Veterans Administration cooperative study of disulfiram in the treatment of alcoholism: study design and methodological considerations

Disulfiram: A novel repurposed drug for cancer therapy

ABSTRACT

Cancer is a major global health issue. Effective therapeutic strategies can prolong patients' survival and reduce the costs of treatment. Drug repurposing, which identifies new therapeutic uses for approved drugs, is a promising approach with the advantages of reducing research costs, shortening development time, and increasing efficiency and safety. Disulfiram (DSF), a Food and Drug Administration (FDA)-approved drug used to treat chronic alcoholism, has a great potential as an anticancer drug by targeting diverse human malignancies. Several studies show the antitumor effects of DSF, particularly the combination of DSF and copper (DSF/Cu), on a wide range of cancers such as glioblastoma (GBM), breast cancer, liver cancer, pancreatic cancer, and melanoma. In this review, we summarize the antitumor mechanisms of DSF/Cu, including induction of intracellular reactive oxygen species (ROS) and various cell death signaling pathways, and inhibition of proteasome activity, as well as inhibition of nuclear factor-kappa B (NF-κB) signaling. Furthermore, we highlight the ability of DSF/Cu to target cancer stem cells (CSCs), which provides a new approach to prevent tumor recurrence and metastasis. Strikingly, DSF/Cu inhibits several molecular targets associated with drug resistance, and therefore it is becoming a novel option to increase the sensitivity of chemo-resistant and radio-resistant patients. Studies of DSF/Cu may shed light on its improved application to clinical tumor treatment.

Riboflavin as an independent and accurate biomarker for adherence in a randomized double-blind and placebo-controlled clinical trial

BACKGROUND

Medication adherence is critical for success of clinical trials.

OBJECTIVE

To assess oral riboflavin is an adherence marker.

METHODS

Riboflavin was incorporated into active treatment and placebo pills for a clinical trial lasting for 2 years.

RESULTS

The accuracy (area under the receiver operating curve) of urinary riboflavin was 0.91 as a binary classifier of adherence, and was similar or better than for two active study ingredients daidzein (0.92) and genistein (0.87) (all p < 0.0001). Decreased adherence over time was similar in the two study groups.

CONCLUSION

Riboflavin is an accurate and useful biomarker for study pill ingestion.

Joint Estimation of Treatment and Placebo Effects in Clinical Trials with Longitudinal Blinding Assessments

In some therapeutic areas, treatment evaluation is frequently complicated by a possible placebo effect (i.e., the psychobiological effect of a patient's knowledge or belief of being treated). When a substantial placebo effect is likely to exist, it is important to distinguish the treatment and placebo effects in quantifying the clinical benefit of a new treatment. These causal effects can be formally defined in a joint causal model that includes treatment (e.g., new versus placebo) and treatmentality (i.e., a patient's belief or mentality about which treatment she or he has received) as separate exposures. Information about the treatmentality exposure can be obtained from blinding assessments, which are increasingly common in clinical trials where blinding success is in question. Assuming that treatmentality has a lagged effect and is measured at multiple time points, this article is concerned with joint evaluation of treatment and placebo effects in clinical trials with longitudinal follow-up, possibly with monotone missing data. We describe and discuss several methods adapted from the longitudinal causal inference literature, apply them to a weight loss study, and compare them in simulation experiments that mimic the weight loss study.

A causal model for joint evaluation of placebo and treatment-specific effects in clinical trials

Evaluation of medical treatments is frequently complicated by the presence of substantial placebo effects, especially on relatively subjective endpoints, and the standard solution to this problem is a randomized, double-blinded, placebo-controlled clinical trial. However, effective blinding does not guarantee that all patients have the same belief or mentality about which treatment they have received (or treatmentality, for brevity), making it difficult to interpret the usual intent-to-treat effect as a causal effect. We discuss the causal relationships among treatment, treatmentality and the clinical outcome of interest, and propose a causal model for joint evaluation of placebo and treatment-specific effects. The model highlights the importance of measuring and incorporating patient treatmentality and suggests that each treatment group should be considered a separate observational study with a patient's treatmentality playing the role of an uncontrolled exposure. This perspective allows us to adapt existing methods for dealing with confounding to joint estimation of placebo and treatment-specific effects using measured treatmentality data, commonly known as blinding assessment data. We first apply this approach to the most common type of blinding assessment data, which is categorical, and illustrate the methods using an example from asthma. We then propose that blinding assessment data can be collected as a continuous variable, specifically when a patient's treatmentality is measured as a subjective probability, and describe analytic methods for that case.

Medication-assisted treatment and HIV/AIDS: aspects in treating HIV-infected drug users

Drug use and HIV/AIDS remain serious public health issues in the US. The intersection of the twin epidemics of HIV and drug/alcohol use, results in difficult medical management issues for the healthcare providers who work in the HIV prevention and treatment fields. Access to care and treatment, medication adherence to multiple therapeutic regimens and concomitant drug-drug interactions of prescribed treatments are difficult barriers for drug users to overcome without directed interventions. Injection drug users are frequently disenfranchised from medical care and suffer stigma and discrimination creating additional barriers to care and treatment for their substance use disorders as well as HIV infection. Controlling the transmission of HIV will require access to care and treatment of individuals who abuse illicit drugs and alcohol. Improving health outcomes (e.g. access to and adherence to antiretroviral therapy) among HIV-infected substance users will also require access to evidenced-based pharmacological therapies for the treatment of drug abuse and dependence. The current review presents an overview of issues regarding the use of medication-assisted treatments for substance abuse and dependence among HIV-infected individuals, providing medical management paradigms for their care and treatment.

Validity of self-report in alcoholism research: results of a Veterans Administration Cooperative Study

The validity of self-report in alcoholism treatment research is controversial. Our recently completed Veterans Administration Cooperative Study evaluating the efficacy of disulfiram treatment for alcoholism provided an opportunity to assess the validity of self-report. To assess treatment response, patients and household contacts were interviewed at seven scheduled points during the 1 year of follow-up. Blood specimens also were obtained from the patients at these times and were analyzed for ethanol. Eighty-eight percent of the patient and/or collateral interviews were obtained at 6 months and 90% at 1 year. The mean number of blood and urine specimens collected per patient was 4.3 and 14.4, respectively. Outcome criteria included continuous abstinence during the year and total number of drinking days. Continuous abstinence: If we had had only the patients' self reports, we would have significantly underestimated the percentage of men who drank. By self-report 58.7% (355/605) relapsed whereas the combination of self report, collaterals' reports, and laboratory tests indicated that 72.4% (438/605) drank (p less than 0.001). Using Bayes' theorem, the conditional probability that a patient is continuously abstinent for 1 year when he so claims is 65%. Total drinking days: Of the 213 patient-collateral pairs each of whom provided all seven scheduled interviews, 46.9% (100/213) agreed on the total number of drinking days during the year.(ABSTRACT TRUNCATED AT 250 WORDS)

Liver toxicity encountered in the Veterans Administration trial of disulfiram in alcoholics

Alcoholic subjects (453) were randomly assigned to disulfiram or placebo therapy and followed for up to 12 months for drinking. Drinking status was determined from interviews of the subject and a household contact each 2 months and from the analysis of eight blood samples or 39 urines submitted at intervals during the year. Liver status was monitored each 2 months by obtaining serum alkaline phosphatase, bilirubin, and AST. Sensitive criteria were arbitrarily selected to identify about 1/5 of the patients with episodic elevations of liver tests. There was no relationship of liver test elevations to disulfiram treatment. However, the elevated AST related significantly to drinking status (p = 0.004) as did elevated bilirubin (p = 0.044), but not elevated alkaline phosphatase (p = 0.146). Two hundred one patients had liver test elevations at least one time and were continued on drug, four were dropped. One hundred seventy-nine of these patients were drinking, 22 were abstinent, and four were indeterminant. It is concluded that patients on disulfiram with minor liver test abnormalities are usually drinking.

Mandatory supervised antabuse therapy in an outpatient alcoholism program: a pilot study

We instituted a program of mandatory supervised antabuse therapy in an outpatient alcoholism clinic for patients who wish to remain connected to the clinic but who have continued to drink repeatedly. Almost 60% of 68 patients who agreed to this regimen achieved significant periods of sobriety. These preliminary findings suggest that a controlled trial of this approach is warranted.