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1350 Section 11 Oncologic Disease

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Canine Human
Differentiation Differentiation
Antigen Antigen

Immunity

Figure 153.1 Xenogeneic DNA immunization concept.

against a self‐tumor differentiation antigen, inducing Based on these studies, a multiinstitutional safety and
antibody, T cell, and antitumor responses. efficacy trial for USDA licensure in dogs with locally
Dogs with stage I–III locoregionally controlled malig- controlled stage II–III oral melanoma was initiated in
nant melanoma receiving the xenogeneic melanoma vac- 2006 with granting of conditional licensure in 2007,
cine have a Kaplan–Meier (KM) median survival time which represented the first US governmental regulatory
(MST) of >1075 days (median not yet reached) whereas agency approval of a vaccine to treat cancer across spe-
those dogs with stage I–III CMM without local tumor cies. Results of this licensure trial documented a statisti-
control given the same vaccination have a KM MST of cally significant improvement in survival for vaccinates
553 days. Dogs which received the xenogeneic mela- versus controls and full licensure for the HuTyr‐based
noma vaccine with stage I, II, III, and IV CMM had KM canine melanoma vaccine from USDA‐CVB was received
MSTs of >939 days (median not reached with 92.8% sur- in 2009 (Oncept TM , Merial, Inc.).
vival), >908 days (median not reached, 79% alive at one We have also investigated the efficacy of local tumor
year, 63% alive at two years), >1646 days (median not control and use of xenogeneic DNA vaccination in dogs
reached, 77%, 65%, 57% alive at one, two, and three with digit malignant melanoma. These investigations
years), and 239 days (40.5% and 18.8% alive at one and led to the development of a canine digit melanoma stag-
two years), respectively. ing scheme and found an improvement in survival com-
The results of these trials demonstrate that xenogeneic pared to historical outcomes with digit amputation
DNA vaccination in CMM: only. We also documented a decreased prognosis for
dogs with advanced stage disease and/or increased time
is safe from digit amputation to the start of vaccination.
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induces a specific antityrosinase immune response in Phillips and co‐investigators have also recently reported
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some dogs the use of Oncept in horses and determined the safety
potentially therapeutic in stage II–III locoregional and optimal use of the needle‐free delivery device into
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controlled disease the pectoral region in addition to documenting antigen‐
is an attractive candidate for further evaluation in an specific humoral responses after vaccination in all
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adjunct, minimal residual disease Phase II setting. horses.