Engineering and characterization of a mouse/human chimeric anti-phencyclidine monoclonal antibody

Antibody-drug conjugates: Principles and opportunities

Antibody-drug conjugates (ADCs) are immunoconjugates that combine the specificity of monoclonal antibodies with a cytotoxic agent. The most appealing aspects of ADCs include their potential additive or synergistic effects of the innate backbone antibody and cytotoxic effects of the payload on tumors without the severe toxic side effects often associated with traditional chemotherapy. Recent advances in identifying new targets with tumor-specific expression, along with improved bioactive payloads and novel linkers, have significantly expanded the scope and optimism for ADCs in cancer therapeutics. In this paper, we will first provide a brief overview of antibody specificity and the structure of ADCs. Next, we will discuss the mechanisms of action and the development of resistance to ADCs. Finally, we will explore opportunities for enhancing ADC efficacy, overcoming drug resistance, and offer future perspectives on leveraging ADCs to improve the outcome of ADC therapy for cancer treatment.

Is immunotherapy an opportunity for effective treatment of drug addiction?

Immunotherapy has a great potential of becoming a new therapeutic strategy in the treatment of addiction to psychoactive drugs. It may be used to treat addiction but also to prevent neurotoxic complications of drug overdose. In preclinical studies two immunological methods have been tested; active immunization, which relies on the administration of vaccines and passive immunization, which relies on the administration of monoclonal antibodies. Until now researchers have succeeded in developing vaccines and/or antibodies against addiction to heroin, cocaine, methamphetamine, nicotine and phencyclidine. Their effectiveness has been confirmed in preclinical studies. At present, clinical studies are being conducted for vaccines against nicotine and cocaine and also anti-methamphetamine monoclonal antibody. These preclinical and clinical studies suggest that immunotherapy may be useful in the treatment of addiction and drug overdose. However, there are a few problems to be solved. One of them is controlling the level of antibodies due to variability between subjects. But even obtaining a suitable antibody titer does not guarantee the effectiveness of the vaccine. Additionally, there is a risk of intentional or unintentional overdose. As vaccines prevent passing of drugs through the blood/brain barrier and thereby prevent their positive reinforcement, some addicted patients may erroneously seek higher doses of psychoactive substances to get "high". Consequently, vaccination should be targeted at persons who have a strong motivation to free themselves from drug dependency. It seems that immunotherapy may be an opportunity for effective treatment of drug addiction if directed to adequate candidates for treatment. For other addicts, immunotherapy may be a very important element supporting psycho- and pharmacotherapy.

Vaccines targeting drugs of abuse: is the glass half-empty or half-full?

The advent of vaccines targeting drugs of abuse heralded a fundamentally different approach to treating substance-related disorders. In contrast to traditional pharmacotherapies for drug abuse, vaccines act by sequestering circulating drugs and terminating the drug-induced 'high' without inducing unwanted neuromodulatory effects. Drug-targeting vaccines have entered clinical evaluation, and although these vaccines show promise from a biomedical viewpoint, the ethical and socioeconomic implications of vaccinating patients against drugs of abuse merit discussion within the scientific community.

Vaccines in the Treatment of Substance Abuse

Reconceptualizing drugs as toxins allowed an important shift in the approach to the treatment of substance abuse, because it ushered in consideration of immunological methods of pharmacotherapy. This paradigm shift represented a dramatic departure from previously considered approaches to pharmacotherapy for substance use disorders (SUDs), which had up until that time focused predominantly on either agonist and/or antagonist medications meant to block drug effects or to decrease reward, reinforcement, or craving. Use of immunological theory in SUD treatment also meant that 1) a potentially addicting medication would not be administered as part of therapy and 2) side effects could be limited, because the individual's immune system would be responsible for delivering treatment.

Development and validation of an LC-MS/MS method for determination of phencyclidine in human serum and its application to human drug abuse cases

A new analytical method was developed and validated for the rapid determination of phencyclidine (PCP) in human blood and serum. Rapid chromatographic separation decreased the analysis time relative to standard gas chromatography (GC)-based methodologies. The method involved the use of solid-phase extraction for sample preparation and cleanup followed by liquid chromatography tandem spectrometric (LC-MS/MS) analysis and an electrospray-ionization (ESI) interface. PCP was quantified using multiple-reaction-monitoring with deuterium labeled PCP (PCP-d(5)) as an internal standard. The method was validated for accuracy, precision, linearity, and recovery. The method was accurate with error <14% and precision with coefficient of variation (CV) <5.0%. The assay was linear over the entire range of calibration standards (r(2) > 0.997). The recovery of PCP after solid-phase extraction was greater than 90% with the lower limit of detection (LLOD) for PCP in 500 µl of human serum after solid-phase extraction at 0.06 ng ml(-1). This method was used to determine the levels of PCP in postmortem human blood samples. The LLOD in blood was 1 ng ml(-1). Blood PCP concentrations were also determined separately using GC and flame ionization detection (FID). Blood calibration standards and serum calibration standards yielded similar concentrations when used to quantitate authentic human blood samples that tested positive for PCP under the GC-FID method. Extraction of PCP from serum required fewer steps and therefore could be used as a calibration matrix in place of blood. The LC-MS/MS methodology shown here was higher throughput compared with GC-based methods because of very short chromatographic run times. This was accomplished without sacrificing analytical sensitivity.

Anti-(+)-methamphetamine monoclonal antibody antagonists designed to prevent the progression of human diseases of addiction

Anti-(+)-methamphetamine monoclonal antibodies (mAbs) have the potential to reduce the devastating behavioral and societal effects of the worldwide epidemic of (+)-methamphetamine (METH) addiction and transform the treatment paradigm for diseases of addiction. These novel, protein-based medications could play a vital role in helping patients to achieve sustainable abstinence from METH abuse by serving as an in vivo, around-the-clock sentry against a patient's vulnerability to relapse.

Drugs of abuse: management of intoxication and antidotes

Illicit drug intoxications are an increasing public health problem for which, in most cases, no antidotes are clinically available. The diagnosis and treatment of these intoxications requires a trained clinician with experience in recognizing the specific signs and symptoms of intoxications to individual drugs as well as polydrug intoxications, which are more the rule than the exception. To make the diagnosis, the clinical observation and a urine toxicology test are often enough. Evaluating the blood levels of drugs is frequently not practical because the tests can be expensive and results may be delayed and unavailable to guide the establishment of a treatment plan. Other laboratory tests may be useful depending on the drug or drugs ingested and the presence of other medical complications. The treatment should be provided in a quiet, safe and reassuring environment. Vital signs should be closely monitored. Changes in blood pressure, respiratory frequency and temperature should be promptly treated, particularly respiratory depression (in cases of opiate intoxication) or hyperthermia (in cases of cocaine or amphetamine intoxication). Intravenous fluids should be administered as soon as possible. Other psychiatric and medical complication should receive appropriate symptomatic treatment. Research on immunotherapies, including vaccines, monoclonal and catalytic antibodies, seems to be a promising approach that may yield specific antidotes for drugs of abuse, helping to ameliorate the morbidity and mortality associated with illicit drug intoxications.