Sponsor: QBiotics Group Limited (industry)
Phase: 2
Start date: April 13, 2023
Planned enrollment: 40
Tigilanol tiglate (EBC‑46; veterinary brand Stelfonta) is a plant‑derived small‑molecule given by intratumoral injection and under investigation for local ablation of solid tumors in humans (not FDA‑approved for human use). It is approved in veterinary medicine for non‑metastatic canine mast cell tumors. (pmc.ncbi.nlm.nih.gov, ema.europa.eu)
Current human programs include: - Head and neck cancers: Phase II single‑arm study (NCT05608876) ongoing; prior Phase I/IIa “window” dose‑escalation study met primary safety/tolerability endpoints. (ichgcp.net, qbiotics.com) - Soft tissue sarcoma: Phase IIa study (NCT05755113) ongoing; FDA granted Orphan Drug Designation for STS (February 16, 2024). (trial.medpath.com, qbiotics.com)
Tigilanol tiglate is a potent activator/modulator of protein kinase C (PKC). Intratumoral dosing produces rapid, PKC‑dependent vascular disruption and hemorrhagic necrosis with local inflammatory responses; preclinical data and early clinical observations suggest associated immunogenic cell death and immune infiltration. (pubmed.ncbi.nlm.nih.gov, thelancet.com)
Notes on other indications: - A Phase Ib/IIa melanoma combination study with pembrolizumab (NCT04834973) was terminated; QBiotics subsequently discontinued melanoma development (Feb 2023). (ichgcp.net, ctv.veeva.com, qbiotics.com)
Stelfonta (tigilanol tiglate) is authorized in the EU and US for intratumoral treatment of non‑metastatic canine mast cell tumors; in a 123‑dog randomized study, complete response was 75% after a single treatment and 87% after up to two treatments. This informs local ablation expectations but is not a substitute for human data. (ema.europa.eu)
If specific, peer‑reviewed Phase II results become available, efficacy and safety sections should be updated accordingly.
Last updated: Sep 2025
Goal: Evaluate preliminary efficacy of intratumoural tigilanol tiglate for local ablation of soft tissue sarcoma lesions and overall disease control in Stage 2, along with safety, pharmacokinetics, and exploratory immunologic and microenvironmental effects.
Patients: Adults ≥18 years with histologically confirmed advanced and/or metastatic soft tissue sarcoma of the extremities, body wall, or scalp, with at least one injectable lesion accessible by palpation or ultrasound guidance. ECOG 0–2, life expectancy >12 weeks, adequate hepatic/renal function. Excludes lesions abutting major vessels, recent major surgery, recent systemic anticancer therapy or investigational agents without adequate washout, planned local therapies to injected lesions, active brain metastases or carcinomatous meningitis (treated/stable allowed), significant bleeding risk, and severe hypersensitivity to study drug/excipients.
Design: Phase IIa, single‑arm, open‑label study with two stages. Allocation is not applicable. Approximately 40 patients will receive intratumoural therapy with predefined assessments at 3 and 6 months for efficacy (RECIST in Stage 2) and 6 months for local ablation and safety.
Treatments: Intratumoural tigilanol tiglate administered as single or multiple injections up to a fixed dose of 3.6 mg/m2 per treatment. Tigilanol tiglate (EBC‑46) is a plant‑derived small molecule and potent modulator of protein kinase C that causes rapid, PKC‑dependent vascular disruption and hemorrhagic necrosis leading to local tumor ablation; preclinical and early clinical data suggest immunogenic cell death and immune infiltration. In a first‑in‑human pan‑tumor Phase I study, responses were observed including complete responses, and dose was escalated without reaching a maximum tolerated dose at or below 3.6 mg/m2. Company communications from Stage 1 of this sarcoma program report high rates of ablation in injected tumors with predominantly local, mechanism‑consistent toxicities; peer‑reviewed confirmation is pending.
Outcomes: Primary: proportion of participants achieving partial or complete ablation of treated tumors/tumor segments at 6 months; in Stage 2, overall objective response rate by RECIST v1.1 at 3 and 6 months. Secondary: incidence of AEs/SAEs and relatedness; systemic exposure via PK after a single injection up to 24 hours. Exploratory: changes in tumor microenvironment and immune infiltration in injected and/or non‑injected tumors, PBMC immunologic assessments, local recurrence rate at 6 months, and metabolite profiling after a single injection (Stage 2).
Burden on patient: Moderate. Patients undergo intratumoural injections that can cause local pain, swelling, necrosis, and wound care needs. Safety monitoring and standard imaging at baseline and at 3 and 6 months are required. Stage 2 includes paired tumor biopsies to assess microenvironmental changes, adding procedure‑related visits and risks. Pharmacokinetic sampling occurs over the first 24 hours after the initial dose, necessitating extended on‑site time or an inpatient/observation period with multiple blood draws. Additional blood collections for immune monitoring and follow‑up visits through 6 months increase visit frequency beyond typical palliative sarcoma care. Travel demands will vary with injection schedule and follow‑up, but overall intensity is less than cytotoxic regimens yet higher than purely observational protocols due to procedures, PK, and biopsies.
Inclusion Criteria:
1. Are willing and able to provide written informed consent for the study prior to any protocol-specific procedures and to comply with all local and study requirements.
2. Are ≥ 18 years of age on the day of providing informed consent.
3. Have advanced and/or metastatic disease of the body wall or extremities that is amenable to intratumoural injection either by palpation or under ultrasound guided injection, that has been histologically or pathologically confirmed as an STS. STS located on the scalp may also be considered for treatment.
4. Have an Eastern Cooperative Oncology Group (ECOG) performance status of ≤ 2.
5. Have life expectancy of more than 12 weeks.
6. Have adequate renal and hepatic function as assessed by the Investigator.
7. Female participants who are Women Of Child-Bearing Potential (WOCBP) must have a negative serum pregnancy test at Screening (within 14 days of the first study drug administration), must be willing to use a highly effective contraception from date of consent, throughout the study period and up to 30 days after the last study drug administration, and must not be breastfeeding.
8. Male participants with a potentially fertile female partner are eligible if they have had a vasectomy or are willing to use adequate contraception from prior to commencement of study drug administration, throughout the study period and up to 30 days after the last study drug administration, and must not donate sperm throughout the study period and up to 30 days after the last study drug administration.
Exclusion Criteria:
1. Are planning to receive intratumoural treatment or radiotherapy to any of the tumours intended for injection within 28 days prior to Screening, or during treatment with tigilanol tiglate.
2. Have a tumour intended for injection that is immediately adjacent to, or with infiltration into, any major artery or vein (e.g., if the tumour for injection is located adjacent to the jugular vein).
3. Are receiving or have received other investigational agents or have used an investigational device without undergoing a 28-day (or 5 half-lives, whichever is shorter) wash-out period prior to their first treatment with tigilanol tiglate. These patients must have recovered from all AEs due to previous investigational therapies to ≤ Grade 1 at baseline.
4. Are receiving or have received systemic anticancer therapy, without undergoing a 28-day (or 5 half-lives, whichever is shorter) wash-out period prior to their first treatment with tigilanol tiglate. These patients must have recovered from all AEs due to previous therapies to ≤ Grade 1 at baseline. Patients with ≤ Grade 2 neuropathy may be eligible following discussion with Sponsor Medical Monitor.
5. Have had major surgery within 28 days of their first treatment with tigilanol tiglate or anticipate the need for major surgery during the study period. Minor surgical procedures are permitted, but with sufficient time for wound healing.
6. Have known, active brain metastases and/or carcinomatous meningitis. Participants who have previously treated brain metastases and are neurologically stable can be included.
7. Have any bleeding diathesis or coagulopathy that would make intratumoural injection or biopsy unsafe, or if they are on therapeutic warfarin therapy.
8. Have a history of allergic reactions or severe hypersensitivity (Grade ≥ 3) attributed to tigilanol tiglate or compounds of similar chemical or biologic composition to tigilanol tiglate, any of its excipients or other agents used in the study.
9. In the opinion of the treating Investigator, they are not an appropriate candidate for the study for any reason (e.g., they have known psychiatric or substance abuse disorder that would interfere with their ability to cooperate with the requirements of the study.
New York, New York, 10065, United States
No email / No phone
Status: Recruiting