Effects of indinavir in a preliminary phase I study on dogs with stage III slenic hemangiosarcoma.

HIV protease inhibitors are antiretroviral drugs able to prevent production of infectious particles. It has been shown that these protease inhibitors are able to inhibit cancer-promoted angiogenesis in patients affected by Kaposi's sarcoma. A preliminary phase I study on dogs with stage III splenic hemangiosarcoma was designed in order to evaluate the efficacy and toxicity of the protease inhibitor Indinavir to delay the progression of this advanced neoplasm. The results suggest that Indinavir is potentially beneficial in dogs affected by microscopic residual disease.