Trends in Medicare Part D Medication Therapy Management Eligibility Criteria

Background

To increase the enrollment rate of medication therapy management (MTM) programs in Medicare Part D plans, the US Centers for Medicare & Medicaid Services (CMS) lowered the allowable eligibility thresholds based on the number of chronic diseases and Part D drugs for Medicare Part D plans for 2010 and after. However, an increase in MTM enrollment rates has not been realized.

Objectives

To describe trends in MTM eligibility thresholds used by Medicare Part D plans and to identify patterns that may hinder enrollment in MTM programs.

Methods

This study analyzed data extracted from the Medicare Part D MTM Programs Fact Sheets (2008–2014). The annual percentages of utilizing each threshold value of the number of chronic diseases and Part D drugs, as well as other aspects of MTM enrollment practices, were analyzed among Medicare MTM programs that were established by Medicare Part D plans.

Results

For 2010 and after, increased proportions of Medicare Part D plans set their eligibility thresholds at the maximum numbers allowable. For example, in 2008, 48.7% of Medicare Part D plans (N = 347:712) opened MTM enrollment to Medicare beneficiaries with only 2 chronic disease states (specific diseases varied between plans), whereas the other half restricted enrollment to patients with a minimum of 3 to 5 chronic disease states. After 2010, only approximately 20% of plans opened their MTM enrollment to patients with 2 chronic disease states, with the remaining 80% restricting enrollment to patients with 3 or more chronic diseases.

Conclusion

The policy change by CMS for 2010 and after is associated with increased proportions of plans setting their MTM eligibility thresholds at the maximum numbers allowable. Changes to the eligibility thresholds by Medicare Part D plans might have acted as a barrier for increased MTM enrollment. Thus, CMS may need to identify alternative strategies to increase MTM enrollment in Medicare plans.     

Immune Modulation by Vitamin D and Its Relevance to Food Allergy

Apart from its classical function in bone and calcium metabolism, vitamin D is also involved in immune regulation and has been linked to various cancers, immune disorders and allergic diseases. Within the innate and adaptive immune systems, the vitamin D receptor and enzymes in monocytes, dendritic cells, epithelial cells, T lymphocytes and B lymphocytes mediate the immune modulatory actions of vitamin D. Vitamin D insufficiency/deficiency early in life has been identified as one of the risk factors for food allergy. Several studies have observed an association between increasing latitude and food allergy prevalence, plausibly linked to lower ultraviolet radiation (UVR) exposure and vitamin D synthesis in the skin. Along with mounting epidemiological evidence of a link between vitamin D status and food allergy, mice and human studies have shed light on the modulatory properties of vitamin D on the innate and adaptive immune systems. This review will summarize the literature on the metabolism and immune modulatory properties of vitamin D, with particular reference to food allergy.     

A Randomized,Double-Blind,Parallel Study to Evaluate the Dose-Response of Three Different Vitamin D Treatment Schemes on the 25-Hydroxyvitamin D Serum Concentration in Patients with Vitamin D Deficiency

Many people worldwide are vitamin D (VTD) deficient or insufficient, and there is still no consensus on the dose of VTD that should be administered to achieve a 25(OH)D concentration of 20 or 30 ng/mL. In this study, we aimed to determine an adapted supplementation of VTD able to quickly and safely increase the vitamin D status of healthy adults with low 25(OH)D. One hundred and fifty (150) subjects were randomized into three groups, each to receive, orally, a loading dose of 50,000, 100,000 or 200,000 IU of VTD3 at Week 0, followed by 25,000, 50,000 or 100,000 IU at Week 4 and Week 8. Whereas 25(OH)D baseline values were not different between groups (p = 0.42), a significant increase was observed at Week 12 (p < 0.0001) with a mean change from baseline of 7.72 ± 5.08, 13.3 ± 5.88 and 20.12 ± 7.79 ng/mL. A plateau was reached after eight weeks. No related adverse event was recorded. This study demonstrated a linear dose-response relationship with an increase in 25(OH)D levels proportional to the dose administered. In conclusion, a loading dose of 200,000 IU VTD3 followed by a monthly dose of 100,000 IU is the best dosing schedule to quickly and safely correct the VTD status.     

Flow cytometry evaluation of in vitro cellular necrosis and apoptosis induced by silver nanoparticles

Particles possess unique properties in the nanoscale, e.g., enhanced catalytic activity, high surface area, and light emission/absorption properties, that might result in interference with colorimetric in vitro cytotoxicity assays such as MTT, XTT or MTS. Alternatively, assays that do not use spectrophotometric detection, such as trypan blue exclusion or flow cytometry (FC) based assays, are less likely to be influenced by nanoparticle interference. The aim of this study was to evaluate FC assays to assess the cytotoxicity of three different sizes (10, 100, or 200 nm) of silver nanoparticles (AgNPs) at different mass concentrations (1, 25, or 50 ug/ml) in L-929 fibroblast cells. After 4 h and 24 h exposure, cell necrosis and apoptosis were assessed using 7-AAD and Annexin V dyes, respectively, with FC. The data indicate that cell necrosis and apoptosis in AgNP-exposed fibroblasts depends on dose, exposure time, and AgNP size. The data indicate that AgNPs produced a dose- and time-dependent decrease in cell viability; however, 10 nm AgNPs were significantly more toxic than larger-sized particles. Thus, standard FC assays can be utilized to assess apoptosis and necrosis in response to nanomaterial exposure.     

Evaluation of the likelihood of a selective CHK1 inhibitor (LY2603618) to inhibit CYP2D6 with desipramine as a probe substrate in cancer patients

LY2603618 is a selective inhibitor of deoxyribonucleic acid damage checkpoint kinase 1 (CHK1) and has been in development for the enhancement of chemotherapeutic agents. The study described was to assess the potential interaction between LY2603618 and cytochrome P450 isoform 2D6 (CYP2D6) substrate desipramine in patients with cancer. Before clinical investigation, in silico simulations (using Simcyp®) were conducted. An open‐label, two‐period, fixed‐sequence study was planned in 30 patients with advanced or metastatic cancers, in which a 50 mg oral dose of desipramine was administered alone and in combination with 275 mg of LY2603618 (i.v. infusion). An interim analysis was planned after 15 patients completed both periods. Ratios of geometric least squares means (LSMs) of primary pharmacokinetic (PK) parameters and 90% repeated confidence intervals (RCIs) between desipramine plus LY2603618 and desipramine alone were calculated. Lack of an interaction was declared if the 90% RCI fell between 0.8 and 1.25. The LSM ratios (90% RCI) for areas under the plasma concentration–time curve from time zero to t_last (AUC_[0‐tlast]) and to infinity (AUC_[0‐∞]) and maximum plasma concentration (C_max) were 1.14 (1.04, 1.25), 1.09 (0.99, 1.21) and 1.16 (1.05, 1.29). In silico simulations were predictive of clinical results. Single doses of 275 mg LY2603618 administered with 50 mg desipramine were generally well tolerated. In conclusion, no clinically significant interaction was observed between LY2603618 and desipramine in patients with cancer. In silico predictions of clinical results demonstrated that mechanistic and physiologically based PK approaches may inform clinical study design in cancer patients. Copyright © 2014 John Wiley & Sons, Ltd.     

HepaRG culture in tethered spheroids as an in vitro three‐dimensional model for drug safety screening

Conventional two‐dimensional (2D) monolayer cultures of HepaRG cells allow in vitro maintenance of many liver‐specific functions. However, cellular dedifferentiation and functional deterioration over an extended culture period in the conventional 2D HepaRG culture have hampered its applications in drug testing. To address this issue, we developed tethered spheroids of HepaRG cells on Arg–Gly–Asp (RGD) and galactose‐conjugated substratum with an optimized hybrid ratio as an in vitro three‐dimensional (3D) human hepatocyte model. The liver‐specific gene expression level and drug metabolizing enzyme activities in HepaRG‐tethered spheorids were markedly higher than those in 2D cultures throughout the culture period of 7 days. The inducibility of three major cytochrome P450 (CYP) enzymes, namely CYP1A2, CYP2B6 and CYP3A4, was improved in both mRNA and activity level in tethered spheroids. Drug‐induced cytotoxic responses to model hepatotoxins (acetaminophen, chlorpromazine and ketoconazole) in tethered spheroids were comparable to 2D cultures as well as other studies in the literature. Our results suggested that the HepaRG‐tethered spheroid would be an alternative in vitro model suitable for drug safety screening. Copyright © 2014 John Wiley & Sons, Ltd.     

Vitamin D3 potentiates the growth inhibitory effects of metformin in DU145 human prostate cancer cells mediated by AMPK/mTOR signalling pathway

Metformin and vitamin D₃ both exhibit a strong antiproliferative action in numerous cancer cell lines, including in human prostate cancer cells. Here we showed that the combination of the two drugs had a much stronger effect on DU145 human prostate cancer cell growth than either drug alone. In this research, cell proliferation was measured by methylthiazol tetrazolium (MTT) assay. Cell apoptosis was determined with Hoechst 33342 staining. Western blotting and cell cycle analyses were used to elucidate potential mechanisms of interaction between the drugs. It is shown that in cultured DU145 cells, vitamin D₃ combined with metformin exhibits synergistic effects on cell proliferation and apoptosis. The underlying antitumor mechanisms may involve altered cycle distribution with a G1/S cell cycle arrest, activation of phospho‐AMPK with subsequent inhibition of downstream mTOR signalling pathway, down‐regulate c‐Myc expression, and reducing the level of anti‐apoptotic protein p‐Bcl‐2. In conclusion, metformin and vitamin D₃ synergistically inhibit DU145 cell growth, indicating a promising clinical therapeutic strategy for the treatment of androgen‐independent prostate cancer.