The impact of omalizumab on paid and unpaid work productivity among severe Japanese cedar pollinosis (JCP) patients

AIMS

Japanese cedar pollinosis (JCP) is a form of seasonal allergic rhinitis that affects 38.8% of the Japanese population. Particularly severe and most severe symptoms among JCP patients can lead to impairments of paid work productivity and unpaid work activities. Indeed, the current standard of care (SoC) is not always able to relieve these symptoms. Omalizumab, a novel JCP treatment recently approved in Japan, provides an effective add-on therapy to the SoC. This study estimates the effect of omalizumab on paid and unpaid work activities (i.e. its social impact) in patients with severe and most severe JCP symptoms in Japan.

METHODS

The impact of omalizumab was estimated through a one-year static cohort model using the Work Productivity and Activity Impairment Allergy Specific (WPAI-AS) questionnaire derived from a clinical trial on omalizumab enrolling patients with severe and most severe JCP symptoms, which had been conducted in Japan. This effect was quantified using Japanese official statistics on employment and time use. The human capital approach and the proxy good approach were employed to monetize paid and unpaid work activities, respectively. A sensitivity analysis was implemented to account for modeling structural uncertainties.

RESULTS

Our results show that the use of omalizumab might reduce the paid and unpaid work productivity losses due to severe and most severe JCP by nearly one-third. In the severe symptom period of three weeks, 36.6 million hours of lost paid and unpaid work hours could be avoided, which sums up to a monetized productivity loss of 728.3 million USD.

CONCLUSIONS

Omalizumab could provide substantial benefits in terms of paid and unpaid work activities in patients with severe and most severe JCP. Our results also highlight the importance of considering unpaid work in estimating productivity costs due to poor health.

Cost-Effectiveness Analysis of Omalizumab for Severe Allergic Asthma in Japan Using Real-World Evidence

OBJECTIVES

Omalizumab is a recommended add-on therapy for patients with severe allergic asthma who remain uncontrolled despite treatment with standard of care (SoC). This study evaluated the cost-effectiveness of omalizumab compared with SoC applying real-world clinical outcomes in adult patients with severe allergic asthma in Japan.

METHODS

A validated Markov model was adapted for Japan and compared the cost-effectiveness of omalizumab as an add-on therapy to SoC versus SoC alone using the most recently updated price of omalizumab. A Japanese real-world postmarketing surveillance and a pivotal randomized clinical trial were used as inputs for clinical effectiveness. Japanese life tables and literature were accessed for mortality data and unit costs were extracted from a Japanese insurance claims database. Quality of life data were retrieved from the clinical trial.

RESULTS

In the base case, the incremental cost-effectiveness ratio for omalizumab add-on therapy was ¥2.85 million per quality-adjusted life-year gained (approximately €21 000; 1€ = ¥133.26) compared with SoC alone. The model appeared to be most sensitive to changes in clinically significant severe exacerbation fatality, day-to-day asthma symptom utilities for SoC, discount rates for benefits, day-to-day asthma symptom utilities for omalizumab responders, time horizon, and the annual cost of omalizumab. The results of the probabilistic sensitivity analysis showed that the probability of omalizumab being cost-effective was 93% to 98% at a threshold of ¥5 to ¥6 million (willingness-to-pay for 1 quality-adjusted life-year).

CONCLUSIONS

Omalizumab add-on therapy is cost-effective compared with SoC alone in Japan in severe allergic asthma population who are uncontrolled with high-dose inhaled corticosteroid and other controllers.

A retrospective cohort study evaluating healthcare resource utilization in patients with asthma in Japan

Although the global economic burden of asthma is well described, detailed data regarding Asia, particularly for Japan, are relatively scarce. This retrospective study aims to fill this evidence gap by evaluating asthma-associated healthcare resource utilization (HCRU) and economic burden in Japanese patients aged ≥16 years, identified using anonymized patient data from the Japan Medical Data Center (JMDC) database from April 2009 to March 2015. Asthma severity was classified according to asthma treatment guidelines from the Japanese Society of Allergology. HCRU was calculated based on hospitalizations, emergency room visits, outpatient visits, and prescriptions. Incidence rate ratios (IRRs) for HCRU and per-patient-per-year direct costs were reported. In addition, differences across HCRU and cost variables for severe versus non-severe asthma patients were also compared. Of 541,434 asthma cases identified from the JMDC database during the study period, 54,433 patients who met the inclusion criteria were included in this analysis. HCRU and costs were heavily concentrated within severe asthma, a subgroup comprising 12.7% of total study population. Moreover, patients with severe asthma had significantly higher all-cause hospitalizations, outpatient visits, outpatient prescriptions (IRR [95% CI], 1.60 [1.46–1.76]; 1.43 [1.41–1.45]; 1.24 [1.22–1.25], respectively), and total medical costs (mean ± SD costs, US$ 4345 ± 11,104 versus US$ 1528 ± 3989, P < 0.001 (t-test); US$ 1 = 110 JPY) compared with those with non-severe asthma. The burden of asthma is significantly and disproportionately concentrated in Japanese severe asthma patients, suggesting clinical failure to achieve adequate disease control. This study highlights the unmet needs for severe asthma in Japan and provides a catalyst for important dialogues in advancing public health.

Differential cellular localization of antioxidant enzymes in the trigeminal ganglion

Because of its high oxygen demands, neural tissue is predisposed to oxidative stress. Here, our aim was to clarify the cellular localization of antioxidant enzymes in the trigeminal ganglion. We found that the transcriptional factor Sox10 is localized exclusively in satellite glial cells (SGCs) in the adult trigeminal ganglion. The use of transgenic mice that express the fluorescent protein Venus under the Sox10 promoter enabled us to distinguish between neurons and SGCs. Although both superoxide dismutases 1 and 2 were present in the neurons, only superoxide dismutase 1 was identified in SGCs. The enzymes relevant to hydrogen peroxide degradation displayed differential cellular localization, such that neurons were endowed with glutathione peroxidase 1 and thioredoxin 2, and catalase and thioredoxin 2 were present in SGCs. Our immunohistochemical finding showed that only SGCs were labeled by the oxidative damage marker 8-hydroxy-2'-deoxyguanosine, which indicates that the antioxidant systems of SGCs were less potent. The transient receptor potential vanilloid subfamily member 1 (TRPV1), the capsaicin receptor, is implicated in inflammatory hyperalgesia, and we demonstrated that topical capsaicin application causes short-lasting mechanical hyperalgesia in the face. Our cell-based assay revealed that TRPV1 agonist stimulation in the presence of TRPV1 overexpression caused reactive oxygen species-mediated caspase-3 activation. Moreover, capsaicin induced the cellular demise of primary TRPV1-positive trigeminal ganglion neurons in a dose-dependent manner, and this effect was inhibited by a free radical scavenger and a pancaspase inhibitor. This study delineates the localization of antioxidative stress-related enzymes in the trigeminal ganglion and reveals the importance of the pivotal role of reactive oxygen species in the TRPV1-mediated caspase-dependent cell death of trigeminal ganglion neurons. Therapeutic measures for antioxidative stress should be taken to prevent damage to trigeminal primary sensory neurons in inflammatory pain disorders.

Clinical relevance of serum levels of matrix metallopeptidase-2, and tissue inhibitor of metalloproteinase-1 and -2 in patients with malignant melanoma

The interaction and/or balance between matrix metallopeptidase (MMP)-2 and tissue inhibitor of metalloproteinase (TIMP)-2 in vivo may play important roles in the process of tumor growth, invasion and metastasis of malignant melanoma. In this study, we investigated the serum levels and immunohistochemical expression of MMP-2, TIMP-1 and TIMP-2 in patients with melanoma and analyzed the correlation with clinicopathological parameters. The level of serum MMP-2 in patients was significantly higher than that of the control. Moreover, the level of MMP-2 was significantly higher than that of the control in patients who were: (i) female; (ii) pT1 and pT4; (iii) with and without lymph node (LN) metastasis; (iv) in stage I and stage IV; (v) with and without recurrence; and (v) alive and dead. The level of serum TIMP-1 in patients with melanoma was significantly higher than that of the control. Among melanoma patients, the level of TIMP-1 with pT4 was significantly higher for patients who were: (i) pT1 and pT3; (ii) with LN metastasis (vs those without); (iii) in stage IV (vs those in stages I, II and III); and (iv) dead (vs those alive). The level of serum TIMP-2 in patients with melanoma was not different from the control. However, the level of TIMP-2 in patients with pT4 was significantly higher than for patients who were: (i) pT1, pT3 and control; (ii) with LN metastasis (vs those without metastasis and control); (iii) with stage IV (vs those in stages I and II and control); (iv) in recurrence (vs control); and (v) dead (vs those alive and control). These results suggest that increased serum levels of TIMP-1 and TIMP-2 reflected the extent of metastatic melanoma lesions, and that serum levels of TIMP-1 may be a new useful marker for melanoma progression.