Monoclonal Antibody Treatment in Dogs

Lili Duda, VMD
Last Modified: August 22, 2007

Dear OncoLink "Ask the Experts,"
Please tell me about the use of Monoclonal Antibody Treatment for treating lymphoma in dogs once remission is achieved.

Lili Duda, VMD, Editor of the OncoLink Veterinary Oncology Section, responds:

Monoclonal antibody (MAb) therapy (drug name CL/MAb 231, Synbiotics Corporation) is licensed for the treatment of canine lymphoma, and has been used for about 10 years. The success rate is comparable to conventional chemotherapy protocols. Although there are several theoretical advantages to the use of MAb, it has not become a standard therapeutic option in canine lymphoma for a variety of reasons. However, it is a reasonable treatment option if it is available through your veterinarian or veterinary oncologist.

The typical protocol used starts with two "cycles" of standard chemotherapy. If the dog is in complete remission following chemotherapy (meaning that there is no detectable evidence of lymphoma), the dog is given a three week rest to allow the immune system to recover. If the dog continues to remain in remission, monoclonal antibodies are administered over one week. The dog then receives no further treatment until relapse of the lymphoma occurs.

At the time of relapse, the above protocol can be repeated if the dog goes into remission after another two "cycles" of standard chemotherapy. However, if the dog does not go into a complete second remission, monoclonal antibodies are not administered a second time, and other "rescue" chemotherapy protocols are used.

UPDATE: Canine Lymphoma Monoclonal Antibody (CL/MAb 231), a specific protein directed against canine lymphoma cells, was used following a conventional chemotherapy regimen in an effort to prolong duration of remission (also known as "disease-free interval"). This product was produced by a company called Synbiotics, but has not been commercially available for many years.

You can learn more about veterinary clinical trials at the Veterinary Cancer Society's website.