Animals : an open access journal from MDPI2026; 16(19); 3090; doi: 10.3390/ani16193090

Proof of Concept for Open Flow Microperfusion for Intratumoural Drug Administration in Equine Cutaneous Neoplasia.

Labens, R
·
Reddell, P
·
Birngruber, T

Abstract: Intratumoural drug delivery can achieve high local therapeutic exposure while limiting systemic effects, but heterogeneous distribution may compromise treatment efficacy and precision. This proof-of-concept study investigated open flow microperfusion (OFM) as a novel platform for local delivery of tigilanol tiglate (TT), an intratumoural antineoplastic agent with immunomodulatory and vascular-disrupting effects. Four horses with histologically confirmed cutaneous neoplasia (three sarcoids and one squamous cell carcinoma) underwent OFM using TT concentrations of 0.01-0.04 mg/mL delivered at 9 µL/min for 7-24 h over one to three consecutive days. OFM systems were well tolerated and remained functional for up to three days. Localized vascular disruption, polymorphonuclear cell recruitment, oncosis and tissue sloughing developed in association with perfused regions, consistent with recognized TT-induced tissue responses. Two sarcoids exhibited biologic responses that did not result in complete local tumour ablation. Tumour ablation was achieved initially in one squamous cell carcinoma, although deep-seated disease subsequently progressed, while one sarcoid was ablated and remained tumour-free 497 days after treatment. These preliminary findings demonstrate that OFM allows precise, sustained intratumoural TT challenge, resulting in characteristic tissue responses supporting further investigation of this local delivery platform for tumour-targeted therapies.

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Publication Date: 2026-10-01 PubMed ID: 42883059PubMed Central: PMC13663526DOI: 10.3390/ani16193090Google Scholar: Lookup

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Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

Overview

This study explores the use of open flow microperfusion (OFM) as a novel method for delivering an anticancer drug directly into skin tumors in horses, aiming to improve treatment precision and effectiveness while minimizing systemic side effects.

Introduction and Objectives

Intratumoural drug delivery methods aim to concentrate therapeutic agents within tumors to enhance local effectiveness and reduce systemic toxicity.
However, uneven distribution of drugs within the tumor can reduce treatment success and precision.
Tigilanol tiglate (TT) is an experimental antineoplastic agent with effects including immune modulation and disrupting tumor blood vessels, making it a promising candidate for direct tumor injection.
The study’s primary objective was to investigate the feasibility and therapeutic impact of using open flow microperfusion (OFM) to deliver TT directly into equine cutaneous tumors.

Methodology

Subjects: Four horses diagnosed with skin tumors – three with sarcoids and one with squamous cell carcinoma.
Intervention: OFM was used to deliver TT at concentrations between 0.01 and 0.04 mg/mL.
Delivery Parameters: The drug was infused at a flow rate of 9 microliters per minute for durations ranging from 7 to 24 hours, over one to three days consecutively.
OFM Platform: This minimally invasive technique allows continuous fluid exchange, enabling sustained and controlled delivery of small molecules directly into tissue.
Tumor response and device tolerance/functionality were monitored throughout treatment.

Key Findings

OFM systems were well tolerated by the horses, maintaining functional infusion capability for up to three days without complications.
Localized effects in perfused tumor areas included:
- Disruption of tumor blood vessels (vascular disruption).
- Recruitment of polymorphonuclear cells, indicating an inflammatory immune response.
- Oncosis (a form of cell death) and tissue sloughing, consistent with TT’s known effects on tumor tissue.
Tumor responses varied:
- Two sarcoids showed biological activity after treatment but did not achieve complete tumor elimination.
- The squamous cell carcinoma initially responded with tumor ablation, but deeper tumor tissues eventually progressed.
- One sarcoid was fully ablated and remained free of tumor recurrence for over 497 days post-treatment, indicating long-term effectiveness.

Significance and Conclusions

This proof-of-concept confirms that OFM can deliver sustained, precise doses of TT directly into tumors in a controlled manner.
The observed tissue responses align with the expected therapeutic actions of TT, supporting the potential of this delivery platform.
OFM may overcome challenges of heterogeneous drug distribution in intratumoural therapy, potentially improving local tumor control.
Although some tumors did not achieve full ablation, these preliminary results justify further research into OFM as a delivery technique for tumor-targeted therapies.
Future studies could optimize dosing, duration, and drug concentrations, and evaluate efficacy across different tumor types and stages.

Cite This Article

APA

Labens R, Reddell P, Birngruber T. (2026). Proof of Concept for Open Flow Microperfusion for Intratumoural Drug Administration in Equine Cutaneous Neoplasia. Animals (Basel), 16(19), 3090. https://doi.org/10.3390/ani16193090

Publication

Animals : an open access journal from MDPI

ISSN: 2076-2615

NlmUniqueID: 101635614

Country: Switzerland

Language: English

Volume: 16

Issue: 19

PII: 3090

Researcher Affiliations

Labens, Raphael

School of Agricultural, Environmental and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia.

Reddell, Paul

QBiotics Group Limited, Brisbane, QLD 4066, Australia.

Birngruber, Thomas

HEALTH-Institute for Biomedical Research and Technologies, Joanneum Research, 8010 Graz, Austria.

Grant Funding

QBiotics Group Ltd

Conflict of Interest Statement

Paul Reddell is an Executive Director and Chief Scientific Officer of QBiotics Group Ltd.; Raphael Labens serves as a scientific consultant for QBiotics Group Ltd., for which a salary is received.

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