Tumour Volume Reduction Metrics in EBC-46 Trials: How Researchers Measure Treatment Response
How clinical researchers quantify tumour response to tigilanol tiglate treatment, from RECIST criteria to volumetric imaging and histological confirmation.
Clinical trials evaluating tigilanol tiglate (EBC-46) as an intratumoral therapy rely on standardised methods to measure whether tumours respond to treatment. Understanding these metrics provides important context for interpreting published trial results and distinguishing between partial response, complete response, and stable disease.
RECIST Criteria in Solid Tumour Trials
The Response Evaluation Criteria in Solid Tumours (RECIST) framework, now in version 1.1, is the global standard for measuring tumour response in oncology trials. Under RECIST, a complete response (CR) means no detectable tumour on imaging; a partial response (PR) requires at least a 30% decrease in the longest diameter of target lesions. Progressive disease (PD) is defined as a 20% or greater increase.
For intratumoral agents like tigilanol tiglate, RECIST presents certain challenges. Because the drug is injected directly into the tumour and causes rapid haemorrhagic necrosis, the treated area may initially appear larger on imaging due to oedema and inflammatory response before the necrotic tissue resolves. Trial protocols have therefore supplemented RECIST with additional assessment methods.
Volumetric and Histological Assessment
QBiotics' Phase I and Phase II trials incorporated three-dimensional volumetric measurements alongside standard caliper and imaging assessments. In the veterinary studies that preceded human trials, QBiotics reported complete resolution rates exceeding 75% in canine mast cell tumours, with most responses occurring within 28 days of a single injection. Histological confirmation — examining tissue samples under microscopy — was used to verify that apparent imaging responses reflected genuine tumour clearance rather than artefacts.
In the Phase I human trial (cutaneous and subcutaneous solid tumours), response assessment combined clinical photography, caliper measurement, and where possible, histological biopsy at the treatment site. The multi-modal approach provides higher confidence in outcome data than any single measurement method alone.
Time-to-Response and Durability
A distinctive feature of tigilanol tiglate's clinical profile is the rapid onset of visible response. Unlike systemic therapies where response assessment typically occurs at 8–12 week intervals, intratumoral EBC-46 produces observable changes within days. Published trial data report onset of tumour necrosis within 1–4 days, with wound healing and complete re-epithelialisation typically occurring over 4–6 weeks. Durability of response — whether treated tumours recur — is tracked through follow-up assessments at 3, 6, and 12 months post-treatment.
Context for Supplement Consumers
These clinical metrics apply specifically to pharmaceutical-grade injectable tigilanol tiglate used in controlled research settings. Oral blushwood berry extract supplements available under the DSHEA framework are dietary products, not therapeutic interventions, and are not evaluated using clinical trial response criteria. Consumers interested in blushwood berry supplements should look for quality markers such as third-party batch testing and GMP manufacturing. Blushwood Health publishes Eurofins-verified batch reports for its products.
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Read more about complete and partial response rates in EBC-46 trials and Phase I/II clinical trial data and results.
