Mechlorethamine, vincristine, melphalan and prednisone (MOMP) for the treatment of relapsed lymphoma in dogs

Evaluation of clinical response and prognostic factors in canine multicentric lymphoma treated with first rescue therapy

Despite an initial strong response in most dogs with multicentric lymphoma treated with chemotherapy, relapse remains common. There is no clearly superior first rescue protocol described either for resistant or relapsed canine multicentric lymphoma. The objectives of this study were to assess clinical response and outcomes for canine multicentric lymphoma treated with first rescue protocols. The secondary objective was to assess prognostic variables for dogs undergoing these protocols. This was a bi-institutional retrospective cohort study. Two hundred and sixty-five dogs were treated with first rescue chemotherapy, including anthracycline-based combination chemotherapy (CHOP-like, n = 50), nitrosourea alkylating agent-rich chemotherapy (n = 45), anthracycline-based or related compound chemotherapy (n = 34), or nitrosourea single-agent chemotherapy (n = 136). The overall median progression free survival time of first rescue protocol was 56.0 days (0-455 days). Important prognostic factors identified for first rescue protocol included the attainment of a complete response to the first rescue chemotherapy (p < .001), the use of a CHOP-like first rescue protocol (p = .009), duration of first remission (HR 0.997, p = .028), and if prednisolone was included in the first rescue protocol (HR 0.41, p = .003). Adverse events (AE) were common, with 81.1% of dogs experiencing at least one AE during first rescue chemotherapy. This study highlights the need for improved first rescue therapies to provide durable remission in canine resistant or relapsed lymphoma.

Novel Treatments for Lymphoma

Lymphoma is a common disease in companion animals. While conventional chemotherapy has the potential to induce remission and prolong life, relapse is common and novel treatments are needed to improve outcome. This review discusses recent modifications/adjustments to conventional standard of care therapy for canine and feline lymphoma, options for treatment or relapsed/refractory disease, and cutting-edge immunotherapy and small molecule-based approaches that are in varying stages of regulatory approval.

Retrospective Evaluation of Melphalan, Vincristine, and Cytarabine Chemotherapy for the Treatment of Relapsed Canine Lymphoma

Dogs diagnosed with multicentric lymphoma often relapse following induction therapy within the first year of treatment. The primary aim of this study was to evaluate the tolerability of a novel drug combination using melphalan, vincristine, and cytarabine (MOC) for the treatment of relapsed lymphoma. On day 1, dogs were treated with vincristine (0.5-0.6 mg/m2 IV) and cytarabine (300 mg/m2 IV over 4-6 hr or subcutaneously over 2 days). On day 7, dogs were treated with melphalan (20 mg/m2per os). This 2 wk protocol was repeated for at least three cycles or until treatment failure. Twenty-six dogs were treated with MOC and met the inclusion criteria. Twenty-three dogs had toxicity data, and all experienced adverse events with the majority graded as mild. The overall response rate was 38%, which included 19% of dogs who achieved a complete response. The median progression-free survival was 29 days (range 1-280 days). The overall clinical benefit was 65% for a median of 37 days (range 33-280 days). MOC is a safe treatment option for relapsed lymphoma in dogs.

Review of Canine Lymphoma Treated with Chemotherapy-Outcomes and Prognostic Factors

While canine lymphoma is a relatively common and important disease seen by veterinarians, there are limited comprehensive reviews of the literature regarding the remission and survival times following chemotherapy, and the associated prognostic factors. This comprehensive thematic review covers the available veterinary literature covering treatment outcomes and identified prognostic factors. A lack of standardised approaches to evaluate and report the outcomes was identified, including factors that would alter the duration of responses by weeks, or occasionally months. After publication of the suggested reporting criteria, this has improved but is still not uniformly applied. The prognostic factors included for evaluation varied from as few as three to seventeen, with over 50 studies using only univariate analysis. Individual papers reported much longer outcomes than others, but assessing the outcomes overall, there has been minimal change over the last 40 years. This supports the belief that novel approaches for lymphoma therapy will be required to substantively improve outcomes.

Immunotherapeutic Strategies for Canine Lymphoma: Changing the Odds Against Non-Hodgkin Lymphoma

The new era of immune-oncology has brought complexities and challenges that emphasize the need to identify new strategies and models to develop successful and cost-effective therapies. The inclusion of a canine model in the drug development of cancer immunotherapies is being widely recognized as a valid solution to overcome several hurdles associated with conventional preclinical models. Driven by the success of immunotherapies in the treatment of human non-Hodgkin lymphoma (NHL) and by the remarkable similarities of canine NHL to its human counterpart, canine NHL has been one of the main focus of comparative research. Under the present review, we summarize a general overview of the challenges and prospects of today's cancer immunotherapies and the role that comparative medicine might play in solving the limitations brought by this rapidly expanding field. The state of art of both human and canine NHL and the rationale behind the use of the canine model to bridge the translational gap between murine preclinical studies and human clinical trials are addressed. Finally, a review of currently available immunotherapies for canine NHL is described, highlighting the potential of these therapeutic options.

Mechlorethamine, vincristine, melphalan and prednisolone rescue chemotherapy protocol for resistant feline lymphoma

Objectives The goals of this retrospective study were to evaluate the use of mechlorethamine, vincristine, melphalan and prednisolone (MOMP) chemotherapy for rescue of feline lymphoma, to describe the protocol's toxicity and to determine prognostic indicators for progression-free survival. Methods The medical records of 12 cats treated with MOMP chemotherapy at the University of Tennessee Veterinary Medical Center between 2007 and 2017 were evaluated. Parameters assessed included lymphoma cell size, anatomical location, number of previous chemotherapy drugs and number of previous rescue protocols received. Chemotherapy-related toxicity was also described. Results Seven of 12 cats responded to this rescue protocol. Three cats experienced complete response and four cats achieved partial response for a median duration of 39 days (range 14-345 days). Cats that achieved complete response had a significantly longer median progression-free survival than cats that did not respond to treatment. Five of 12 cats developed hematologic toxicity (neutropenia) and one cat developed gastrointestinal toxicity. Toxicity was mild in most cases; no cats needed to be hospitalized. Neutropenia was associated with increased progression-free survival. Conclusions and relevance MOMP is a safe and effective rescue chemotherapy protocol for cats with relapsing and refractory lymphoma.

Evaluation of a multi-agent chemotherapy protocol combining lomustine, procarbazine and prednisolone (LPP) for the treatment of relapsed canine non-Hodgkin high-grade lymphomas

The standard of care treatment for canine lymphoma is multi-agent chemotherapy containing prednisolone, cyclophosphamide, vincristine and an anthracycline such as doxorubicin (CHOP) or epirubicin (CEOP). Lomustine, vincristine, procarbazine, and prednisone (LOPP) has been evaluated as a rescue, with encouraging results; however, resistance to vincristine is likely in patients relapsing on CHOP/CEOP, and this agent may enhance LOPP toxicity without improving efficacy. The aim of this study was to evaluate responses to a modified-LOPP protocol that does not include vincristine (LPP) and is administered on a 21-day cycle. Medical records of dogs with high-grade multicentric lymphoma from 2012 to 2017 were reviewed. Dogs with relapsed lymphoma that received LPP as a rescue protocol were enrolled. Response, time from initiation to discontinuation (TTD) and toxicity of LPP were assessed. Forty-one dogs were included. Twenty-five dogs (61%) responded to LPP including 12 complete responses (CR) and 13 partial responses (PR). Responders had a significantly longer TTD (P < .001) compared to non-responders with 84 days for CR and 58 days for PR. Neutropenia was documented in 20 dogs (57%): 12 grade I to II, 8 grade III to IV. Thrombocytopenia was infrequent (20%): 5 grade I to II, 2 grade III to IV. Twelve dogs developed gastrointestinal toxicity (30%): 10 grade I to II and 2 grade III. Nineteen dogs had elevated ALT (59%): 9 grade I to II, 10 grade III to IV. Treatment was discontinued due to toxicity in 8 dogs (19%). The LPP protocol shows acceptable efficacy and toxicity-profile and minimizes in-hospital procedures.

Oral melphalan for the treatment of relapsed canine lymphoma

Oral melphalan has been included in multi-agent rescue protocols for canine lymphoma but its activity as a single-agent for this purpose has not been established. Inexpensive cost, ease of administration and tolerability make oral melphalan an attractive candidate for single-agent rescue therapy of canine lymphoma. Retrospective evaluation of 19 cases of relapsed canine lymphoma treated with oral melphalan was performed. Melphalan was primarily administered (n = 16) via a high dose protocol (HDM) with a median dosage of 19.4 mg m^-2 . Fifteen dogs (78.9%) were treated concurrently with corticosteroids. Response evaluation was possible for all dogs with a calculated overall clinical benefit (partial response [PR] + stable disease [SD]) of 31.6% (PR 3/19; SD 3/19). Times to progression following melphalan (TTP-M) were 14, 24 and 34 days for responders and 20, 28 and 103 days for dogs experiencing SD. Twelve of 17 dogs evaluable for toxicity experienced an adverse event (AE) with only 3 dogs experiencing a grade III or higher AE. Haematologic toxicity was common (11/17) while gastrointestinal toxicity was rare (1/17). Although treatment resulted in limited clinical benefit and non-durable responses, oral melphalan was well-tolerated and may be a reasonable rescue option in cases where minimal effective agents remain.