A New Era in Dog Lymphoma Treatment: Tanovea and Laverdia Redefine Canine Cancer Care

Dog lymphoma is one of the most common and aggressive cancers in dogs, long managed with human‑labeled chemotherapies used off‑label. That changed with Tanovea (rabacfosadine), the first FDA‑approved therapy specifically indicated for canine lymphoma and a landmark advance in veterinary oncology. Developed by VetDC and later brought to market by Elanco, Tanovea provides a targeted, evidence‑based option for this disease. In 2026 the FDA granted full approval to Laverdia (verdinexor tablets) as the first oral treatment for canine lymphoma, further expanding the armamentarium.

Together, Tanovea and Laverdia represent a shift toward a more sophisticated, human‑style approach combining injectable and oral, mechanism‑specific agents tailored to disease biology, prior therapy, and owner preferences. This article outlines the background of canine lymphoma, the pharmacology and clinical profile of Tanovea, its role in current treatment algorithms, and how Laverdia is reshaping veterinary oncology practice.

A New Era in Canine Lymphoma Treatment

Tanovea (rabacfosadine), developed by the biotechnology company VetDC, is the first drug specifically approved by the U.S. Food and Drug Administration (FDA) for the treatment of canine lymphoma, representing a landmark advance in veterinary oncology. Initially granted conditional approval in December 2016 under the FDA’s Minor Use and Minor Species (MUMS) pathway, Tanovea later earned full approval in July 2021 after additional clinical studies demonstrated robust evidence of efficacy and safety in dogs with lymphoma.

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As a purine nucleoside analog, Tanovea works by inhibiting DNA synthesis in rapidly dividing lymphoma cells, offering a mechanism distinct from many conventional chemotherapies used off‑label in dogs. Its approval addresses a long‑standing unmet need for a labeled, evidence‑based therapy for this common and often aggressive cancer, which affects tens of thousands of dogs in the United States each year. By establishing a clear indication, dosing regimen, and safety profile, Tanovea not only expands treatment options for veterinarians and pet owners but also sets a precedent for more rigorous, targeted drug development and regulatory approval in companion‑animal oncology.

The Burden of Canine Lymphoma

Canine lymphoma is one of the most common cancers in dogs and represents a major cause of morbidity and mortality in veterinary oncology. Epidemiologic data estimate that lymphoma occurs in roughly 20–24 cases per 100,000 dogs per year, with incidence rising sharply in older animals; in dogs aged 10–11 years, the annual rate can exceed 80 cases per 100,000. Lymphoma accounts for up to 25% of all canine malignancies and about 83% of hematopoietic (blood‑cell) cancers in dogs, making it a leading indication for chemotherapy in small‑animal practice.

Clinically, canine lymphoma most often presents as multicentric disease, with rapidly enlarging peripheral lymph nodes, but it can also arise in the gastrointestinal tract, mediastinum, skin, or other extranodal sites. Immunophenotypically, the majority of cases are B‑cell lymphomas, which typically respond well to standard chemotherapy and carry a relatively favorable prognosis compared with T‑cell subtypes. Roughly two‑thirds of dogs with lymphoma have B‑cell disease, while about one‑third have T‑cell lymphoma, which tends to be more aggressive, less responsive to conventional drugs, and associated with poorer outcomes.

For decades, the standard of care for canine lymphoma has relied on CHOP‑like combination chemotherapy protocols multi‑drug regimens adapted from human medicine that typically include cyclophosphamide, doxorubicin (hydroxydaunorubicin), vincristine (Oncovin), and prednisone. These protocols can induce remission in more than 80% of dogs with B‑cell lymphoma, with median remission durations often in the range of 8–10 months or longer, depending on subtype, stage, and supportive care. In addition to CHOP, veterinarians have used single‑agent doxorubicin, mitoxantrone, and other human‑labeled chemotherapies, usually administered off‑label.

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Crucially, before the approval of Tanovea (rabacfosadine), there were no FDA‑approved drugs specifically indicated for canine lymphoma. Clinicians managed this common and often aggressive disease using human‑approved agents repurposed for dogs, without formal labeling, standardized canine‑specific dosing, or robust regulatory‑grade safety and efficacy data tailored to the species. The absence of a labeled, lymphoma‑specific therapy underscored a major gap in veterinary oncology and highlighted the need for more rigorous, evidence‑based drug development in companion‑animal cancer—setting the stage for Tanovea’s conditional and later full FDA approval as the first truly lymphoma‑specific drug for dogs.

How Tanovea Works: A Targeted Attack on Lymphoma

Tanovea (rabacfosadine) is a novel, intravenous chemotherapy agent developed specifically for the treatment of canine lymphoma. It is a purine nucleoside analog and a double prodrug of the active metabolite PMEG (9‑(2‑phosphonylmethoxyethyl) guanine), which preferentially accumulates in lymphoid and neoplastic lymphoid cells.

Once inside target cells, rabacfosadine is converted to PMEG diphosphate (PMEGpp), a structural analog of deoxyguanosine triphosphate (dGTP). PMEGpp acts as a competitive inhibitor of DNA polymerases α, δ, and ε, the enzymes responsible for DNA replication, thereby blocking DNA synthesis and causing S‑phase cell‑cycle arrest. This disruption triggers DNA‑damage signaling and activation of the intrinsic apoptotic pathway, leading to programmed cell death in rapidly dividing lymphoma cells. Because the prodrug is preferentially taken up and activated in lymphoid tissue, Tanovea has a relatively selective effect on lymphoma cells, which helps limit off‑target toxicity compared with many conventional chemotherapies.

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From Clinic to Canine: Dosing, Schedule, and Who Benefits

Tanovea is administered intravenously, typically as a single‑agent infusion repeated at three‑week intervals. The standard regimen is designed to balance efficacy with manageable toxicity, allowing for repeated cycles in both treatment‑naïve and relapsed dogs. Because it has a non‑overlapping mechanism of action with common agents like doxorubicin or vincristine, Tanovea can also be incorporated into salvage or combination protocols, particularly in dogs who have progressed on or become refractory to CHOP‑like regimens.

Tanovea is indicated for dogs with lymphoma, including both B‑cell and T‑cell subtypes, and has shown activity in relapsed or refractory disease as well as in previously untreated intermediate‑ to large‑cell lymphoma. It is especially valuable in dogs that have failed or cannot tolerate conventional chemotherapy, offering an FDA‑approved, evidence‑based option where previously only off‑label human drugs were available.

The Road to FDA Approval: Conditional and Full Approval

Tanovea (rabacfosadine) followed a structured, two‑stage FDA approval pathway under the Minor Use and Minor Species (MUMS) program, reflecting both its novelty and the relatively small but clinically important canine lymphoma population.

Tanovea received conditional approval from the FDA’s Center for Veterinary Medicine (CVM) in December 2016 as Tanovea‑CA1 (rabacfosadine for injection). At that stage, the agency determined that the drug was safe for its intended use and had a “reasonable expectation of effectiveness” in treating canine lymphoma, based on early clinical data and pharmacologic studies. Conditional approval allowed Tanovea to be marketed and used in practice while the sponsor (VetDC, later Elanco) continued to collect additional field‑study data to meet the higher “substantial evidence of effectiveness” standard required for full approval.

In July 2021, the FDA granted full approval for Tanovea as a treatment for lymphoma in dogs, making it the first animal drug for dogs to advance from conditional to full approval under the MUMS program. This decision was based on a well‑controlled, multicenter clinical field study involving 158 dogs with multicentric lymphoma, which demonstrated objective response rates, durable remissions, and a manageable toxicity profile. With full approval, Tanovea became one of the most comprehensively studied treatment options for canine lymphoma, providing veterinarians with a labeled, evidence‑based therapy rather than relying solely on off‑label human drugs.

Tanovea’s approval pathway is notable because it marked the first time a drug was specifically approved by the FDA for canine lymphoma, a disease that previously was managed almost entirely with human‑labeled chemotherapies used off‑label (e.g., doxorubicin, vincristine, cyclophosphamide). Before Tanovea, there were no FDA‑approved agents with a labeled indication for lymphoma in dogs, so dosing, safety, and efficacy relied on extrapolation from human oncology and small‑animal clinical experience. By establishing a clear indication, dosing schedule, and safety data package, Tanovea’s approval set a precedent for more rigorous, species‑specific drug development in veterinary oncology and signaled growing regulatory recognition of companion‑animal cancer as a distinct therapeutic area.

Where Tanovea Fits in the Treatment Plan

Tanovea is most commonly used after first‑line CHOP or as part of salvage regimens, rather than as the primary induction protocol. In dogs with relapsed B‑cell lymphoma who have failed one prior chemotherapy regimen, Tanovea has demonstrated an overall response rate of about 73% and a median progression‑free survival of roughly 151 days in responders, making it a compelling “first‑rescue” option.

Because it has a non‑overlapping mechanism of action with doxorubicin and vincristine, Tanovea can also be incorporated into combination or alternating regimens, such as alternating Tanovea with doxorubicin every three weeks, which in early studies produced remission rates and durations comparable to full CHOP‑like protocols. For owners who cannot commit to intensive, multi‑drug protocols, Tanovea may also be used as a single‑agent induction or maintenance option, typically given once every three weeks for up to five treatments.

Practical Considerations: Cost, Access, and Safety

Tanovea is generally more expensive than standard CHOP components, with reports of full courses (around six doses) costing several thousand dollars depending on the dog’s weight and the practice’s pricing structure. Because it is an intravenous chemotherapy drug with specific handling and safety requirements, it is typically administered in oncology referral centers or specialty hospitals, although some well‑equipped general‑practice clinics may offer it under strict protocols.

Supply has occasionally been constrained by manufacturing back orders, which can limit access and force clinicians to plan treatment timing carefully or consider alternative rescue options. Owners must also be counseled about short‑term immunosuppression and GI toxicity, and advised to take precautions (e.g., glove use, careful waste handling) for several days after each dose.

Looking Ahead: Companion Diagnostics and Precision Medicine

Currently, there are no FDA‑approved companion diagnostics or routine pharmacogenomic tests specifically for Tanovea in dogs, but research is beginning to explore predictive biomarkers for response and toxicity. Large‑scale genomic studies of canine lymphoma are mapping the mutational landscape of B‑ and T‑cell subtypes, which may eventually help identify tumors more likely to respond to DNA‑polymerase–targeting agents like rabacfosadine.Josephine Tsang, Nature. 12 June 2025.

Some academic centers are also evaluating Tanovea in lymphoid leukemia and multiple myeloma, using immunophenotyping and molecular profiling as part of clinical trial eligibility and response assessment, which could lay the groundwork for future response‑prediction tools analogous to those in human oncology. For now, however, treatment decisions remain largely based on histology, immunophenotype, prior therapy, and owner preferences, with Tanovea positioned as a targeted, evidence‑based rescue or alternative option in the broader canine lymphoma armamentarium.

Tanovea in Action: Efficacy and Safety in Practice

Tanovea (rabacfosadine) has demonstrated strong clinical activity in canine lymphoma, supported by a pivotal multicenter, randomized, double‑blinded, placebo‑controlled trial in 158 dogs with naïve or relapsed multicentric lymphoma. In that study, the best overall response rate in the Tanovea group was 73.2%, with more than half of dogs achieving complete remission and an additional one‑fifth showing partial response, compared with only about 5.6% overall response and no complete responses in the placebo arm. Median progression‑free survival was 82 days with Tanovea versus 21 days with placebo, and among responders, median progression‑free survival extended to roughly 151–172 days, with complete responders often exceeding 168 days.

Earlier single‑arm and retrospective reports describe response rates between 74% and 100% across both B‑cell and T‑cell lymphoma, including treatment‑naïve and relapsed cases, with response rates around 89% in naïve dogs and about 70% in relapsed dogs.Kristen M Weishaar, Multicenter Study J Vet Intern Med . 2022

Tanovea is generally well tolerated, with adverse events that are predominantly gastrointestinal and hematologic. The most common side effects include vomiting, diarrhea, and anorexia, which are typically low‑grade and manageable with supportive care. Transient neutropenia and lymphopenia occur due to the drug’s lymphoid‑targeting mechanism, but severe myelosuppression is uncommon. Other reported events include mild lethargy, weight loss, and occasional dermatologic or pulmonary findings, usually in a minority of dogs. Compared with CHOP‑type regimens, Tanovea avoids anthracycline‑related cardiotoxicity and has a different toxicity spectrum, with more emphasis on gastrointestinal effects and less cumulative organ damage, though serious adverse events still occur in about one‑fifth of treated dogs versus roughly one‑eighth in placebo.

Clinicians most often choose Tanovea in relapsed or refractory disease, where it serves as a first‑line rescue option for dogs that have failed or progressed on CHOP or similar protocols and where owners seek a labeled, evidence‑based alternative rather than additional off‑label chemotherapy. It is also useful in dogs who cannot tolerate standard protocols due to prior cardiotoxicity, severe gastrointestinal or hematologic toxicity, or other comorbidities, offering a single‑agent, three‑week regimen with a different safety profile.

For owners who prioritize treatment simplicity or fewer clinic visits, Tanovea can be used as induction or maintenance monotherapy, typically up to five doses at 21‑day intervals, balancing convenience with meaningful remission duration. Overall, Tanovea provides robust response rates and clinically relevant progression‑free survival in both naïve and relapsed canine lymphoma, with a manageable safety profile that makes it a compelling option for rescue therapy, anthracycline‑sparing strategies, and cases where treatment simplicity or reduced cumulative toxicity is a priority.

Laverdia: The First Oral Option for Canine Lymphoma

In 2026 the FDA granted full approval to Laverdia (verdinexor tablets) as the first oral treatment for canine lymphoma, marking a major expansion of the therapeutic armamentarium beyond intravenous agents. While Tanovea (rabacfosadine) remains the first overall FDA‑approved drug specifically for canine lymphoma, Laverdia is notable as the first oral option, allowing owners to administer treatment at home under veterinary supervision, typically twice weekly with at least 72 hours between doses and always with food to optimize absorption.

Laverdia works by inhibiting the nuclear export of tumor‑suppressor proteins, helping to restore their normal regulatory function in lymphoma cells and exerting selective cytotoxicity against malignant lymphocytes. In a clinical field study, dogs treated with verdinexor experienced a significantly longer time to disease progression compared with controls, supporting its role in both newly diagnosed and relapsed cases.

Together, Tanovea and Laverdia represent complementary advances: Tanovea as the pioneering injectable, DNA‑synthesis–targeting agent and Laverdia as a convenient, orally bioavailable, targeted therapy. This dual‑drug landscape moves veterinary lymphoma care closer to the human‑style paradigm of multiple, mechanism‑specific options—including IV and oral agents—that can be sequenced or combined based on subtype, prior therapy, and owner preferences, while still addressing the practical and economic constraints of companion‑animal oncology.

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Written by Aharon Tsaturyan, MD, Editor at OncoDaily Intelligence Unit