Tigilanol tiglate is a novel small molecule approved as a veterinary pharmaceutical in Europe for intratumoural treatment of non-metastatic, non-resectable canine mast cell tumors. The drug has a “tumor agnostic” mode of action associated with induction of an acute inflammatory response at the treatment site, immune cell recruitment, and disruption of tumor vasculature. Consequently, tigilanol tiglate has potential in treating a range of tumor types in humans and companion animals. However, it is likely that species-specific dosing and concomitant medication protocols will be required, especially to manage the drug-induced acute inflammatory response at the treatment site. As an initial step in evaluating tigilanol tiglate for treating cutaneous tumors in horses, we developed an equine-specific protocol involving (a) a 30% reduction in intratumoural tigilanol tiglate dose rate compared to that used in dogs, and (b) a regime of concomitant medications to manage the drug-induced acute inflammatory response at the treatment site. Here we report a preliminary study in two horses using the protocol to treat (i) an aggressive fibroblastic sarcoid that had recurred following surgical excision and (ii) a fast-growing peri-ocular squamous cell carcinoma. Clinical response to tigilanol tiglate treatment in these cases was similar to that observed in canine and human patients. Localized inflammation and bruising developed rapidly at the treatment site with haemorrhagic necrosis of the tumor evident within 24 h. Slough of necrotic tumor mass occurred within 6–16 days followed by infill of the tissue defect and full re-epithelialisation of the treatment site with good functional outcome. Drug-induced inflammation and oedema at the treatment site were well controlled by the concomitant medications and largely resolved within 3 days, while the wound that formed following tumor slough healed uneventfully. Both patients displayed minor lethargy during the first 36 h after treatment and localized treatment-site discomfort was apparent over the first 3–5 days. There was no evidence of recurrence of the sarcoid at 93 days, or the squamous cell carcinoma at 189 days. The results from this study support continued development and evaluation of tigilanol tiglate as a potential future treatment option for cutaneous equine tumors.

替加洛尔tiglate是一种新型小分子药物，在欧洲被批准为兽药用于肿瘤内治疗非转移性，不可切除的犬肥大细胞肿瘤。该药物具有“肿瘤不可知”作用模式，与在治疗部位诱发急性炎症反应，免疫细胞募集和肿瘤脉管系统破裂有关。因此，tigilanol tiglate在治疗人类和伴侣动物的多种肿瘤类型方面具有潜力。但是，可能需要特定物种的剂量和伴随的药物治疗方案，尤其是在治疗部位管理药物引起的急性炎症反应时。作为评估tigilanol tiglate治疗马匹皮肤肿瘤的第一步，我们开发了一种特定于马的方案，其中包括：（a）与犬相比，瘤内tigilanol tiglate的剂量率降低30％，以及（b）在治疗部位控制药物引起的急性炎症反应的同时用药方案。在这里，我们报告了使用该方案治疗（i）外科切除后复发的侵袭性纤维母细胞肉瘤和（ii）快速生长的眼周鳞状细胞癌的初步研究。在这些情况下，对tigilanol tiglate治疗的临床反应类似于在犬和人类患者中观察到的反应。在治疗部位局部发炎和瘀伤迅速发展，在24小时内明显出现肿瘤出血坏死。坏死性肿瘤块在6至16天之内出现淤泥，随后组织缺损被充满，治疗部位完全重新上皮化，功能良好。伴随药物的治疗，药物引起的炎症和水肿在治疗部位得到了很好的控制，并在3天内基本消退，而肿瘤脱落后形成的伤口愈合不佳。两名患者在治疗后的头36小时都表现出轻微的嗜睡，并且在头3-5天内明显出现局部的治疗部位不适。没有证据显示93天时肌瘤复发，或189天时鳞状细胞癌复发。这项研究的结果支持了tigilanol tiglate的持续开发和评估，将其作为皮肤马肿瘤的潜在未来治疗选择。