Assessment of GS-9219 in a pet dog model of non-Hodgkin's lymphoma.

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.

Continuous low-dose oral chemotherapy for adjuvant therapy of splenic hemangiosarcoma in dogs.

Background: Hemangiosarcoma (HSA) is a highly metastatic and often rapidly fatal tumor in dogs. At present, conventional adjuvant chemotherapy provides only a modest survival benefit for treated dogs. Continuous oral administration of low-dose chemotherapy (LDC) has been suggested as an alternative to conventional chemotherapy protocols.

Diagnosis of mediastinal masses in dogs by flow cytometry.

Background: Biopsy of mediastinal masses can be invasive, but the procedure may be necessary if cytology of a mass aspirate is inconclusive. The 2 most common mediastinal masses, lymphoma and thymoma, may both be comprised of small lymphocytes. We investigated the ability of flow cytometry to distinguish between these 2 neoplasms.