Evaluation of serum thymidine kinase 1 activity as a biomarker for treatment effectiveness and prediction of relapse in dogs with non-Hodgkin lymphoma

Immunotherapeutic efficacy of recombinant canine IL-15 as an adjunct to chemotherapy in canine lymphoma

Introduction

Canine lymphoma is a common hematopoietic malignancy with variable response to standard chemotherapy. Interleukin-15 (IL-15) is known to enhance cytotoxic lymphocyte activity, and this study aimed to evaluate the efficacy and safety of a recombinant canine IL-15 (rcIL-15) as an adjunct to chemotherapy in dogs with lymphoma.

Methods

A total of 61 dogs diagnosed with lymphoma were enrolled in a 12-week clinical study. The test group received rcIL-15 in combination with standard chemotherapy, while the control group received chemotherapy alone. Outcome measures included tumor response rates, tumor biomarker levels (TK-1, LDH, β2-microglobulin), quality of life (QOL) assessments, and adverse event monitoring.

Results

Of the 61 dogs enrolled, 37 completed the study. The test group demonstrated a higher overall response rate (complete + partial response: 77.8%) compared to the control group (57.9%). Disease progression was observed in 16.7% of dogs in the test group versus 31.6% in controls. Tumor biomarkers were significantly reduced in the test group: TK-1 at 8 weeks (p < 0.0001), LDH at 12 weeks (p = 0.005), and β2-microglobulin at both 8 and 12 weeks (p < 0.05). IFN-γ levels remained stable. QOL parameters, including appetite, activity, and happiness, showed significant improvement. Adverse events were mild, mostly gastrointestinal, and manageable.

Discussion

Adjunctive rcIL-15 therapy improved tumor response, reduced biomarker levels, and enhanced QOL with an acceptable safety profile. These findings support the potential of rcIL-15 as a safe and effective immunotherapeutic adjunct for canine lymphoma, meriting further investigation in larger-scale trials.

Diagnostic value of serum survivin, Ki-67 and thymidine kinase in dogs with nasal cavity disease

Background

The most common nasal cavity disease (ND) in dogs is the malignant nasal cavity tumor. Prognosis and survival after radiation therapy are reported to correlate with tumor size, and therefore indirectly with the time to diagnosis. Diagnosis of a nasal tumor requires imaging procedures under anesthesia. Thus, diagnostic serum markers are urgently needed for early detection and for therapeutic monitoring.

Materials and methods

This prospective, blinded study included dogs with nasal discharge that completed a comprehensive diagnostic workup for ND. Dogs were evaluated by blood testing and whole-body CT and those with concomitant diseases or with steroid pre-treatment were excluded. Serum survivin, Ki-67, and thymidine kinase 1 (TK1) concentrations were determined, and the survivin-lymphocyte ratio (SLR) calculated. Results were compared between groups of dogs with different NDs and to ten healthy controls.

Results

A total of 55 dogs were included, consisting of 25 with malignant ND (12 sarcomas, 13 carcinomas) and 30 with benign ND (7 benign tumors, 13 dogs with idiopathic rhinitis (IR), 10 others including dogs with dental diseases and sinonasal aspergillosis). Survivin and SLR were significantly increased in dogs with malignant ND and in subgroup comparison in sarcomas compared to controls. In addition, the SLR was significantly increased in carcinomas and IR compared to controls. In dogs with IR, no differences were observed in survivin concentrations or SLR based on microbiological or histopathological findings. Survivin concentrations or SLR in dogs with nasal tumors were not significantly different between T-categories. No significant differences were detected in TK1 concentrations among the groups, nor in Ki-67, except for significantly lower Ki-67 concentrations in benign tumors compared to carcinomas and the group others including, e.g., dental diseases.

Conclusion

Although not diagnostic for ND, increased survivin serum concentrations or SLR can be detected in dogs with malignant nasal tumors and IR. In malignant nasal tumors, survivin and SLR did not correlate with tumor size and therefore may be useful in the detection of even small nasal tumors. Therefore, in dogs with nasal tumors and IR, survivin and SLR could serve as a target for disease monitoring or as therapeutic target.

Serum thymidine kinase 1 activity as a prognostic biomarker in dogs with chemotherapy-treated diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is frequently treated with chemotherapy incorporating cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP), which induces remission in 80% to 95% of cases. However, not all dogs derive meaningful benefit from CHOP, and prognostic factors for dogs with DLBCL are poorly defined. Serum thymidine kinase 1 (TK1) activity, a marker of tumour cell proliferation, has shown promising initial results as a prognostic biomarker in dogs with multicentric lymphomas. The purpose of this study was to determine if baseline serum TK1 activity is associated with clinical outcome in dogs with CHOP-treated DLBCL. Baseline serum TK1 activity was measured in banked sera from 98 dogs with CHOP-treated DLBCL using a commercially available ELISA kit. Data on other potential prognostic factors were abstracted retrospectively from electronic medical records. Multivariable statistical methods were used to identify associations between TK1 and other potential prognostic factors with progression-free survival (PFS) and attainment of complete remission. TK1 activity at baseline was not associated with PFS (p = .299) or attainment of complete remission (p = .910) following CHOP chemotherapy. Of the other prognostic factors analysed, only purebred (vs. mixed breed) status (HR 8.81, 95% CI 1.68-46.30, p = .010), attainment of complete (vs. partial) remission (HR 0.09, 95% CI 0.02-0.49, p = .006), and baseline serum C-reactive protein concentration (HR 1.19, 95% CI 1.07-1.32, p = .001) were independently associated with PFS. Based on these findings, baseline serum TK1 activity does not appear to be a useful prognostic biomarker in dogs with CHOP-treated DLBCL.

Blood biomarkers for canine cancer, from human to veterinary oncology

In recent decades, interest in circulating tumour biomarkers is increasing both in human and veterinary oncology. An ideal tumour biomarker would allow early diagnosis of neoplasia, identify it specifically, accurately, establish a prognosis and predict its behaviour, especially regarding different therapeutic solutions. It would also allow to monitor its evolution over time and all this in a non-invasive and inexpensive way. Actually, no biomarkers meeting all of these criteria have been identified in veterinary medicine, particularly due to a lack of specificity of the main protein tumour biomarkers studied to date. However, great hope is currently placed in biomarkers grouped under the name of liquid biopsy, which could prove to be effective tools for common clinical use in the near future. This review gives an update on blood cancer biomarkers studied in dogs, such as ions, proteins, nucleic acids and also circulating cells, of which some might become more prominent in the coming years to help improve the management of animal care.

Circulating Endocannabinoids in Canine Multicentric Lymphoma Patients

The endocannabinoid system is increasingly being implicated in the pathogenesis and progression of various human cancers. Specifically, increased levels of 2-arachidonoylglycerol (2-AG) and oleoythanolamide (OEA) have been demonstrated in human diffuse large B-cell lymphoma (DLBCL) and chronic lymphocytic leukemia (CLL) patients, respectively. The objectives of this paper were to compare 2-AG, OEA, N-arachidonoylethanolamine (AEA), and palmitoylethanolamide (PEA) levels between dogs with multicentric lymphoma and healthy control dogs. In addition, evaluate 2-AG, OEA, AEA, and PEA levels as biomarkers for progression free interval (PFI) and overall survival time (OST) in the dogs with lymphoma. The study consisted of 26 dogs with multicentric B cell lymphoma, 14 dogs with multicentric T cell lymphoma, and 12 healthy control dogs. Serum 2-AG, OEA, AEA, and PEA levels were measured using liquid chromatography combined with tandem mass spectrometry (LC—MS/MS) in dogs with lymphoma and in healthy dogs. OEA, AEA, and PEA levels were significantly elevated in dogs with lymphoma compared to healthy controls (p &lt; 0.05). Total AG was significantly higher in healthy control dogs (p = 0.049). There was no significant difference between dogs with B cell and T cell lymphoma for any of the measured endocannabinoids. Elevated PEA was significantly associated with decreased PFI (p = 0.04) in dogs with lymphoma with a hazards ratio of 1.816 [95% Confidence Interval (CI): 1.020–3.232]. Overall, dogs with lymphoma have elevated levels of OEA, AEA, and PEA. PEA levels have the potential to be a prognostic biomarker.

Prognostic value of pretreatment plasma D-dimer level in dogs with intermediate to high-grade non-Hodgkin lymphoma

Pretreatment D-dimer levels have been reported to predict survival in several types of malignancies in human patients. The objective of this study was to evaluate the prognostic value of pretreatment D-dimer level in dogs with intermediate to high-grade non-Hodgkin lymphoma (NHL). In a prospective, randomized, double-blind study of F14512 vs etoposide phosphate, we assessed the prognostic value of pretreatment plasma D-dimer level in 48 client-owned dogs diagnosed with intermediate to high-grade NHL. The correlation between pretreatment plasma D-dimer level and various clinical features, progression-free survival (PFS) and overall survival (OS) was analysed. The median value of pretreatment plasma D-dimer level was 0.4 μg/mL (range: 0.1-14.3 μg/mL). High pretreatment plasma D-dimer level (>0.5 μg/mL) was detected in 44% (21/48) of dogs. High D-dimer levels were not correlated with naive vs relapsed lymphoma, clinical stage, substage, immunophenotype or treatment group. D-dimer levels >0.5 μg/mL were significantly associated with inferior median PFS (54 vs 104 days, P = .011) and OS (93 vs 169 days, P = .003). In the multivariate analysis, high D-dimer levels remained an independent predictor for worse PFS (HR: 3.21, 95% CI: 1.57-6.56, P = .001) and OS (HR: 3.87, 95% CI: 1.88-7.98; P < .001). This study suggests that pretreatment plasma D-dimer level can serve as a predictor of prognosis in dogs with intermediate to high-grade NHL. Further studies are warranted to confirm these findings.

Randomized, double-blind trial of F14512, a polyamine-vectorized anticancer drug, compared with etoposide phosphate, in dogs with naturally occurring lymphoma

Purpose: F14512 is an epipodophyllotoxin derivative from etoposide, combined with a spermine moiety introduced as a cell delivery vector. The objective of this study was to compare the safety and antitumor activity of F14512 and etoposide phosphate in dogs with spontaneous non-Hodgkin lymphoma (NHL) and to investigate the potential benefit of F14512 in P-glycoprotein (Pgp) overexpressing lymphomas.

Experimental Design: Forty-eight client-owned dogs with intermediate to high-grade NHL were enrolled into a randomized, double-blind trial of F14512 versus etoposide phosphate. Endpoints included safety and therapeutic efficacy.

Results: Twenty-five dogs were randomized to receive F14512 and 23 dogs to receive etoposide phosphate. All adverse events (AEs) were reversible, and no treatment-related death was reported. Hematologic AEs were more severe with F14512 and gastrointestinal AEs were more frequent with etoposide phosphate. F14512 exhibited similar response rate and progression-free survival (PFS) as etoposide phosphate in the global treated population. Subgroup analysis of dogs with Pgp-overexpressing NHL showed a significant improvement in PFS in dogs treated with F14512 compared with etoposide phosphate.

Conclusion: F14512 showed strong therapeutic efficacy against spontaneous NHL and exhibited a clinical benefice in Pgp-overexpressing lymphoma superior to etoposide phosphate. The results clearly justify the evaluation of F14512 in human clinical trials.

Evaluation of serum thymidine kinase 1 activity as a biomarker for treatment effectiveness and prediction of relapse in dogs with non-Hodgkin lymphoma

BACKGROUND

Serum thymidine kinase 1 (sTK1) activity is closely correlated with DNA synthesis.

OBJECTIVES

Evaluate sTK1 activity as a biomarker for treatment response and early detection of relapse in dogs with lymphoma.

ANIMALS

Ninety-seven client-owned dogs with naive or relapsed lymphoma and 23 healthy dogs.

METHODS

Prospective study. Serum TK1 activity measured by refined ELISA-based method (DiviTum assay, Biovica International) before treatment, at clinical response, and every 4 weeks until relapse or last follow-up.

RESULTS

Serum TK1 activity was ≤20 Du/L in 96% (22/23) of healthy dogs. Pretreatment sTK1 activity was >20 Du/L in 88% (85/97) dogs with lymphoma. At clinical response, sTK1 activity was significantly lower in dogs with complete (CR, n = 36) versus partial (PR, n = 29) response (P < .0001). Sensitivity (Se) and specificity (Sp) of sTK1 activity for detecting nonfully responders were 76% and 100%, respectively, with cutoff of 119.5 Du/L (AUC, 0.90; 95%-CI, 0.81-0.98; P < .0001). In dogs with CR, a 5-fold increase in sTK1 activity at a 4-week interval predicted relapse at the subsequent 4-week assessment with a Se 50% and Sp 94% (AUC, 0.72; 95%-CI, 0.55-0.90; P = .02). An increase of sTK1 activity (>2.7-fold value measured at clinical response) predicted relapse at subsequent 4-week assessment with a Se 61% and Sp 88% (AUC, 0.79; 95%-CI, 0.64-0.95; P = .004).

CONCLUSIONS AND CLINICAL IMPORTANCE

Monitoring sTK1 activity could help to detect complete responders and early disease progression in dogs with lymphoma.