Intersections between HIV and obesity in emerging economies

PURPOSE OF REVIEW

HIV epidemics are increasing in many emerging economy countries, whilst the very process of 'economic emergence' is obesogenic. Annual deaths related to obesity and overweight are now four times more than for HIV globally. We describe the intersections between HIV and obesity in emerging economies, and highlight potential mitigation options, including antiobesity medications (AOMs), which are safe and effective, but inaccessibly priced.

RECENT FINDINGS

We summarize what is known about weight-change in HIV and review strategies including public health policies and clinical interventions for emerging economy countries to fight obesity. We also illustrate the landscape from a selection of 'emerging economy' countries with available data from UNAIDS, World Bank and World Obesity Federation to visualize the developing challenges faced. AOM course prices are high in many countries, but could be manufactured and sold profitably for much less. We present lessons from the early HIV/AIDS movements on how to improve access and pricing for AOMs for people with HIV with obesity in emerging economy countries.

SUMMARY

We illustrate the complex intersectional issues that 'emerging economy countries' may experience, with a 'double burden' of increasing HIV and obesity epidemics, and explore potential mitigation options, focussing on AOM access and pricing.

Estimated minimum prices and lowest available national prices for antiobesity medications: Improving affordability and access to treatment

OBJECTIVE

Novel antiobesity treatments are highly effective in recent clinical trials. Access to these medications is needed to supplement lifestyle and surgical interventions for millions living with obesity worldwide, but high prices are limiting. This study aimed to review current treatment costs and calculate potential estimated minimum prices (EMPs).

METHODS

The authors searched national drug price databases across various countries for orlistat, naltrexone-bupropion, topiramate-phentermine, liraglutide, semaglutide, and tirzepatide. EMPs for antiobesity medications were calculated using established methodology, using active pharmaceutical ingredients (API) from the Panjiva database. EMPs were calculated per 30-day course and include costs of active pharmaceutical ingredients, excipients, formulation, taxation, and 10% profit margin.

RESULTS

National prices of antiobesity medications were significantly higher than calculated EMPs. Semaglutide 30-day course prices ranged from $804 (United States) to $95 (Turkey) while the EMP was $40. Liraglutide prices ranged from $1418 (United States) to $252 (Norway) while the EMP was $50. Some oral treatments could be generically manufactured at very low costs per course ($7 for orlistat; $5 for phentermine/topiramate combination tablets), while naltrexone/bupropion was more expensive ($54).

CONCLUSIONS

This study shows that certain weight loss treatments can be manufactured and sold profitably at low costs, but prices currently range widely between countries, limiting access for those in need.

Comparing Prospective Incident Severe Acute Respiratory Syndrome Coronavirus 2 Infection Rates During Successive Waves of Delta and Omicron in Johannesburg, South Africa

In high-risk individuals in Johannesburg, during the Delta coronavirus disease 2019 wave, 22% (125/561) were positive, with 33% symptomatic (2 hospitalizations; 1 death). During Omicron, 56% (232/411) were infected, with 24% symptomatic (no hospitalizations or deaths). The remarkable speed of infection of Omicron over Delta poses challenges to conventional severe acute respiratory syndrome coronavirus 2 control measures.

Efficacy of Approved versus Unapproved Vaccines for SARS-CoV-2 Infection in Randomised Blinded Clinical Trials

Background

Five severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines are approved in North America and/or Europe: Pfizer/BioNTech, Moderna, Janssen, Oxford-AstraZeneca, and Novavax. Other vaccines have been developed, including Sinopharm, SinoVac, QazVac, Covaxin, Soberana, Zifivax, Medicago, Clover, and Cansino, but they are not approved in high-income countries. This meta-analysis compared the efficacy of US Food and Drug Administration (FDA)/European Medicines Agency (EMA)-approved and -unapproved vaccines in randomized clinical trials (RCTs).

Methods

A systematic review of trial registries identified RCTs of SARS-CoV-2 vaccines. Risk of bias was assessed using the Cochrane tool (RoB 2). In the meta-analysis, relative risks of symptomatic infection and severe disease were compared for each vaccine versus placebo, using Cochrane-Mantel Haenszel Tests (random effects method).

Results

Twenty-two RCTs were identified and 1 was excluded for high-risk of bias. Ten RCTs evaluated 5 approved vaccines and 11 RCTs evaluated 9 unapproved vaccines. In the meta-analysis, prevention of symptomatic infection was 84% (95% confidence interval [CI], 68%–92%) for approved vaccines versus 72% (95% CI, 66%–77%) for unapproved vaccines, with no significant difference between vaccine types (P = .12). Prevention of severe SARS-CoV-2 infection was 94% (95% CI, 75%–98%) for approved vaccines versus 86% (95% CI, 76%–92%) for unapproved vaccines (P = .33). The risk of serious adverse events was similar between vaccine types (P = .12).

Conclusions

This meta-analysis of 21 RCTs in 390 459 participants showed no significant difference in efficacy between the FDA/EMA-approved and -unapproved vaccines for symptomatic or severe infection. Differences in study design, endpoint definitions, variants, and infection prevalence may have influenced results. New patent-free vaccines could lower costs of worldwide SARS-CoV-2 vaccination campaigns significantly.

Minimum Manufacturing Costs, National Prices, and Estimated Global Availability of New Repurposed Therapies for Coronavirus Disease 2019

Background

Currently, only dexamethasone, tocilizumab, and sarilumab have conclusively been shown to reduce mortality of coronavirus disease 2019 (COVID-19). Safe and effective treatments will need to be both affordable and widely available globally to be used alongside vaccination programs. This analysis will estimate and compare potential generic minimum costs of a selection of approved COVID-19 drug candidates with available international list prices.

Methods

We searched for repurposed drugs that have been approved by at least one of the World Health Organization, US Food and Drug Administration, or the United Kingdom National Institute of Health and Care Excellence organizations or at least given emergency use authorization or recommended for off-label prescription. Drug prices were searched for dexamethasone, budesonide, baricitinib, tocilizumab, casirivimab, and imdevimab, and sarilumab, using active pharmaceutical ingredients (APIs) data extracted from global shipping records. This was compared with national pricing data from a range of low-, medium-, and high-income countries. Annual API export volumes from India were used to estimate the current availability of each drug.

Results

Repurposed therapies can be generically manufactured for some treatments at very low per-course costs, ranging from US $2.58 for intravenous (IV) dexamethasone (or US $0.19 orally) and US $4.34 for inhaled budesonide. No export price data were available for baricitinib, tocilizumab, casirivimab, and imdevimab, or sarilumab, but courses of these treatments have higher prices, ranging from US $6.67 for baricitinib to US $875.5 for sarilumab. When comparing international list prices, we found wide variations between countries.

Conclusions

Successful management of COVID-19 will require equitable access to treatment for all populations, not just those able to pay high prices. Dexamethasone and budesonide are widely available and affordable, whereas monoclonal antibodies and IV treatment courses are more expensive.

The Joint United Nations Programme on HIV/AIDS 95-95-95 targets: worldwide clinical and cost benefits of generic manufacture

BACKGROUND

The Joint United Nations Programme on HIV/AIDS aims for HIV testing, treatment and viral suppression rates to be 95%--95%--95% by 2025. Patented drug prices remain a barrier to HIV treatment. Generic alternatives are being produced and exported from countries without patent barriers at a fraction of the cost.

METHODS

We collated export records of active pharmaceutical ingredient for HIV drugs to estimate the minimum costs of production. Using epidemiological data describing national HIV epidemics, we calculated the cost to treat 164 countries at 95%--95%-95%. Using weighted log-linear regression models, we estimated the mother-to-child transmissions (MTCTs), HIV-related deaths and new HIV infections preventable every year by increased treatment.

FINDINGS

We estimated that TDF/3TC/DTG could be produced for $59 per person per year. At this price, the 164 countries in our analysis could be treated at 95%--95%--95% for $2 billion a year, preventing 66 308 MTCTs, 241 811 HIV-related deaths and 631 398 new HIV infections every year. In comparison, global expenditure on HIV pharmaceuticals in 2019 was $28 billion.

INTERPRETATION

At $2 billion/year, the 164 countries in our analysis could be treated for the price of 4 weeks of current global sales. Global access to generic alternatives could reduce expenditure and improve clinical outcomes.

407. Minimum Manufacturing Costs, National Prices and Estimated Global Availability of New Repurposed Therapies for COVID-19

Background

Currently, only dexamethasone, tocilizumab and sarilumab have conclusively been shown to reduce mortality of COVID-19. No drug for prevention or treatment in earlier stages of COVID-19 are yet found, with previously promising drugs such as hydroxychloroquine and remdesivir have been shown to be ineffective. Several new candidates are now being studied in clinical trials. Safe and effective treatments will need to be both affordable and widely available. We therefore revised our original 2020 analysis to reflect recent developments. In this update we analysed the cost of production, current national list prices, and API availability for oral and IV dexamethasone, ivermectin, colchicine, dutasteride, budesonide, baricitinib and monoclonal antibodies tocilizumab and sarilumab.

Methods

Costs of production for new and potential COVID-19 drugs (dexamethasone, ivermectin, dutasteride, budesonide, baricitinib, tocilizumab, sarilumab and colchicine) were estimated using an established and published methodology based on costs of active pharmaceutical ingredients (API), extracted from the global shipping records database Panjiva. This was compared with national pricing data from low, medium, and high-income countries. Annual API export volumes from India were used to estimate the current availability of each drug.

Results

Repurposed therapies can be generically manufactured at very low per-course costs: ranging from &2.58 for IV dexamethasone (or &0.19 orally) to &0.12 for ivermectin. No export price data was available for baricitinib, tocilizumab or sarilumab. When compared against international list prices, we found wide variations between countries. Drug API availability was generally good, with colchicine being the most available with sufficient annual API exported for 59.8 million treatment courses. A summary is shown in Table 1.

Table 1. Summary of list prices, estimated production costs, and current availability of potential COVID-19 drugs selected for analysis. OD = Once daily, BD = twice per day, EUA = Emergency Use Authorisation (only to be given with remdesivir) *In most recent 12-month period.

Conclusion

Successful management of COVID-19 will require equitable access to treatment for all, not just those able to pay. Repurposed drugs can be manufactured at very low costs if shown to be clinically effective, and offers an affordable, widely available option for patients at all stages of the disease from pre-exposure prophylaxis to asymptotic and mild infections, through to critical care until vaccination coverage is expanded.

Disclosures

All Authors: No reported disclosures

529. Systematic Review and Meta-Analysis of Ivermectin Safety Profile in COVID-19 Trials

Background

There is a continued and pressing need for safe and effective treatment of COVID-19. Significant survival benefits have been shown by dexamethasone, tocilizumab and sarilumab, however they are only recommended in hospitalised COVID-19 patients. Ivermectin is a well-established and readily available antiparasitic drug which may be suitable for treatment in mild and moderate disease stages. It recently demonstrated anti-viral properties in vitro and now over 80 clinical trials have been registered worldwide to test its effectiveness in COVID-19 patients. This meta-analysis aims to collect data on adverse events reported in new COVID-19 treatment trials for the use of ivermectin as a repurposed medication.

Methods

Data was extracted from randomised trials of COVID-19 treatment trials identified through systematic searches of PUBMED, EMBASE, MedRxiv and trial registries. The primary outcome of this meta-analysis is the frequency of adverse events. Key safety events included serious, gastrointestinal, neurological, cardiovascular and dermatological adverse events.

Results

Overall, 18 trials investigating ivermectin for COVID-19 in a total of 2496 participants reported safety data and were included. There was no significant difference in the proportion of all adverse events between ivermectin and the comparator. There were 371/1261 (29%) adverse events recorded in the ivermectin containing arms and 376/1284 (29%) in the control arms (RR 1.02 [95% CI 0.77 - 1.34]; p = 0.91). There was no significant difference in the rate of serious adverse events across treatment arms (RR 1.95 [95% CI 0.75 - 5.11]; p = 0.18). No significant differences between ivermectin and the control were seen across different subcategories of adverse events. Figure 1 shows a summary of the results for all adverse events.

Forest plot comparing ivermectin and the control for all adverse events in COVID-19 trials, subdivided into single-day dosing trials and multi-day dosing trials.

Conclusion

The results of recent COVID-19 trials show that overall, ivermectin is safe and well-tolerated. No significant difference in adverse event reporting was found across all subgroups in single and multi-day treatment regimens for the studies analysed. Safety reporting methodologies often varied across trials. Future and ongoing trials should be encouraged to collect and monitor safety data systematically.

Disclosures

All Authors: No reported disclosures

891. Minimum Manufacturing Costs and National Prices for Weight Loss Treatments, as Potential Mitigation for Anti-Retroviral Related Weight Gain in HIV

Background

Weight gain is being observed for a wide range of antiretroviral treatments. Weight gains are higher for people taking first-line integrase inhibitor based treatments, especially those including TAF/FTC. Weight gains are higher for women and people of colour. Clinical obesity increases the risks of cardiovascular disease, diabetes, adverse birth outcomes and could lower survival rates. Anti-obesity treatments are needed to supplement lifestyle interventions and counteract progressive weight gains, but are not routinely provided as part of HIV care.

Methods

Costs of production for FDA-recommended weight loss treatments and anti-diabetic medications (orlistat, naltrexone-bupropion, topiramate, phentermine, semaglutide, liraglutide and metformin) were estimated using an established and published methodology based on costs of active pharmaceutical ingredients (API), extracted from the global shipping records database Panjiva. This was compared with national drug list price data from a range of low, medium, and high-income countries.

Results

Weight loss and anti-diabetic treatments can be generically manufactured at low per-course costs, e.g. &85 per person per year for oral treatments such as orlistat and &1 per person per month for metformin. However, prices for a year of treatment with orlistat are as high as &1,205 in the USA and as low as &11 in Vietnam. In comparison, a month of ARV treatment costs about &15 via global health institutions like CHAI. Price for injectable (subcutaneous) treatments were higher, ranging from &1,985 for liraglutide in USA to &330 in Morocco, whilst they could potentially be profitably sold for &155 for a 12-week course. No export price data was available for semaglutide. When compared against international list prices, we found wide variations between countries.

Table 1. Summary of drug prices and minimum cost estimates

Conclusion

We show that weight loss treatments can be manufactured and sold profitably for low prices, but have a wide price range between countries. Government and non-governmental healthcare systems should be evaluating weight loss agents for inclusion within ART programmes.

Disclosures

All Authors: No reported disclosures

Evaluation of the effect of sofosbuvir and daclatasvir in hospitalized COVID-19 patients: a randomized double-blind clinical trial (DISCOVER)

Background

The combination of sofosbuvir and daclatasvir has shown preliminary efficacy for hospitalized patients with COVID-19 in four open-label studies with small sample sizes. This larger trial aimed to assess if the addition of sofosbuvir/daclatasvir to standard care improved clinical outcomes in hospitalized patients with COVID-19.

Methods

This was a placebo-controlled, double-blind, randomized clinical trial in adults hospitalized with COVID-19 at 19 hospitals in Iran. Patients were randomized to oral sofosbuvir/daclatasvir 400/60 mg once-daily or placebo in addition to standard of care. Patients were included if they had positive PCR or diagnostic chest CT, O₂ saturation <95% and compatible symptoms. The primary outcome was hospital discharge within 10 days of randomization. Secondary outcomes included mortality and time to clinical events. The trial is registered on the Iran Registry of Clinical Trials under IRCT20200624047908N1.

Results

Between July and October 2020, 1083 patients were randomized to either the sofosbuvir/daclatasvir arm (n = 541) or the placebo arm (n = 542). No significant difference was observed in the primary outcome of hospital discharge within 10 days, which was achieved by 415/541 (77%) in the sofosbuvir/daclatasvir arm and 411/542 (76%) in the placebo arm [risk ratio (RR) 1.01, 95% CI 0.95–1.08, P = 0.734]. In-hospital mortality was 60/541 (11%) in the sofosbuvir/daclatasvir arm versus 55/542 (10%) in the placebo arm (RR 1.09, 95% CI 0.77–1.54, P = 0.615). No differences were observed in time to hospital discharge or time to in-hospital mortality.

Conclusions

We observed no significant effect of sofosbuvir/daclatasvir versus placebo on hospital discharge or survival in hospitalized COVID-19 patients.

Meta-analysis of randomized trials of ivermectin to treat SARS-CoV-2 infection

Ivermectin is an antiparasitic drug being investigated for repurposing against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Ivermectin showed in vitro activity against SARS-COV-2, but only at high concentrations. This meta-analysis investigated ivermectin in 23 randomized clinical trials (3349 patients) identified through systematic searches of PUBMED, EMBASE, MedRxiv, and trial registries. The primary meta-analysis was carried out by excluding studies at a high risk of bias. Ivermectin did not show a statistically significant effect on survival (risk ratio [RR], 0.90; 95% CI, 0.57 to 1.42; P = .66) or hospitalizations (RR, 0.63; 95% CI, 0.36 to 1.11; P = .11). Ivermectin displayed a borderline significant effect on duration of hospitalization in comparison with standard of care (mean difference, –1.14 days; 95% CI, –2.27 to –0.00; P = .05). There was no significant effect of ivermectin on time to clinical recovery (mean difference, –0.57 days; 95% CI, –1.31 to 0.17; P = .13) or binary clinical recovery (RR, 1.19; 95% CI, 0.94 to 1.50; P = .15). Currently, the World Health Organization recommends the use of ivermectin only inside clinical trials. A network of large clinical trials is in progress to validate the results seen to date.

Sofosbuvir and daclatasvir for the treatment of COVID-19 outpatients: a double-blind, randomized controlled trial

INTRODUCTION

Effective treatments are urgently needed to tackle the novel coronavirus disease 2019 (COVID-19). This trial aims to evaluate sofosbuvir and daclatasvir versus standard care for outpatients with mild COVID-19 infection.

METHODS

This was a randomized controlled clinical trial in outpatients with mild COVID-19. Patients were randomized into a treatment arm receiving sofosbuvir/daclatasvir plus hydroxychloroquine or a control arm receiving hydroxychloroquine alone. The primary endpoint of the trial was symptom alleviation after 7 days of follow-up. The secondary endpoint of the trial was hospital admission. Fatigue, dyspnoea and loss of appetite were investigated after 1 month of follow-up. This study is registered with the IRCT.ir under registration number IRCT20200403046926N1.

RESULTS

Between 8 April 2020 and 19 May 2020, 55 patients were recruited and allocated to either the sofosbuvir/daclatasvir treatment arm (n = 27) or the control arm (n = 28). Baseline characteristics were similar across treatment arms. There was no significant difference in symptoms at Day 7. One patient was admitted to hospital in the sofosbuvir/daclatasvir arm and four in the control arm, but the difference was not significant. After 1 month of follow-up, two patients reported fatigue in the sofosbuvir/daclatasvir arm and 16 in the control arm; P < 0.001.

CONCLUSIONS

In this study, sofosbuvir/daclatasvir did not significantly alleviate symptoms after 7 days of treatment compared with control. Although fewer hospitalizations were observed in the sofosbuvir/daclatasvir arm, this was not statistically significant. Sofosbuvir/daclatasvir significantly reduced the number of patients with fatigue and dyspnoea after 1 month. Larger, well-designed trials are warranted.

Comparison of automated beam hardening correction (ABHC) algorithms for myocardial perfusion imaging using computed tomography

PURPOSE

Myocardial perfusion imaging using computed tomography (MPI-CT) and coronary CT angiography (CTA) have the potential to make CT an ideal noninvasive imaging gatekeeper exam for invasive coronary angiography. However, beam hardening can prevent accurate blood flow estimation in dynamic MPI-CT and can create artifacts that resemble flow deficits in single-shot MPI-CT. In this work, we compare four automatic beam hardening correction algorithms (ABHCs) applied to CT images, for their ability to produce accurate single images of contrast and accurate MPI flow maps using images from conventional CT systems, without energy sensitivity.

METHODS

Previously, we reported a method, herein called ABHC-1, where we iteratively optimized a cost function sensitive to beam hardening artifacts in MPI-CT images and used a low order polynomial correction on projections of segmentation-processed CT images. Here, we report results from two new algorithms with higher order polynomial corrections, ABHC-2 and ABHC-3 (with three and seven free parameters, respectively), having potentially better correction but likely reduced estimability. Additionally, we compared results to an algorithm reported by others in the literature (ABHC-NH). Comparisons were made on a digital static phantom with simulated water, bone, and iodine regions; on a digital dynamic anthropomorphic phantom, with simulated blood flow; and on preclinical porcine experiments. We obtained CT images on a prototype spectral detector CT (Philips Healthcare) scanner that provided both conventional and virtual keV images, allowing us to quantitatively compare corrected CT images to virtual keV images. To test these methods' parameter optimization sensitivity to noise, we evaluated results on images obtained using different mAs.

RESULTS

In images of the static phantom, ABHC-2 reduced beam hardening artifacts better than our previous ABHC-1 algorithm, giving artifacts smaller than 1.8 HU, even in the presence of high noise which should affect parameter optimization. Taken together, the quality of static phantom results ordered ABHC-2> ABHC-3> ABHC-1>> ABHC-NH. In an anthropomorphic MPI-CT simulator with homogeneous myocardial blood flow of 100 ml⋅min-1 ⋅100 g-1 , blood flow estimation results were 122 ± 24 (FBP), 135 ± 24 (ABHC-NH), 104 ± 14 (ABHC-1), 100 ± 12 (ABHC-2), and 108 ± 18 (ABHC-3) ml⋅min-1 ⋅100 g-1 , showing ABHC-2 as a clear winner. Visual and quantitative evaluations showed much improved homogeneity of myocardial flow with ABHC-2, nearly eliminating substantial artifacts in uncorrected flow maps which could be misconstrued as flow deficits. ABHC-2 performed universally better than ABHC-1, ABHC-3, and ABHC-NH in simulations with different acquisitions (varying noise and kVp values). In the presence of a simulated flow deficit, all ABHC methods retained the flow deficit, and ABHC-2 gave the most accurate flow ratio and homogeneity. ABHC-3 corrected phantom flow values were slightly better than ABHC-2, in noiseless images, suggesting that reduced quality in noisy images was due to reduced estimability. In an experiment with a pig expected to have uniform flow, ABHC-2 applied to conventional images improved flow maps to compare favorably to those from 70keV images.

CONCLUSION

The automated algorithm can be used with different parametric BH correction models. ABHC-2 improved MPI-CT blood flow estimation as compared to other approaches and was robust to noisy images. In simulation and preclinical experiments, ABHC-2 gave results approaching gold standard 70 keV measurements.

Evaluation of the efficacy of sofosbuvir plus daclatasvir in combination with ribavirin for hospitalized COVID-19 patients with moderate disease compared with standard care: a single-centre, randomized controlled trial

BACKGROUND

New therapeutic options are urgently needed to tackle the novel coronavirus disease 2019 (COVID-19). Repurposing existing pharmaceuticals provides an immediate treatment opportunity. We assessed the efficacy of sofosbuvir and daclatasvir with ribavirin for treating patients with COVID-19.

METHODS

This was a single-centre, randomized controlled trial in adults with moderate COVID-19 admitted to the Ghaem Shahr Razi Hospital in Mazandaran Province, Iran. Patients were randomly assigned to 400 mg sofosbuvir, 60 mg daclatasvir and 1200 mg ribavirin (intervention group) or to standard care (control group). The primary endpoint of this study was length of hospital stay. This study is registered by IRCT.ir under the ID: IRCT20200328046886N1.

RESULTS

Between 20 March 2020 and 8 April 2020, 48 patients were recruited; 24 patients were randomly assigned to the intervention group and 24 to the control group. The median duration of hospital stay was 6 days in both groups (P = 0.398). The number of ICU admissions in the sofosbuvir/daclatasvir/ribavirin group was not significantly lower than the control group (0 versus 4, P = 0.109). There was no difference in the number of deaths between the groups (0 versus 3, P = 0.234). The cumulative incidence of recovery was higher in the sofosbuvir/daclatasvir/ribavirin arm (Gray's P = 0.033).

CONCLUSIONS

This randomized trial was too small to make definitive conclusions. There were trends in favour of the sofosbuvir/daclatasvir/ribavirin arm for recovery and lower death rates. However, there was an imbalance in the baseline characteristics between the arms. Larger randomized trials should be conducted to investigate this treatment further.

Sofosbuvir and daclatasvir compared with standard of care in the treatment of patients admitted to hospital with moderate or severe coronavirus infection (COVID-19): a randomized controlled trial

Background

Currently no effective antiviral therapy has been found to treat COVID-19. The aim of this trial was to assess if the addition of sofosbuvir and daclatasvir improved clinical outcomes in patients with moderate or severe COVID-19.

Methods

This was an open-label, multicentre, randomized controlled clinical trial in adults with moderate or severe COVID-19 admitted to four university hospitals in Iran. Patients were randomized into a treatment arm receiving sofosbuvir and daclatasvir plus standard care, or a control arm receiving standard care alone. The primary endpoint was clinical recovery within 14 days of treatment. The study is registered with IRCT.ir under registration number IRCT20200128046294N2.

Results

Between 26 March and 26 April 2020, 66 patients were recruited and allocated to either the treatment arm (n = 33) or the control arm (n = 33). Clinical recovery within 14 days was achieved by 29/33 (88%) in the treatment arm and 22/33 (67%) in the control arm (P = 0.076). The treatment arm had a significantly shorter median duration of hospitalization [6 days (IQR 4–8)] than the control group [8 days (IQR 5–13)]; P = 0.029. Cumulative incidence of hospital discharge was significantly higher in the treatment arm versus the control (Gray’s P = 0.041). Three patients died in the treatment arm and five in the control arm. No serious adverse events were reported.

Conclusions

The addition of sofosbuvir and daclatasvir to standard care significantly reduced the duration of hospital stay compared with standard care alone. Although fewer deaths were observed in the treatment arm, this was not statistically significant. Conducting larger scale trials seems prudent.

Minimum costs to manufacture new treatments for COVID-19

INTRODUCTION

'Repurposing' existing drugs to treat COVID-19 is vital to reducing mortality and controlling the pandemic. Several promising drugs have been identified and are in various stages of clinical trials globally. If efficacy of these drugs is demonstrated, rapid, mass availability at an affordable cost would be essential to ensuring equity and access especially amongst low- and middle-income economies.

METHODS

Minimum costs of production were estimated from the costs of active pharmaceutical ingredients using established methodology, which had good predictive accuracy for medicines for hepatitis C and HIV amongst others. Data were extracted from global export shipment records or analysis of the route of chemical synthesis. The estimated costs were compared with list prices from a range of countries where pricing data were available.

RESULTS

Minimum estimated costs of production were US $0.93/day for remdesivir, $1.45/day for favipiravir, $0.08/day for hydroxychloroquine, $0.02/day for chloroquine, $0.10/day for azithromycin, $0.28/day for lopinavir/ritonavir, $0.39/day for sofosbuvir/daclatasvir and $1.09/day for pirfenidone. Costs of production ranged between $0.30 and $31 per treatment course (10-28 days). Current prices of these drugs were far higher than the costs of production, particularly in the US.

CONCLUSIONS

Should repurposed drugs demonstrate efficacy against COVID-19, they could be manufactured profitably at very low costs, for much less than current list prices. Estimations for the minimum production costs can strengthen price negotiations and help ensure affordable access to vital treatment for COVID-19 at low prices globally.

Minimum costs to manufacture new treatments for COVID-19

Introduction

‘Repurposing’ existing drugs to treat COVID-19 is vital to reducing mortality and controlling the pandemic. Several promising drugs have been identified and are in various stages of clinical trials globally. If efficacy of these drugs is demonstrated, rapid, mass availability at an affordable cost would be essential to ensuring equity and access especially amongst low- and middle-income economies.

Methods

Minimum costs of production were estimated from the costs of active pharmaceutical ingredients using established methodology, which had good predictive accuracy for medicines for hepatitis C and HIV amongst others. Data were extracted from global export shipment records or analysis of the route of chemical synthesis. The estimated costs were compared with list prices from a range of countries where pricing data were available.

Results

Minimum estimated costs of production were US $0.93/day for remdesivir, $1.45/day for favipiravir, $0.08/day for hydroxychloroquine, $0.02/day for chloroquine, $0.10/day for azithromycin, $0.28/day for lopinavir/ritonavir, $0.39/day for sofosbuvir/daclatasvir and $1.09/day for pirfenidone. Costs of production ranged between $0.30 and $31 per treatment course (10–28 days). Current prices of these drugs were far higher than the costs of production, particularly in the US.

Conclusions

Should repurposed drugs demonstrate efficacy against COVID-19, they could be manufactured profitably at very low costs, for much less than current list prices. Estimations for the minimum production costs can strengthen price negotiations and help ensure affordable access to vital treatment for COVID-19 at low prices globally.

Rare giant inguinal hernia causing end-stage dialysis-dependent renal failure

A 72-year-old man presented with urinary retention, weight loss, haematuria and severe acute kidney injury. He had never before been admitted to hospital and his past medical history included only an inguinal hernia. On examination, he appeared uraemic and had a right-sided painful hernia. A three-way catheter was inserted, bladder washouts performed and irrigation started. An ultrasound showed severe bilateral hydronephrosis and a ‘thickened bladder’ and this was thought to be obstructive uropathy secondary to bladder cancer. Twenty-four hours later his hernia doubled in diameter, became incarcerated and a CT of the abdomen and pelvis showed an inguinal hernia of both bladder and bowel, with the catheter tip inside the bladder hernia. He was taken to theatres and an open mesh repair was performed with a rigid cystoscopy to assist in locating and reducing the bladder. He required intensive care and dialysis postoperatively and remains on regular dialysis following discharge.

SLICR super-voxel algorithm for fast, robust quantification of myocardial blood flow by dynamic computed tomography myocardial perfusion imaging

We created and evaluated a processing method for dynamic computed tomography myocardial perfusion imaging (CT-MPI) of myocardial blood flow (MBF), which combines a modified simple linear iterative clustering algorithm (SLIC) with robust perfusion quantification, hence the name SLICR. SLICR adaptively segments the myocardium into nonuniform super-voxels with similar perfusion time attenuation curves (TACs). Within each super-voxel, an α-trimmed-median TAC was computed to robustly represent the super-voxel and a robust physiological model (RPM) was implemented to semi-analytically estimate MBF. SLICR processing was compared with another voxel-wise MBF preprocessing approach, which included a spatiotemporal bilateral filter (STBF) for noise reduction prior to perfusion quantification. Image data from a digital CT-MPI phantom and a porcine ischemia model were evaluated. SLICR was ∼ 50 -fold faster than voxel-wise RPM and other model-based methods while retaining sufficient resolution to show clinically relevant features, such as a transmural perfusion gradient. SLICR showed markedly improved accuracy and precision, as compared with other methods. At a simulated MBF of 100 mL/min-100 g and a tube current-time product of 100 mAs (50% of nominal), the MBF estimates were 101 ± 12 , 94 ± 56 , and 54 ± 24    mL / min - 100    g for SLICR, the voxel-wise Johnson-Wilson model, and a singular value decomposition-model independent method with STBF, respectively. SLICR estimated MBF precisely and accurately ( 103 ± 23    mL / min - 100    g ) at 25% nominal dose, while other methods resulted in larger errors. With the porcine model, the SLICR results were consistent with the induced ischemia. SLICR simultaneously accelerated and improved the quality of quantitative perfusion processing without compromising clinically relevant distributions of perfusion characteristics.

UK Medical Students' Experience of Culture & Communication in Cuban Health Care

Final-year medical students at UK universities are able to do elective placements elsewhere, to learn about other health care systems. We chose Cuba because of its excellent health outcomes despite relatively few resources. We were struck, for instance, when Cuba made global headlines in 2015 as the first country to eliminate mother-to-child transmission of HIV and syphilis. And, since the UK's underfunded National Health Service is experiencing high demand and increasing pressure, we sought to understand more about Cuba's socialist health system, where health care spending per capita is much lower than the UK's, but life expectancy is almost the same.

Dose intensity in anthracycline-based chemotherapy for metastatic breast cancer: mature results of the randomised clinical trial ANZ 9311

PURPOSE

The separate impacts of dose and dose intensity of chemotherapy for metastatic breast cancer remain uncertain. The primary objective of this trial was to compare a short, high-dose, intensive course of epirubicin and cyclophosphamide (EC) with a longer conventional dose regimen delivering the same total dose of chemotherapy.

METHODS

This open label trial randomised 235 women with metastatic breast cancer to receive either high-dose epirubicin 150 mg/m² and cyclophosphamide 1500 mg/m² with filgrastim support every 3 weeks for 3 cycles (HDEC) or standard dose epirubicin 75 mg/m² and cyclophosphamide 750 mg/m² every 3 weeks for 6 cycles (SDEC). Primary outcomes were time to progression, overall survival and quality of life.

RESULTS

In 118 patients allocated HDEC 90% of the planned dose was delivered, compared to 96% in the 117 participants allocated SDEC. There were no significant differences in the time to disease progression (5.7 vs. 5.8 months, P = 0.19) or overall survival (14.5 vs. 16.5 months, P = 0.29) between HDEC and SDEC, respectively. Patients on HDEC reported worse quality of life during therapy, but scores improved after completion to approximate those reported by patients allocated SDEC. Objective tumour response was recorded in 33 (28%) on HDEC and 42 patients (36%) on SDEC. HDEC produced more haematologic toxicity.

CONCLUSION

For women with metastatic breast cancer, disease progression, survival or quality of life were no better with high-dose intensity compared to standard dose EC chemotherapy. Australian Clinical Trials Registry registration number ACTRN12605000478617.

Calibration-free beam hardening correction for myocardial perfusion imaging using CT

PURPOSE

Computed tomography myocardial perfusion imaging (CT-MPI) and coronary CTA have the potential to make CT an ideal noninvasive imaging gatekeeper exam for invasive coronary angiography. However, beam hardening (BH) artifacts prevent accurate blood flow calculation in CT-MPI. BH correction methods require either energy-sensitive CT, not widely available, or typically, a calibration-based method in conventional CT. We propose a calibration-free, automatic BH correction (ABHC) method suitable for CT-MPI and evaluate its ability to reduce BH artifacts in single "static-perfusion" images and to create accurate myocardial blood flow (MBF) in dynamic CT-MPI.

METHODS

In the algorithm, we used input CT DICOM images and iteratively optimized parameters in a polynomial BH correction until a BH-sensitive cost function was minimized on output images. An input image was segmented into a soft tissue image and a highly attenuating material (HAM) image containing bones and regions of high iodine concentrations, using mean HU and temporal enhancement properties. We forward projected HAM, corrected projection values according to a polynomial correction, and reconstructed a correction image to obtain the current iteration's BH corrected image. The cost function was sensitive to BH streak artifacts and cupping. We evaluated the algorithm on simulated CT and physical phantom images, and on preclinical porcine with optional coronary obstruction and clinical CT-MPI data. Assessments included measures of BH artifact in single images as well as MBF estimates. We obtained CT images on a prototype spectral detector CT (SDCT, Philips Healthcare) scanner that provided both conventional and virtual keV images, allowing us to quantitatively compare corrected CT images to virtual keV images. To stress test the method, we evaluated results on images from a different scanner (iCT, Philips Healthcare) and different kVp values.

RESULTS

In a CT-simulated digital phantom consisting of water with iodine cylinder insets, BH streak artifacts between simulated iodine inserts were reduced from 13 ± 2 to 0 ± 1 HU. In a similar physical phantom having higher iodine concentrations, BH streak artifacts were reduced from 48 ± 6 to 1 ± 5 HU and cupping was reduced by 86%, from 248 to 23 HU. In preclinical CT-MPI images without coronary obstruction, BH artifact was reduced from 24 ± 6 HU to less than 5 ± 4 HU at peak enhancement. Standard deviation across different regions of interest (ROI) along the myocardium was reduced from 13.26 to 6.86 HU for ABHC, comparing favorably to measurements in the corresponding virtual keV image. Corrections greatly reduced variations in preclinical MBF maps as obtained in normal animals without obstruction (FFR = 1). Coefficients of variations were 22% (conventional CT), 9% (ABHC), and 5% (virtual keV). Moreover, variations in flow tended to be localized after ABHC, giving result which would not be confused with a flow deficit in a coronary vessel territory.

CONCLUSION

The automated algorithm can be used to reduce BH artifact in conventional CT and improve CT-MPI accuracy particularly by removing regions of reduced estimated flow which might be misinterpreted as flow deficits.

The role of acquisition and quantification methods in myocardial blood flow estimability for myocardial perfusion imaging CT

In this work, we clarified the role of acquisition parameters and quantification methods in myocardial blood flow (MBF) estimability for myocardial perfusion imaging using CT (MPI-CT). We used a physiologic model with a CT simulator to generate time-attenuation curves across a range of imaging conditions, i.e. tube current-time product, imaging duration, and temporal sampling, and physiologic conditions, i.e. MBF and arterial input function width. We assessed MBF estimability by precision (interquartile range of MBF estimates) and bias (difference between median MBF estimate and reference MBF) for multiple quantification methods. Methods included: six existing model-based deconvolution models, such as the plug-flow tissue uptake model (PTU), Fermi function model, and single-compartment model (SCM); two proposed robust physiologic models (RPM1, RPM2); model-independent singular value decomposition with Tikhonov regularization determined by the L-curve criterion (LSVD); and maximum upslope (MUP). Simulations show that MBF estimability is most affected by changes in imaging duration for model-based methods and by changes in tube current-time product and sampling interval for model-independent methods. Models with three parameters, i.e. RPM1, RPM2, and SCM, gave least biased and most precise MBF estimates. The average relative bias (precision) for RPM1, RPM2, and SCM was  ⩽11% (⩽10%) and the models produced high-quality MBF maps in CT simulated phantom data as well as in a porcine model of coronary artery stenosis. In terms of precision, the methods ranked best-to-worst are: RPM1  >  RPM2  >  Fermi  >  SCM  >  LSVD  >  MUP [Formula: see text] other methods. In terms of bias, the models ranked best-to-worst are: SCM  >  RPM2  >  RPM1  >  PTU  >  LSVD [Formula: see text] other methods. Models with four or more parameters, particularly five-parameter models, had very poor precision (as much as 310% uncertainty) and/or significant bias (as much as 493%) and were sensitive to parameter initialization, thus suggesting the presence of multiple local minima. For improved estimates of MBF from MPI-CT, it is recommended to use reduced models that incorporate prior knowledge of physiology and contrast agent uptake, such as the proposed RPM1 and RPM2 models.

The impact of HIV prevalence, conflict, corruption, and GDP/capita on treatment cascades: data from 137 countries

OBJECTIVE

In 2014, UNAIDS and partners set the 90-90-90 targets for the HIV treatment cascade. Multiple social, political and structural factors might influence progress towards these targets. We assessed how close countries and regions are to reaching these targets, and compared cascade outcomes with HIV prevalence, gross domestic product (GDP)/capita, conflict and corruption.

METHODS

Country-level HIV cascade data on diagnosis, ART coverage and viral suppression, from 2010 to 2016 were extracted from national reports, published papers and the www.AIDSinfoOnline database, and analysed. Weighted least-squares regression was used to assess predictors of cascade achievement: region, HIV prevalence, GDP/capita, the 2016 Corruption Perceptions Index (CPI), which is an international ranking system, and the 2016 Global Peace Index (GPI), which ranks all countries based on three main categories: societal safety, militarisation and conflict.

RESULTS

Data were available for diagnosis for 84 countries, ART coverage for 137 countries, and viral suppression for 94 countries. Regions with the lowest ART coverage were South-east Asia and Pacific (36%), Eastern Europe and Central Asia (17%), and Middle East and North Africa (13%). Lower HIV prevalence was associated with poorer cascade results. Countries with higher GDP/capita achieved higher ART coverage (P<0.001). Furthermore, countries with lower levels of peace and higher corruption had lower ART coverage (P<0.001). Countries with a GPI >2.5 all had ART coverage of <40%.

CONCLUSION

Only one country has reached the UNAIDS 90-90-90 targets. International comparison remains difficult due to heterogeneous data reporting. Difficulty meeting UNAIDS targets is associated with lower GDP/capita, lower HIV prevalence, higher corruption and conflict levels.

SLIC robust (SLICR) processing for fast, robust CT myocardial blood flow quantification

There are several computational methods for estimating myocardial blood flow (MBF) using CT myocardial perfusion imaging (CT-MPI). Previous work has shown that model-based deconvolution methods are more accurate and precise than model-independent methods such as singular value decomposition and max-upslope. However, iterative optimization is computationally expensive and models are sensitive to image noise, thus limiting the utility of low x-ray dose acquisitions. We propose a new processing method, SLICR, which segments the myocardium into super-voxels using a modified simple linear iterative clustering (SLIC) algorithm and quantifies MBF via a robust physiologic model (RPM). We compared SLICR against voxel-wise SVD and voxel-wise model-based deconvolution methods (RPM, single-compartment and Johnson-Wilson). We used image data from a digital CT-MPI phantom to evaluate robustness of processing methods to noise at reduced x-ray dose. We validate SLICR in a porcine model with and without partial occlusion of the LAD coronary artery with known pressure-wire fractional flow reserve. SLICR was ~50 times faster than voxel-wise RPM and other model-based methods while retaining sufficient resolution to show all clinically interesting features (e.g., a flow deficit in the endocardial wall). SLICR showed much better precision and accuracy than the other methods. For example, at simulated MBF=100 mL/min/100g and 100 mAs exposure (50% of nominal dose) in the digital simulator, MBF estimates were 101 ± 12 mL/min/100g, 160 ± 54 mL/min/100g, and 122 ± 99 mL/min/100g for SLICR, SVD, and Johnson-Wilson, respectively. SLICR even gave excellent results (103 ± 23 ml/min/100g) at 50 mAs, corresponding to 25% nominal dose.

Can the UNAIDS 90-90-90 target be achieved? A systematic analysis of national HIV treatment cascades

Background

In 2014, the Joint United Nations Programme on HIV and AIDS (UNAIDS) and partners set the ‘90-90-90 targets’; aiming to diagnose 90% of all HIV positive people, provide antiretroviral therapy (ART) for 90% of those diagnosed and achieve viral suppression for 90% of those treated, by 2020. This results in 81% of all HIV positive people on treatment and 73% of all HIV positive people achieving viral suppression. We aimed to analyse how effective national HIV treatment programmes are at meeting these targets, using HIV care continuums or cascades.

Methods

We searched for HIV treatment cascades for 196 countries in published papers, conference presentations, UNAIDS databases and national reports. Cascades were constructed using reliable, generalisable, recent data from national, cross-sectional and longitudinal study cohorts. Data were collected for four stages; total HIV positive people, diagnosed, on treatment and virally suppressed. The cascades were categorised as complete (four stages) or partial (3 stages), and analysed for ‘break points’ defined as a drop >10% in coverage between consecutive 90-90-90 targets.

Results

69 country cascades were analysed (32 complete, 37 partial). Diagnosis (target one—90%) ranged from 87% (the Netherlands) to 11% (Yemen). Treatment coverage (target two—81% on ART) ranged from 71% (Switzerland) to 3% (Afghanistan). Viral suppression (target three—73% virally suppressed) was between 68% (Switzerland) and 7% (China).

Conclusions

No country analysed met the 90-90-90 targets. Diagnosis was the greatest break point globally, but the most frequent key break point for individual countries was providing ART to those diagnosed. Large disparities were identified between countries. Without commitment to standardised reporting methodologies, international comparisons are complex.

Calibration Free Beam Hardening Correction for Cardiac CT Perfusion Imaging

Myocardial perfusion imaging using CT (MPI-CT) and coronary CTA have the potential to make CT an ideal noninvasive gate-keeper for invasive coronary angiography. However, beam hardening artifacts (BHA) prevent accurate blood flow calculation in MPI-CT. BH Correction (BHC) methods require either energy-sensitive CT, not widely available, or typically a calibration-based method. We developed a calibration-free, automatic BHC (ABHC) method suitable for MPI-CT. The algorithm works with any BHC method and iteratively determines model parameters using proposed BHA-specific cost function. In this work, we use the polynomial BHC extended to three materials. The image is segmented into soft tissue, bone, and iodine images, based on mean HU and temporal enhancement. Forward projections of bone and iodine images are obtained, and in each iteration polynomial correction is applied. Corrections are then back projected and combined to obtain the current iteration's BHC image. This process is iterated until cost is minimized. We evaluate the algorithm on simulated and physical phantom images and on preclinical MPI-CT data. The scans were obtained on a prototype spectral detector CT (SDCT) scanner (Philips Healthcare). Mono-energetic reconstructed images were used as the reference. In the simulated phantom, BH streak artifacts were reduced from 12±2HU to 1±1HU and cupping was reduced by 81%. Similarly, in physical phantom, BH streak artifacts were reduced from 48±6HU to 1±5HU and cupping was reduced by 86%. In preclinical MPI-CT images, BHA was reduced from 28±6 HU to less than 4±4HU at peak enhancement. Results suggest that the algorithm can be used to reduce BHA in conventional CT and improve MPI-CT accuracy.

Quantitative myocardial perfusion imaging in a porcine ischemia model using a prototype spectral detector CT system

We optimized and evaluated dynamic myocardial CT perfusion (CTP) imaging on a prototype spectral detector CT (SDCT) scanner. Simultaneous acquisition of energy sensitive projections on the SDCT system enabled projection-based material decomposition, which typically performs better than image-based decomposition required by some other system designs. In addition to virtual monoenergetic, or keV images, the SDCT provided conventional (kVp) images, allowing us to compare and contrast results. Physical phantom measurements demonstrated linearity of keV images, a requirement for quantitative perfusion. Comparisons of kVp to keV images demonstrated very significant reductions in tell-tale beam hardening (BH) artifacts in both phantom and pig images. In phantom images, consideration of iodine contrast to noise ratio and small residual BH artifacts suggested optimum processing at 70 keV. The processing pipeline for dynamic CTP measurements included 4D image registration, spatio-temporal noise filtering, and model-independent singular value decomposition deconvolution, automatically regularized using the L-curve criterion. In normal pig CTP, 70 keV perfusion estimates were homogeneous throughout the myocardium. At 120 kVp, flow was reduced by more than 20% on the BH-hypo-enhanced myocardium, a range that might falsely indicate actionable ischemia, considering the 0.8 threshold for actionable FFR. With partial occlusion of the left anterior descending (LAD) artery (FFR < 0.8), perfusion defects at 70 keV were correctly identified in the LAD territory. At 120 kVp, BH affected the size and flow in the ischemic area; e.g. with FFR ≈ 0.65, the anterior-to-lateral flow ratio was 0.29 ± 0.01, over-estimating stenosis severity as compared to 0.42 ± 0.01 (p < 0.05) at 70 keV. On the non-ischemic inferior wall (not a LAD territory), the flow ratio was 0.50 ± 0.04 falsely indicating an actionable ischemic condition in a healthy territory. This ratio was 1.00 ± 0.08 at 70 keV. Results suggest that projection-based keV imaging with the SDCT system and proper processing could enable useful myocardial CTP, much improved over conventional CT.

Effect of Beam Hardening on Transmural Myocardial Perfusion Quantification in Myocardial CT Imaging

The detection of subendocardial ischemia exhibiting an abnormal transmural perfusion gradient (TPG) may help identify ischemic conditions due to micro-vascular dysfunction. We evaluated the effect of beam hardening (BH) artifacts on TPG quantification using myocardial CT perfusion (CTP). We used a prototype spectral detector CT scanner (Philips Healthcare) to acquire dynamic myocardial CTP scans in a porcine ischemia model with partial occlusion of the left anterior descending (LAD) coronary artery guided by pressure wire-derived fractional flow reserve (FFR) measurements. Conventional 120 kVp and 70 keV projection-based mono-energetic images were reconstructed from the same projection data and used to compute myocardial blood flow (MBF) using the Johnson-Wilson model. Under moderate LAD occlusion (FFR~0.7), we used three 5 mm short axis slices and divided the myocardium into three LAD segments and three remote segments. For each slice and each segment, we characterized TPG as the mean "endo-to-epi" transmural flow ratio (TFR). BH-induced hypoenhancement on the ischemic anterior wall at 120 kVp resulted in significantly lower mean TFR value as compared to the 70 keV TFR value (0.29±0.01 vs. 0.55±0.01; p<1e-05). No significant difference was measured between 120 kVp and 70 keV mean TFR values on segments moderately affected or unaffected by BH. In the entire ischemic LAD territory, 120 kVp mean endocardial flow was significantly reduced as compared to mean epicardial flow (15.80±10.98 vs. 40.85±23.44 ml/min/100g; p<1e-04). At 70 keV, BH was effectively minimized resulting in mean endocardial MBF of 40.85±15.3407 ml/min/100g vs. 74.09±5.07 ml/min/100g (p=0.0054) in the epicardium. We also found that BH artifact in the conventional 120 kVp images resulted in falsely reduced MBF measurements even under non-ischemic conditions.

Comparison of quantitative myocardial perfusion imaging CT to fluorescent microsphere-based flow from high-resolution cryo-images

Myocardial perfusion imaging using CT (MPI-CT) has the potential to provide quantitative measures of myocardial blood flow (MBF) which can aid the diagnosis of coronary artery disease. We evaluated the quantitative accuracy of MPI-CT in a porcine model of balloon-induced LAD coronary artery ischemia guided by fractional flow reserve (FFR). We quantified MBF at baseline (FFR=1.0) and under moderate ischemia (FFR=0.7) using MPI-CT and compared to fluorescent microsphere-based MBF from high-resolution cryo-images. Dynamic, contrast-enhanced CT images were obtained using a spectral detector CT (Philips Healthcare). Projection-based mono-energetic images were reconstructed and processed to obtain MBF. Three MBF quantification approaches were evaluated: singular value decomposition (SVD) with fixed Tikhonov regularization (ThSVD), SVD with regularization determined by the L-Curve criterion (LSVD), and Johnson-Wilson parameter estimation (JW). The three approaches over-estimated MBF compared to cryo-images. JW produced the most accurate MBF, with average error 33.3±19.2mL/min/100g, whereas LSVD and ThSVD had greater over-estimation, 59.5±28.3mL/min/100g and 78.3±25.6 mL/min/100g, respectively. Relative blood flow as assessed by a flow ratio of LAD-to-remote myocardium was strongly correlated between JW and cryo-imaging, with R²=0.97, compared to R²=0.88 and 0.78 for LSVD and ThSVD, respectively. We assessed tissue impulse response functions (IRFs) from each approach for sources of error. While JW was constrained to physiologic solutions, both LSVD and ThSVD produced IRFs with non-physiologic properties due to noise. The L-curve provided noise-adaptive regularization but did not eliminate non-physiologic IRF properties or optimize for MBF accuracy. These findings suggest that model-based MPI-CT approaches may be more appropriate for quantitative MBF estimation and that cryo-imaging can support the development of MPI-CT by providing spatial distributions of MBF.

Target prices for mass production of tyrosine kinase inhibitors for global cancer treatment

OBJECTIVE

To calculate sustainable generic prices for 4 tyrosine kinase inhibitors (TKIs).

BACKGROUND

TKIs have proven survival benefits in the treatment of several cancers, including chronic myeloid leukaemia, breast, liver, renal and lung cancer. However, current high prices are a barrier to treatment. Mass production of low-cost generic antiretrovirals has led to over 13 million people being on HIV/AIDS treatment worldwide. This analysis estimates target prices for generic TKIs, assuming similar methods of mass production.

METHODS

Four TKIs with patent expiry dates in the next 5 years were selected for analysis: imatinib, erlotinib, lapatinib and sorafenib. Chemistry, dosing, published data on per-kilogram pricing for commercial transactions of active pharmaceutical ingredient (API), and quotes from manufacturers were used to estimate costs of production. Analysis included costs of excipients, formulation, packaging, shipping and a 50% profit margin. Target prices were compared with current prices. Global numbers of patients eligible for treatment with each TKI were estimated.

RESULTS

API costs per kg were $347-$746 for imatinib, $2470 for erlotinib, $4671 for lapatinib, and $3000 for sorafenib. Basing on annual dose requirements, costs of formulation/packaging and a 50% profit margin, target generic prices per person-year were $128-$216 for imatinib, $240 for erlotinib, $1450 for sorafenib, and $4020 for lapatinib. Over 1 million people would be newly eligible to start treatment with these TKIs annually.

CONCLUSIONS

Mass generic production of several TKIs could achieve treatment prices in the range of $128-$4020 per person-year, versus current US prices of $75161-$139,138. Generic TKIs could allow significant savings and scaling-up of treatment globally, for over 1 million eligible patients.

Dynamic Myocardial Perfusion in a Porcine Balloon-induced Ischemia Model using a Prototype Spectral Detector CT

Myocardial CT perfusion (CTP) imaging is an application that should greatly benefit from spectral CT through the significant reduction of beam hardening (BH) artifacts using mono-energetic (monoE) image reconstructions. We used a prototype spectral detector CT (SDCT) scanner (Philips Healthcare) and developed advanced processing tools (registration, segmentation, and deconvolution-based flow estimation) for quantitative myocardial CTP in a porcine ischemia model with different degrees of coronary occlusion using a balloon catheter. The occlusion severity was adjusted with fractional flow reserve (FFR) measurements. The SDCT scanner is a single source, dual-layer detector system, which allows simultaneous acquisitions of low and high energy projections, hence enabling accurate projection-based material decomposition and effective reduction of BH-artifacts. In addition, the SDCT scanner eliminates partial scan artifacts with fast (0.27s), full gantry rotation acquisitions. We acquired CTP data under different hemodynamic conditions and reconstructed conventional 120kVp images and projection-based monoenergetic (monoE) images for energies ranging from 55keV-to-120keV. We computed and compared myocardial blood flow (MBF) between different reconstructions. With balloon completely deflated (FFR=1), we compared the mean attenuation in a myocardial region of interest before iodine arrival and at peak iodine enhancement in the left ventricle (LV), and we found that monoE images at 70keV effectively minimized the difference in attenuation, due to BH, to less than 1 HU compared to 14 HU with conventional 120kVp images. Flow maps under baseline condition (FFR=1) were more uniform throughout the myocardial wall at 70keV, whereas with 120kVp data about 12% reduction in blood flow was noticed on BH-hypoattenuated areas compared to other myocardial regions. We compared MBF maps at different keVs under an ischemic condition (FFR < 0.7), and we found that flow-contrast-to-noise-ratio (CNR f ) between LAD ischemic and remote healthy territories attains its maximum (2.87 ± 0.7) at 70keV. As energies diverge from 70keV, we noticed a steady decrease in CNRf and an overestimation of mean-MBF. Flow overestimation was also noticed for conventional 120kVp images in different myocardial regions.

Hepatic leptin signalling and subdiaphragmatic vagal efferents are not required for leptin-induced increases of plasma IGF binding protein-2 (IGFBP-2) in ob/ob mice

AIMS/HYPOTHESIS

The fat-derived hormone leptin plays a crucial role in the maintenance of normal body weight and energy expenditure as well as in glucose homeostasis. Recently, it was reported that the liver-derived protein, insulin-like growth factor binding protein-2 (IGFBP-2), is responsible for at least some of the glucose-normalising effects of leptin. However, the exact mechanism by which leptin upregulates IGFBP-2 production is unknown. Since it is believed that circulating IGFBP-2 is predominantly derived from the liver and leptin has been shown to have both direct and indirect actions on the liver, we hypothesised that leptin signalling in hepatocytes or via brain-liver vagal efferents may mediate leptin control of IGFBP-2 production.

METHODS

To address our hypothesis, we assessed leptin action on glucose homeostasis and plasma IGFBP-2 levels in both leptin-deficient ob/ob mice with a liver-specific loss of leptin signalling and ob/ob mice with a subdiaphragmatic vagotomy. We also examined whether restoring hepatic leptin signalling in leptin receptor-deficient db/db mice could increase plasma IGFBP-2 levels.

RESULTS

Continuous leptin administration increased plasma IGFBP-2 levels in a dose-dependent manner, in association with reduced plasma glucose and insulin levels. Interestingly, leptin was still able to increase plasma IGFBP-2 levels and improve glucose homeostasis in both ob/ob mouse models to the same extent as their littermate controls. Further, restoration of hepatic leptin signalling in db/db mice did not increase either hepatic or plasma IGFBP-2 levels.

CONCLUSIONS/INTERPRETATION

Taken together, these data indicate that hepatic leptin signalling and subdiaphragmatic vagal inputs are not required for leptin upregulation of plasma IGFBP-2 nor blood glucose lowering in ob/ob mice.

Phase II trial of capecitabine and docetaxel as second line therapy for locally advanced and metastatic pancreatic cancer

15029

Background: Docetaxel and Capecitabine in combination are synergistic in preclinical models. The role of second line chemotherapy in pancreatic cancer is palliative and the role under investigation. Methods: Capecitabine 800 mg/m2 PO bid on days 1–14 in combination with docetaxel 30 mg/m2 IV on days 1 and 8 of each 21-day cycle were given to patients with advanced and metastatic pancreatic cancer previously treated with Gemcitabine. A 3-stage sequential design phase II trial was used with early stopping rules for efficacy at 13 and 26 enrolled patients Results: Twenty-four patients are evaluable for toxicity and evaluable for response. Thirteen are females and 11 male patients. Median age was 65 years. ECOG PS was as follows: PS 0: 2 patients; PS 1: 15 patients; PS 2: 5 patients. Three patients achieved a PR, with a RR of 12.5%. Stable disease for 2 or more cycles was observed in 70.8% of patients (n=17). 45 % (n=11) of patients had a 50% or more decrease in CA 19–9 levels. Treatment was well tolerated with no toxic deaths. Grade III and IV toxicities consisted of fatigue in 4 pts (17%); hand-foot syndrome in 4 patients (17%); diarrhea, anemia and mucositis in 2 patients (9%) and peripheral neuropathy in one patient (4%) Conclusions: The combination of capecitabine and docetaxel is active and well tolerated in pancreatic cancer previously treated with gemcitabine based-therapy. Enrollment continues.

[Table: see text]

A phase II trial of capecitabine and docetaxel in patients with previously treated pancreatic cancer

14111

Background: There is no accepted standard treatment for patients with advanced pancreatic cancer who progress after gemcitabine-based therapy. Capecitabine and docetaxel have single-agent activity in pancreatic cancer and have documented synergy in both pre-clinical models and in the treatment of other solid tumors. Methods: A phase II trial with a 3-stage sequential design was planned to assess the efficacy (primary end-point: response rate) and toxicity of capecitabine 800 mg/m2 PO bid on days 1–14 in combination with docetaxel 30 mg/m2 IV on days 1 and 8 of each 21-day cycle in patients with advanced pancreatic cancer who failed first-line gemcitabine-based chemotherapy. If no responses are observed after 13 patients or less than 3 responses are seen after 26 patients, accrual will stop and the combination deemed ineffective. Results: Eight patients have been enrolled (5 women, 3 men). Median age was 67 years. ECOG PS was as follows: PS 1, three patients; PS 2, five patients. All patients had adequate organ function. A total of 26 cycles have been administered (median: 2 cycles, range 1 to 8). Four patients had stable disease (median duration 9 weeks, range 6 to 24), and 3 had progressed at the time of first evaluation (2 cycles). One patient has not yet completed 2 cycles and is therefore not assessable for radiologic response. Out of 7 patients with an elevated CA 19–9, four had a decrease of 50% or greater while on chemotherapy. Grade 1 or 2 toxicity was seen in 3 patients (diarrhea, 1 patient; fatigue, 2 patients). Grade 3 or 4 toxicity was as follows: fatigue, 2 patients; dehydration, 1 patient; neuropathy, 1 patient. There were no treatment related deaths. Enrollment continues. Efficacy data fulfilling the first stage sequential design should be available at the time of the meeting. Median survival for all patients is currently 13 weeks (range 7–23 weeks) Conclusions: Capecitabine in combination with docetaxel is a well-tolerated regimen in the treatment of patients with pancreatic cancer who have failed prior gemcitabine-based therapy. Four out of 8 patients have had stable disease. Four of 7 patients have had a decrease of 50% or greater in CA 19.9 levels. Enrollment continues. Median survival of 13 weeks underscores the poor prognosis of this patient population.

[Table: see text]

Phase I study of docetaxel plus ifosfamide in patients with advanced cancer

The aim of this study was to determine the maximum tolerated dose of a fixed dose of docetaxel when combined with continuous infusion ifosfamide, with and without G-CSF support, in the treatment of advanced cancer, and to evaluate anti-tumour activity of this combination. Thirty-one patients with advanced malignancies were treated with docetaxel 75 mg/m(2) intravenously on days 1, and ifosfamide at increasing dose levels from 1500 mg/m(2)/day to 2750 mg/m(2)/day as a continuous infusion from day 1-3, every 3 weeks. A total of 107 cycles of treatment were administered. Without G-CSF support dose-limiting toxicity of grade 4 neutropenia greater than 5 days duration occurred at dose level 1. With the addition of G-CSF the maximum tolerated dose was docetaxel 75 mg/m(2) on day 1 and ifosfamide 2750 mg/m(2)/day on days 1-3. Dose limiting toxicity (DLT) included ifosfamide-induced encephalopathy, febrile neutropenia and grade three mucositis. Three complete responses and 3 partial responses were seen. This combination of docetaxel and infusional ifosfamide is feasible and effective. The recommended dose for future phase II studies is docetaxel 75 mg/m(2) on day 1 and ifosfamide 2500 mg/m(2)/day continuous infusion on days 1-3.

New approaches to HIV surveillance: means and ends. Summary report of conference held at Yale University, 21-22 May 1998, by the Law, Policy and Ethics Core, Center for Interdisciplinary Research on AIDS, Yale University

A system of HIV surveillance based on AIDS case reporting is no longer adequate to monitor the epidemic of HIV/AIDS in the U.S. We are now faced with the challenge of designing an effective system of HIV surveillance. The "New Approaches to HIV Surveillance: Means and Ends" conference emphasized that there are several alternatives, each with strengths and limitations. The CDC has recommended that all states adopt a system of HIV surveillance based on case reporting. Although it has not specified that such systems need be name-based, CDC appears to reward states that adopt name-reporting systems. The rationale for this stance should be reviewed and made explicit. Name reporting may be superior in some respects to a system of case reports based on unique identifiers (UIs), especially in its greater ability to link surveillance activities to follow up at the individual level. Neither a name-reporting nor a UI approach to case reporting would provide HIV incidence data. The only currently envisioned means of providing incidence data is statistical estimation based on "snapshot estimates" of HIV incidence in sample cohorts. Calibration of this new instrument for HIV incidence estimation against existing data or through field trials is of critical importance.