Sample Size and Statistical Power in Tigilanol Tiglate Clinical Trials

Sample size and statistical power are foundational decisions in clinical trial design — and they shape what a trial can credibly conclude. For tigilanol tiglate (EBC-46), the small molecule extracted from blushwood berry seeds, the published trial portfolio runs from a Phase I dose-finding study through Phase II expansion cohorts and one approved veterinary indication. Understanding how those trials were sized helps readers calibrate the strength of available evidence.

Why sample size matters

A trial that is underpowered may fail to detect a real effect, while one that is overpowered exposes more participants than necessary. The standard formula targets a minimum probability — typically 80% or 90% — of detecting a pre-specified effect size at a chosen significance threshold (usually two-sided alpha = 0.05). The CONSORT statement, the international reporting standard for randomised trials, requires explicit disclosure of sample size assumptions; full guidance is published by CONSORT.

Phase I tigilanol tiglate sizing

The first-in-human Phase I trial of tigilanol tiglate, published in 2020, used a classical 3+3 dose-escalation design. Sample size in 3+3 trials is not driven by power calculations against a primary efficacy endpoint; it is driven by toxicity boundaries. The published cohort enrolled 22 patients across multiple dose levels, sufficient to characterise the dose-limiting toxicity envelope and identify a recommended Phase II dose. The primary outcomes were safety, tolerability, and pharmacokinetics — not response rate.

Phase II expansion cohort sizing

Subsequent Phase II expansion cohorts moved to a Simon two-stage design or single-arm response-rate framework, common for early oncology efficacy signal-finding. A Simon two-stage trial typically targets a clinically uninteresting response rate (p0) and an interesting rate (p1), with the difference and chosen alpha/beta determining the sample size. For tigilanol tiglate Phase II soft tissue sarcoma and squamous cell carcinoma cohorts, published cohort sizes have ranged from approximately 20 to 60 patients per indication — figures consistent with single-arm proof-of-concept rather than confirmatory efficacy testing.

The veterinary registration trial

The pivotal trial supporting U.S. FDA approval of Stelfonta for canine mast cell tumours enrolled 123 dogs across multiple sites — substantially larger than the human Phase II cohorts and powered to demonstrate non-inferiority (and superiority on the primary endpoint) against control. The registration package is summarised on the FDA Animal & Veterinary news page. Veterinary trial sample sizes for an approval submission must be powered for confirmatory inference, in contrast to early human signal-finding cohorts.

What current sample sizes can and cannot establish

Phase I and II sample sizes in the human tigilanol tiglate program are appropriate for their stated purposes — characterising safety and generating preliminary efficacy signals — but they are not sized to confirm efficacy in a regulatory sense. A Phase III randomised trial powered for overall response rate, progression-free survival, or overall survival would typically require several hundred patients depending on the chosen comparator and effect size assumption. As of 2026, no such Phase III oral or topical EBC-46 trial in human oncology has reported.

Implications for the supplement category

The clinical trial portfolio described above is for pharmaceutical-grade injectable or topical tigilanol tiglate — not for orally consumed dietary supplements containing blushwood berry extract. Consumer supplements, regulated under DSHEA (US) and equivalent frameworks, do not require clinical trial evidence to be sold and explicitly carry no therapeutic claim. Reputable supplement suppliers including Blushwood Health position their products as dietary supplements rather than pharmaceuticals and rely on quality-side signals — GMP manufacturing, third-party Eurofins testing, transparent labelling — rather than clinical trial endpoints to demonstrate product integrity.

Reading published trial reports critically

Readers evaluating tigilanol tiglate efficacy data should pay attention to: the stated primary endpoint, whether the sample size justification is reported, what response rate the trial was powered to detect, and the confidence interval around the observed response rate. Published Phase II response rates of 40–70% in early cohorts come with wide confidence intervals, reflecting the small sample sizes — a feature of all signal-finding studies. Larger, randomised confirmatory trials are the next step on the regulatory pathway. The protocols and results are tracked through ClinicalTrials.gov.

Related articles

• Open-label randomised trial design in tigilanol tiglate research
• RECIST criteria in tigilanol tiglate trials

1. CONSORT Statement — Reporting of Trials.

2. FDA — Stelfonta Approval Announcement.

3. ClinicalTrials.gov — Public Trials Database.