Abiraterone for Prostate Cancer Not Previously Treated with Hormone Therapy

BACKGROUND

Abiraterone acetate plus prednisolone improves survival in men with relapsed prostate cancer. We assessed the effect of this combination in men starting long-term androgen-deprivation therapy (ADT), using a multigroup, multistage trial design.

METHODS

We randomly assigned patients in a 1:1 ratio to receive ADT alone or ADT plus abiraterone acetate (1000 mg daily) and prednisolone (5 mg daily) (combination therapy). Local radiotherapy was mandated for patients with node-negative, nonmetastatic disease and encouraged for those with positive nodes. For patients with nonmetastatic disease with no radiotherapy planned and for patients with metastatic disease, treatment continued until radiologic, clinical, or prostate-specific antigen (PSA) progression; otherwise, treatment was to continue for 2 years or until any type of progression, whichever came first. The primary outcome measure was overall survival. The intermediate primary outcome was failure-free survival (treatment failure was defined as radiologic, clinical, or PSA progression or death from prostate cancer).

RESULTS

A total of 1917 patients underwent randomization from November 2011 through January 2014. The median age was 67 years, and the median PSA level was 53 ng per milliliter. A total of 52% of the patients had metastatic disease, 20% had node-positive or node-indeterminate nonmetastatic disease, and 28% had node-negative, nonmetastatic disease; 95% had newly diagnosed disease. The median follow-up was 40 months. There were 184 deaths in the combination group as compared with 262 in the ADT-alone group (hazard ratio, 0.63; 95% confidence interval [CI], 0.52 to 0.76; P<0.001); the hazard ratio was 0.75 in patients with nonmetastatic disease and 0.61 in those with metastatic disease. There were 248 treatment-failure events in the combination group as compared with 535 in the ADT-alone group (hazard ratio, 0.29; 95% CI, 0.25 to 0.34; P<0.001); the hazard ratio was 0.21 in patients with nonmetastatic disease and 0.31 in those with metastatic disease. Grade 3 to 5 adverse events occurred in 47% of the patients in the combination group (with nine grade 5 events) and in 33% of the patients in the ADT-alone group (with three grade 5 events).

CONCLUSIONS

Among men with locally advanced or metastatic prostate cancer, ADT plus abiraterone and prednisolone was associated with significantly higher rates of overall and failure-free survival than ADT alone. (Funded by Cancer Research U.K. and others; STAMPEDE ClinicalTrials.gov number, NCT00268476 , and Current Controlled Trials number, ISRCTN78818544 .).

Adding abiraterone for men with high-risk prostate cancer (PCa) starting long-term androgen deprivation therapy (ADT): Survival results from STAMPEDE (NCT00268476)

LBA5003

Background: Abiraterone showed a survival advantage in men with castration-refractory prostate cancer. We assessed whether abiraterone would work earlier in the disease. STAMPEDE is a randomized controlled trial using a multi-arm multi-stage platform design. It recruits patients (pts) with high-risk locally advanced or metastatic PCa starting long-term ADT. We report the first comparative survival data. Methods: The standard-of-care (SOC) was ADT for 2+yrs; radiotherapy (RT) was mandated for men with N0M0 disease & encouraged for N+M0. Stratified randomization allocated pts 1:1 to SOC or SOC+abiraterone 1000mg + prednisolone 5mg daily. Treatment duration depended on stage & intent to give radical RT: pts not having RT or M1 disease, treatment continued until PSA, radiological & clinical progression; otherwise treatment continued until the earlier of 2 years or all types of progression. The primary outcome measure was death from any cause. Comparison to control for survival had 90% power at 2.5% 1-sided alpha for hazard ratio (HR) of 0.75, requiring ~267 control arm deaths, accounting for 3 intermediate lack-of-benefit analyses on failure-free survival (FFS). Analyses used Cox proportional hazards & flexible parametric models, adjusted for stratification factors. Results: 1,917 pts were contemporaneously randomized to these arms (Nov 2011- Jan 2014). Groups were balanced: median age 67yrs; 52% metastatic, 20% N+/X M0, 28% N0M0; 95% newly-diagnosed; median PSA 53ng/ml. Median follow-up was 40m. There were 262 control arm deaths (82% PCa). The adjusted HR = 0.63 (95% CI 0.52-0.76; p=0.115x10-7; 184 deaths) for SOC+Abi vs SOC, with 3yr OS improved from 76% to 83%. There were 535 control arm FFS events; the adjusted HR = 0.29 (95% CI 0.25-0.34; p = 0.377x10-63, 248 FFS events) for SOC+Abi vs SOC. Grade 3 & 4 adverse events were seen in 29% & 3% SOC, 41% & 5% SOC+Abi; Grade 5: 3 & 9 (1 & 2 related). Conclusions: The results show a clinically & statistically significant effect on overall survival & failure-free survival from adding abiraterone at start of ADT with a manageable increase in toxicity. ADT (+/- RT) + abiraterone is a new standard of care for this group. Clinical trial information: NCT00268476.

Adding abiraterone for men with high-risk prostate cancer (PCa) starting long-term androgen deprivation therapy (ADT): Survival results from STAMPEDE (NCT00268476)

LBA5003

The full, final text of this abstract will be available at abstracts.asco.org at 7:30 AM (EDT) on Saturday, June 3, 2017, and in the Annual Meeting Proceedings online supplement to the June 20, 2017, issue of the Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Saturday edition of ASCO Daily News.

Are current case-finding methods under-diagnosing tuberculosis among women in Myanmar? An analysis of operational data from Yangon and the nationwide prevalence survey

Background

Although there is a large increase in investment for tuberculosis control in Myanmar, there are few operational analyses to inform policies. Only 34 % of nationally reported cases are from women. In this study, we investigate sex differences in tuberculosis diagnoses in Myanmar in order to identify potential health systems barriers that may be driving lower tuberculosis case finding among women.

Methods

From October 2014 to March 2015, we systematically collected data on all new adult smear positive tuberculosis cases in ten township health centres across Yangon, the largest city in Myanmar, to produce an electronic tuberculosis database. We conducted a descriptive cross-sectional analysis of sex differences in tuberculosis diagnoses at the township health centres. We also analysed national prevalence survey data to calculate additional case finding in men and women by using sputum culture when smear microscopy was negative, and estimated the sex-specific impact of using a more sensitive diagnostic tool at township health centres.

Results

Overall, only 514 (30 %) out of 1371 new smear positive tuberculosis patients diagnosed at the township health centres were female. The proportion of female patients varied by township (from 21 % to 37 %, p = 0.0172), month of diagnosis (37 % in February 2015 and 23 % in March 2015 p = 0.0004) and age group (26 % in 25–64 years and 49 % in 18–25 years, p < 0.0001). Smear microscopy grading of sputum specimens was not substantially different between sexes. The prevalence survey analysis indicated that the use of a more sensitive diagnostic tool could result in the proportion of females diagnosed at township health centres increasing to 36 % from 30 %.

Conclusions

Our study, which is the first to systematically compile and analyse routine operational data from tuberculosis diagnostic centres in Myanmar, found that substantially fewer women than men were diagnosed in all study townships. The sex ratio of newly diagnosed cases varied by age group, month of diagnosis and township of diagnosis. Low sensitivity of tuberculosis diagnosis may lead to a potential under-diagnosis of tuberculosis among women.

Primary care management of early stage chronic lymphocytic leukaemia is safe and effective

BACKGROUND

Chronic lymphocytic leukaemia (CLL) is the commonest leukaemia in western society. Most patients are detected incidentally at an early stage and require 'watch and wait' follow-up. In the UK, management of Stage A0 CLL varies with some centres advising regular outpatient haematology follow-up, whereas others recommend management within primary care. The safety and effectiveness of these two management options are currently unknown.

METHODS

An observational retrospective cohort study in outpatient Haematology clinics at Queen Elizabeth Hospital Birmingham (QEH) and Birmingham Heartlands Hospital (BHH) and primary care practices in West Midlands, UK. All patients diagnosed with stable stage A0 CLL since 2002 at BHH or QEH were identified. At BHH, patients were discharged to primary care follow-up, whilst QEH patients remained under haematology for follow-up. Evidence of disease progression, need for treatment and overall mortality was documented.

RESULTS

Two hundred and forty-six Stage A0 CLL patients were identified. One hundred and five (43%) patients were discharged to primary care, whilst 141 (57%) patients were followed up in haematology outpatient clinics. No difference in mortality or need for treatment was found between the two groups. Of those discharged, 93 (66%) remained in primary care.

CONCLUSION

The management of stable-stage A0 CLL within primary or secondary care leads to equivalent clinical outcomes. The prevalence of early-stage CLL is expected to increase with the ageing population and management within primary care should be considered as a potentially effective approach.

Alternative mechanisms of respiratory syncytial virus clearance in perforin knockout mice lead to enhanced disease

Virus-specific cytotoxic T lymphocytes are key effectors for the clearance of virus-infected cells and are required for the normal clearance of respiratory syncytial virus (RSV) in mice. Although perforin/granzyme-mediated lysis of infected cells is thought to be the major molecular mechanism used by CD8(+) cytotoxic T lymphocytes for elimination of virus, its role in RSV has not been reported. Here, we show that viral clearance in perforin knockout (PKO) mice is slightly delayed but that both PKO and wild-type mice clear virus by day 10, suggesting an alternative mechanism of RSV clearance. Effector T cells from the lungs of both groups of mice were shown to lyse Fas (CD95)-overexpressing target cells in greater numbers than target cells expressing low levels of Fas, suggesting that Fas ligand (CD95L)-mediated target cell lysis was occurring in vivo. This cell lysis was associated with a delay in RSV-induced disease in PKO mice compared to the time of disease onset for wild-type controls, which correlated with increased and prolonged production of gamma interferon and tumor necrosis factor alpha levels in PKO mice. We conclude that while perforin is not necessary for the clearance of primary RSV infection, the use of alternative CTL target cell killing mechanisms is less efficient and can lead to enhanced disease.

Promotion of insecticide-treated mosquito nets in Myanmar

A simple health promotion message administered by village midwives raised bednet usage to over 60% in trial hamlets in north Shan State, Myanmar. Treatment of the nets in the study villages produced a reduction in malaria cases. Most villagers were prepared to buy their nets at market prices and were willing to pay for the cost of re-treatment of nets, but very poor, members of the Wa ethnic group required a half-price subsidy for them to afford them. The use of insecticide treated bednets was felt to be appropriate for undeveloped and remote areas of the country where malaria control was difficult.

IL-4 diminishes perforin-mediated and increases Fas ligand-mediated cytotoxicity In vivo

CTL have evolved two major mechanisms for target cell killing: one mediated by perforin/granzyme secretion and the other by Fas/Fas ligand (L) interaction. Although cytokines are integral to the development of naive CTL into cytolytic effectors, the role of cytokines on mechanisms of CTL killing is just emerging. In this study, we evaluate the effects of IL-4 in Fas(CD95)/FasL(CD95L)-mediated killing of Fas-overexpressing target cells. Recombinant vaccinia viruses (vv) were constructed to express respiratory syncytial virus M2 Ag alone (vvM2) or coexpress M2 and IL-4 (vvM2/IL-4). MHC-matched Fas-overexpressing target cells (L1210Fas+) were used to measure both perforin- and FasL-mediated killing pathways. In contrast to Fas-deficient (L1210Fas-) target cells, effectors from vvM2/IL-4-immunized mice were able to lyse L1210Fas+ target cells with similar magnitude as vvM2-infected mice. Addition of EGTA/Mg2+ revealed that effectors from vvM2/IL-4-infected mice primarily lyse targets by a Ca2+-independent Fas/FasL pathway. Analysis of FasL expression by flow cytometry showed that IL-4 increased cell surface FasL expression on CD4+ and CD8+ splenocytes, with peak expression on day 4 after infection. These data demonstrate that IL-4 increases FasL expression on T cells, resulting in a shift of the mechanism of CTL killing from a dominant perforin-mediated cytolytic pathway to a dominant FasL-mediated cytolytic pathway.

Interleukin-4 diminishes CD8(+) respiratory syncytial virus-specific cytotoxic T-lymphocyte activity in vivo

Although interleukin-4 (IL-4) has been implicated in respiratory syncytial virus (RSV)-enhanced disease, the mechanism by which it modulates immune responses to primary RSV infection remains unclear. We have developed a system to investigate the effect of IL-4 on RSV epitope-specific cytotoxic T-lymphocyte (CTL) effector function in vivo, using an H-2K(d)-restricted RSV M2 epitope. BALB/c mice were infected with recombinant vaccinia virus (rVV) constructed to express RSV M2 protein (vvM2) alone or coexpress M2 and IL-4 (vvM2/IL-4). Splenocytes were assessed for M2-specific CTL activity in a direct (51)Cr release assay and intracellular gamma interferon (IFN-gamma) production by fluorescence-activated cell sorting analysis. Mice infected with vvM2/IL-4 had less M2-specific primary CTL activity than those infected with vvM2. M2-specific CTL frequency, as measured by M2 peptide-induced intracellular IFN-gamma production, was diminished in the vvM2/IL-4 group, partially accounting for the reduction of CTL activity. Mice immunized with either construct were challenged intravenously with RSV 4 weeks postimmunization, and direct CTL were measured. These results demonstrate that local expression of IL-4, at the time of antigen presentation, diminishes the cytolytic activity of primary and memory CD8(+) RSV-specific CTL responses in vivo.

Acceptance of short course artesunate plus mefloquine drug combination by malaria patients in rural Myanmar

A cross sectional study was carried out in a rural area of Myanmar to identify malaria patients' acceptance of artesunate plus mefloquine drug combination and to determine the cost borne by patients. The majority (88.5%) preferred this new regimen rather than the other ones they had used before; conviction of drug efficacy was the reason given for the preference by most of them. Traveling on foot to rural health centers or a health assistant's residence for getting the drugs was found to be the main route. Average cost incurred by a patient to get the drug was found to be 274.22 Kyats. Among the cost items, drug cost was the highest item that they had used.

Response of falciparum malaria to different antimalarials in Myanmar

The purpose of the study was to ascertain the therapeutic efficacy of different treatments for uncomplicated falciparum malaria in the hospitals in Sagaing, northern and eastern Shan, to facilitate updating the existing national antimalarial drug policy. The proposed 14-day trial for monitoring the efficacy of treatments of uncomplicated falciparum malaria is an efficient method for identifying treatment failure patterns at the intermediate level (township hospital) in the Union of Myanmar. Minimal clinical and parasitological data for days 0-14 were required to classify treatment failure and success. Clinical and parasitiological responses on day 3 and days 4-14 were used as clear examples of early and late treatment failure, respectively. Mefloquine is five times more likely to be effective than chloroquine and sulfadoxine pyrimethamine (S-P), whereas chloroquine and S-P treatments have nearly identical failure patterns. The alarming frequency of clinical and parasitological failure (failure rate > 50%) following chloroquine treatment was reported in Sagaing and following S-P treatment in Sagaing and eastern Shan.

Hospital-based study of severe malaria and associated deaths in Myanmar

The present study identifies factors that contribute to malaria deaths in township hospitals reporting large numbers of such deaths in Myanmar. Between July and December 1995, we identified a total of 101 patients with severe and complicated malaria by screening the cases admitted to hospital with a primary diagnosis of falciparum malaria. Unrousable coma and less marked impairment of consciousness with or without other severe malaria complications, in contrast to severe malaria anaemia, were associated with all malaria deaths. Adult patients with severe malaria were 2.8 times more likely to die than child patients, with the higher risk of death among adults probably being associated with previous exposure to malaria, delay in seeking treatment and severity of the illness before admission. In view of this, we consider that malaria mortality could be reduced by improving peripheral facilities for the management of severe malaria and providing appropriate education to communities, without stepping up vector control activities.

Influence of blister packaging on the efficacy of artesunate + mefloquine over artesunate alone in community-based treatment of non-severe falciparum malaria in Myanmar

Three studies were carried out to determine the need, acceptability, and efficacy of adding mefloquine to artemisinin derivatives (AD) for the first-line treatment of uncomplicated falciparum malaria. The first was a retrospective study of 255 basic health workers which showed that their recommendation of AD to patients depended on their level of training. None of the paramedics/midwives and only 9% of 129 doctors had prescribed AD, and no one had recommended AD in combination with mefloquine; 72% of patients used courses that were too short for parasitological cure. To promote the addition of mefloquine to AD regimens we conducted intervention workshops with health care providers and subsidized the cost of mefloquine to patients. In the second study, we interviewed 200 patients before and after the intervention to evaluate drug compliance with full doses of AD and use of subsidized mefloquine. After the intervention, we found that only 3.6% had used mefloquine and 62% had taken non-curative doses of AD. In the third study, we provided blister packs of medication in daily doses and compared the intake of AD + placebo (158 patients) with that of AD + mefloquine (222 patients) for 5 days. The compliance with both regimens was 99%. Blood smears for parasites on day 28 showed one positive in the AD + mefloquine group and 7 positive in the AD group. We conclude that provision of blister packs of daily doses is a very effective way to improve compliance with short courses and drug combinations, but the efficacy of the combination in Myanmar in this particular study was only marginally higher than that of AD alone.

Overexpression of interleukin-4 delays virus clearance in mice infected with respiratory syncytial virus

Although interleukin-4 (IL-4) expression has been implicated in vaccine-enhanced respiratory syncytial virus (RSV) disease, its role in mediating the immune response to primary RSV infection remains unclear. To assess the effect of IL-4 production on typical RSV infection, transgenic mice which either overexpress or fail to express IL-4 were challenged intranasally with RSV and their responses were compared to those of the parent strains. IL-4-deficient mice eliminated virus from the lung as quickly as did C57BL/6 controls. In contrast, mice which constitutively overexpress IL-4 showed delayed virus clearance compared with mice of the FVB/N control strain, although peak viral titers did not differ. IL-4 overexpression increased the magnitude of the subsequent antibody response. Lung lymphocytes harvested from IL-4-overexpressing mice post-RSV challenge showed diminished RSV-specific cytolytic activity compared with controls. Both IL-4-deficient and IL-4-overexpressing strains resisted rechallenge. These data imply that constitutive IL-4 expression delays or suppresses the development of a virus-specific cytotoxic lymphocyte population important in clearing primary RSV infection.

A simplified in vivo drug sensitivity test for malaria in the field

The study was intended to develop a simple and reliable in vivo field test for monitoring of sensitivity of P.falciparum to antimalarials. The test is to be used as a built in sustainable monitoring system and applied at regular frequencies to provide guidance in developing a country-wide antimalarial drug policy. The study was conducted as a hospital based study in Mon State in Mudon, Kamawet and Pa-auk hospitals. The criteria matched malaria patients were treated with standard dosages of chloroquine, sulfadoxine-pyrimethamine and mefloquine and blood films were taken on days 0, 2, 3, 4, 7, 14 and 28. The assessment of the in vivo drug response of P.falciparum on days 2, 3 and 4 were compared with WHO standard 28 days and 7 day tests. The following successful tests were carried out for 7 days with different antimalarials: 171 tests with chloroquine and sulfadoxine-pyrimethamine and 167 tests with mefloquine. Tests were also carried out for 28 days: 59 tests with chloroquine, 77 tests with sulfadoxine-pyrimethamine and 78 tests with mefloquine. The results found that 3 day tests, taking blood films on days 0 and 3, can be reliably used as an adjunct to 28-day tests. Since the test is simple and can be used extensively and sustainably throughout the country and the results are applicable to be used for epidemiological purposes, the method is suggested for use as a built-in monitoring method for the malaria control program.