MOPP Chemotherapy for Treatment of Resistant Lymphoma in Dogs: A Retrospective Study of 117 Cases (1989–2000)

Abstract

The purpose of this retrospective study was to evaluate the efficacy and toxicity of the MOPP chemotherapy protocol (mechlorethamine, vincristine, procarbazine, and prednisone) as a rescue regimen in dogs with lymphoma. One hundred seventeen dogs that had resistance to previously administered chemotherapy were evaluated. Before treatment with MOPP, all dogs received a median of 6 chemotherapy drugs for a median duration of 213 days. Thirty-one percent (36 of 117) had a complete response (CR) to MOPP for a median of 63 days, and 34% (40 of 117) had a partial response (PR) for a median of 47 days. Sixteen percent (19 of 117) had stable disease (SD) for a median of 33 days. Predictors for response to MOPP were not identified. Gastrointestinal (GI) toxicity occurred in 28% (33 of 117) of the dogs, and 13% (15 dogs) required hospitalization. Five dogs developed septicemia, and 2 died as a result. MOPP was an effective treatment for dogs with resistant lymphoma and was well tolerated by the majority of affected dogs.Key words: Canine; Lymphosarcoma; Rescue. The MOPP chemotherapy protocol (mechlorethamine, a vincristine, b procarbazine, c and prednisone) was designed by DeVita et al in 1964 and was the 1st successful combined drug regimen for the treatment of humans with Hodgkin's and non-Hodgkin's lymphoma.1,2 Up to 85% of humans with advanced lymphoma and no previous chemotherapy exposure will achieve a complete remission when treated with MOPP. Approximately 70% of these remissions are durable, and disease-free long-term survivors have a high chance of being cured.2,3 Currently, several alternative chemotherapeutic regimens with superior results and often fewer toxicities exist for use in humans. 4,5 However, the development of MOPP was a milestone in oncology, demonstrating that advanced disease could be controlled.Durable 1st remissions are achievable in Ͼ80% of previously untreated dogs with lymphoma by combination chemotherapy protocols. 1st remissions last 4-14 months. [6][7][8][9][10][11][12][13][14] Rescue therapy attempts to establish remission in an animal with lymphoma that has failed 1st-line treatments or to reestablish remission in an animal that has relapsed after previous treatment. Unfortunately, durable remissions with rescue therapy are uncommon in dogs. Most rescue protocols Veterinary Medicine, Cornell University, Ithaca, NY 14853; e-mail: kmr32@cornell.edu. Submitted December 10, 2001; Revised February 19, 2002; Accepted March 19, 2002. Copyright ᭧ 2002 result in 30-50% response rates. 2nd remission durations using rescue protocols are also relatively short, generally 1-5 months. 15-18Although high response rates and prolonged remission durations are documented in humans with lymphoma treated with the MOPP chemotherapy, few reports describe the use of the MOPP protocol in dogs with lymphoma (Rosenberg and Matus, personal communication). The objectives of this retrospective study were to evaluate the toxicity and relative efficacy of the MOPP protocol when used as a rescue therapy in dogs wi...

Assessment of GS-9219 in a Pet Dog Model of Non-Hodgkin's Lymphoma

“…In particular, GS-9219 is clearly superior to the only other nucleotide analogues for which single-agent response data are available in pet dogs with non-Hodgkin's lymphoma; gemcitabine and cytosine arabinoside have published singleagent response rates of <7% (26,27). Additionally, the median FRD for dogs with relapsed non-Hodgkin's lymphoma observed following GS-9219 monotherapy is nearly double that reported previously in dogs with relapsed non-Hodgkin's lymphoma treated with other single-agent or standard multiagent chemotherapy protocols (16,(28)(29)(30)(31)(32)(33).…”

Efficacy of temozolomide or dacarbazine in combination with an anthracycline for rescue chemotherapy in dogs with lymphoma

“…These dogs would typically be expected to have shorter durations of response to rescue chemotherapy than the 3-to 5-month rescue remission durations expected for dogs that relapsed after completion of the induction chemotherapy protocol. 5,[20][21][22][23][24] In addition, because of the dose escalation aspect of the study, some dogs received relatively low doses of temozolomide. Although we did not find a significant relationship between temozolomide dose and duration of response to rescue chemotherapy, the statistical power for detecting such a relationship was low.…”

Asparaginase and MOPP Treatment of Dogs with Lymphoma

“…CR-2 refers to dogs that achieved a CR, relapsed between days 7 and 28, and subsequently responded to the next MOPP cycle. 16 Partial response (PR) was considered a 450% reduction but o100% reduction in measurable disease for 1 chemotherapy cycle, stable disease (SD) was considered o50% reduction or no change in size of all measurable disease for 1 chemotherapy cycle and progressive disease (PD) was considered a 425% increase in measurable disease or appearance of new neoplastic lesions. In addition, a dog was also considered to have PD if hypercalcemia recurred despite no change in gross disease in a dog that was previously in CR/PR/SD with normal plasma ionized calcium concentration.…”

“…3,4,[13][14][15] The mechlorethamine, vincristine, prednisone, procarbazine (MOPP) chemotherapy protocol (mechlorethamine, vincristine, procarbazine, and prednisone) is an effective protocol for dogs with lymphoma that failed to respond or became refractory to previous chemotherapy. 16 MOPP was originally used in people as a first line chemotherapy protocol for both Hodgkin's and nonHodgkin's lymphoma. 17,18 The protocol induces a complete remission in up to 85% of the humans treated.…”