (tumour cell death), stimulates a systemic immune response3 and initiates wound healing at the treatment site, supporting favourable functional and cosmetic outcomes.

  1. Sun et al. Global burden of head and neck cancer. Front Oncol. 2025 Sep 25
  2. https://www.grandviewresearch.com/industry-analysis/head-neck-cancer-drugs-therapeutics-market
  3. Cullen et al., 2022. Tigilanol tiglate is a naturally occurring small molecule oncolytic that effectively ablates tumors via intratumoral injection and can enhance response to immune checkpoint blockade. Journal Immunotherapy of Cancer 10 (Suppl 2): A1–A1595.

 

FURTHER INFORMATION
EBRU DAVIDSON, INTERIM 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 Group Limited (QBiotics) is an Australian public unlisted biotechnology company, advancing two clinical-stage, differentiated, small molecule programmes derived from our epoxytigliane platform.

QBiotics’ lead intratumoural oncology asset, tigilanol tiglate, is demonstrating strong efficacy and safety in human clinical Phase II studies. In addition to the head and neck cancer clinical trial reported here, tigilanol tiglate delivered an Objective Response Rate (ORR) in injected tumours of 82% in a Phase II Soft Tissue Sarcoma study, with, most adverse events consistent with the expected local mode of action of the drug and translational research validating immunological responses. Impressive efficacy and safety outcomes have been achieved in a range of other tumour types under Compassionate Use. No Maximum Tolerated Dose (MTD) was declared in a Phase I safety study and efficacy reported in nine different tumour types. QBiotics is soon to implement a Phase II trial in breast cancer in partnership with Unicancer, the French Federation of cancer centres and is currently exploring the treatment of visceral tumours by tigilanol tiglate in a preclinical study.

QBiotics’ second programme is a topically applied regenerative wound therapy EBC-1013 that accelerates wound infill and closure, minimises scarring, and provides local antimicrobial activity. This drug candidate has demonstrated impressive safety and efficacy against chronic and acute wounds and burns in veterinary studies. It is currently in a human clinical Phase I study treating Venous Leg Ulcers.

Patent coverage for tigilanol tiglate and EBC-1013 is broad and Chemistry, Manufacturing and Controls (CMC) is mature, with commercial supply of tigilanol tiglate secured.

QBiotics employs a capital-efficient model that integrates its EcoLogic™ discovery technology with phenotypic screening and early validation in veterinary disease models. This approach enables rapid identification of biologically active molecules, early demonstration of efficacy and safety in complex disease settings in the veterinary environment, and meaningful de-risking prior to human clinical development. Product development is led by an experienced team and complemented by internationally recognised Key Opinion Leaders on our Clinical and Scientific Advisory Boards, who bring deep expertise in oncology, wound healing, antimicrobials, small molecule chemistry and translational drug development.

QBiotics’ business strategy is to advance therapeutic programmes with the potential to address multiple high-value indications through to Phase II proof-of-concept in human clinical studies, and then pursue strategic partnering to accelerate late-stage development and commercialisation.

For more, head to: QBiotics.com or LinkedIn