RESUMO
BACKGROUND: KIT inhibitors, such as toceranib (TOC), and vinblastine (VBL) have not been prospectively compared in the treatment of macroscopic mast cell tumors (MCTs). Also, it is unknown whether VBL or TOC is superior for treating MCT without c-kit mutations. HYPOTHESIS/OBJECTIVES: To determine the value of KIT genotyping and localization in treatment decisions for dogs with macroscopic MCT. We hypothesized that c-kit mutated MCT would have a better response to TOC than VBL. ANIMALS: Eighty-eight client-owned dogs with macroscopic MCT. METHODS: Prospective, randomized trial. Dogs were randomized to TOC (2.75 mg/kg EOD) or VBL (2.5 mg/m2 weekly × 4 then EOW) by KIT localization and c-kit mutation status using an adaptive randomization scheme. RESULTS: Sixty dogs were allocated to TOC and 28 to VBL. Of the dogs receiving TOC, 20% had c-kit mutations, compared to 30% receiving VBL (P = 0.74). Overall response rates were 46% (TOC) and 30% (VBL) (odds ratio = 1.56 [0.62-3.92]; P = 0.28). Median progression-free survival (PFS) for dogs receiving VBL was 78 days (7-1,521) and for TOC 95.5 (14-990); hazard ratio (HR) = 1.34 [0.72-2.50]; P = 0.36. Median overall survival (OS) was 241.5 days (10-1,521) for the VBL group and 159 (20-990) for the TOC group; HR = 0.80 ([0.45-1.41]; P = 0.44). CONCLUSIONS AND CLINICAL IMPORTANCE: Neither PFS nor OS was significantly different between treatment groups. As the proportion of dogs with c-kit mutations was not different between treatment groups in this population of dogs, c-kit mutation status did not predict treatment response.
Assuntos
Doenças do Cão/tratamento farmacológico , Indóis/uso terapêutico , Mastocitose Cutânea/veterinária , Prednisona/uso terapêutico , Proteínas Proto-Oncogênicas c-kit/genética , Pirróis/uso terapêutico , Vimblastina/uso terapêutico , Animais , Antineoplásicos/uso terapêutico , Intervalo Livre de Doença , Cães , Feminino , Masculino , Mastocitose Cutânea/tratamento farmacológico , Mastocitose Cutânea/genética , Mutação , Estudos ProspectivosRESUMO
BACKGROUND: Standard of care treatment for multicentric lymphoma in dogs remains doxorubicin (DOX)-based combination chemotherapy, but owners may hesitate to commit the time and financial resources to complete such a protocol, typically requiring 12-16 visits. Rabacfosadine (RAB), a double prodrug of the nucleotide analog 9-(2-phosphonylmethoxyethyl) guanine, has substantial single-agent activity in dogs with lymphoma, and a different mechanism of action than DOX. HYPOTHESIS/OBJECTIVES: Our objective was to evaluate the efficacy and adverse effect (AE) profile of alternating doses of RAB and DOX in dogs with naïve multicentric lymphoma. ANIMALS: Fifty-four dogs with previously untreated lymphoma. METHODS: Open-label, multicenter prospective clinical trial. Dogs received alternating RAB (1.0 mg/kg IV weeks 0, 6, 12) and DOX (30 mg/m2 IV weeks 3, 9, 15). Dogs that achieved complete response (CR) were followed by monthly evaluations. Complete clinicopathological evaluation and assessment of remission and AEs were performed every 21 days. RESULTS: The overall response rate was 84% (68%; CR; 16%; partial response [PR)]. The overall median progression-free interval (PFI) was 194 days (216 for CR and 63 for PR). Most AEs were mild and self-limiting: gastrointestinal and hematologic AEs were most common. Thirteen dogs experienced dermatologic AEs, and 2 dogs developed grade 5 pulmonary fibrosis. CONCLUSIONS AND CLINICAL IMPORTANCE: Alternating RAB/DOX generally was well tolerated and resulted in PFIs comparable to standard DOX-based multi-agent protocols, with fewer treatment visits. Most adverse events were mild or moderate and self-limiting. Further studies are warranted to explore long-term outcome and other RAB chemotherapy combinations.
Assuntos
Alanina/análogos & derivados , Antineoplásicos/uso terapêutico , Doenças do Cão/tratamento farmacológico , Doxorrubicina/uso terapêutico , Linfoma/veterinária , Pró-Fármacos/uso terapêutico , Purinas/uso terapêutico , Alanina/administração & dosagem , Alanina/efeitos adversos , Alanina/uso terapêutico , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Cães , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Esquema de Medicação/veterinária , Feminino , Linfoma/tratamento farmacológico , Masculino , Pró-Fármacos/administração & dosagem , Pró-Fármacos/efeitos adversos , Purinas/administração & dosagem , Purinas/efeitos adversos , Resultado do TratamentoRESUMO
BACKGROUND: Nonresectable mast cell tumors (MCT) in dogs remain a therapeutic challenge, and investigation of novel combination therapies is warranted. Intermittent administration of tyrosine kinase inhibitors (TKI) combined with cytotoxic chemotherapy may effectively chemosensitize canine MCT while decreasing cost and adverse effects associated with either agent administered as monotherapy. HYPOTHESIS/OBJECTIVES: The primary study objectives were to (1) identify the maximally tolerated dose (MTD), (2) determine the objective response rate (ORR) and (3) describe the adverse event profile of pulse-administered toceranib phosphate (TOC) combined with lomustine. ANIMALS: Forty-seven client-owned dogs with measurable MCT. METHODS: Toceranib phosphate was given PO on days 1, 3 and 5 of a 21-day cycle at a target dosage of 2.75 mg/kg. Lomustine was given PO on day 3 of each cycle at a starting dosage of 50 mg/m(2) . All dogs were concurrently treated with diphenhydramine, omeprazole, and prednisone. RESULTS: The MTD of lomustine was established at 50 mg/m(2) when combined with pulse-administered TOC; the dose-limiting toxicity was neutropenia. Forty-one dogs treated at the MTD were evaluable for outcome assessment. The ORR was 46% (4 complete response, 15 partial response) and the overall median progression-free survival (PFS) was 53 days (1 to >752 days). On multivariate analysis, variables significantly associated with improved PFS included response to treatment, absence of metastasis, and no previous chemotherapy. CONCLUSIONS AND CLINICAL IMPORTANCE: Combined treatment with pulse-administered TOC and lomustine generally is well tolerated and may be a reasonable treatment option for dogs with unresectable or metastatic MCT.
Assuntos
Antineoplásicos Alquilantes/uso terapêutico , Doenças do Cão/tratamento farmacológico , Indóis/uso terapêutico , Lomustina/uso terapêutico , Mastocitose/veterinária , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirróis/uso terapêutico , Animais , Antineoplásicos Alquilantes/administração & dosagem , Doenças do Cão/genética , Cães , Esquema de Medicação/veterinária , Quimioterapia Combinada , Feminino , Indóis/administração & dosagem , Lomustina/administração & dosagem , Masculino , Mastocitose/tratamento farmacológico , Mastocitose/genética , Reação em Cadeia da Polimerase/veterinária , Proteínas Proto-Oncogênicas c-kit/genética , Pirróis/administração & dosagemRESUMO
BACKGROUND: Canine cutaneous T-cell lymphoma (CTCL) is an uncommon disease for which efficacious therapies are lacking. The novel anticancer nucleotide prodrug VDC-1101 (formerly known as GS-9219) has shown efficacy in dogs with multicentric lymphoma. One of the observed adverse effects with this drug was a skin change characterized by hair loss, erythema, and pruritus, implying delivery of VDC-1101 to the skin. HYPOTHESIS/OBJECTIVES: The primary study objective was to identify the objective response rate (ORR) to VDC-1101 in canine CTCL; secondary objectives included characterization of progression-free survival (PFS) and adverse events (AEs). ANIMALS: Twelve dogs with chemotherapy-naïve or relapsed, histologically and immunohistochemically confirmed CTCL. METHODS: Dogs received VDC-1101 as a 30-minute IV infusion once every 21 days. Prednisone (1 mg/kg PO q48h) was administered concurrently. RESULTS: In 11 evaluable patients, responses included 1 complete response (CR), 4 partial responses (PR), 2 stable disease (SD), and 4 progressive disease for an ORR of 45% and biologic response rate (CR/PR/SD) of 64%. The median PFS was 37.5 days (26 to >399 days), which includes 1 durable and ongoing CR (>1 year). Gastrointestinal and hematologic AEs were mild; no dogs developed grade 3 or 4 AEs. Three dogs developed dermatopathies and 1 of these dogs was removed from the study as a result of this AE. CONCLUSIONS AND CLINICAL IMPORTANCE: VDC-1101 has activity against canine CTCL and could provide another treatment option in a disease process with a poor prognosis.