Sponsor: QBiotics Group Limited (industry)
Phase: 2
Start date: April 13, 2023
Planned enrollment: 40
Tigilanol tiglate (EBC‑46; brand name Stelfonta in veterinary medicine) is a small‑molecule, intratumoral agent under investigation for human cancers. It is a plant-derived epoxytigliane diterpene developed by QBiotics and functions primarily as a protein kinase C (PKC) activator; it is approved for canine mast cell tumors in the EU, US, UK, and Australia. (pmc.ncbi.nlm.nih.gov)
Active Phase II trials are evaluating intratumoral tigilanol tiglate in head and neck cancers (NCT05608876) and soft tissue sarcoma (NCT05755113); the latter has FDA Orphan Drug Designation. (qbiotics.com)
Phase I, first‑in‑human (multicenter, single‑arm; n=22): Intratumoral tigilanol tiglate produced objective responses in 6/22 patients, including 4 complete responses (CRs) across several tumor types (e.g., melanoma, angiosarcoma, atypical fibroxanthoma). Durable local control was documented in some cases (e.g., CR maintained beyond 25–30 months in select patients). (thelancet.com)
No Phase II efficacy readouts in humans have been peer‑reviewed as of October 7, 2025; trials are ongoing in head and neck cancer and soft tissue sarcoma. (clinconnect.io)
Note: Robust efficacy in dogs with mast cell tumors has been shown in a randomized controlled study (single‑dose CR 75% at Day 28; 88% after retreatment), but veterinary results may not translate directly to human cancers. (pubmed.ncbi.nlm.nih.gov)
In the Phase I study, the maximum tolerated dose was not reached (up to 3.6 mg/m²). Adverse events were mostly localized injection‑site effects consistent with the mechanism; there was one dose‑limiting toxicity (upper airway obstruction), two serious adverse events (upper airway obstruction and septicemia), and no treatment‑related deaths reported. (thelancet.com)
Limitations: Human data are currently limited to a small Phase I study with heterogeneous tumor types; ongoing Phase II trials should clarify efficacy and safety in defined indications. (thelancet.com)
Last updated: Oct 2025
Goal: Evaluate preliminary efficacy of intratumoural tigilanol tiglate for local ablation of soft tissue sarcoma (STS) lesions in the extremities and body wall, and, in a later stage, its effect on overall disease control beyond injected lesions. Key secondary aims are to characterize safety/tolerability and systemic pharmacokinetics after intratumoural dosing, with exploratory assessments of tumor microenvironment, immune activation, local recurrence, and metabolite profiling.
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 lesion amenable to palpation- or ultrasound-guided intratumoural injection. ECOG performance status ≤2 and adequate organ function are required. Key exclusions include lesions abutting major vessels, recent systemic anticancer therapy or investigational agents without appropriate washout, recent major surgery, active brain metastases or carcinomatous meningitis, significant bleeding diathesis or therapeutic warfarin use, and severe hypersensitivity to study drug.
Design: Phase IIa, single-arm, open-label study with staged objectives. Approximately 40 participants will receive protocol-defined intratumoural treatment and undergo efficacy, safety, PK, and translational assessments. No randomization or comparator.
Treatments: Single or multiple intratumoural injections of tigilanol tiglate up to a fixed dose of 3.6 mg/m2 per treatment. Tigilanol tiglate (EBC-46) is a plant-derived small molecule and a potent modulator of protein kinase C that induces rapid vascular disruption and hemorrhagic necrosis leading to local tumor ablation, with signals of immunogenic cell death and immune infiltration. First-in-human data across refractory injectable solid tumors showed responses, including complete responses, with primarily local, mechanism-consistent adverse events; dose-limiting toxicity was uncommon and the maximum tolerated dose was not reached up to 3.6 mg/m2. Company-reported Stage 1 data in STS suggest high rates of ablation of injected lesions, with generally local and manageable toxicity; peer-reviewed confirmation is pending.
Outcomes: Primary: proportion of participants achieving partial or complete ablation of injected tumors/segments within 6 months; in Stage 2, objective response rate by RECIST v1.1 at 3 and 6 months to evaluate overall disease control. Secondary: incidence of adverse events and serious adverse events over 6 months; systemic exposure by pharmacokinetics up to 24 hours after first injection. Exploratory: changes in tumor microenvironment and immune cell infiltration in injected and/or non-injected tumors, peripheral blood mononuclear cell analyses, local recurrence at injection sites 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, and necrosis requiring wound care and follow-up visits. Safety monitoring includes regular clinical assessments and laboratory tests. Pharmacokinetic sampling within the first 24 hours after the initial dose entails multiple blood draws and likely at least one prolonged on-site visit. Imaging at 3 and 6 months and protocol tumor biopsies for microenvironment and immune analyses (including potential biopsies of injected and non-injected lesions) add procedural burden and travel. Overall intensity is higher than standard surveillance due to procedures, PK draws, and translational biopsies, but treatment is localized and systemic therapy is not mandated within the study, which may mitigate systemic toxicity-related burden.
Last updated: Oct 2025
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