Murine syngeneic tumor models have revealed efficacious systemic antitumor responses following primary tumor in situ vaccination combined with targeted radionuclide therapy to secondary or metastatic ...tumors. Here we present studies on the safety and feasibility of this approach in a relevant translational companion dog model (n = 17 dogs) with advanced cancer.
The three component of the combination immuno-radiotherapy approach were employed either separately or in combination in companion dogs with advanced stage cancer. In situ vaccination was achieved through the administration of hypofractionated external beam radiotherapy and intratumoral hu14.18-IL2 fusion immunocytokine injections to the index tumor. In situ vaccination was subsequently combined with targeted radionuclide therapy using a theranostic pairing of IV 86Y-NM600 (for PET imaging and subject-specific dosimetry) and IV 90Y-NM600 (therapeutic radionuclide) prescribed to deliver an immunomodulatory 2 Gy dose to all metastatic sites in companion dogs with metastatic melanoma or osteosarcoma. In a subset of dogs, immunologic parameters preliminarily assessed.
The components of the immuno-radiotherapy combination were well tolerated either alone or in combination, resulting in only transient low grade (1 or 2) adverse events with no dose-limiting events observed. In subject-specific dosimetry analyses, we observed 86Y-NM600 tumor:bone marrow absorbed-dose differential uptakes ≥2 in 4 of 5 dogs receiving the combination, which allowed subsequent safe delivery of at least 2 Gy 90Y-NM600 TRT to tumors. NanoString gene expression profiling and immunohistochemistry from pre- and post-treatment biopsy specimens provide evidence of tumor microenvironment immunomodulation by 90Y-NM600 TRT.
The combination of external beam radiotherapy, intratumoral immunocytokine, and targeted radionuclide immuno-radiotherapy known to have activity against syngeneic melanoma in murine models is feasible and well tolerated in companion dogs with advanced stage, spontaneously arising melanoma or osteosarcoma and has immunomodulatory potential. Further studies evaluating the dose-dependent immunomodulatory effects of this immuno-radiotherapy combination are currently ongoing.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To evaluate the safety and efficacy of a vaccine containing plasmid DNA with an insert encoding human tyrosinase (ie, huTyr vaccine) as adjunctive treatment for oral malignant melanoma (MM) in dogs.
...111 dogs (58 prospectively enrolled in a multicenter clinical trial and 53 historical controls) with stage II or III oral MM (modified World Health Organization staging scale, I to IV) in which locoregional disease control was achieved.
58 dogs received an initial series of 4 injections of huTyr vaccine (102 μg of DNA/injection) administered transdermally by use of a needle-free IM vaccination device. Dogs were monitored for adverse reactions. Surviving dogs received booster injections at 6-month intervals thereafter. Survival time for vaccinates was compared with that of historical control dogs via Kaplan-Meier survival analysis for the outcome of death.
Kaplan-Meier analysis of survival time until death attributable to MM was determined to be significantly improved for dogs that received the huTyr vaccine, compared with that of historical controls. However, median survival time could not be determined for vaccinates because < 50% died of MM before the end of the observation period. No systemic reactions requiring veterinary intervention were associated with vaccination. Local reactions were primarily limited to acute wheal or hematoma formation, mild signs of pain at the injection site, and postvaccination bruising.
Results support the safety and efficacy of the huTyr DNA vaccine in dogs as adjunctive treatment for oral MM.
Response to DNA vaccination in dogs with oral MM may be useful in development of plasmid DNA vaccination protocols for human patients with similar disease.
Canine malignant melanoma provides a clinically relevant, large animal parallel patient population to study the GD2-reactive hu14.18-IL-2 immunocytokine as it is similar to human melanoma and ...expresses GD2. The objectives of this study were to evaluate safety, radiation fractionation, and identify informative biomarkers of an in-situ tumor vaccine involving local radiation therapy plus intratumoral-immunocytokine in melanoma tumor-bearing dogs. Twelve dogs (six dogs/arm) with locally advanced or metastatic melanoma were randomized to receive a single 8 Gy fraction (arm A) or three 8 Gy fractions over 1 week (arm B) to the primary site and regional lymph nodes (when clinically involved) with the single or last fraction 5 days before intratumoral-immunocytokine at 12 mg/m2 on 3 consecutive days. Serial tumor biopsies were obtained. All 12 dogs completed protocol treatment, and none experienced significant or unexpected adverse events. Evidence of antitumor activity includes one dog with a complete response at day 60, one dog with a partial response at day 60, and four dogs with mixed responses. Histology of serial biopsies shows a variably timed increase in intratumoral lymphocytic inflammation in some dogs. Canine NanoString analyses of serial biopsies identified changes in gene signatures of innate and adaptive cell types versus baseline. There were no significant differences in NanoString results between arm A and arm B. We conclude that intratumoral-immunocytokine in combination with local radiation therapy in canine melanoma is well tolerated and has antitumor activity with the potential to inform clinical development in melanoma patients.
Purpose: Genetically modified bacteria are a potentially powerful anticancer therapy due to their tumor targeting capacity, inherent
antitumor activity, and ability to serve as efficient vectors for ...gene delivery. This study sought to characterize the acute
and short-term toxicities and tumor colonization rates of a genetically modified Salmonella typhimurium (VNP20009) in dogs with spontaneous tumors, in the context of a phase I dose escalation trial.
Experimental Design: Forty-one pet dogs with a variety of malignant tumors received weekly or biweekly i.v. infusions of VNP20009, at doses ranging
from 1.5 × 10 5 to 1 × 10 8 cfu/kg. Vital signs and clinicopathologic variables were monitored regularly. Incisional biopsies were obtained before and
1 week following the first infusion for histopathology and bacterial culture.
Results: The nominal maximum tolerated dose was 3 × 10 7 cfu/kg, with refractory fever and vomiting being the dose-limiting toxicities. One treatment-related acute death occurred.
Bacteria were cultured from tumor tissue in 42% of cases. Thirty-five patients were evaluable for antitumor response. Major
antitumor responses were seen in 15% (4 complete response and 2 partial response), and disease stabilization for at least
6 weeks in 10%.
Conclusions: Administration of VNP20009 at doses with acceptable toxicity results in detectable bacterial colonization of tumor tissue
and significant antitumor activity in tumor-bearing dogs.
Preventative anti-cancer vaccination strategies have long been hampered by the challenge of targeting the diverse array of potential tumor antigens, with successes to date limited to cancers with ...viral etiologies. Identification and vaccination against frameshift neoantigens conserved across multiple species and tumor histologies is a potential cancer preventative strategy currently being investigated. Companion dogs spontaneously develop cancers at a similar incidence to those in people and are a complementary comparative patient population for the development of novel anti-cancer therapeutics. In addition to an intact immune system with tumors that arise in an autochthonous tumor microenvironment, dogs also have a shorter lifespan and temporally compressed tumor natural history as compared to humans, which allows for more rapid evaluation of safety, immunogenicity, and efficacy of cancer vaccination strategies. Here we describe the study protocol for the Vaccination Against Canine Cancer Study (VACCS), the largest interventional cancer clinical trial conducted in companion dogs to date. In addition to safety and immunogenicity, the primary endpoint of VACCS is the cumulative incidence (CI) of dogs developing malignant neoplasia of any type at the end of the study period. Secondary endpoints include changes in incidence of specific tumor types, survival times following neoplasia diagnosis, and all-cause mortality.
Purpose: To assess, in dogs with naturally occurring non-Hodgkin's lymphoma, pharmacokinetics, safety, and activity of GS-9219, a
prodrug of the nucleotide analogue 9-(2-phosphonylmethoxyethyl) ...guanine (PMEG), which delivers PMEG and its phosphorylated
metabolites to lymphoid cells with preferential cytotoxicity in cells with a high proliferation index such as lymphoid malignancies.
Experimental Design: To generate proof-of-concept, a phase I/II trial was conducted in pet dogs ( n = 38) with naturally occurring non-Hodgkin's lymphoma using different dose schedules of GS-9219. A subset of dogs was further
evaluated with 3′-deoxy-3′- 18 F-fluorothymidine positron emission tomography/computed tomography imaging before and after treatment.
Results: The prodrug had a short plasma half-life but yielded high and prolonged intracellular levels of the cytotoxic metabolite
PMEG diphosphate in peripheral blood mononuclear cells in the absence of detectable plasma PMEG. Dose-limiting toxicities
were generally manageable and reversible and included dermatopathy, neutropenia, and gastrointestinal signs. Antitumor responses
were observed in 79% of dogs and occurred in previously untreated dogs and dogs with chemotherapy-refractory non-Hodgkin's
lymphoma. The median remission durations observed compare favorably with other monotherapies in dogs with non-Hodgkin's lymphoma.
High 3′-deoxy-3′- 18 F-fluorothymidine uptake noted in lymphoid tissues before treatment decreased significantly after treatment ( P = 0.016).
Conclusions: GS-9219 was generally well tolerated and showed significant activity against spontaneous non-Hodgkin's lymphoma as modeled
in pet dogs and, as such, supports clinical evaluation in humans.
To characterize demographics and clinical signs and evaluate outcomes of treatments in cats with transitional cell carcinoma (TCC) of the urinary bladder.
Retrospective case series.
20 cats with TCC.
...Medical records of 20 cats with a bladder mass identified as a TCC that were examined at 2 veterinary institutions between 1990 and 2004 were evaluated. Signalment, treatments, and outcome were assessed.
Breeds included domestic short hair (n=14), long hair (2), and medium hair (2) cats, Siamese (1), and Abyssinian (1). All cats had been neutered at an early age (< 1 year old; 13 neutered males and 7 spayed females). The median age at diagnosis of TCC was 15.2 years. The trigone region was affected in 9 cats. Treatments included piroxicam administration, chemotherapy, or surgery as single interventions or in combination; 6 cats were not treated. At the time of diagnosis, 3 cats had pulmonary metastasis and 1 cat had metastasis to local lymph nodes. Median survival time for all 20 cats was 261 days. Nearly all deaths were attributable to progressive disease in the urinary tract. Five cats were lost to follow-up.
In cats, TCC of the urinary bladder appears to be a rare and aggressive disease that is more prevalent in male cats and frequently develops at sites distant from the trigone (unlike TCC in dogs). Nevertheless, initial clinical signs of TCC in cats in this study were similar to those reported for affected dogs.
Tumor necrosis factor-alpha (TNF) is a cytokine with potent antitumor activity; however, toxicity and short half-life have limited its utility. Polyethylene glycol (PEG) conjugation of ...biotherapeutics can decrease immunogenicity while improving bioactivity and half-life. PEGylation of TNF (PEG-TNF) significantly improved half-life and toxicity in mice, resulting in enhanced antitumor activity. This study characterized toxicity, biological effect, and antitumor activity of PEG-TNF in pet dogs with spontaneous cancer.
A phase I clinical trial enrolled dogs with measurable tumors in which standard therapy had failed or been declined. Physiologic, hematologic, and biochemical parameters were evaluated and tumor biopsies obtained serially. A subset of patients underwent serial dynamic contrast-enhanced magnetic resonance imaging.
Fifteen dogs were enrolled at doses from 20.0 to 30.0 microg/kg. Dose-limiting toxicity at 30.0 microg/kg consisted of vascular leak in one and hypotension/coagulopathy in one, establishing 26.7 microg/kg as the maximum tolerated dose. Mean elimination half-life was 15.3 +/- 4.9 hours. Biological activity (transient fever and leukopenia, increased tumor inflammation, and necrosis) was observed at all dosages. A significant increase in tumor blood flow was observed with dynamic contrast-enhanced magnetic resonance imaging. Minor/transient antitumor responses were observed in dogs with melanoma, squamous cell carcinoma, and mammary carcinoma, and a partial response was observed in a dog with angiosarcoma.
Using a clinically relevant, spontaneous large animal model of neoplasia, we have shown that biologically effective doses of PEG-TNF can be administered safely, and that PEG-TNF administration is associated with encouraging biological activity. These results justify the clinical evaluation of PEG-TNF in human cancer.
Multiple myeloma (MM) is an important human and canine cancer for which novel therapies remain necessary. VDC-1101 (formerly GS-9219), a novel double prodrug of the anti-proliferative nucleotide ...analog 9-(2-phosphonylmethoxyethyl) guanine (PMEG), possesses potent cytotoxic activity in vitro in human lymphoblasts and leukemia cell lines and in vivo in spontaneous canine lymphoma. Given the similarity in lineage between lymphoma and MM, we hypothesized that VDC-1101 would be active against MM.
We evaluated the in vitro antiproliferative effects of VDC-1101 against 3 human MM cell lines, and we performed a phase-II clinical trial in 14 dogs with spontaneous MM. Each dog was treated with a maximum of 6 doses of VDC-1101 monotherapy over 10-15 weeks. Dose-dependent antiproliferative activity was observed in all evaluated cell lines. Major antitumor responses (reduction of serum paraprotein and resolution of hypercalcemia, peripheral cytopenias and bone marrow plasmacytosis) were observed in 9 of 11 evaluable dogs for a median of 172 days, including a durable stringent complete response (>1047 days) in a dog with melphalan-refractory disease. 2 dogs were euthanized due to presumed pulmonary fibrosis; there were no other dose-limiting toxicities encountered.
In conclusion, VDC-1101 has significant anti-tumor activity at well-tolerated doses in spontaneous canine MM.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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