Real-world experience of CAR T-cell therapy in older patients with relapsed/refractory diffuse large B-cell lymphoma.

The emergence of chimeric antigen receptor (CAR) T-cell therapy has changed the treatment landscape for diffuse large B-cell lymphoma (DLBCL); however, real-world experience reporting outcomes among older patients treated with CAR T-cell therapy is limited. We leveraged the 100% Medicare fee-for-service claims database and analyzed outcomes and cost associated with CAR T-cell therapy in 551 older patients (aged ≥65 years) with DLBCL who received CAR T-cell therapy between 2018 and 2020. CAR T-cell therapy was used in third line and beyond in 19% of patients aged 65 to 69 years and 22% among those aged 70 to 74 years, compared with 13% of patients aged ≥75 years. Most patients received CAR T-cell therapy in an inpatient setting (83%), with an average length of stay of 21 days. The median event-free survival (EFS) following CAR T-cell therapy was 7.2 months. Patients aged ≥75 years had significantly shorter EFS compared with patients aged 65 to 69 and 70 to 74 years, with 12-month EFS estimates of 34%, 43%, and 52%, respectively (P = .002). The median overall survival was 17.1 months, and there was no significant difference by age groups. The median total health care cost during the 90-day follow-up was $352 572 and was similar across all age groups. CAR T-cell therapy was associated with favorable effectiveness, but the CAR T-cell therapy use in older patients was low, especially in patients aged ≥75 years, and this age group had a lower rate of EFS, which illustrates the unmet need for more accessible, effective, and tolerable therapy in older patients, especially those aged ≥75 years.

Modeling diverse genetic subtypes of lung adenocarcinoma with a next-generation alveolar type 2 organoid platform.

Lung cancer is the leading cause of cancer-related death worldwide. Lung adenocarcinoma (LUAD), the most common histological subtype, accounts for 40% of all cases. While existing genetically engineered mouse models (GEMMs) recapitulate the histological progression and transcriptional evolution of human LUAD, they are time-consuming and technically demanding. In contrast, cell line transplant models are fast and flexible, but these models fail to capture the full spectrum of disease progression. Organoid technologies provide a means to create next-generation cancer models that integrate the most advantageous features of autochthonous and transplant-based systems. However, robust and faithful LUAD organoid platforms are currently lacking. Here, we describe optimized conditions to continuously expand murine alveolar type 2 (AT2) cells, a prominent cell of origin for LUAD, in organoid culture. These organoids display canonical features of AT2 cells, including marker gene expression, the presence of lamellar bodies, and an ability to differentiate into the AT1 lineage. We used this system to develop flexible and versatile immunocompetent organoid-based models of KRAS, BRAF, and ALK mutant LUAD. Notably, organoid-based tumors display extensive burden and complete penetrance and are histopathologically indistinguishable from their autochthonous counterparts. Altogether, this organoid platform is a powerful, versatile new model system to study LUAD.

Matching-adjusted Indirect Comparison of the Efficacy of Loncastuximab Tesirine Versus Treatment in the Chemoimmunotherapy Era for Relapsed/Refractory Diffuse Large B-cell Lymphoma.

BACKGROUND: Loncastuximab tesirine (Lonca) and chemoimmunotherapy (CIT) have been assessed in patients with relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL), but direct evidence from head-to-head randomized clinical trials is not available. MATERIALS AND METHODS: Matching-adjusted indirect comparison (MAIC) was used to evaluate the efficacy of Lonca versus CIT-era treatment in R/R DLBCL. The analysis used individual patient data from the phase II LOTIS-2 trial of Lonca (NCT03589469) and pooled aggregated data from 2 extension studies of the CORAL trial for CIT. The LOTIS-2 trial included 145 patients who had relapsed or progressed following 2 or more multi-agent systemic treatment regimens; the CORAL extension studies included 203 patients who received 2 prior lines of therapy and 75 patients who relapsed after autologous hematopoietic cell transplantation. MAIC analyses were performed to adjust for cross-trial differences in inclusion/exclusion criteria and the distribution of observed baseline characteristics. Overall response rate (ORR) and overall survival (OS) were compared between the balanced trial populations. RESULTS: A total of 80 patients in LOTIS-2 were included in the analysis. After matching to the characteristics of 278 patients from the pooled CORAL extension studies, the ORR was significantly higher for Lonca compared with CIT-era treatment (53.4% vs. 40.3%, P < .05). Lonca was also associated with a significantly improved OS compared with CIT-era treatment (median OS 10.8 vs. 6.4 months; adjusted hazard ratio: 0.67 [95% CI: 0.48, 0.92], P < .05). CONCLUSION: This study indicates that Lonca was associated with significantly improved efficacy compared with CIT-era treatments for R/R DLBCL.

Health-Related Quality of Life, Symptoms, and Tolerability of Loncastuximab Tesirine in Patients With Relapsed or Refractory Diffuse Large B-Cell Lymphoma.

BACKGROUND: Loncastuximab tesirine has shown antitumor activity with an acceptable toxicity profile in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) who were relapsed or refractory after ≥2 prior therapies, including activity in patients with high-risk disease characteristics. This analysis examined health-related quality of life (HRQoL), symptoms, and tolerability in patients receiving loncastuximab tesirine for relapsed or refractory DLBCL. PATIENTS AND METHODS: The single-arm, open-label phase II LOTIS-2 study (ADCT-402-201; NCT03589469) enrolled 145 patients aged ≥18 years. Patients received loncastuximab tesirine as a 30-minute intravenous infusion on day 1 of each 3-week treatment cycle. Patient-reported outcomes were measured using EQ-5D and FACT-Lym at baseline, day 1 of each cycle, and the end-of-treatment visit. RESULTS: During the course of treatment, EQ VAS overall health score was improved over time. The adjusted improvement was 0.65 per cycle (95% CI, 0.26-1.04; P = .001), and the adjusted mean change from baseline score was 5.00 (95% CI, 1.75-8.25; P = .003) at cycle 9, day 1. FACT-Lym total scores remained stable during treatment. More patients reported improvement compared to baseline in pain, lumps/swelling, and losing weight for a majority of visits. More than 60% of patients reported being "not at all" or "a little bit" bothered by treatment side effects for all treatment visits. Findings in elderly patients were similar to the population as whole. CONCLUSION: The findings on HRQoL, symptoms, and tolerability further support the clinical use of loncastuximab tesirine for the treatment of relapsed or refractory DLBCL. FUNDING: This work was funded by ADC Therapeutics SA. Authors affiliated with ADC Therapeutics SA participated in designing the study; in collecting, analyzing, and interpreting the data; in writing the report; and in the decision to submit the article for publication.

Characteristics and Clinical Outcomes of Patients With Relapsed/Refractory Diffuse Large B-cell Lymphoma Who Received At Least 3 Lines of Therapies.

INTRODUCTION: The treatment landscape for diffuse large B-cell lymphoma (DLBCL) has recently changed. We examined characteristics and clinical outcomes of DLBCL patients who initiated a third (3L) and fourth (4L) line of therapy during a contemporary time frame. MATERIALS AND METHODS: Adult patients diagnosed with DLBCL who received ≥ 3L after January 1, 2014 were selected from the COTA database. Patients were grouped into cohorts by 3L or 4L initiation and further stratified by type of treatment received: chemotherapy or chemoimmunotherapy (CT/CIT), targeted therapy (TT), chimeric antigen receptor T cells (CAR-T), or salvage therapy consolidated with hematopoietic cell transplant (HCT). Patient characteristics, response rates, and overall survival (OS) were examined. RESULTS: Among adult patients with relapsed/refractory (r/r) DLBCL, 212 (mean age; 61.8 years; 59.0% male) received their 3L and 127 (mean age: 61.0 years; 61.4% male) their 4L. Among those treated with their 3L and 4L, 55.2% and 50.4%, respectively, received CT/CIT; 26.9% and 34.6% received TT. The complete response rate of 3L patients was 9.4% for CT/CIT, 10.5% for TT, and 60% for CAR-T. Similar findings were seen with 4L patients (CT/CIT: 6.3%; TT: 15.9%; CAR-T: 53.8%). For those who received pharmacological treatment in 3L and 4L, median OS times were 7.7 and 4.4 months, respectively. Median OS times of patients who received cell-based therapies (CAR-T/HCT) were not reached. CONCLUSION: In this study, a majority of r/r DLBCL patients were treated with CT/CIT or TT in 3L and 4L settings and had poor clinical outcomes, underscoring the need for more effective treatments.

Characteristics and treatment patterns of relapsed/refractory diffuse large B-cell lymphoma in patients receiving ≥3 therapy lines in post-CAR-T era.

OBJECTIVE: Several novel treatments have been approved for relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) since chimeric antigen receptor T-cell (CAR-T) therapy became available. The objective of this study was to describe characteristics and treatment patterns in patients with R/R DLBCL post-CAR-T approval. METHODS: Adult patients with R/R DLBCL who initiated third-line treatment or later (3 L+) since 18 October 2017 were identified using administrative claims from IQVIA PharMetrics Plus (1 January 2014-31 March 2020). Treatments were categorized as chemotherapy/chemoimmunotherapy (CT/CIT), targeted therapies, CAR-T and stem cell transplant (SCT). Treatment distribution, treatment duration of CT/CIT and targeted therapies, and initiation of next-line therapy were described for patients receiving 3 L; analyses were repeated for 4 L. RESULTS: A total of 145 patients received 3 L between 18 October 2017 and 31 March 2020. Mean age was 57 years, and 34% were female. CT/CIT (44.9%), targeted therapies (26.9%), CAR-T (17.2%) and SCT (11.0%) were administered in 3 L. The median treatment duration was 2.9 months for CT/CIT and targeted therapies combined. 31% of patients initiated 4 L within a median follow-up of 5.8 months. Among patients who received 4 L (N = 55), targeted therapies were most commonly used (36.4%), and the median treatment duration was 2.5 months. CONCLUSIONS: Post-CAR-T approval, the majority of patients were treated with CT/CIT or targeted therapies in 3 L and 4 L, though most of the targeted therapies prescribed are not indicated for DLBCL. Treatment duration was short. A high proportion of patients moved to the next line of therapy (LOT) during a short follow-up period. This study highlights the unmet need for more effective treatments for patients with R/R DLBCL in 3 L+.

Hospital Readmissions and Mortality Among Intubated and Mechanically Ventilated Adult Subjects With Pneumonia Due to Gram-Negative Bacteria.

BACKGROUND: Ventilator-associated pneumonia (VAP) is one of the most common hospital-acquired infections in ICUs and is associated with significant morbidity and mortality. Gram-negative bacteria cause 55-85% of hospital-acquired pneumonia and are associated with increased mortality. METHODS: This study sought to describe mortality rates and 30-d readmission rates among intubated and mechanically ventilated subjects with Gram-negative pneumonia and to explore associated risk factors for mortality and rehospitalization using data from the 2013 Healthcare Cost and Utilization Project (HCUP) National Readmission Database. The study sample included adults age ≥ 18 y who were hospitalized with invasive, continuous mechanical ventilation; were discharged between February 1, 2013, and November 30, 2013; and had a primary or secondary diagnosis of Gram-negative bacterial pneumonia. Logistic regression was used to identify subject characteristics significantly associated with mortality and readmissions. RESULTS: Using the HCUP projected sample of 32,683 intubated and mechanically ventilated subjects with Gram-negative pneumonia, the mortality rate during the index hospitalization was 24.3%. More than one fifth of subjects (22.9%) who survived the index hospitalization were readmitted within 30 d of discharge. Among subjects with readmissions, 18% occurred within 3 d of discharge, 39% occurred within 7 d of discharge, and 65% occurred within 14 d of discharge. Subjects with prior hospitalization within 30 d of the index hospitalization had a higher risk of readmission with an odds ratio of 1.70 (95% CI 1.48-1.94). CONCLUSIONS: Mortality was high and readmissions were substantial among intubated and mechanically ventilated subjects with Gram-negative pneumonia.

CD8 lymphocyte depletion enhances the latency reversal activity of the SMAC mimetic AZD5582 in ART-suppressed SIV-infected rhesus macaques.

Inducing latency reversal to reveal infected cells to the host immune system represents a potential strategy to cure HIV infection. In separate studies, we have previously shown that CD8+ T cells may contribute to the maintenance of viral latency and identified a novel SMAC mimetic/IAP inhibitor (AZD5582) capable of reversing HIV/SIV latency in vivo by activating the non-canonical (nc) NF-κB pathway. Here, we use AZD5582 in combination with antibody-mediated depletion of CD8α+ cells to further evaluate the role of CD8+ T cells in viral latency maintenance. Six rhesus macaques (RM) were infected with SIVmac239 and treated with ART starting at week 8 post-infection. After 84-85 weeks of ART, all animals received a single dose of the anti-CD8α depleting antibody (Ab), MT807R1 (50mg/kg, s.c.), followed by 5 weekly doses of AZD5582 (0.1 mg/kg, i.v.). Following CD8α depletion + AZD5582 combined treatment, 100% of RMs experienced on-ART viremia above 60 copies per ml of plasma. In comparator groups of ART-suppressed SIV-infected RMs treated with AZD5582 only or CD8α depletion only, on-ART viremia was experienced by 56% and 57% of the animals respectively. Furthermore, the frequency of increased viremic episodes during the treatment period was greater in the CD8α depletion + AZD5582 group as compared to other groups. Mathematical modeling of virus reactivation suggested that, in addition to viral dynamics during acute infection, CD8α depletion influenced the response to AZD5582. This work suggests that the latency reversal induced by activation of the ncNF-κB signaling pathway with AZD5582 can be enhanced by CD8α+ cell depletion.

Quantification of Ebola virus replication kinetics in vitro.

Mathematical modelling has successfully been used to provide quantitative descriptions of many viral infections, but for the Ebola virus, which requires biosafety level 4 facilities for experimentation, modelling can play a crucial role. Ebola virus modelling efforts have primarily focused on in vivo virus kinetics, e.g., in animal models, to aid the development of antivirals and vaccines. But, thus far, these studies have not yielded a detailed specification of the infection cycle, which could provide a foundational description of the virus kinetics and thus a deeper understanding of their clinical manifestation. Here, we obtain a diverse experimental data set of the Ebola virus infection in vitro, and then make use of Bayesian inference methods to fully identify parameters in a mathematical model of the infection. Our results provide insights into the distribution of time an infected cell spends in the eclipse phase (the period between infection and the start of virus production), as well as the rate at which infectious virions lose infectivity. We suggest how these results can be used in future models to describe co-infection with defective interfering particles, which are an emerging alternative therapeutic.

Quantifying the contribution of Fc-mediated effector functions to the antiviral activity of anti-HIV-1 IgG1 antibodies in vivo.

In combating viral infections, the Fab portion of an antibody could mediate virus neutralization, whereas Fc engagement of Fc-γ receptors (FcγRs) could mediate an array of effector functions. Evidence abounds that effector functions are important in controlling infections by influenza, Ebola, or HIV-1 in animal models. However, the relative contribution of virus neutralization versus effector functions to the overall antiviral activity of an antibody remains unknown. To address this fundamental question in immunology, we utilized our knowledge of HIV-1 dynamics to compare the kinetics of the viral load decline (ΔVL) in infected animals given a wild-type (WT) anti-HIV-1 immunoglobulin G1 (IgG1) versus those given a Fc-Null variant of the same antibody. In three independent experiments in HIV-1-infected humanized mice and one pivotal experiment in simian-human immunodeficiency virus (SHIV)-infected rhesus macaques, an earlier and sharper decline in viral load was consistently detected for the WT antibody. Quantifications of the observed differences indicate that Fc-mediated effector functions accounted for 25-45% of the total antiviral activity in these separate experiments. In this study, Fc-mediated effector functions have been quantified in vivo relative to the contribution of virus neutralization mediated by the Fab.

Fc-mediated effector function contributes to the in vivo antiviral effect of an HIV neutralizing antibody.

Treatment of HIV infection with either antiretroviral (ARV) therapy or neutralizing monoclonal antibodies (NAbs) leads to a reduction in HIV plasma virus. Both ARVs and NAbs prevent new rounds of viral infection, but NAbs may have the additional capacity to accelerate the loss of virus-infected cells through Fc gamma receptor (FcγR)-mediated effector functions, which should affect the kinetics of plasma-virus decline. Here, we formally test the role of effector function in vivo by comparing the rate and timing of plasma-virus clearance in response to a single-dose treatment with either unmodified NAb or those with either reduced or augmented Fc function. When infused into viremic simian HIV (SHIV)-infected rhesus macaques, there was a 21% difference in slope of plasma-virus decline between NAb and NAb with reduced Fc function. NAb engineered to increase FcγRIII binding and improve antibody-dependent cellular cytotoxicity (ADCC) in vitro resulted in arming of effector cells in vivo, yet led to viral-decay kinetics similar to NAbs with reduced Fc function. These studies show that the predominant mechanism of antiviral activity of HIV NAbs is through inhibition of viral entry, but that Fc function can contribute to the overall antiviral activity, making them distinct from standard ARVs.

Keap1 mutation renders lung adenocarcinomas dependent on Slc33a1.

Approximately 20-30% of human lung adenocarcinomas (LUAD) harbor loss-of-function (LOF) mutations in Kelch-like ECH Associated-Protein 1 (KEAP1), which lead to hyperactivation of the nuclear factor, erythroid 2-like 2 (NRF2) antioxidant pathway and correlate with poor prognosis1-3. We previously showed that Keap1 mutation accelerates KRAS-driven LUAD and produces a marked dependency on glutaminolysis4. To extend the investigation of genetic dependencies in the context of Keap1 mutation, we performed a druggable genome CRISPR-Cas9 screen in Keap1-mutant cells. This analysis uncovered a profound Keap1 mutant-specific dependency on solute carrier family 33 member 1 (Slc33a1), an endomembrane-associated protein with roles in autophagy regulation5, as well as a series of functionally-related genes implicated in the unfolded protein response. Targeted genetic and biochemical experiments using mouse and human Keap1-mutant tumor lines, as well as preclinical genetically-engineered mouse models (GEMMs) of LUAD, validate Slc33a1 as a robust Keap1-mutant-specific dependency. Furthermore, unbiased genome-wide CRISPR screening identified additional genes related to Slc33a1 dependency. Overall, our study provides a strong rationale for stratification of patients harboring KEAP1-mutant or NRF2-hyperactivated tumors as likely responders to targeted SLC33A1 inhibition and underscores the value of integrating functional genetic approaches with GEMMs to identify and validate genotype-specific therapeutic targets.

Within-host mathematical models of hepatitis B virus infection: Past, present, and future.

Mathematical modeling has been instrumental in enhancing our understanding of the viral dynamics of hepatitis B virus (HBV) infection. We give a primer on HBV infection in humans and a brief overview of the development of within-host mathematical models of HBV infection. In the last decade, models have advanced from considering chronic HBV infections under therapy to the pathogenesis of infection. We also summarize estimates of key viral dynamic parameters that have varied greatly among studies, and show that they impact model predictions. Future directions for mathematical modeling of HBV infection are proposed to better understand emerging therapies, the HBV life cycle, predicting cure, and the mechanisms involved in the immune response to HBV infection.

Twelve-month discontinuation rates of levonorgestrel intrauterine system 13.5 mg and subdermal etonogestrel implant in women aged 18-44: A retrospective claims database analysis.

OBJECTIVE: To investigate the 12-month discontinuation rates of levonorgestrel intrauterine system 13.5 mg (LNG-IUS 13.5) and subdermal etonogestrel (ENG) implant in the US. STUDY DESIGN: We identified women aged 18-44 who had an insertion of LNG-IUS 13.5 or ENG implant from the MarketScan Commercial claims database (7/1/2013-9/30/2014). Women were required to have 12 months of continuous insurance coverage prior to the insertion (baseline) and at least 12-months after (follow-up). Discontinuation was defined as presence of an insurance claim for pregnancy-related services, hysterectomy, female sterilization, a claim for another contraceptive method, or removal of the index contraceptive without re-insertion within 30 days. Using Cox regression we examined the potential impact of ENG implant vs. LNG-IUS 13.5 on the likelihood for discontinuation after controlling for patient characteristics. RESULTS: A total of 3680 (mean age: 25.4 years) LNG-IUS 13.5 and 23,770 (mean age: 24.6 years) ENG implant users met the selection criteria. Prior to insertion, 56.6% of LNG-IUS 13.5 and 42.1% of ENG implant users had used contraceptives, with oral contraceptives being most common (LNG-IUS 13.5: 42.1%; ENG implant: 28.5%). Among users of LNG-IUS 13.5 and ENG implant, rates of discontinuation were similar during the 12-month follow-up (LNG-IUS 13.5: 24.9%; ENG implant: 24.0%). Regression results showed that women using LNG-IUS 13.5 vs. ENG implant had similar likelihood for discontinuation (hazard ratio: 0.97, 95% confidence interval: 0.90-1.05, p=.41). CONCLUSION: In the real-world US setting, women aged 18-44 using LNG-IUS 13.5 and ENG implant have similar discontinuation rates after 12 months. IMPLICATIONS: In the United States, women aged 18-44 using levonorgestrel intrauterine system (13.5 mg) and subdermal etonogestrel implant have similar discontinuation rates after 12 months.

Exploring virus release as a bottleneck for the spread of influenza A virus infection in vitro and the implications for antiviral therapy with neuraminidase inhibitors.

Mathematical models (MMs) have been used to study the kinetics of influenza A virus infections under antiviral therapy, and to characterize the efficacy of antivirals such as neuraminidase inhibitors (NAIs). NAIs prevent viral neuraminidase from cleaving sialic acid receptors that bind virus progeny to the surface of infected cells, thereby inhibiting their release, suppressing infection spread. When used to study treatment with NAIs, MMs represent viral release implicitly as part of viral replication. Consequently, NAIs in such MMs do not act specifically and exclusively on virus release. We compared a MM with an explicit representation of viral release (i.e., distinct from virus production) to a simple MM without explicit release, and investigated whether parameter estimation and the estimation of NAI efficacy were affected by the use of a simple MM. Since the release rate of influenza A virus is not well-known, a broad range of release rates were considered. If the virus release rate is greater than ∼0.1 h-1, the simple MM provides accurate estimates of infection parameters, but underestimates NAI efficacy, which could lead to underdosing and the emergence of NAI resistance. In contrast, when release is slower than ∼0.1 h-1, the simple MM accurately estimates NAI efficacy, but it can significantly overestimate the infectious lifespan (i.e., the time a cell remains infectious and producing free virus), and it will significantly underestimate the total virus yield and thus the likelihood of resistance emergence. We discuss the properties of, and a possible lower bound for, the influenza A virus release rate.

Glycaemic control and hypoglycaemia burden in patients with type 2 diabetes initiating basal insulin in Europe and the USA.

AIMS: To evaluate short- and long-term glycaemic control and hypoglycaemia incidence in insulin-naïve patients ≥30 years of age with type 2 diabetes (T2DM) initiating basal insulin (BI) with or without oral anti-hyperglycaemic drugs (OADs). METHODS: This was an observational, retrospective longitudinal analysis of electronic medical records from 5 European countries and the USA. A multivariable logistic regression model assessed baseline and short-term (0-3 months post BI initiation) factors associated with long-term (3-24 months) glycaemic control and hypoglycaemia. RESULTS: Overall, 40 627 patients were included; 20.9% and 27.8% achieved the general HbA1c target of ≤7% at 3 and 24 months post BI initiation, respectively. Failure to achieve HbA1c ≤7% at 3 months was associated with increased risk of failing to achieve target at 24 months (odds ratio [OR], 3.70 [95% CI, 3.41-4.00]). Over 24 months, 8.9% of patients experienced a recorded hypoglycaemic event. Hypoglycaemia during the initial 3-month period was associated with longer-term risk of these events over the ensuing 3 to 24 months (OR, 5.71 [95% CI, 4.67-6.99]). CONCLUSIONS: Initiating BI with or without OADs is associated with short- and long-term suboptimal glycaemic control; the majority of patients fail to achieve HbA1c target ≤7% in the first 3 months, or after 2 years of BI treatment. Treatment response and hypoglycaemia incidence by 3 months post BI initiation are associated with longer-term glycaemic control and hypoglycaemic risk, respectively. These results support the need for early anti-hyperglycaemic interventions that more effectively control blood glucose levels without increasing the risk of hypoglycaemia.

(In)validating experimentally derived knowledge about influenza A defective interfering particles.

A defective interfering particle (DIP) in the context of influenza A virus is a virion with a significantly shortened RNA segment substituting one of eight full-length parent RNA segments, such that it is preferentially amplified. Hence, a cell co-infected with DIPs will produce mainly DIPs, suppressing infectious virus yields and affecting infection kinetics. Unfortunately, the quantification of DIPs contained in a sample is difficult because they are indistinguishable from standard virus (STV). Using a mathematical model, we investigated the standard experimental method for counting DIPs based on the reduction in STV yield (Bellett & Cooper, 1959, Journal of General Microbiology 21, 498-509 (doi:10.1099/00221287-21-3-498)). We found the method is valid for counting DIPs provided that: (i) an STV-infected cell's co-infection window is approximately half its eclipse phase (it blocks infection by other virions before it begins producing progeny virions), (ii) a cell co-infected by STV and DIP produces less than 1 STV per 1000 DIPs and (iii) a high MOI of STV stock (more than 4 PFU per cell) is added to perform the assay. Prior work makes no mention of these criteria such that the method has been applied incorrectly in several publications discussed herein. We determined influenza A virus meets these criteria, making the method suitable for counting influenza A DIPs.

Outcomes and healthcare resource utilization associated with medically attended hypoglycemia in older patients with type 2 diabetes initiating basal insulin in a US managed care setting.

OBJECTIVE: To assess health outcomes and the economic burden of hypoglycemia in older patients with type 2 diabetes initiating basal insulin (BI). RESEARCH DESIGN AND METHODS: Medicare Advantage claims data were extracted for patients with type 2 diabetes initiating BI and patients were stratified into two groups: those with medically attended hypoglycemia during the first year of BI treatment (HG group) and those without (non-HG group). Main outcome measures were hospitalization, mortality, healthcare utilization and costs 1 year before and 1 year after BI initiation. RESULTS: Of 31,035 patients included (mean age 72 years [SD 9.2]), 3066 (9.9%; HG group) experienced hypoglycemia during 1 year post-BI initiation. After adjustment for demographic, comorbidity and medication history, hypoglycemia was associated with risk of hospitalization (HR 1.59; 95% CI: 1.53-1.65) and death (HR 1.50; 95% CI: 1.40-1.60). Healthcare utilization was higher pre-index and showed greater increases post-BI initiation in the HG vs. the non-HG group. Per-patient healthcare costs were substantially higher for the HG group than the non-HG group, both pre-index ($54,057 vs. $30,249, respectively) and post-BI initiation ($75,398 vs. $27,753, respectively). CONCLUSIONS: Based on available claims data, hypoglycemia during the first year of BI treatment is associated with risk of hospitalization or death in older people, increasing healthcare utilization and costs. Due to the observational nature of this study, causality cannot be attributed, and further prospective studies into the effect of hypoglycemia on health outcomes in this population are warranted.