Incidence of pneumococcal disease in children ≤48 months old in the United States: 1998-2019.

BACKGROUND: Pneumococcal disease (PD) is a major cause of morbidity and mortality among children, particularly in the youngest age groups. This study aimed to assess the incidence of PD over time by age group in young children with commercial or Medicaid coverage in the US. METHODS: Episodes of invasive pneumococcal disease (IPD), all-cause pneumonia (ACP), and acute otitis media (AOM) were identified in the MarketScan® Commercial and Medicaid claims databases using diagnosis codes among children aged ≤ 48 months with confirmed date of birth (DoB), at any time during the study period (1998-2019). DoB was assigned using diagnosis codes for birth or delivery using the child's or mother's medical claims to ensure accurate age determination. Annual incidence rates (IRs) were calculated as number of disease episodes/100,000 person-years (PY) for IPD and ACP and episodes/1,000 PY for AOM, for children aged 0-6, 7-12, 12-24, and 25-48 months. RESULTS: Annual IPD IRs declined from 53 to 7 episodes/100,000 PY between 1998 and 2019 in commercially-insured and 58 to 9 episodes/100,000 PY between 2001 and 2019 in Medicaid-insured children. Annual ACP IRs declined from 5,600 to 3,952 episodes/100,000 PY, and from 6,706 to 4,521 episodes/100,000 PY, respectively, over these periods. In both populations, children aged 0-6 months had the highest incidence of IPD and inpatient ACP. Annual AOM IRs declined from 1,177 to 738 episodes/1,000 PY (commercially-insured) and 633 to 624 episodes/1,000 PY (Medicaid-insured), over these periods. IRs were higher in rural vs. urban areas for all disease manifestations. CONCLUSIONS: Incidence rates of IPD, ACP, and AOM decreased in children with commercial insurance and Medicaid coverage from 1998 to 2019. However, burden of disease remained substantial, with higher annual IRs for IPD and ACP for Medicaid-insured vs. commercially-insured children. IPD and inpatient ACP were most common in the youngest children 0-6 months old, followed by the 7-12-month age group.

Cytochrome P450 inhibitor/inducer treatment patterns among patients in the United States with advanced ovarian cancer who were prescribed or were eligible for poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitors in the first-line maintenance setting.

Poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitors (PARPi) are metabolized either via carboxylesterase (niraparib) or cytochrome P450 (CYP) enzymes (olaparib and rucaparib). Patients with advanced epithelial ovarian cancer (aOC) who receive concomitant medication metabolized by the CYP system may be at risk of drug-drug interactions impacting PARPi efficacy and tolerability. This study investigated CYP inhibitor/inducer treatment patterns in the first-line maintenance (1Lm) setting for patients with aOC. This retrospective cohort study used de-identified databases of US patients with aOC. Eligible patients were aged ≥18 years, diagnosed with aOC between January 2015-March 2021, and received CYP inhibitors/inducers during 1Lm PARPi initiation or the eligibility window (90 days before to 120 days after first-line platinum-based therapy ended [index]). Patients were either prescribed 1Lm PARPi monotherapy (PARPi cohort) or were not prescribed any 1Lm therapy within 120 days post-index (PARPi-eligible cohort). Strong/moderate CYP inhibitors/inducers were defined as area under the plasma concentration-time curve ratio (AUCR) ≥2 or clearance ratio (CL) ≤0.5 (inhibitors), and AUCR ≤0.5 or CL ratio ≥2 (inducers). Of 1411 patients (median age 63), 158 were prescribed PARPis and 1253 were PARPi-eligible. Among the PARPi cohort, 46.2%, 48.7%, and 5.1% were prescribed niraparib, olaparib, and rucaparib, respectively. For patients prescribed olaparib or rucaparib, 42.4% also received strong and/or moderate CYP inhibitors/inducers. This real-world study indicated a considerable proportion of patients received strong and/or moderate CYP inhibitors/inducers and were prescribed PARPis metabolized by the CYP system. Understanding potential impacts of concomitant CYP inhibitors/inducers on PARPi efficacy and safety is warranted.

Comparative efficacy and safety of tisagenlecleucel and axicabtagene ciloleucel among adults with r/r follicular lymphoma.

Regulatory approvals of tisagenlecleucel (tisa-cel) and axicabtagene ciloleucel (axi-cel) have established the feasibility of chimeric antigen receptor T-cell therapies for the treatment of adults with relapsed or refractory follicular lymphoma (r/r FL). This study used individual patient data from ELARA (tisa-cel) and aggregate published patient data from ZUMA-5 (axi-cel) to compare efficacy and safety outcomes in r/r FL using matching-adjusted indirect comparison methods. After adjustment for baseline differences in the trial populations, the results suggested that tisa-cel (n = 52), compared with axi-cel (n = 86), had similar effects on overall response rate (91.2% vs. 94.2%; p = .58), complete response rate (74.0% vs. 79.1%; p = .60), progression-free survival (HR [95% CI]: 0.8 [0.4, 1.9]; p = .67), and overall survival (HR [95% CI]: 0.5 [0.2, 1.5]; p = .21). Tisa-cel (n = 53) was associated with better safety outcomes than axi-cel (n = 124), reflected by lower rates of any grade and grade ≥3 cytokine release syndrome and neurological events.

Real-World Treatment Patterns among Patients with Alopecia Areata in the USA: A Retrospective Claims Analysis.

Alopecia areata is an autoimmune disorder characterized by hair loss, for which there are few treatment options. This claims-based study characterized recent real-world treatment patterns among patients in the USA with alopecia areata, including the subtypes alopecia totalis and alopecia universalis, in the first year after diagnosis of an episode of alopecia areata. Approximately 5% of all patients (adults (age ≥ 18 years), n = 7,703; adolescents (age 12-17 years), n = 595) had alopecia totalis or alopecia universalis. Corticosteroids were the most common first-line (1L) and second-line (2L) treatments. The mean time from diagnosis of alopecia areata to initiation of 1L treatment was 2.2 days for adults and 2.6 days for adolescents; mean 1L duration was 76.9 and 64.3 days, respectively. For adults (57.5%) and adolescents (59.7%) with 2L therapy, the mean time from 1L discontinuation to 2L initiation was 57.2 and 53.6 days, respectively; the mean duration of 2L treatment was 55.5 and 50.1 days, respectively. More patients with vs without alopecia totalis or alopecia universalis initiated 2L therapy (adults: 71.9% vs 56.8%; adolescents: 71.4% vs 58.9%). The proportion of days covered during the first year post-diagnosis was 36.7% (adults) and 34.1% (adolescents). These results highlight the substantial disease burden of alopecia areata and a need for more effective treatments.

Trends in Prevalence and Incidence of Alopecia Areata, Alopecia Totalis, and Alopecia Universalis Among Adults and Children in a US Employer-Sponsored Insured Population.

Importance: Alopecia areata (AA) is characterized by nonscarring hair loss of the scalp, face, and/or body. Alopecia totalis (AT) and alopecia universalis (AU) involve complete loss of the scalp and body hair, respectively. The epidemiology of AA in the US remains unclear, having previously been extrapolated from older studies that were limited to specific geographic areas or clinical settings, or from self-reported data. Objective: To estimate the annual prevalence and incidence of AA and AT and/or AU (AT/AU) in the US. Design, Setting, and Participants: This retrospective, population-based cohort study was conducted from January 2016 to December 2019 and included enrollees in the IBM MarketScan Commercial Claims and Encounters and Medicare Supplemental databases and their dependents, with plan enrollment during each study calendar year and the year prior. Exposures: Prevalent cases were identified by 1 or more claims for AA or AT/AU (International Statistical Classification of Diseases, Tenth Revision, Clinical Modification [ICD-10-CM] codes L63.x, L63.0, L63.1) during each year of interest or the year prior. Incident cases were identified by 1 or more claims for AA or AT/AU during a specific year and no diagnosis the year prior. Main Outcomes and Measures: Annual incidence and prevalence rates were calculated and stratified by age, sex, and region. National employer-sponsored insurance population estimates were obtained using population-based weights. Results: Among eligible patients (2016: n = 18 368 [mean (SD) age, 40.6 (17.9) years; 12 295 women (66.9%)]; 2017: n = 14 372 [mean (SD) age, 39.6 (17.7) years; 9195 women (64.0%)]; 2018: n = 14 231 [mean (SD) age, 38.9 (17.3) years; 8998 women (63.2%)]; 2019: n = 13 455 [mean (SD) age, 39.1 (17.4) years; 8322 women (61.9%)]), AA prevalence increased from 0.199% (95% CI, 0.198%-0.200%) in 2016 to 0.222% (95% CI, 0.221%-0.223%) in 2019. Roughly 5% to 10% of prevalent and incident cases of AA were AT/AU. The prevalence of AT/AU increased from 0.012% (95% CI, 0.012%-0.013%) to 0.019% (95% CI, 0.018%-0.019%) from 2016 to 2019. Incidence of AA per 100 000 person-years ranged from 87.39 (95% CI, 86.84-87.96) in 2017 to 92.90 (95% CI, 92.35-93.45) in 2019. Incidence of AT/AU ranged from 7.09 (95% CI, 6.94-7.25) in 2017 to 8.92 (95% CI, 8.75-9.09) in 2016. Prevalence and incidence of AA and AT/AU were higher among female vs male individuals, adults vs children and adolescents, and in the Northeast vs other regions. Conclusions and Relevance: The results of this cohort study suggest that these recent AA prevalence and incidence estimates could help improve current understanding of the disease burden. Further research is warranted to elucidate subpopulation differences and trends in AA in the broader US population.

Patient characteristics associated with all-cause healthcare costs of alopecia areata in the United States.

Evidence on the factors of medical costs involved in the care of people with alopecia areata (AA) is limited, but mounting evidence points to significant variation in financial impact for patients with AA in the absence of effective treatments. This study explored drivers of medical costs among privately insured adults and adolescents with AA in the United States. The study found that patients of middle age (45­64 years), located in the Northeast region, with comprehensive health insurance, with greater extent of hair loss, or with other health disorders face greater all-cause medical costs. Adult females of young (18­44 years) and older (65+ years) age also faced greater costs on average. This research confirms high variability in the burden of AA, pointing to population subgroups that may be more affected by the disease and its commonly associated disorders.

Nivolumab versus placebo as adjuvant therapy for resected stage III melanoma: a propensity weighted indirect treatment comparison and number needed to treat analysis for recurrence-free survival and overall survival.

BACKGROUND: Recurrence-free survival (RFS) and overall survival (OS) data for adjuvant nivolumab versus placebo (proxy for routine surveillance) in patients with high-risk, resected melanoma are lacking. This post hoc, indirect treatment comparison (ITC) used pooled data from the phase 3 EORTC 18,071 (ipilimumab vs. placebo) and CheckMate 238 (nivolumab vs. ipilimumab) trials to assess RFS and OS with nivolumab versus placebo and the numbers needed to treat (NNT) over 4 years. METHODS: Patients with resected stage IIIB-C cutaneous melanoma (American Joint Committee on Cancer seventh edition) were included. Inverse probability treatment weighting (IPTW) was used to balance baseline characteristics. RFS NNTs were calculated for nivolumab versus ipilimumab and placebo. OS NNTs were calculated for nivolumab versus placebo. To adjust for different post-recurrence treatments, the difference in post-recurrence survival between the two ipilimumab arms was added to OS of the placebo arm. RESULTS: This ITC included 278, 643, and 365 patients treated with nivolumab, ipilimumab, and placebo, respectively. Following IPTW, nivolumab was associated with improved RFS versus placebo (hazard ratio [HR]: 0.49; 95% confidence interval [CI] 0.39-0.61) and ipilimumab (HR: 0.69; 95% CI 0.56-0.85). RFS NNT was 4.2 for nivolumab versus placebo and 8.9 for nivolumab versus ipilimumab. After post-recurrence survival adjustment, weighted 4-year OS rates were 75.8% for nivolumab and 64.1% for placebo; OS NNT for nivolumab versus placebo was 8.5. CONCLUSIONS: In patients with resected stage IIIB-C cutaneous melanoma in this ITC, nivolumab improved RFS versus placebo and ipilimumab, and OS versus placebo after post-recurrence survival adjustment.

Healthcare Utilization and Costs Among US Adolescents With Alopecia Areata.

Background: Alopecia areata (AA) is an autoimmune disease of hair loss affecting people of all ages. Alopecia totalis (AT) and universalis (AU) involve scalp and total body hair loss, respectively. AA significantly affects quality of life, but evidence on the economic burden in adolescents is limited. Objectives: To assess healthcare resource utilization (HCRU) and all-cause direct healthcare costs, including out-of-pocket (OOP) costs, of US adolescents with AA. Methods: IBM MarketScan® Commercial and Medicare databases were used to identify patients aged 12-17 years with ≥2 claims with AA/AT/AU diagnosis (prevalent cases), from October 1, 2015, to March 31, 2018, enrolled for ≥12 months before and after the first AA diagnosis (index). Patients were matched 1:3 to non-AA controls on index year, demographics, plan type, and Charlson Comorbidity Index. Per patient per year HCRU and costs were compared post-index. Results: Patients comprised 130 AT/AU adolescents and 1105 non-AT/AU adolescents (53.8% female; mean age, 14.6 years). Post-index, AT/AU vs controls had more outpatient (14.5 vs 7.1) and dermatologist (3.6 vs 0.3) visits, higher mean plan costs ($9397 vs $2267), including medical ($7480 vs $1780) and pharmacy ($1918 vs $487) costs, and higher OOP costs ($2081 vs $751) (all P<.001). The non-AT/AU cohort vs controls had more outpatient (11.6 vs 8.0) and dermatologist (3.4 vs 0.4) visits, higher mean plan costs ($7587 vs $4496), and higher OOP costs ($1579 vs $805) (all P<.001). Discussion: This large-sample, real-world analysis found that adolescents with prevalent AA had significantly higher HCRU and all-cause costs than matched controls. The greater burden was driven by more frequent outpatient visits, and higher payer medical and pharmacy costs in comparison with controls. Oral corticosteroid use was higher among patients with AT/AU; topical and injectable corticosteroid use was higher for non-AT/AU. Although the data preclude the identification of AA-attributable costs, the matched-control design allows an estimation of incremental all-cause costs associated with AA. Conclusions: Adolescents with AA incurred substantial incremental healthcare costs, with greater costs incurred among those with AT/AU. Study findings suggest that AA incurs costs as a medical condition with a high burden on adolescent patients and health plans.

Real-world healthcare resource utilization and costs associated with tisagenlecleucel and axicabtagene ciloleucel among patients with diffuse large B-cell lymphoma: an analysis of hospital data in the United States.

This study compared the real-world healthcare resource utilization (HRU), costs, adverse events (AEs), and AE treatments associated with the chimeric antigen receptor T-cell (CAR-T) therapies, tisagenlecleucel (tisa-cel) and axicabtagene ciloleucel (axi-cel), for relapsed/refractory diffuse large B-cell lymphoma (r/r DLBCL). Adults with DLBCL who received tisa-cel or axi-cel were identified in the Premier Healthcare Database (2017-2020). Non-CAR-T costs, HRU, and AE rates during the infusion and follow-up periods were compared between the tisa-cel and axi-cel cohorts. Of 119 patients, 33 received tisa-cel (86% as inpatient infusion) and 86 received axi-cel (100% inpatient). Tisa-cel was associated with significantly shorter mean inpatient length of stay than axi-cel during infusion (11.3 vs. 18.3 days) and follow-up ([monthly] 3.9 vs. 6.9 days). Non-CAR-T costs were significantly lower for tisa-cel compared with axi-cel during infusion ($27594.8 vs. $51378.3) and follow-up ([monthly] $28777.3 vs. $46575.7; both p< .05). Rates of AEs and AE treatments were similar.

All-cause health care resource utilization and costs among adults with alopecia areata: A retrospective claims database study in the United States.

BACKGROUND: Alopecia areata (AA) is an autoimmune disorder characterized by hair loss. Patients may present with hair loss of the scalp, eyelashes, eyebrows, and/or body. Alopecia totalis (AT), total scalp hair loss, or alopecia universalis (AU), total body hair loss, are extensive forms. Although the impact of AA on quality of life is understood, evidence of its economic burden is limited. A better understanding of the all-cause health care costs for health plans and patients with AA is critical to comprehend disease burden. OBJECTIVE: To evaluate all-cause health care resource utilization and direct health care costs in US adults with AA with or without AT or AU, vs matched control subjects. METHODS: Patients (≥ 18 years) with AA with no less than 2 claims of AA at diagnosis (October 31, 2015, to March 3, 2018) were identified in the IBM MarketScan Commercial Claims and Encounters and Medicare Supplemental databases. Patients were enrolled no less than 12 months before and after first diagnosis (index). Patients were grouped according to AT or AU status (AT/AU group) or AA without AT/AU (non-AT/AU group) and matched 1:3 to control subjects without AA/AT/AU. Summary statistics were calculated for demographic and clinical characteristics at baseline and follow-up. RESULTS: At baseline, there were 14,972 adult patients with AA and 44,916 control subjects. Of patients with AA, 1,250 and 13,722 were in the AT/AU and non-AT/AU groups, respectively. A significantly greater proportion of patients with AA had atopic and autoimmune comorbidities vs control subjects. After index, patients with AA used significantly more corticosteroid treatments (injectable/oral/topical) than control subjects. A greater mean number of annual outpatient and dermatologist visits was observed for both AA groups vs control subjects (outpatient visits: AT/AU group: 17.8 vs 11.8; non-AT/AU group: 15.4 vs 11.2; dermatologist visits: AT/AU group: 3.4 vs 0.4; non-AT/AU group: 3.4 vs 0.4; P < 0.001 for all). Mean total all-cause medical and pharmacy costs (2018 US$) were higher in both AA groups vs control subjects (AT/AU group: $18,988 vs $11,030; non-AT/AU group: $13,686 vs $9,336; P < 0.001 for both). Patient out-of-pocket costs were higher for AA vs control subjects (AT/AU group: $2,685 vs $1,457; non-AT/AU group: $2,223 vs $1,341; P < 0.001 for both). CONCLUSIONS: Compared with control subjects, patients with AA are more likely to have atopic and autoimmune comorbidities, to use corticosteroids, and to make outpatient visits. Patients with AA have greater all-cause medical (including pharmacy) and out-of-pocket costs. The difference in total medical costs for patients with AT/AU vs control subjects is higher than the difference for patients with non-AT/AU vs control subjects. DISCLOSURES: This study was sponsored by Pfizer Inc. Pfizer Inc was involved in the study design; collection, analysis, and interpretation of data; writing of the report; and the decision to submit this report for publication. A. Mostaghimi reports consulting fees from Pfizer Inc, Concert, Lilly, AbbVie, hims, and Digital Diagnostics; reports equity from Lucid and hims; and is an associate editor at JAMA Dermatology. K. Gandhi, M. Ray, and V. Sikirica are former employees of Pfizer Inc and held stock and/or stock options with Pfizer Inc at the time of writing. N. Done, W. Gao, C. Carley, T. Wang, and E. Swallow are employees of Analysis Group, Inc, a consultancy that received payment from Pfizer Inc for participation in this analysis.

The Economic Burden of Recurrence in Triple-Negative Breast Cancer Among Working Age Patients in the United States.

INTRODUCTION: Triple-negative breast cancer (TNBC) is associated with a high recurrence risk. However, the magnitude of direct and indirect costs associated with recurrence is lacking in the literature. METHODS: Adults 18-65 years old diagnosed with TNBC were identified from the OptumHealth Reporting and Insights claims database (1999-2017) and stratified by recurrence. For patients with recurrence, the index date was defined as 30 days before recurrence; for patients without recurrence, it was randomly assigned based on the distribution of time between first treatments and index dates of the recurrence cohort. All-cause and breast cancer-related healthcare resource utilization (HRU), direct and indirect costs, and work loss up to 1 year were compared between cohorts using generalized linear models. Kaplan-Meier analyses and Cox proportional hazards models compared the risk of leaving the workforce. RESULTS: Among the 2340 patients analyzed, mean age was 54 years and > 75% of patients had stage 0-2 cancer. Among the 1170 patients with recurrence, 236 were categorized as having metastatic recurrence and 934 as having locoregional recurrence. Relative to patients without recurrence, those with recurrence had significantly higher all-cause and breast cancer-related HRU. For instance, adjusted incidence rates (IRs) for all-cause inpatient admissions were 3.67 and 10.19 times higher for patients with locoregional and metastatic recurrence, respectively (p < 0.001). Adjusted all-cause healthcare costs were $8575/month higher for metastatic recurrence and $3609/month higher for locoregional recurrence vs. patients without recurrence (p < 0.001). Adjusted IRs for work loss days were approximately two times higher for locoregional and metastatic recurrence vs. without recurrence (p < 0.001). Patients with locoregional recurrence incurred $335/month more indirect costs vs. patients without recurrence; those with metastatic recurrence incurred $769/month more (p < 0.05). Patients with recurrence had a 63% higher rate of leaving the work force (p = 0.003). CONCLUSION: The incremental direct and indirect economic burden associated with recurrent TNBC is substantial relative to non-recurrence.

Canine Lafora Disease: An Unstable Repeat Expansion Disorder.

Canine Lafora disease is a recessively inherited, rapidly progressing neurodegenerative disease caused by the accumulation of abnormally constructed insoluble glycogen Lafora bodies in the brain and other tissues due to the loss of NHL repeat containing E3 ubiquitin protein ligase 1 (NHLRC1). Dogs have a dodecamer repeat sequence within the NHLRC1 gene, which is prone to unstable (dynamic) expansion and loss of function. Progressive signs of Lafora disease include hypnic jerks, reflex and spontaneous myoclonus, seizures, vision loss, ataxia and decreased cognitive function. We studied five dogs (one Chihuahua, two French Bulldogs, one Griffon Bruxellois, one mixed breed) with clinical signs associated with canine Lafora disease. Identification of polyglucosan bodies (Lafora bodies) in myocytes supported diagnosis in the French Bulldogs; muscle areas close to the myotendinous junction and the myofascial union segment had the highest yield of inclusions. Postmortem examination of one of the French Bulldogs revealed brain Lafora bodies. Genetic testing for the known canine NHLRC1 mutation confirmed the presence of a homozygous mutation associated with canine Lafora disease. Our results show that Lafora disease extends beyond previous known breeds to the French Bulldog, Griffon Bruxellois and even mixed-breed dogs, emphasizing the likely species-wide nature of this genetic problem. It also establishes these breeds as animal models for the devastating human disease. Genetic testing should be used when designing breeding strategies to determine the frequency of the NHLRC1 mutation in affected breeds. Lafora diseases should be suspected in any older dog presenting with myoclonus, hypnic jerks or photoconvulsions.

Skeletal Muscle Glycogen Chain Length Correlates with Insolubility in Mouse Models of Polyglucosan-Associated Neurodegenerative Diseases.

Lafora disease (LD) and adult polyglucosan body disease (APBD) are glycogen storage diseases characterized by a pathogenic buildup of insoluble glycogen. Mechanisms causing glycogen insolubility are poorly understood. Here, in two mouse models of LD (Epm2a-/- and Epm2b-/-) and one of APBD (Gbe1ys/ys), the separation of soluble and insoluble muscle glycogen is described, enabling separate analysis of each fraction. Total glycogen is increased in LD and APBD mice, which, together with abnormal chain length and molecule size distributions, is largely if not fully attributed to insoluble glycogen. Soluble glycogen consists of molecules with distinct chain length distributions and differential corresponding solubility, providing a mechanistic link between soluble and insoluble glycogen in vivo. Phosphorylation states differ across glycogen fractions and mouse models, demonstrating that hyperphosphorylation is not a basic feature of insoluble glycogen. Lastly, model-specific variances in protein and activity levels of key glycogen synthesis enzymes suggest uninvestigated regulatory mechanisms.

Nationwide genetic testing towards eliminating Lafora disease from Miniature Wirehaired Dachshunds in the United Kingdom.

BACKGROUND: Canine DNA-testing has become an important tool in purebred dog breeding and many breeders use genetic testing results when planning their breeding strategies. In addition, information obtained from testing of hundreds dogs in one breed gives valuable information about the breed-wide genotype frequency of disease associated allele. Lafora disease is a late onset, recessively inherited genetic disease which is diagnosed in Miniature Wirehaired Dachshunds (MWHD). It is one of the most severe forms of canine epilepsy leading to neurodegeneration and, frequently euthanasia within a few years of diagnosis. Canine Lafora disease is caused by a dodecamer repeat expansion mutation in the NHLRC1 gene and a DNA test is available to identify homozygous dogs at risk, carriers and dogs free of the mutation. RESULTS: Blood samples were collected from 733 MWHDs worldwide, mostly of UK origin, for canine Lafora disease testing. Among the tested MWHD population 7.0% were homozygous for the mutation and at risk for Lafora disease. In addition, 234 dogs were heterozygous, indicating a carrier frequency of 31.9% in the tested population. Among the tested MWHDs, the mutant allele frequency was 0.2. In addition, data from the tested dogs over 6 years (2012-2017) indicated that the frequency of the homozygous and carrier dogs has decreased from 10.4% to 2.7% and 41.5% to 25.7%, respectively among MWHDs tested. As a consequence, the frequency of dogs free of the mutation has increased from 48.1% to 71.6%. CONCLUSIONS: This study provides valuable data for the MWHD community and shows that the DNA test is a useful tool for the breeders to prevent occurrence of Lafora disease in MWHDs. DNA testing has, over 6 years, helped to decrease the frequency of carriers and dogs at risk. Additionally, the DNA test can continue to be used to slowly eradicate the disease-causing mutation in the breed. However, this should be done carefully, over time, to avoid further compromising the genetic diversity of the breed. The DNA test also provides a diagnostic tool for veterinarians if they are presented with a dog that shows clinical signs associated with canine Lafora disease.