PDGFRβ (Ki = 5 nM); Flk-1 (Ki = 6 nM)

Fifty-seven dogs with a variety of cancers were enrolled; of these, 10 experienced progressive disease within the first 3 weeks. Measurable objective responses were observed in 16 dogs (including 6 complete responses), primarily in mast cell tumors (n = 11), mixed mammary carcinomas (n = 2), soft tissue sarcomas (n = 2), and multiple myeloma (n = 1), for an overall response rate of 28% (16 of 57). Stable disease of sufficient duration to be considered clinically meaningful (>10 weeks) was seen in an additional 15 dogs, for a resultant overall biological activity of 54% (31 of 57). Conclusions: This study provides the first evidence that p.o. administered kinase inhibitors can exhibit activity against a variety of spontaneous malignancies. Given the similarities of canine and human cancers with regard to tumor biology and the presence of analogous RTK dysregulation, it is likely that such agents will demonstrate comparable antineoplastic activity in people.[1]

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Administration of toceranib significantly decreased the number and percentage of Treg in the peripheral blood of dogs with cancer. Dogs receiving toceranib and CYC demonstrated a significant increase in serum concentrations of IFN-γ, which was inversely correlated with Treg numbers after 6 weeks of combination treatment. Conclusions: In addition to antitumor effects, these data support further investigations into the immunomodulatory effects of toceranib, administered alone or in combination with CYC in dogs with cancer.[3]

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The purpose of this study was to provide an initial assessment of the potential biologic activity of toceranib phosphate (Palladia®) in select solid tumours in dogs. Cases in which toceranib was used to treat dogs with apocrine gland anal sac adenocarcinoma (AGASACA), metastatic osteosarcoma (OSA), thyroid carcinoma, head and neck carcinoma and nasal carcinoma were included. Clinical benefit (CB) was observed in 63/85 (74%) dogs including 28/32 AGASACA [8 partial response (PR), 20 stable disease (SD)], 11/23 OSAs (1 PR and 10 SD), 12/15 thyroid carcinomas (4 PR and 8 SD), 7/8 head and neck carcinomas [1 complete response (CR), 5 PR and 1 SD] and 5/7 (1 CR and 4 SD) nasal carcinomas. For dogs experiencing CB, the median dose of toceranib was 2.8 mg kg(-1) , 36/63 (58.7%) were dosed on a Monday/Wednesday/Friday basis and 47/63 (74.6%) were treated 4 months or longer. Although these data provide preliminary evidence that toceranib exhibits CB in dogs with certain solid tumours, future prospective studies are necessary to define its true activity.[4]

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The amount and proportion of Treg in the peripheral blood of cancer-stricken dogs are dramatically reduced by the administration of toceranib phosphate (PHA 291639 phosphate). After receiving Toceranib phosphate (PHA 291639 phosphate) and cyclophosphamide (CYC) for six weeks, dogs show a significant increase in serum concentrations of IFN-γ, which is inversely correlated with Treg numbers[3].

For PDGFR and Flk-1/KDR, two members of the split kinase RTK family, toceranib (SU11654) selectively inhibits tyrosine kinase activity at 5 and 6 nM, respectively.
The canine C2 mastocytoma cell line contains an activating mutation in c-kit. Three Toceranib (TOC)-resistant C2 sublines (TR1, TR2, TR3) were established over seven months by growing cells in increasing concentrations of TOC. TOC inhibited KIT phosphorylation and cell proliferation in a dose-dependent manner in the treatment-naïve, parental C2 line (IC50 < 10 nM). In contrast, the three sublines were resistant to growth inhibition by TOC (IC50 > 1,000 nM) and phosphorylation of the KIT receptor was less inhibited compared to the TOC-sensitive C2 cells. Interestingly, sensitivity to three structurally distinct KIT RTK inhibitors was variable among the sublines, and all 3 sublines retained sensitivity to the cytotoxic agents vinblastine and lomustine. Sequencing of c-kit revealed secondary mutations in the juxtamembrane and tyrosine kinase domains of the resistant sublines. These included point mutations in TR1 (Q574R, M835T), TR2 (K724R), and TR3 (K580R, R584G, A620S). Additionally, chronic TOC exposure resulted in c-kit mRNA and KIT protein overexpression in the TOC-resistant sublines compared to the parental line. C2, TR1, TR2, and TR3 cells demonstrated minimal P-glycoprotein (P-gp) activity and no functional P-gp. Conclusions: This study demonstrates the development of an in vitro model of acquired resistance to targeted therapy in canine MCTs harboring a c-kit-activating mutation. This model may be used to investigate the molecular basis of and strategies to overcome TOC resistance [2].

The parental cell line is the canine C2 mastocytoma c-kit mutant cell line, which was obtained from spontaneously occurring cutaneous mast cell tumors (MCTs). In an incubator set at 37°C with 5% CO2 humidity and supplemented with 2 mM L-glutamine, 10% FBS, 100 g/mL Streptomycin, and 100 U/mL Penicillin, cells are grown in RPMI 1640 medium. C2 cells are grown in Toceranib concentrations ranging from 0.02 uM to 0.3 uM and increasing in increments of 0.025-0.05 uM to select C2 cells that are resistant to the drug. Over the course of seven months, three separate sublines that are resistant to toceranib are established[2].

Dogs: We utilize fifteen dogs owned by clients who have advanced tumors. Toceranib 2.75 mg/kg is given to dogs once every other day. An oral cyclophosphamide (CYC) dose of 15 mg/m² per day is added after two weeks. During the eight-week study period, flow cytometry is used to measure the number of Treg and lymphocyte subsets in blood. ELISA is utilized to quantify the levels of IFN-γ in serum.

[1]. Phase I dose-escalating study of SU11654, a small molecule receptor tyrosine kinase inhibitor, in dogs with spontaneous malignancies. Clin Cancer Res. 2003 Jul;9(7):2755-68.

[2]. Development of an in vitro model of acquired resistance to toceranib phosphate (Palladia?) in canine mast cell tumor. BMC Vet Res. 2014 May 6;10:105.

[3]. Clinical and immunomodulatory effects of toceranib combined with low-dose cyclophosphamide in dogs with cancer. J Vet Intern Med. 2012 Mar-Apr;26(2):355-62.

[4]. Preliminary evidence for biologic activity of toceranib phosphate (Palladia(®)) in solid tumours. Vet Comp Oncol. 2012;10(3):194-205.

See also: Toceranib (has active moiety).

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Drug Indication
Treatment of non-resectable Patnaik grade-II (intermediate-grade) or -III (high-grade), recurrent, cutaneous mast-cell tumours in dogs.

C22H28FN4O6P

494.46

494.173

C, 53.44; H, 5.71; F, 3.84; N, 11.33; O, 19.41; P, 6.26

874819-74-6

Toceranib;356068-94-5

16034840

Yellow to orange solid powder

2.758

6

8

5

34

713

0

P(=O)(O[H])(O[H])O[H].FC1C([H])=C([H])C2=C(C=1[H])/C(/C(N2[H])=O)=C(/[H])\C1=C(C([H])([H])[H])C(=C(C([H])([H])[H])N1[H])C(N([H])C([H])([H])C([H])([H])N1C([H])([H])C([H])([H])C([H])([H])C1([H])[H])=O

OORBROPMMRREB-HBPAQXCTSA-N

InChI=1S/C22H25FN4O2.H3O4P/c1-13-19(12-17-16-11-15(23)5-6-18(16)26-21(17)28)25-14(2)20(13)22(29)24-7-10-27-8-3-4-9-27;1-5(2,3)4/h5-6,11-12,25H,3-4,7-10H2,1-2H3,(H,24,29)(H,26,28);(H3,1,2,3,4)/b17-12-;

5-[(Z)-(5-fluoro-2-oxo-1H-indol-3-ylidene)methyl]-2,4-dimethyl-N-(2-pyrrolidin-1-ylethyl)-1H-pyrrole-3-carboxamide;phosphoric acid

SU-11654 phosphate; PHA291639 phosphate; SU 11654; PHA-291639 phosphate; SU11654; PHA 291639; Toceranib phosphate; Trade name: Palladia; PHA-291639E; Toceranib phosphate [USAN]; UNII-24F9PF7J3R; 24F9PF7J3R;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)