Canine lymphoma: new approaches to diagnostics and treatment
As the industry learns more about canine lymphoma, it’s clear that there is no one-size-fits-all approach to treatment
Content sponsored by Dechra Veterinary Products, Inc.
“[Phenotyping] provides me information when I see the case and allows me to make more streamlined consult with the [patients’] owners,” said Craig A. Clifford, DVM, MS, DACVIM (Oncology), at the recent Fetch dvm360 conference in Long Beach, California.1 As the veterinary industry shifts toward more individualized care approaches, canine lymphoma treatments and diagnostics are undergoing notable change. Because the different types of lymphoma have varying survivability rates and respond to treatment differently, the veterinary world is starting to put more focus on diagnostics and phenotyping.
Phenotyping
Prior to planning treatment for canine lymphoma, a crucial step is to determine which classification the patient falls into; around one third of dogs are considered to have T-cell lymphoma, while around two thirds are considered to have B-cell lymphoma, and <2% of dogs are null cell.1
T-cell lymphoma typically comes with a worse prognosis, with only around 50% of T-cell patients responding to a single dose of doxorubicin compared to around 100% of B-cell patients.1 T-cell lymphoma is also more common in certain breeds like Boxers, Golden Retrievers, Australian Shepherds, Asian lap dogs, and Siberian Huskies. Breeds that more commonly have B-cell lymphoma include Cocker Spaniels and Dobermans.
Because the phenotype of lymphoma drastically affects prognosis, it’s imperative that practitioners consider a patient’s classification prior to speaking with pet parents to ensure there is transparency throughout that conversation. “Now that we’re treating [canine lymphoma phenotypes] differently, it is important to know.” said Clifford. “It certainly plays a role in prognosis and knowing this information is going to be important.”
Tests involving immunohistochemistry, immunocytochemistry, PARR, and flow cytometry can be performed to determine the patient’s phenotype and the resulting treatment protocol.
The need for updated protocol
“Many oncologists—most of us now, I would say—utilize different protocols, but for the longest time, we kept just giving [patients] cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP),” said Clifford. “It didn’t do as well, and we never changed what we were doing.”
Veterinarians turned to mustargen, vincristine, procarbazine and prednisone (MOPP), which led to improved remission periods compared to previous methods.1 “The overall survival was better than CHOP,” said Clifford. “The challenge with MOPP…because of the mustargen, you have to have a fume hood and closed chemotherapy system.” Additionally, because of the number of drugs involved in CHOP protocol, it’s considered intensive.
Laverdia®-CA1 (verdinexor tablets)
Later in his session, Clifford introduced a Laverdia®-CA1 (verdinexor tablets), a noveltreatment for all types of canine lymphoma. He explained that in a phase II study, the clinical benefit rate across both B-cell and T-cell, naïve, and relapse cases was 55%, with a median duration of benefit of 71 days (range 21-273 days).2 T-cell cases demonstrated clinical benefit in 71% of the dogs, whether naïve or relapse.2
Laverdia®-CA1 is conditionally approved, which means it has demonstrated a reasonable expectation of effectiveness for the treatment of canine lymphoma.Its use is limited to canine lymphoma while it is under conditional approval. Conditional approval allows commercial sales and marketing of the medication for a period of up to five years while the pivotal field efficacy study is being conducted.The results of the pivotal field efficacy study will be submitted to the FDA CVM for full approval.
The key takeaway Clifford presented to the audience is that Laverdia®-CA1 empowers general practitioners to take an active role in treating lymphoma patients, especially in cases where chemotherapy is not an option. When pet owners do not want to move forward with chemotherapy (or cannot due to financial constraints), Laverdia®-CA1 adds another tool to the toolbelt in treating canine lymphoma. As an oral drug administered by the pet owner at home, it is convenient as well.
“We know that for the clinicians in primary care practice, all they had before this was just prednisone to send the dog home with…” said Clifford. “So, to be able to offer a viable alternative, there’s no reason that primary care should not have this in their clinic.”
References
- Clifford C. What’s New in Canine Lymphoma? Presented at: Fetch dvm360® Conference; Long Beach, California. December 1-3, 2023.
- Sadowski AR, Gardner HL, Borgatti A, et al. Phase II study of the oral selective inhibitor of nuclear export (SINE) KPT-335 (verdinexor) in dogs with lymphoma. BMC Vet Res. 2018;14(1):250. Published 2018 Aug 24. doi:10.1186/s12917-018-1587-9
