Toceranib phosphate in the management of canine insulinoma: A retrospective multicentre study of 30 cases (2009-2019)

Toceranib phosphate for treatment of hypercalcaemia of malignancy in two dogs with metastatic anal sac apocrine gland adenocarcinoma

CASE HISTORY

Two dogs, a 10-year-old male Siberian Husky cross and an 11-year-old male Cocker Spaniel were referred to a specialist veterinary hospital in Melbourne, Australia, for treatment of metastatic anal sac apocrine gland adenocarcinoma (ASAGAC) and concurrent hypercalcaemia (concentration of ionised calcium in serum > 1.5 mmol/L) of malignancy.

CLINICAL FINDINGS

Case 1 had a left anal sac mass approximately 5.5 cm in diameter, enlarged sub-lumbar lymph nodes palpable on rectal examination and a concentration of ionised calcium in serum of 2.45 (reference range 1.2-1.32) mmol/L. Soft tissue opacities suspicious for metastatic pulmonary nodules were observed on thoracic radiographs. CT of Case 2 revealed bilateral anal gland masses (left: 4.7 × 3.2 cm; right: 2.8 × 2.1 cm) and a large, ill-defined, intrapelvic mass (7.0 × 6.0 cm) encompassing the medial iliac and internal iliac lymph nodes and intimately associated with the aortic blood vessels. Cytology of fine-needle aspirates of the anal gland masses of both dogs was consistent with ASAGAC. The owners of both dogs declined surgical intervention and medical management with toceranib phosphate was initiated in the gross disease setting.

TREATMENT AND OUTCOME

Toceranib was initially administered at a dose of 2.5 mg/kg orally every other day in both dogs. Due to side effects from this medication, including hypocalcaemia, the dosing schedule was adjusted to Monday, Wednesday, and Friday with a dose range of 2.25-2.5 mg/kg. Both dogs remained alive, Case 1 after 519 days and Case 2 after 477 days, and were normocalcaemic at the time of writing. Both dogs experienced resolution of hypercalcaemia of malignancy while being treated with toceranib alone: hypercalcaemia was controlled for a total of 12 months in Case 1 and 15 months in Case 2. During treatment the anal sac mass of Case 1 remained approximately 5 cm in diameter and the sub-lumbar lymph node remained subjectively stable though no objective measurements were taken. Case 2's anal sac masses and intrapelvic lymph node mass subjectively reduced in size based on palpation.

CLINICAL RELEVANCE

This case series highlights two instances where toceranib monotherapy effectively managed hypercalcaemia of malignancy secondary to metastatic ASAGAC. Despite the presence of extensive macroscopic neoplastic disease, both dogs achieved durable control of hypercalcaemia with toceranib treatment.Abbreviations: ASAGAC: Anal sac apocrine gland adenocarcinoma; cRECIST: Canine response evaluation criteria in solid tumours; HHM: Humoral hypercalcaemia of malignancy; OST: Overall survival time; PFS: Progression-free survival; PTH: Parathyroid hormone; PTHrP: Parathyroid-related hormone peptide; RTK: Receptor tyrosine kinase; TKI: Tyrosine kinase inhibitor.

Toceranib phosphate for the treatment of dogs with high-risk adrenal gland tumours: 16 cases (2019-2023)

OBJECTIVES

The aims of this study were to evaluate the response rate, time to progression (TTP) and survival times of dogs with high-risk adrenal gland tumours (ATs) treated with toceranib phosphate, in both macroscopic and microscopic setting, and to report the adverse event (AE) profiles.

MATERIALS AND METHODS

Medical records of dogs diagnosed with a high-risk adrenocortical carcinoma (ACC) or phaeochromocytoma (PCC), treated with toceranib, were retrospectively reviewed. High-risk ATs were defined as inoperable and/or metastatic ATs or cortical tumours with high Utrecht score. Endpoints were response rate, TTP and overall progression-free survival time (PFST). Adverse events were reported according to VCOG-CTCAE.

RESULTS

Sixteen dogs were included: 10 diagnosed with PCC and six with ACC. All dogs with ACC received adjuvant toceranib due to a high Utrecht score or metastatic disease, while all dogs with PCC were treated with toceranib in the macroscopic setting. A clinical benefit was detected in 80% of dogs with PCC: four achieved stable disease for a median TTP of 176.5 days, and two achieved partial response for 182 and >100 days, respectively. Median PFST for dogs with PCC was 112 days. Among dogs with ACC, 3 (50%) progressed and were euthanized after 237, 364 and 273 days; the remaining 3 (50%) dogs were alive and disease free 382, 508 and 583 days after starting toceranib. Overall, toceranib was well-tolerated.

CLINICAL SIGNIFICANCE

Toceranib may offer clinical benefit and improve outcome in dogs with high-risk ATs in both the macroscopic and microscopic disease setting.

Determination of QLNC-3A6 in canine plasma by UHPLC-MS/MS and its application in pharmacokinetic studies

Multi-targeted tyrosine kinase inhibitor QLNC-3A6 Di-maleate, a structurally novel small molecule compound, has therapeutic efficacy for the treatment of canine cutaneous mast cell tumor (CMCT) caused by mutations in the c-Kit gene. Since pharmacokinetic (PK) information plays an important role in the development and application of new drugs, etc., a rapid, highly sensitive and selective UHPLC-MS/MS analytical method was developed and validated for the first time in this study for the quantitative detection of QLNC-3A6 in canine plasma. 100 µL of plasma was precipitated using 350 µL of acetonitrile, and Chromatographic separation was performed on a Phenomenex Kinetex C18 column (50 × 2.1 mm, 2.6 µm) at a flow rate of 0.4 mL/min, the mobile phases were set to 0.1% formic acid aqueous solution (A) and 0.1% formic acid acetonitrile (B). The calibration curve linear range was 0.5-100 ng/mL (R2>0.99). The intraday and interday precision values (relative standard deviation, RSD) were 2.06-13.57% and 6.90-9.14%. Intraday and interday accuracies were -10.73 to 9.54% and -3.86 to 0.70% respectively. The dilution integrity RSD value and stability RSD value were less than 3.77 and 7.45%, respectively. Subsequently, the pharmacokinetics were investigated in canine after oral administration of QLNC-3A6 Di-maleate tablets at a dose of 3 mg/kg BW using this method. The results showed that QLNC-3A6 showed fast absorption rate, rapid distribution and slow metabolic elimination in canine plasma. The results of the main PK parameters including λz, T1/2λz, Cmax, Tmax and AUClast were 0.07 ± 0.01/h, 11.00 ± 2.57 h, 50.88 ± 31.94 ng/mL, 9.08 ± 11.57 h and 836.48 ± 230.53 ng h/mL, respectively.

Retrospective Safety Evaluation of Combined Chlorambucil and Toceranib for the Treatment of Different Solid Tumours in Dogs

Chlorambucil is used in veterinary medicine for various cancers, while Toceranib, which was licenced for treating canine mast cell tumours, is now used against other solid tumours. Both drugs are generally safe, but their combined use has not been studied. This study aimed to investigate retrospectively the safety profile of the Chlorambucil-Toceranib combination against canine solid tumours. Thirty-eight dogs received this combination. Chlorambucil was administered at a median dose intensity of 15.1 mg/m2 per week, while Toceranib was given at the median dosage of 2.5 mg/kg on a Monday-Wednesday-Friday schedule. Dosages were individually adjusted according to commercially available tablet formulation, co-morbidities, and adverse events (AEs). The resulting clinical benefit rate (CBR) and overall response rate (ORR) were 55.3% and 10.5%, respectively. The median progressive free survival (PFS) and median survival time (MST) were 45.5 (12-537) days and 259 (42-1178) days, respectively. Gastrointestinal AEs occurred in 39.5% of cases (n = 15), 15.8% (n = 6) experienced UPC elevation, while hematological and biochemistry AEs affected 13.2% (n = 5) each. Most of these AEs were grades 1-2 (G1-2). None of the dogs interrupted treatment due to AEs, and the combination appeared safe. Larger prospective clinical trials are required to confirm our findings and investigate its efficacy across various cancers.

Percutaneous Ultrasound-Guided Radiofrequency Ablation as a Therapeutic Approach for the Management of Insulinomas and Associated Metastases in Dogs

Insulinomas are the most common neoplasms of the endocrine pancreas in dogs, leading to persistent hypoglycemia due to inappropriate insulin secretion. The standard treatment is surgical resection, but it carries significant risks, including pancreatitis and diabetes mellitus. This study investigates the efficacy and safety of percutaneous ultrasound-guided radiofrequency ablation (RFA) as an alternative to surgery. A total of 29 dogs diagnosed with insulinoma were treated with RFA, targeting both primary pancreatic tumors and metastases in regional lymph nodes or the liver. Blood glucose levels and tumor size were monitored before and after the procedure. RFA led to a significant increase in blood glucose levels and a reduction in tumor size in all patients, with minimal postoperative complications. The results suggest that RFA is a feasible and effective treatment option for insulinomas in dogs.

Immunohistochemistry Screening of Different Tyrosine Kinase Receptors in Canine Solid Tumors-Part I: Proposal of a Receptor Panel to Predict Therapies

The use of tyrosine kinase inhibitors (TKI) has been growing in veterinary oncology and in the past few years several TKI have been tested in dogs. However, different from human medicine, we lack strategies to select patients to be treated with each TKI. Therefore, this study aimed to screen different tumor subtypes regarding TKI target immunoexpression as a predictor strategy to personalize the canine cancer treatment. It included 18 prostatic carcinomas, 36 soft tissue sarcomas, 20 mammary gland tumors, 6 urothelial bladder carcinomas, and 7 tumors from the endocrine system. A total of 87 patients with paraffin blocks were used to perform immunohistochemistry (IHC) of human epidermal growth factor receptor 2 (HER-2), epidermal growth factor receptors 1 (EGFR1), vascular endothelial growth factor receptor 2 (VEGFR-2), platelet derived growth factor receptor beta (PDGFR-β), c-KIT, and extracellular signal-regulated kinase 1/2 (ERK1/ERK2). The immunohistochemical screening revealed a heterogeneous protein expression among histological types with mesenchymal tumors showing the lowest expression level and carcinomas the highest expression. We have demonstrated by IHC screening that HER2, EGFR1, VEGFR-2, PDGFR-β and ERK1/ERK2 are commonly overexpressed in dogs with different carcinomas, and KIT expression is considered relatively low in the analyzed samples.

Establishment and characterization of six canine hepatocellular carcinoma cell lines

Background

Hepatocellular carcinoma (HCC) is the most common malignant liver tumor in dogs. Although surgical resection is a major treatment option for canine HCC, there are no distinct strategies for unresectable tumor subtypes or adjuvant chemotherapy for tumors with positive margins. We aimed to establish and characterize novel HCC cell lines from canine patients.

Methods

The cellular morphology, general growth features and tumorigenicity of the established cell lines were evaluated. We also examined the sensitivity of the cell lines to multi-target tyrosine kinase inhibitors (TKIs).

Results

We established novel canine HCC cell lines from hepatic tumors and an additional kidney tumor of six canine patients. All cell lines showed colony forming and migratory ability. KU-cHCC-001 and KU-cHCC-001-Kidney, two cell lines exhibiting high epithelial-mesenchymal transition characteristics, showed tumorigenicity in xenografted mice. Toceranib, a veterinary TKI that targets vascular endothelial growth factor (VEGFR)/platelet-derived growth factor receptor (PDGFR)/c-kit, effectively inhibited the mitogen-activated protein kinase pathway and induced apoptosis. The established canine HCC cell lines showed greater sensitivity to toceranib than to sorafenib, a first-line treatment for human HCC targeting RAF/VEGFR/PDGFR. Sorafenib showed improved anti-tumor effects when co-treated with SCH772984, an extracellular signal-regulated kinase inhibitor.

Conclusion

Our study suggests new therapeutic strategies for canine HCC, and these cell lines are valuable research materials for understanding HCC tumor biology in both humans and dogs.

Laparoscopic partial pancreatectomy through an advanced lateral approach as treatment for insulinoma in dogs: a case series

A minimally invasive partial pancreatectomy was performed through a novel laparoscopic lateral flank approach in sternal-oblique recumbency in four clinical cases presented with an insulinoma. All four cases were female castrated dogs of older age (range 7-9 years) and different breeds (Wire haired dachshund, German shepherd, Jack Russel terrier, and Boxer), and all presented with episodic weakness, tremors, and/or seizures. The diagnosis was based on plasma glucose level below reference range with concomitant increased or normal insulin level. A laparoscopic approach was considered based on triple-phase contrast-enhanced computed tomography findings of the abdomen, revealing a pancreatic mass situated in the right pancreatic limb or left pancreatic limb without suspicion of metastasis. Laparoscopic procedures were performed without any major complications, and peri-operative glycemia increased to (supra-)normal levels in all cases. Histopathologic reports qualified the masses as neuroendocrine carcinomas, and in conjunction with the clinical picture, this neoplasia was further defined as insulinoma. Post-operative care in an intensive care unit was of short duration, and all animals were discharged being clinically normal and normoglycemic in between 1.5 and 2.5-day post-surgery. At short-term follow-up, no dogs showed clinical abnormalities, all recovered well from the surgical procedure, and blood glucose levels remained in the normal range. During long-term follow-up, 2 cases remained clinically normal at the time of writing, 564 and 1,211 days after surgery, 1 dog had recurrence of hypoglycemic episodes after 246 days and was euthanized after 673 days of surgery due to progressing disease, and 1 dog was euthanized after 1,028 days of surgery due to reasons unrelated to the insulinoma. Survival times ranged from 599 to 1,232 days after diagnosis. Considering the highly metastatic nature and difficulty of full laparoscopic staging of insulinoma patients, thorough pre-operative disease staging is warranted when considering a laparoscopic approach. This case series shows the feasibility of a novel laparoscopic flank approach for right and left partial pancreatectomy in dogs. Furthermore, proper case selection resulted in favorable outcome in these insulinoma patients.

Case report: Adjuvant therapy with toceranib for an incompletely resected renal cell carcinoma with suspected pulmonary metastasis in a dog

Primary renal neoplasia is rare in humans and dogs, with renal cell carcinoma (RCC) being the most common form of this cancer. As RCC is often diagnosed at an advanced stage, pulmonary metastasis is frequently observed. Tyrosine kinase inhibitors (TKIs) are the standard adjuvant treatments for metastatic RCC in humans. Similarly, in veterinary medicine, recent trials have employed TKIs for early-stage RCC patients who underwent complete surgical resection and showed no distant metastasis. However, the use of TKIs has not yet been reported commonly in cases of advanced RCC with metastasis. This case study presents the first clinical outcomes of TKI therapy in a dog with incompletely resected RCC and metastasis. A 5-year-old spayed female Chihuahua was referred to our hospital with a right renal mass and multiple pulmonary nodules suspected to be metastases. A portion of the renal mass was surgically removed, and histopathological examination revealed RCC with a high mitotic index. Adjuvant chemotherapy was administered, owing to incomplete resection with suspected pulmonary metastasis. An anticancer drug response prediction test was conducted using patient tissues. Since toceranib showed the most favorable responsiveness, it was selected as a therapeutic agent. Toceranib was orally administered at a dosage of 2.27 mg/kg every 48 h. Regular medical records for potential adverse effects were obtained, including systemic blood pressure, complete blood count, serum biochemical examination, and urinalysis. After 2 weeks of toceranib therapy, partial remission of pulmonary nodules continued for 2 months. The patient did not experience any adverse effects of the anticancer drug during the 4-month follow-up period. However, the patient died from an unidentified cause 6 months after the initial detection of the renal mass. This report describes the use of toceranib in dogs with RCC. In the present case, the patient showed an initial response to chemotherapy, and despite the presence of several poor prognostic factors, the dog survived beyond the expected 3-month lifespan to 6 months. Notably, no adverse events were observed during treatment.

Toceranib phosphate and firocoxib-mediated partial response in a dog with advanced intranasal sarcoma

A nine-year-old, castrated male mixed-breed dog presented with a three-month history of sneezing and stertorous breathing. Computed tomography revealed a soft tissue mass in the left nasal cavity with lysis of the cribriform plate. The mass was diagnosed as intranasal sarcoma based on histopathological analysis. The tumor cells were immunohistochemically positive for KIT and platelet-derived growth factor receptor α/β and negative for vascular endothelial growth factor receptor 2 and cyclooxygenase-2. Treatment with toceranib phosphate (TOC) and firocoxib reduced the tumor size, which was defined as partial response (PR). After PR induction, TOC alone mediated survival for 205 days. This case report suggests that the combination of TOC and possibly firocoxib may be a therapeutic option for canine intranasal sarcoma.